UMass Extension's Professional Management Guide for Diseases of Trees and Shrubs
Author: Nicholas J. Brazee, UMass Extension Plant Pathologist
Most of the disease pathogens known to be pests of woody ornamentals in the Northeast region are covered in this guide. Included is host plant information, along with appropriate fungicides, bactericides, biological control materials, and also cultural management information where applicable. Refer to the bottom section of this page for more information about pesticide use.
This guide assumes accurate identification of disease problems, as correct identification informs management options and can reduce pesticide use. UMass has a lab that diagnoses plant problems, refer to the UMass Extension Plant Diagnostic Lab for more information.
| DISEASE | PATHOGEN* | HOSTS | SYMPTOMS & MANAGEMENT | ACTIVE INGREDIENT(S) |
|---|---|---|---|---|
| Needle Casts & Blights: Cause premature needle loss, typically on lower, heavily shaded branches. Disease establishment generally favored by rainy and mild weather in the spring. | Rhizosphaera (55‐56) | Spruce (Picea ; especially P. pungens and P. glauca ) Fir (Abies) Secondary hosts include: Pine (Pinus) True cedar (Cedrus) Hemlock (Tsuga ) Douglas‐fir (Pseudotsuga ) Arborvitae (Thuja ) | New infections are initiated in late spring after wet periods, but symptoms may not appear until the autumn, and in some cases, symptoms may not appear until 12‐15 months after infection. Symptoms appear as brown/purple needles, especially on interior sections near the main trunk. The disease typically develops on lower canopy branches first, then progresses upward in the canopy. Small, dark purple to black pads of fungal tissue may be visible on needles and resemble a black powder. Prune dead branches to remove needles harboring the pathogen and to increase air‐flow; rake up or cover fallen needles with mulch; apply fungicides when young needles are partially elongated and again after 21 days if wet conditions persist. | Chlorothalonil (R ) Chlorothalonil+Thiophanate‐methyl (R ) Copper Salts of Fatty and/or Rosin Acids Copper Hydroxide Copper Hydroxide+Mancozeb Mancozeb Thiophanate‐methyl |
| Mycosphaerella dearnessii (brown needle spot) (26‐29) | Pine (Pinus; especially P. strobus) | New infections develop in the spring, and recent epidemics have been linked to very wet conditions in spring months. Symptoms first appear as necrotic spots, which may coalesce over time. Lower branches are most susceptible. Infections are initiated in the spring and typically spread from needle tips to the base. Promote sunlight and air‐flow; heavily infected branches may be pruned to reduce inoculum in the infected tree. If the infection is severe, fungicides can be applied at bud break, with reapplication necessary if wet conditions persist. | Chlorothalonil+Thiophanate‐methyl (R ) Copper Salts of Fatty and/or Rosin Acids Mancozeb Thiophanate‐methyl | |
| Mycosphaerella pini (also known as Dothistroma septosporum ) (Dothistroma needle blight) (28‐29) | Pine (Pinus; especially P. nigra ) | New infections can develop from late spring through autumn. Symptoms typically first appear in the autumn as tan‐brown to reddish‐brown foliar lesions. Needle tips often die back to the spot of the lesions until they completely die later on. The disease leads to premature needle shedding and stunted growth. When severe, trees can suffer serious needle loss. | Chlorothalonil+Thiophanate‐methyl (R ) Copper Salts of Fatty and/or Rosin Acids Mancozeb Thiophanate‐methyl | |
| Canavirgella (50‐51) | Eastern white pine (Pinus strobus) | Symptoms appear as yellow to tan lesions that expand towards needle tips, while the base remains a healthy green. Elongated black strips of fungal tissue may be visible on infected needles but are not always present. Maintain plant vigor, promote sunlight and air‐flow to reduce moisture and prune heavily infected branches, if possible. Remove heavily infected trees. | Chemical management not warranted | |
| Lophodermium (46‐47) | Pine (Pinus) Secondary hosts include: Fir (Abies) Spruce (Picea ) Incense cedar (Calocedrus) False‐cypress (Chamaecyparis) Juniper (Juniperus) Arborvitae (Thuja ) | Symptoms appear as patchy, brown necrotic lesions of the needles. Small, football‐shaped black pads of fungal tissue are often visible with the naked eye at any time of the year. New infections are initiated in late summer to early autumn, when the fungus sporulates from dead needles. Symptoms may appear shortly after infection or the following spring. For chemical control to be effective, it must take place between July and September; apply three to four treatments at 14‐21 day intervals during this time. | Azoxystrobin, Chlorothalonil (R ) Chlorothalonil+Thiophanate‐methyl (R ) Copper Hydroxide+Mancozeb Mancozeb Triadimefon | |
| Ploioderma (48‐49) | Pine (Pinus; mostly two‐ and three‐ needle species) | New infections occur during the late spring to early summer, during wet periods. However, visible symptoms do not develop until the following winter and spring and appear as yellow to orange spots scattered along the needles. Over time, the spots coalesce and the tissue becomes tan to brown. Symptoms typically appear on needle tips, leaving the needle base green. Maintain tree vigor during extended dry periods by watering, especially for young landscape and Christmas trees. Fungicide application should occur when new shoots are 0.5‐2" long and new needles are just emerging; reapplications can be made at 14‐21 day intervals, depending on environmental conditions. | Chlorothalonil (R ) Chlorothalonil+Thiophanate‐methyl (R ) Copper Hydroxide Copper Hydroxide+Mancozeb Mancozeb | |
| Rhabdocline (58‐59) | Douglas‐fir (Pseudotsuga menziesii ) | New infections develop just after bud break, when immature needles are expanding. Symptoms first appear as scattered yellow to reddish‐brown lesions on needles in late summer or autumn. By the following spring (one year after infection), the lesions may appear as raised, brown callus tissue. Over time, lesions coalesce to kill needles, leading to defoliation. Avoid overhead watering and planting on moist and shaded sites. Promote air‐flow and maintain good light exposure, especially on lower branches. Mow or prune underlying vegetation to reduce free moisture on needles. Chemical control requires multiple (up to four) applications, so follow the label carefully regarding the timing of each application. | Chlorothalonil (R ) Copper Hydroxide Copper Hydroxide+Mancozeb Copper Salts of Fatty and/or Rosin Acids Copper Sulfate Thiophanate‐methyl | |
| Needle Casts & Blights (continued): | Phaeocryptopus (Swiss needle cast) (58‐59) | Douglas‐fir (Pseudotsuga menziesii ) | New infections initiate in the spring when the current season's needles are developing. Symptoms first appear as scattered yellowing of older needles and over time, numerous older needles die and are shed prematurely. While current year's needles are infected, they remain green and asymptomatic until the following year. Small, black pads of fungal tissue may be visible on the underside of needles, appearing as a fine black powder. Maintain proper spacing and control weeds around the base to promote air‐flow. Apply fungicides if wet conditions occur when new shoots are 0.5‐2 inches long and reapply 14‐21 days later if wetness persists | Azoxystrobin Chlorothalonil (R ) Chlorothalonil+Thiophanate‐methyl (R ) Mancozeb Thiophanate‐methyl |
| Meria (60‐61) | Larch (Larix ) | Infection and the onset of symptoms develop quickly after long periods of rain in the spring and appear as yellow to brown lesions scattered along the needle surface. If wet conditions persist, the entire needle becomes chlorotic and many needles are shed early. Remove fallen needles to reduce inoculum at the site. For high‐value trees, apply fungicides if wet conditions occur at bud break; reapplications can be made at 14‐21 day intervals. | Chlorothalonil (R ) Propiconazole | |
| Stem Cankers & Shoot Blights: Generally characterized as opportunistic pathogens exploiting stressed and weakened trees and shrubs. | Botryosphaeria (120‐129) | Numerous hardwoods and conifers | Infection can occur at any time from spring to autumn, but most infections are initiated in late spring to early summer. Symptoms include stem cankers and foliar dieback. Stress is often linked to disease incidence and severity. Prune and discard twigs and infected branches. Promote sunlight and air‐flow as moisture and shade favor the pathogen. For severe infections or high‐value trees and shrubs, apply fungicides in spring during new shoot development. | Azoxystrobin Azoxystrobin+Propinconazole Chlorothalonil (R ) Boscalid+Pyraclostrobin Copper Salts of Fatty and/or Rosin Acids Copper Hydroxide Mancozeb Thiophanate‐methyl Trifloxystrobin |
| Sphaeropsis sapinea (also known as Diplodia pinea ) (130‐131) | Pine (Pinus; mostly two‐ and three‐ needle species) | New infections develop most often in the spring, after prolonged wet periods. Symptoms appear as stunted and chlorotic needles, bud dieback and stem cankers. Prune and remove blighted buds and shoots and also remove and destroy fallen cones, as the pathogen will overwinter in all these types of tissue. Promote sunlight and airflow to reduce moisture. Abiotic stresses, especially drought, are linked to disease incidence and severity. Apply fungicides just prior to bud break and reapply until needles are fully elongated. Avoid nitrogen fertilization on trees known to be infected; fertilization promotes succulent shoot growth that is susceptible to infection. | Azoxystrobin Azoxystrobin+Propinconazole Chlorothalonil+Propiconazole (R ) Chlorothalonil+Thiophanate‐methyl (R ) Copper Hydroxide Copper Hydroxide+Mancozeb Copper Salts of Fatty and/or Rosin Acids Mancozeb Potassium Bicarbonate Propiconazole Thiophanate‐methyl Triadimefon | |
| Botryodiplodia hypodermia (also known as Sphaeropsis ulmicola ) (132‐133) | Elm (Ulmus; especially U. americana ) | Symptoms appear as flagging and wilt of small‐diameter branches, typically higher in the canopy. Infected stems may exhibit brown to black, water‐soaked stem lesions. Infections most often occur on small diameter branches (less than 4" in diameter). Wilt and dieback symptoms mimic Dutch elm disease, so careful inspection of vascular tissue is necessary to rule out the latter. Prune and destroy infected stems to reduce inoculum and promote sunlight and air‐ flow, especially for heavily shaded trees. Apply fungicides during wet periods in the spring and early summer to protect young shoots. | Azoxystrobin Azoxystrobin+Propinconazole Chlorothalonil+Thiophanate‐methyl (R ) Copper Hydroxide Copper Hydroxide+Mancozeb Copper Salts of Fatty and/or Rosin Acids Mancozeb Thiophanate‐methyl | |
| Phytophthora spp. (bleeding canker of deciduous hardwoods) (354‐357) | European beech (Fagus sylvatica ) Maple (Acer ) Oak (Quercus) Horsechestnut (Aesculus) Dogwood (Cornus) Linden (Tilia ) Elm (Ulmus) Numerous other hardwoods | Symptoms appear as water‐soaked stem and branch cankers, often with profuse resin/sap flow from the damaged site. Depending on canker size, crown wilting and dieback may also occur. However, resin/sap production is a generalized host response and is not caused by Phytophthora alone. On some hosts, small branches, stems, foliage and fruit may also be infected and symptomatic. | Copper Salts of Fatty and/or Rosin Acids Mefenoxam/Metalaxyl Phosphorous Acid | |
| Stem Cankers & Shoot Blights (continued) | Phytophthora spp. (shoot and foliar blight of rhododendron) (358) | Rhododendron/azalea (Rhododendron spp.) Japanese holly/andromeda (Pieris japonica ) | Infections typically initiate during warm and humid weather when spores are splashed from the soil to the foliage of susceptible plants. Symptoms first appear as water‐soaked, dark green spots and blotches at the base of buds and on the foliage. Within three days of infection, the diseased tissue becomes brown and necrotic. Infections sometimes expand beyond the foliage to the succulent shoots. Once established in the canopy, spores are blown or splashed to nearby leaves and plants. Therefore, do not irrigate using overhead watering if the disease is a concern. The disease causes early leaf drop and the pathogen then survives in dead plant parts that remain moist over the winter. Generally speaking, winter conditions are often too cold for pathogen survival in the soil or in desiccated plant tissues. Nurseries and greenhouses can often harbor the pathogen because of moderate winter temperatures. Regular scouting should take place for recently planted shrubs during hot and humid weather. | Copper Salts of Fatty and/or Rosin Acids Mefenoxam/Metalaxyl |
| Phomopsis (also known as Diaporthe ) (138‐151) | Numerous conifers and hardwoods, including: maple (Acer ; especially A. palmatum ), dogwood (Cornus; especially C. kousa ), juniper (Juniperus), hemlock (Tsuga ), spruce (Picea ) and rhododendron/azalea (Rhododendron ) | New infections can develop anytime from spring to autumn but many develop in late spring to early summer. Symptoms include foliar/needle blight, stem cankers and branch dieback. Evergreen shrubs (holly, rhododendron, azalea) can suffer both foliar and stem blight. Prune and destroy infected leaves and stems and clean up all fallen leaves and stems. Avoid overhead watering and excessive pruning, which creates additional infection sites. Fungicides are often not effective in controlling Phomopsis, but can be applied to newly developing shoots and foliage on high‐value trees and shrubs during the spring to help prevent new infections. | Azoxystrobin Azoxystrobin+Propiconazole Chlorothalonil (R ) Chlorothalonil+Thiophanate‐methyl (R ) Copper Hydroxide Copper Hydroxide+Mancozeb Copper Salts of Fatty and/or Rosin Acids Copper Sulfate Debacarb+Carbendazim Mancozeb Thiophanate‐methyl Trifloxystrobin | |
| Leucostoma kunzei (also known as Cytospora kunzei ) (168‐169) | Fir (Abies), larch (Larix ) spruce (Picea ; especially P. pungens), pine (Pinus), Douglas‐fir (Pseudotsuga ) and hemlock (Tsuga ) | Blue spruce is the most susceptible to this pathogen. Symptoms appear as scattered branch dieback, usually in the lower canopy. Infected branches often exhibit cankers with callused margins and resin flow, which appears white once it has hardened. Small, black pads of fungal tissue can often be observed at the outer margins of the cankers. Prune out and discard cankered branches before infections become severe on mature trees. Disease severity intensifies with drought stress and high levels of shade, so plant susceptible trees in full sun with good air‐flow and water younger trees during prolonged dry periods. | Copper Hydroxide Copper Salts of Fatty and/or Rosin Acids Debacarb+Carbendazim | |
| Valsa persoonii (also known as Leucostoma persoonii ) (170‐171) | Hawthorn (Crataegus), apple (Malus), cherry/peach/plum (Prunus), pear (Pyrus), among other hardwoods | Sap flow is a primary symptom of infection, along with open cankers that may have rough callus tissue at the margins. On stone fruits, "gummosis" (excessive resin production from cankers with hardened masses of resin) is a common symptom. Prune and destroy infected branches to reduce inoculum and avoid overhead watering or planting trees in deep shade. Water trees with a thorough soaking of the roots during extended dry periods to avoid stress. | Copper Hydroxide Copper Salts of Fatty and/or Rosin Acids Debacarb+Carbendazim (microinjections) | |
| Valsa and Leucostoma spp. (also known as Cytospora spp.) (166‐167; 172‐175) | Numerous hardwoods, especially: maple (Acer ), dogwood (Cornus), cherry (Prunus), poplar (Populus). Numerous conifers, especially: fir (Abies), juniper (Juniperus), larch (Larix ) spruce (Picea ), pine (Pinus), Douglas‐fir (Pseudotsuga ) and hemlock (Tsuga ). | Flagging, wilt and general dieback are symptoms of infection. Abiotic stress and attack from other pathogens and insects can predispose trees and shrubs to infection. Prune and destroy infected stems and branches and avoid overhead watering and deep shade that limits air‐flow. | Copper Hydroxide Copper Salts of Fatty and/or Rosin Acids Debacarb+Carbendazim (microinjections) | |
| Pestalotiopsis (190‐191) | Numerous conifers and some hardwoods, including: juniper (Juniperus), arborvitae (Thuja ), Japanese holly (Cryptomeria ), true cedar (Cedrus), false cypress (Chamaecyparis), rhododendron/azalea (Rhododendron ) and holly/inkberry (Ilex ) | Symptoms vary by host, but typically include shoot tip and leaf/needle margin dieback. Small, eruptive pads of fungal tissue can often be seen on blighted plant parts. Prune and remove infected branches and foliage and avoid pruning during wet periods. Rake up and destroy any fallen leaves that may be harboring the pathogen. Apply fungicides to high‐value plants in the spring during new shoot and leaf development. Drought is a major predisposing stress, so thorough watering during dry periods can limit disease development on infected plants. | Chlorothalonil+Thiophanate‐methyl (R ) Copper Hydroxide Copper Salts of Fatty and/or Rosin Acids Debacarb+Carbendazim (microinjections) Mancozeb Thiophanate‐methyl | |
| Stem Cankers & Shoot Blights (continued) | Kabatina (146‐147) | Juniper (Juniperus); secondary hosts include: arborvitae (Thuja ), Japanese cedar (Cryptomeria ), cypress (Cupressus), Douglas‐fir (Pseudotsuga ), fir (Abies) and yew (Taxus) | (Chemical management is only warranted in extreme cases). Symptoms include dieback and death of one‐year‐old stems and needles, occasionally attacking older parts. Infection occurs in the spring with the pathogen invading insect wounds and snow and ice damage. Symptoms and signs of the pathogen (small, black eruptive pads of fungal mycelium on diseased parts) resemble those caused by Phomopsis, which is a more common pathogen. Prune and destroy infected plant parts and sanitize pruning tools between plants. | Azoxystrobin Thiophanate‐methyl |
| Sirococcus (118‐119) | Numerous conifers, especially: spruce (Picea ), pine (Pinus) and hemlock (Tsuga ) | Primary symptoms include branch tip dieback (hemlock), stem cankers, oozing and hardened resin on stems and branch dieback. Prune and destroy infected branches to reduce inoculum. Apply fungicides during wet periods when new needles are forming; repeat at 21‐28 day intervals if wet conditions persist. | Azoxystrobin Mancozeb Propiconazole Triadimefon | |
| Calonectria pseudonaviculata (also known as Cylindrocladium buxicola ) (boxwood blight) (N/A) | Boxwood (Buxus; all varieties) | Primary symptoms include rapid dieback and death of branches, leading to defoliation and death of the plant. Dark brown to black circular lesions occur on leaves and stems. Regular scouting for branch dieback on newly planted shrubs is necessary for early detection. Prior to planting new boxwoods, cease all fungicide treatments and quarantine the plants for several weeks to ensure symptoms do not develop. Avoid overhead watering, which facilitates spore production and dissemination. Maintain proper spacing between shrubs and carefully sanitize all pruning equipment. If plants are diseased, remove immediately and discard them off‐site. Contact supplier/grower to inform them of disease incidence. | Boscalid+Pyraclostrobin Chlorothalonil (R ) Chlorothalonil+Propiconazole (R ) Chlorothalonil+Thiophanate‐methyl ® Fludioxonil+Cyprodinil Mancozeb Myclobutanil Kresoxim‐methyl (R ) Propiconazole Pyraclostrobin Tebuconazole Thiophanate‐methyl Trifloxystrobin Triflumizole | |
| Volutella buxi (N/A) | Boxwood (Buxus; all varieties) | Symptoms appear as brown foliage, stunted shoots and general wilt and dieback. In many cases, salmon‐colored spore masses are visible on the underside of infected leaves and on stems, especially after periods of rain. Prune and destroy diseased branches, making sure to sanitize pruning equipment frequently and avoid overhead watering. Promote air‐flow through proper spacing and limit drought stress and insect feeding, especially from boxwood leaf miner. Fungicides generally have little effect against Volutella . | Copper Hydroxide Copper Salts of Fatty and/or Rosin Acids Mancozeb Myclobutanil Thiophanate‐methy | |
| Apiosporina (syn. Dibotryon ) (black knot) (152‐153) | Cherry/ plum/ peach (Prunus) | New infections occur in the spring during wet weather. The pathogen overwinters in the knots, allowing it to spread easily to nearby canopy branches. Primary symptoms include swelling and galls on small branches and stems. Over time, galls can become very large, occurring on main branches and occasionally on the trunk. The galls are a combination of fungal and host tissue. Prune and destroy galls on small twigs and stems, preferably during dormant periods when galls are easier to locate. Sanitize pruning equipment frequently. Chemical management is often not practical, especially when numerous galls are present throughout the canopy. | Chlorothalonil (R ) Chlorothalonil+Thiophanate‐methyl (R ) Copper Hydroxide Thiophanate‐methyl | |
| Monilinia (brown rot of stone fruits) (76‐77) | Cherry/ plum/ peach (Prunus) | Blossom and twig blight occurs primarily in the spring, facilitated by periods of rain and wind. Blossoms wilt within 3‐6 days after infection, and stem and branch dieback mostly occurs within a month of infection. Fruit rot occurs later in the summer, usually within a few weeks of a typical harvest period. Fruit rot can occur rapidly and fruits that remain on the tree become "mummified". A sign of the pathogen includes gray tufts of mycelium on infected fruit and blossoms. Remove and destroy all mummified fruits (from the tree and ground) and prune stem cankers that harbor the pathogen. Spores of the pathogen are spread via wind, running and splashing rain, pruning tools and insect vectors. The timing of pesticide application varies widely between chemicals, read the label carefully prior to application. | Azoxystrobin Azoxystrobin+Propiconazole Boscalid+Pyraclostrobin Chlorothalonil (R ) Iprodione Iprodione+Thiophanate‐methyl Mancozeb Myclobutanil Propiconazole Tebuconazole Thiophanate‐methyl Triflumizole | |
| Nectria (176‐182) | Numerous hardwoods and some conifers, especially: maple (Acer ), boxwood (Buxus) and elm (Ulmus) | Symptoms typically appear as sporadic dieback of small twigs and branches. Infected areas are often sunken and may appear water‐soaked as sap flows from the lesions on larger branches. Over time, sloughing bark and rupturing cankers appear on the branches. Signs of the pathogen include salmon to pink‐colored spore masses oozing from the canker margins. The infected host may produce callus tissue surrounding the canker. Prune and destroy blighted stems, pruning several inches below the canker (if possible). Avoid pruning during wet weather and sanitize pruning equipment frequently between branches. | Chemical management not warranted. | |
| Stem Cankers & Shoot Blights (continued) | Neonectria (beech bark disease and target canker) (184‐185) | Hardwoods, especially: American beech (Fagus grandifolia ) and birch (Betula ) | On beech, symptoms appear as rough, irregular cankers on the bark, leading to bird scaling and infection from wood‐decay fungi. On birch, symptoms appear as target‐shaped cankers surrounded by host callus tissue. Neonectria does not decay wood; the fungus parasitizes the cambium, killing the bark tissue. Cankers often develop on the main trunk, making cultural management impossible. Cankers developing on birch branches can be pruned when trees are small but cankers often develop on the main trunk, negating any cultural control methods. | Chemical management not warranted. |
| Ophiognomonia clavigignenti‐ juglandacearum (previously known as Sirococcus c‐j ) (butternut canker) (116‐117) | butternut (Juglans cinera ) | The pathogen initiates new infections from early spring to mid‐autumn. Cankers can develop on twigs, branches, the main trunk and root flares. They are often elliptical in shape and accompanied by sap flow that stains the bark. The disease is lethal and there are no known control measures, aside from pruning out cankered twigs and branches. The fungus ultimately girdles the main trunk. Butternuts are often infected by additional pathogens (e.g. Armillaria ) that hasten their decline. | Chemical management not warranted | |
| Fusarium (186‐189) | Numerous hardwoods and conifers | In New England, Fusarium is often a secondary disease agent acting in concert with other pathogens and abiotic stresses. Canker symptoms mimic many others described here and there are no diagnostic signs unique to this pathogen. | Etridiazole+Thiophanate‐methyl Iprodione Iprodione+Thiophanate‐methyl Mancozeb Thiophanate‐methyl | |
| Seiridium (192‐193) | Fir (Abies) | Symptoms appear as stem cankers, and shoot and bud blight. Trees predisposed by needle cast, drought, freeze or sunscald injury, and mechanical damage are especially susceptible. Often occurs as secondary pathogen after pathogen/insect attack and abiotic stress. | Chemical management not warranted | |
| Botrytis (gray mold) (72‐73) | Numerous hardwoods and conifers, especially: dogwood (Cornus), apple (Malus) and rose (Rosa ) | Primary symptoms include flower and bud blight, and dieback of young, succulent stems. A sign of the pathogen is a gray, fuzzy mold (mycelium) occurring on blighted buds, stems and foliage. When present on stems, Botrytis is often a secondary colonizer of plant parts damaged by disease, insect and abiotic stresses. On woody plants, the pathogen often causes disease on senescing plant parts in the autumn during cool and wet periods. | Chlorothalonil (R ) Copper Hydroxide Copper Salts of Fatty and/or Rosin Acids Copper Sulfate Iprodione Thiophanate‐methyl | |
| Erwinia (fire blight) (376‐ 377) | Members of the Rosaceae, including: Cotoneaster , hawthorn (Crataegus), quince (Cydonia ), apple (Malus), firethorn (Pyracantha ), pear (Pyrus), raspberry (Rubus) and mountain‐ash (Sorbus) | New infections occur in the spring, especially during the flowering period. The bacterium is spread through pollinating insects, and splashing/running rainwater. Disease spread can occur rapidily in orchards. Symptoms of infection include blighted buds and new shoots (that appear black or burnt and could be confused with spring frost damage) and bacterial ooze from lenticels. Infected fruits and stems are often colonized secondarily by cankering fungi like Botryosphaeria and Phomopsis. CAUTION: some bactericides are not for use on fruit intended for human consumption. Read labels carefully. | Copper Hydroxide Copper Hydroxide+Mancozeb Copper Salts of Fatty and/or Rosin Acids Copper Sulfate Fosetyl‐Aluminum Mancozeb Phosphorous Acid Steptomycin Sulfate | |
| Pseudomonas(bacterial blight) (368‐371) | Numerous hardwoods, especially: cherry/plum/peach (Prunus), pear (Pyrus) and lilac (Syringa ) | Water‐soaked lesions and gummosis are the primary symptoms of infection. Prune and destroy infected plant material during dry and dormant periods to avoid spreading the pathogen. Always disinfect pruning equipment frequently between pruning cuts. Apply bactericides in the spring to protect newly emerging shoots. CAUTION: some bactericides are not for use on fruit intended for human consumption. Read labels carefully. | Copper Hydroxide Copper Hydroxide+Mancozeb Copper Salts of Fatty and/or Rosin Acids Copper Sulfate Mancozeb Phosphorous Acid Steptomycin Sulfate | |
| Anthracnose: Symptoms include: bud and shoot blight, early leaf drop, angular, water‐soaked foliar lesions occurring along the leaf veins, or as numerous circular leaf spots and stem cankers on larger branches that are typically elongated with splitting bark. | A complex of fungal genera are collectively described as anthracnose. Important members and their hosts are listed below. Because of the confused fungal taxonomy, diseases are sorted by primary hosts. | Wet and cool periods in the spring favor canker establishment and expansion, in addition to new shoot and bud blight which may delay leaf‐out. Anthracnose fungi typically go dormant during hot and dry periods in mid‐summer only to re‐emerge during cool periods in the fall. Trees and shrubs in fog pockets or near bodies of water, in deep shade or forest settings are more susceptible. Foliar lesions are often angular and occur along leaf veins and margins. Stem cankers are often elongated in the direction of the stem. | ||
| Anthracnose (continued) | Sycamore anthracnose (Apiognomonia veneta ; previously known as Discula platani ) (102‐103) | American sycamore (Platanus occidentalis); London planetree (P . × acerifolia ) is resistant but not immune | During wet springs, sycamores are severely defoliated and may push several sets of leaves before the disease subsides with drier weather. Foliar lesions are angular in shape and often occur along leaf veins or the leaf midrib. The pathogen also causes elongated stem cankers and is the primary cause of the right angle branching pattern exhibited by sycamores. However, only occassionaly does the disease cause severe crown dieback or death and chemical management is rarely warranted. | Chlorothalonil (R ) Copper Hydroxide Copper Hydroxide+Mancozeb Copper Salts of Fatty and/or Rosin Acids Copper Sulfate Debacarb+Carbendazim Mancozeb Propiconazole Thiabendazole Hypophosphite |
| Dogwood anthracnose (Discula desctructiva ) (106‐ 107) | Flowering dogwood (Cornus florida ) and occasionally on kousa dogwood (C. kousa ) | Symptoms of infection include leaf spots and blotches, early leaf drop, defoliation of lower branches, elongated stems cankers, crown dieback and outright death. Epicormic sprouts are often formed on diseased trees, usually near the site of stem cankers on larger branches. Prune out and discard cankered and blighted branches, regularly sanitize pruning tools when working with diseased trees, avoid overhead watering and plant trees in full sun with good air‐flow to promote drying of leaves and stems. | Chlorothalonil (R ) Chlorothalonil+Propiconazole (R ) Mancozeb Myclobutanil Potassium Bicarbonate Propiconazole Trifloxystrobin | |
| Numerous hardwoods and some conifers (Glomerella spp.; also known as Colletotrichum ) (114‐115) | Broad host range, including: maple, birch, oak, pear, privet, honey locust, cherry, elm, basswood, hawthorn, lilac, azalea, magnolia, redbud, dogwood, tulip poplar, hydrangea, rhododendron, burning bush and many others | Foliar symptoms range from numerous small, circular leaf spots to large, irregularly‐shaped necrotic lesions. Elongated cankers with rough, callused margins can also occur on twigs and small branches. Signs of the pathogen include pinkish spore masses oozing from the margins of stem cankers and on blighted foliage. The pathogen is widespread on the landscape, making eradication impossible. Cleaning up downed foliage and pruning out cankered branches can help mitigate disease pressure in subsequent years on infected trees and shrubs. | Azoxystrobin Azoxystrobin+Propinconazole Copper Hydroxide Chlorothalonil (R ) Iprodione Iprodione+Thiophanate‐methyl Propiconazole Thiophanate‐methyl Thiophanate‐methyl+Mancozeb Triadimefon Triadimefon+Trifloxystrobin Trifloxystrobin | |
| Maple anthracnose (Aureobasidium apocryptum , Discula campestris, D. umbrinella and Glomerella spp. [described above]) (110‐ 111) | Maple (Acer ) | Irregularly‐shaped, angular spots and blotches occur along the leaf veins and midrib or along the leaf margins. Lesions often first appear water‐soaked and over time, become brown and cause leaf curling. When severe, infection can lead to premature defoliation. Symptoms can develop anytime between spring and late summer after wet periods. The pathogen overwinters on fallen leaves and possibly in killed twigs and buds. Thoroughly clean up all fallen leaves and downed twigs and remove them from the site. Fungicide application is often unnecessary but chemicals can be applied near bud break and at 7‐14 day intervals afterwards, depending on rainfall. | Chlorothalonil (R ) Chlorothalonil+Thiophanate‐methyl (R ) Copper Hydroxide+Mancozeb Mancozeb Propiconazole | |
| Oak anthracnose (Apiognomonia errabunda ; previously known as Apiognomonia quercina and Discula quercina ) (100‐101) | Oak (Quercus; Q. alba is highly susceptible) | Irregularly‐shaped lesions develop in spring and early summer. Foliar lesions are often confined by leaf veins or central midrib. Twig blight can also occur in the spring to early summer, depending on rainfall. The fungus overwinters in leaves, buds and twigs and can cause disease at any time during the growing season as long as environmental conditions are conducive. | Chlorothalonil (R ) Copper Hydroxide Copper Hydroxide+Mancozeb Copper Salts of Fatty and/or Rosin Acids Copper Sulfate Debacarb+Carbendazim Mancozeb Propiconazole Thiophanate‐methyl+Mancozeb Triadimefon+Trifloxystrobin | |
| Birch anthracnose (Ophiognomonia spp.; previously known as Discula betulina ) (108‐109) | Birch (Betula ) | To date, five species of Ophiognomonia are known to attack birch in North America. Symptoms develop in the spring and range from numerous scattered leaf spots, to large necrotic blotches occurring along the leaf margins. The pathogen overwinters on fallen leaves and is not known to produce stem cankers. Thoroughly rake up and destroy all fallen leaves in the autumn to prevent the pathogen from overwintering and reinfecting the tree in the spring. | Chemical management not warranted | |
| Elm anthracnose (black spot) (Gnomonia ulmea ; previously known as Stegophora ulmea ) (96‐97) | Elm (Ulmus) | Black spot can cause serious defoliation during wet years. Symptoms first appear as small, circular leaf spots that are yellow in color. Over time, they develop a black center and become raised. Spots often coalesce to cause a complete foliar blight. Early leaf drop and death of succulent shoots can occur (especially in conjunction with cankering fungi). Rake up and destroy fallen foliage and prune branches exhibiting symptoms of severe dieback. Monitor closely for Sphaeropsis canker and Dutch elm disease. Several elm varieties are resistant to black spot. | Copper Hydroxide+Mancozeb Mancozeb | |
| Anthracnose (continued) | Ash anthracnose (Plagiostoma fraxini ; previously known as Discula fraxinea and Gnomoniella fraxini ) (98‐99) | Ash (Fraxinus) | Irregularly‐shaped, angular, water‐soaked lesions appear in the spring after prolonged wet periods. In wet springs, young leaves and shoots can be killed, leading to a second flush of foliage. Symptoms sometimes resemble frost injury. Successive years of defoliation can lead to significant crown dieback. The fungus overwinters in twigs, petioles, leaves and on seeds. The pathogen does not cause stem cankers on established branches and twigs. | Copper Hydroxide+Mancozeb Mancozeb |
| Walnut, Hickory and Pecan anthracnose (Ophiognomonia spp.) (104‐ 105) | Walnut (Juglans) Hickory and pecan (Carya ) | Symptoms appear as small, irregular leaf spots scattered across the foliage, primarily near leaf veins. Symptoms generally appear late in the season after annual growth by the host has been accomplished. Therefore, the pathogen does little damage. Rake up and destroy fallen leaves that harbor the pathogen to reduce inoculum. Chemical management is only warranted in extreme cases. | Copper Hydroxide+Mancozeb Mancozeb | |
| Leaf Spots, Blights & Powdery Mildew: Diverse group of fungal pathogens causing a wide array of symptoms. Some diseases are mostly cosmetic while others can cause severe damage through early leaf drop, stunted growth and susceptibility to other pests/pathogens. | Venturia (apple scab) (86‐92) | Primary host is apple (Malus); secondary hosts include: Cotoneaster , firethorn (Pyracantha ), pear (Pyrus) and mountain‐ash (Sorbus) | Symptoms develop in the spring and appear as olive‐brown to black circular spots on leaves and fruit. Fruit lesions are superficial and do not penetrate beyond the cuticle. During wet years, numerous foliar spots can develop, leading to yellowing of leaves and early leaf drop. Rake up and destroy fallen leaves and fruit to reduce inoculum at the site. In most landscape settings, apple scab is a cosmetic disease that does not warrant chemical management. CAUTION: some fungicides are not for use on fruit intended for human consumption. Read labels carefully. Also note that azoxystrobin is phytotoxic on certain apple cultivars. | Azoxystrobin Chlorothalonil+Propiconazole (R ) Copper Hydroxide Kresoxim‐methyl Mancozeb Myclobutanil Phosphorous Acid Propiconazole Tebuconazole+Trifloxystrobin Triadimefon+Trifloxystrobin Triflumizole |
| Phyllosticta (purple‐eye leaf spot) (42‐43) | Maple (Acer ), dogwood (Cornus), hazelnut (Corylus), witch‐hazel (Hamamelis) among other hardwoods | New infections and associated symptoms develop in the spring and appear as (mostly) circular leaf spots with brown centers and purple margins. As the lesions dry, the center may fall out. Partial defoliation or early leaf drop may occur on trees or branches in deep shade. When conditions are optimal, witch‐hazels can suffer a severe foliar blight. Remove fallen leaves in the autumn to reduce inoculum at the site. | Chemical management not warranted | |
| Guignardia (40‐41) | Horse‐chestnut and buckeye (Aesculus spp.; especially A. hippocastanum ) | Infections initiate on emerging leaves in late spring and blotches begin to appear two to four weeks after infection. Symptoms consist of large, irregularly‐shaped foliar lesions (blotches). When the lesions are actively expanding, they often appear water‐soaked. Over time, blighted foliage dries and curls. Remove fallen leaves in the autumn to reduce inoculum at the site; promote sunlight and air‐flow to reduce moisture. While the disease disfigures ornamental trees, growth is mostly unaffected. Therefore, chemical control is rarely warranted. If fungicide application is desired, it should occur at bud break and continue until conditions become dry or leaves are fully elongated. | Mancozeb Thiophanate‐methyl | |
| Rhytisma (tar spot) (66‐67) | Maple (Acer ) | Spores disseminated from fallen leaves initiate new infections in the spring, with symptoms developing four to eight weeks after infection. Very conspicuous circular, black spots develop on the foliage in early to mid‐summer. Leaf spots are considerably larger on Norway maple. When trees are heavily shaded, especially in forest understories, numerous spots can form and coalesce. Rarely is the disease of concern in landscape settings. Remove fallen leaves to reduce inoculum at site; chemical management is not warranted. | Chemical management not warranted | |
| Marssonina (82‐83) | Birch (Betula ), aspen/cottonwood/poplar (Populus) and willow (Salix ) | Infections are initiated from overwintering inoculum in fallen leaves and in small twig cankers. Symptoms develop approximately two weeks after infection and appear as small, irregularly‐ shaped, brown spots and blotches. If wet conditions persist beyond spring and early summer, infections can be severe. Remove fallen leaves to reduce inoculum at site; chemical management is not warranted in most cases. | Mancozeb | |
| Entomosporium (78‐79) | Hawthorn (Crataegus), and occasionally on serviceberry (Amelanchier ), cotoneaster (Cotoneaster ), apple/crabapple (Malus), pear (Pyrus) and mountain‐ ash (Sorbus) | New infections initiate in the spring, but symptoms are not usually present until mid‐summer. Symptoms appear as small, dark leaf spots. In wet years, or for trees residing in deep shade, numerous spots coalesce to cause a complete foliar blight. Typically, the pathogen does little damage, but can cause early leaf drop. Remove fallen leaves to reduce inoculum at site. In rare cases, fungicide applications during wet periods in the spring may be warranted for severe infections. Note that azoxystrobin is phytotoxic on certain apple cultivars. | Azoxystrobin Copper Hydroxide Copper Salts of Fatty and/or Rosin Acids Copper Sulfate Mancozeb Myclobutanil Thiophanate‐methyl Triadimefon Triadimefon+Trifloxystrobin | |
| Leaf Spots, Blights & Powdery Mildew (continued) | Pseudocercospora and Passalora (previously known as Cercospora ) (30‐35) | (1) Pseudocercospora kalmiae : mountain laurel (Kalmia ); (2) P. handelii : rhododendron/azalea (Rhododendron ); (3) P. juniperi : juniper (Juniperus); and (4) Passalora sequoiae : cypress (Cupressus) | Symptoms appear as circular leaf spots with purple centers and grey margins or browning needles on juniper, beginning on the lower branches and spreading upward. Numerous leaf spots may coalesce to cause a foliar blight. If possible, transplant shrubs from deep shade to sunnier areas; prune dead branches to increase air‐flow and remove fallen leaves to reduce inoculum at site. Chemical management is only warranted in extreme cases. | Azoxystrobin Copper Hydroxide Copper Hydroxide+Mancozeb Mancozeb Myclobutanil Propiconazole Thiophanate‐methyl Triadimefon |
| Macrophoma (N/A) | Boxwood (Buxus) | Infection usually requires a predisposing stress, such as root or stem cankering disease or drought. Symptoms appear as leaf spots and general dieback of the foliage. Macrophoma produces black, circular fruiting bodies on the underside of the foliage and can be seen with the naked eye. Management should focus on pruning dead branches and raking up fallen foliage. Address other predisposing factors causing stress such as drought, root disease, Volutella and Calonectria (boxwood blight). | Chemical management not warranted | |
| Tubakia (44‐45) | Oak (Quercus) and numerous secondary hosts. | Infections are likely initiated in late spring to early summer, with symptoms appearing in mid‐ summer as large, circular leaf spots. Often, the spots coalesce to create large patches of necrotic tissue. Later in the season, the spots can be very large as the pathogen continues to expand on the surface of the leaf. As a result, the disease is most often reported in July and August. Rake up and remove fallen leaves to reduce inoculum at the site. Chemical management is not usually necessary. | Copper Hydroxide Copper Hydroxide+Mancozeb Copper Salts of Fatty and/or Rosin Acids Mancozeb Mancozeb+Thiophanate‐methyl Propiconazole Thiophanate‐methyl | |
| Diplocarpon (black spot) (80‐ 81) | Rose (Rosa ; yellow‐ and gold‐ flowering varieties are more susceptible) | The pathogen overwinters on fallen leaves and infected canes and though new infections can initiate throughout the growing season, most occur in the spring. Several resistant rose varieties exist, but they are not immune to the disease. Black spots develop on leaves and canes of susceptible plants. Spots are mostly circular and surrounding tissue may become yellow. Newly expanding leaves, 6‐14 days old, are most susceptible to infection. Remove and destroy fallen leaves, prune out dead canes and avoid overhead watering. | Chlorothalonil (R ) Chlorothalonil+Thiophanate‐methyl (R ) Copper Hydroxide Copper Sulfate Kresoxim‐methyl (R ) Mancozeb Myclobutanil Propiconazole Sulfur Triadimefon+Trifloxystrobin Trifloxystrobin Thiophanate‐methyl | |
| Septoria (24‐25) | Aspen/cottonwood/poplar (Populus), birch (Betula ), dogwood (Cornus), rhododendron/azalea (Rhododendron ) and other hardwoods | Symptoms of infection include small, dark, circular to angular leaf spots and blotches. Often, the lesions are limited in size by the leaf veins. Severe infections lead to coalescing spots that can cause a complete foliar blight under optimal conditions. Most foliar infections are inconsequential to the health of the plant. In addition, Septoria can cause a damaging branch and trunk canker on Populus. Cankers often appear as sunken lesions and over time have rough margins with various stages of callus tissue. | Chlorothalonil (R ) Mancozeb Thiophanate‐methyl | |
| Taphrina (peach leaf curl) (4‐ 5) | Peach and nectarine (Prunus persica ), almond (P. dulcis) and apricot (P. armeniaca ) | New infections occur in the spring on leaves, flowers and fruit of susceptible trees. Spores are disseminated in late spring to early summer and the fungus goes dormant until the following spring. Newly forming foliage and succulent shoots become curled, twisted and deformed. Leaves turn from green to yellow, finally becoming reddish when the disease is fully developed. Early leaf drop can occur after severe infections. Signs of the pathogen include a white, powdery appearance on deformed plant parts. This is the spore mass produced by Taphrina and extreme care should be taken when handling plants at this stage to avoid spreading the pathogen. Rake up and destroy fallen leaves to reduce inoculum at the site. Apply fungicides in the spring prior to bud break. | Mancozeb | |
| Leaf Spots, Blights & Powdery Mildew (continued) | Erysiphe , Phyllactinia , Podosphaera (powdery mildew) (8‐13) | Numerous angiosperms, especially hydrangea (Hydrangea ), lilac (Syringa ) and oak (Quercus); gymnosperms are not hosts | Symptoms appear as white to grey powder or dust on leaf surfaces and undersides. Powdery mildew fungi only invade the epidermis and most have evolved to infect a single host genus or family. Many powdery mildew fungi are inhibited by the presence of free water on plant surfaces, while others can tolerate wet leaf surfaces. High humidity often drives powdery mildew outbreaks. Spore production can take as little as four to six hours and fungi can rapidly colonize plant surfaces under optimal conditions. In greenhouse settings, powdery mildew fungi can reproduce all year. In our region, disease severity usually corresponds with high humidity and a lack of rainfall (August). | Azoxystrobin Chlorothalonil (R ) Chlorothalonil+Propiconazole (R ) Copper Hydroxide Copper Salts of Fatty and/or Rosin Acids Copper Sulfate Fernarimol Mineral Oil Myclobutanil Neem Oil Phosphorous Acid Potassium Bicarbonate Propiconazole Sulfur Tebuconazole+Trifloxystrobin Trifloxystrobin Thiophanate‐methyl Triadimefon |
| Rusts: Characterized by their orange‐brown rust‐ colored spores. Symptoms are highly variable by host. | Gymnosporangium juniperi‐ virginianae (cedar‐apple rust) (260‐262) | Juniper (Juniperus; especially J. virginiana ) and apple/crabapple (Malus) | On juniper, symptoms appear as small, woody galls on fine twigs and stems. Some galls may become quite large (e.g. the size of a golf ball), but most are small and can be hard to find. During wet periods in the spring, orange, jelly‐like masses will extrude from the galls. On rosaceous hosts, the primary symptom of infection are leaf spots. On apple and crabapple, the fungus produces large reddish‐orange, circular lesions that are very conspicuous. Over the summer, cream‐colored tendrils develop on the underside of the lesion. In many cases, the disease is cosmetic and does little damage to landscape trees. Fungicide application prevents infection of apple foliage in the spring from the spores produced on juniper. Conversely, the spores produced on apple leaves infect juniper in the late summer and autumn. | Chlorothalonil+Propiconazole (R ) Chlorothalonil+Thiophnate‐methyl (R ) Copper Salts of Fatty and/or Rosin Acids Copper Sulfate Kresoxim‐methyl (R ) Mancozeb Propiconazole Sulfur Tebuconazole Tebuconazole+Trifloxystrobin Triadimefon Triadimefon+Trifloxystrobin Trifloxystrobin Triflumizole |
| Gymnosporangium claviceps (cedar‐quince rust) (264‐266) | Juniper (Juniperus; especially J. virginiana ) and rosaceous hosts: apple/crabapple (Malus), quince (Cydonia ), flowering quince (Chaenomeles), serviceberry (Amelanchier ), mountain‐ash (Sorbus) and hawthorn (Crataegus) | On juniper, symptoms appear as small, woody galls on fine twigs and stems. Some galls may become quite large (e.g. the size of a golf ball), but most are small and can be hard to find. During wet periods in the spring, orange, jelly‐like masses will extrude from the galls. On rosaceous hosts, the primary symptom of infection are leaf spots, fruit lesions and stem galls. Serviceberry suffers the most damage, as the pathogen produces galls that become perennial and, over time, can girdle the stems. This can lead to significant lower crown dieback, especially on plants that are heavily shaded. On hawthorn and quince, the fruit is often infected and conspicuous, pinkish‐colored tendrils develop in mid‐summer. Damage varies by host, condition and environmental factors. | Chlorothalonil+Thiophnate‐methyl (R ) Copper Salts of Fatty and/or Rosin Acids Copper Sulfate Kresoxim‐methyl (R) Mancozeb Propiconazole Sulfur Tebuconazole Tebuconazole+Trifloxystrobin Triadimefon Triadimefon+Trifloxystrobin Trifloxystrobin Triflumizole | |
| Chrysomyxa weirii (spruce needle rust; Weir's cushion rust) (288‐289) | Spruce (Picea ); especially blue (P. pungens) | On spruce, symptoms appear as orange‐red lesions surrounded by chlorotic tissue, scattered across the needles. These lesions are actually blisters that swell in late spring and rupture to release spores. Early needle drop can occur but the damage is generally not severe on established trees. The disease is often concurrent with needle cast from Rhizosphaera , which is a more serious threat to long‐term health. Management should focus on protecting new needles prior to spore dispersal from nearby, infected needles. Fungicide application should occur just prior to budbreak and reapplications can be made on 7‐10 day intervals until approximately one month after budbreak. | Chlorothalonil (R ) | |
| Rusts (continued) | Cronartium ribicola (white pine blister rust) (292‐295) | Pine (Pinus: five‐needle species) and gooseberry/currant (Ribes; especially R. nigrum ) | Infection of pine needles occurs from mid‐summer to autumn and initiates a long life cycle that can take three to six years to complete. The fungus spreads from the needles to the twigs the same year or by the following summer, then grows in living bark to larger branches and/or the main stem. Disseminated spores then infect Ribes species, a required host for completion of the life cycle. Symptoms appear as needle blight, premature needle loss, twig and branch dieback and stem cankers with oozing blisters. The blisters may produce copious volumes of resin, while the fungal fruiting bodies rupture through the bark and appear as gelatinous masses. Pruning and destruction of the infected twigs/branches before the fungus reaches the main stem, can help to control the pathogen. Lower branches where moisture and humidity levels are higher are often infected first. | Copper Hydroxide Copper Hydroxide+Mancozeb Mancozeb Myclobutanil Triadimefon |
| Vascular Wilts: Prominent symptoms include wilting, browning and early shedding of foliage along with staining of vascular tissue (olive‐green to dark brown). These diseases target the water‐ conducting tissues and symptoms typically first appear in upper‐canopy branches. | Verticillium albo‐atrum & V. dahliae (242‐245) | Numerous hardwoods, especially: maple (Acer ), smoke‐tree (Cotinus), elm (Ulmus) and lilac (Syringa ) | Many hardwoods are resistant and all gymnosperms are immune. Confusion is rampant because some plant genera have both resistant and susceptible species. Symptoms appear as flagging of upper canopy branches, wilt and dieback. Vascular staining appears green to olive‐ green to brown and penetrates several millimeters into the sapwood. Water‐soaked, stem lesions may also be present, especially on hosts that produce abundant sap (e.g. Liquidambar and Acer ). Maintain vigor by watering during extended dry periods; replace infected plants with resistant species such as pine, dogwood, hawthorn, apple, walnut, willow, oak and pear. Verticillium will persist in the soil for many years after infected plants are removed. Soil fumigation is not effective nor is it recommended for landscape settings. | Debacarb+Carbendazim |
| Ophiostoma ulmi & O. novo‐ ulmi (Dutch elm disease) (240‐241) | American elm (Ulmus americana ); numerous resistant hybrids of American elm exist | Symptoms appear as flagging of upper canopy branches, wilt and yellowing of leaves and general crown dieback. Vascular staining appears brown to dark brown within the sapwood. Management includes regular scouting and pruning of branches exhibiting symptoms. Prune approximately five (or more) feet below the infected area to ensure removal. Remove and destroy nearby elm logs, as they may harbor the elm bark beetle and Ophiostoma . Apply insecticides during dormant periods to kill overwintering beetles; apply fungicides using trunk injections (macro‐ or micro‐injections). Several resistant varieties are available for planting, but none are immune to the disease | Debacarb+Carbendazim Imidacloprid+Debacarb Propiconazole Tebuconazole Thiabendazole Hypophosphite | |
| Ceratocystis fagacearum (oak wilt) (238‐239) | Oak (Quercus; especially the red oak group) | Not currently known to occur in New England, but the oak wilt pathogen has been steadily spreading eastward and was confirmed in eastern New York in '06. It is vectored by sap‐feeding beetles and also spreads through root grafts. Symptoms appear in spring and early summer as foliar wilt, chlorosis and branch dieback. Signs of the pathogen include grey pads of fungal tissue underneath the bark. The pads rupture the bark, but may not be immediately visible; remove the bark and investigate the sapwood for the presence of the fungal pads on dead trees. Oaks can die in as little as six weeks to one year after infection. Trenching to sever root grafts can limit the spread of oak wilt to nearby trees. | Debacarb+Carbendazim Imidacloprid+Debacarb Propiconazole | |
| Root & Lower Trunk Rot: The most cryptic and difficult group of pathogens to identify and manage. The most important root rot pathogens live as parasites of living hosts and as saprophytes on dead organic matter. | Phytophthora spp. (354‐367) | Numerous hardwoods and conifers, especially ericaceous shrubs (Rhododendron ) and oak (Quercus) | Symptoms appear as crown dieback, stunted growth, yellowing and shriveling of foliage, early leaf drop and resin/sap flow near the base of the trunk. Infected roots often appear brown to black, water‐soaked and soft. Phytophthora produces no visible signs, making field diagnosis tenuous. Plants growing at sites with standing water or where seasonal flooding occurs are more susceptible, as Phytophthora produces a swimming asexual spore. Dry sites with sandy soils often do not support the pathogen. Remove and discard infected plants, keeping in mind that Phytophthora can survive for many years in the soil. Fungicides applied to the soil often fail to reach their target or leach away prior to contact with roots. | Copper Salts of Fatty and/or Rosin Acids Etridiazole Etridiazole+Thiophanate‐methyl Fosetyl‐Aluminum Mefenoxam/Metalaxyl Phosphorous acid |
| Pythium spp. (N/A) | Numerous hardwoods and conifers in seedling stage of development | Pythium is not considered a pathogen of established forest and landscape trees and shrubs. However, the pathogen does readily kill seedlings growing in soil‐less media when other microorganisms are absent. Symptoms include stunted growth, wilting (damping off), and crown lesions. Fine roots are often absent while main roots are brown to black with little integrity. | Azoxystrobin Copper Salts of Fatty and/or Rosin Acids Etridiazole Etridiazole+Thiophanate‐methyl Mancozeb Mefenoxam Phosphorous acid Thiophanate‐methyl | |
| Root & Lower Trunk Rot (continued): | Armillaria spp. (honey fungus, shoestring root rot) (326‐331) | Nearly all woody plants, especially maple (Acer ) and oak (Quercus) | New infections can develop at almost anytime during the growing season. Symptoms appear as wilting and yellowing of foliage, canopy dieback, undersized or stunted foliage, excessive cone production, basal sap/resin flow, basal swelling and open wounds at the base of infected plants. Signs of the pathogen include rhizomorphs (black, root‐like structures attached to roots and the lower bole underneath the soil line), mycelial fans (white pads of fungal tissue beneath the bark) and mushrooms (produced sporadically for very short periods of time in the fall). | Chemical management not warranted |
| Phaeolus schweinitzii (velvet top fungus; brown cubical rot) (340‐341) | Pine (especially white pine; P. strobus), spruce (Picea ), fir (Abies), larch (Larix ) and Douglas‐fir (Pseudotsuga ) | Symptoms of infection are often not present on infected trees. Generally speaking, symptoms of root and lower trunk rot on conifers include: crown dieback, stunted and chlorotic needles, basal resinosis, and a stress cone crop. Typically, the only indication of infection are the conks, produced most often from infected roots close to the lower bole. The annual conks are tan to yellow and have a soft texture when fresh, only to become brown with age. Trees suffering stem failure have decaying wood that appears brown and separates easily into cubical pieces. | Chemical management not warranted | |
| Several fungi: (1) Laetiporus spp. (310‐311); (2) Grifola frondosa (N/A); (3): Inonotus dryadeus; 344‐345; (4): Bondarzewia berkleyii (N/A) | Numerous hardwoods, especially oak (Quercus) | Numerous fungal pathogens cause root and lower trunk rot of oaks of all ages. However, older trees can be more susceptible to stem failure, creating a threat to people and property. Symptoms are very general and can include: basal seams and cavities, basal swelling, sap flow, crown dieback, undersized foliage, scorch and early leaf drop, among others. In many cases, the fruiting body (conk/mushroom) is the only indication the tree is infected. Internal decay that does not affect the outer sapwood may cause little physiological damage, but structurally the tree may be unsound. | Chemical management not warranted | |
| Trunk Rots: Wood‐decaying fungi that often go unnoticed until an annual or perennial conk (mushroom) appears on branches or the main trunk. | Phellinus (white trunk rot of hardwoods) (306‐309) | Maple (Acer ) Birch (Betula ) Beech (Fagus) Aspen (Populus) Numerous other hardwoods | Infections often initiate on branch and trunk wounds from windborne spores (often branch stubs) and the fungus then attacks the sapwood and also colonizes the heartwood. Widely regarded as the most important trunk rot pathogen of northern hardwoods, the pathogen can be very aggressive. Conks are usually the only indicator of infection and have a dark blue, cracked pileus (cap) and a concave to convex, brown to dark brown hymenium (underside). The existence of a conk on the main trunk indicates that severe decay is present. | Chemical management not warranted |
| Ganoderma applanatum (artist's conk) (350‐351) | Cottonwood (Populus deltoides) Sugar maple (Acer saccharum ) Numerous other hardwoods | The fungus invades susceptible trees through the roots and wounds on the lower and upper trunk. The pathogen has a wide host range but in our region it is found most often on cottonwood, maple, beech and oak. While often described as a saprophyte, the fungus can cause severe root and trunk rot. The presence of a conk on a living tree indicates extensive decay is present in the surrounding area. Trees with conks present in residential and commercial settings should be considered a hazard. The perennial conks have a tan to brown pileus (cap) and a brilliant white hymenium (underside) and can be quite large. | Chemical management not warranted | |
| Climacodon septentrionalis (northern tooth fungus) (308‐ 309) | Sugar maple (Acer saccharum ) Hickory (Carya ) | The fungus often colonizes trunk wounds and less often gains entry through branch stubs. A spongy, white trunk rot ensues and the presence of the annual conk indicates extensive decay. The fungus produces cream‐colored to pale yellow, overlapping shelves of fleshy conks, with a hymenium (underside) composed of numerous slender spines or 'teeth'. The conks are usually very conspicuous and begin to appear in late summer. | Chemical management not warranted | |
| Fomes fomentarius (308‐309) | Birch (Betula ) Beech (Fagus) | Secondary white rot pathogen of hardwoods, targeting wounds in the sapwood for colonization. Trees in serious decline or recently killed often have multiple conks from the pathogen. They are generally small with a grey‐blue to tan colored pileus (cap) and a cream‐ colored, concave hymenium (underside). | Chemical management not warranted |
*Numbers in parenthesis refer to page numbers in Sinclair and Lyon (2005): Diseases of Trees and Shrubs.
(R ) denotes chemical has restricted use status in Massachusetts.
Table 1 is organized according to major disease categories for woody plant material in New England. Plant hosts, symptoms & management, and currently labeled fungicide or bactericide active ingredients are listed for specific pathogens within each category.
While chemical management options are listed for these pathogens, bear in mind that the application of a fungicide or bactericide is not always the first, or best, approach. Alternative and cultural management strategies are detailed for many pathogens in the ‘Symptoms & Management’ column.
Numbers in parentheses listed in association with individual pathogens refer to page numbers in Diseases of Trees and Shrubs - Second Edition by Wayne Sinclair and Howard Lyon (Cornell University Press). This book, a definitive resource in the field, is a primary source of additional detailed information about each pathogen.
| ACTIVE INGREDIENT(S) | TRADE NAME* | SUPPLIER | 2014 EPA REG. # |
| Azoxystrobin | Abound Flowable Heritage Quadris |
Syngenta Crop Protection, Inc Syngenta Crop Protection, Inc. Syngenta Crop Protection, Inc. |
100‐1098 100‐1093 100‐1098 |
| Azoxystrobin + Propiconazole | Quilt Xcel | Syngenta Crop Protection, Inc. | 100‐1324 |
| Calcium Polysulfide (Lime Sulfur) | BSP Sulforix BSP Lime‐Sulfur Solution Rex Lime Sulfur Solution |
AG Formulators, Inc. AG Formulators, Inc. OR‐CAL, Inc. |
66196‐3‐72 66196‐2‐72 71096‐6‐7401 |
| Boscalid + Pyraclostrobin | Pristine | BASF Corporation | 7969‐199 |
| Chlorothalonil (R) | Bravo Ultrex Bravo Weather Stik Chloronil 720 Cholorthalonil 720 SC Quali‐Pro Chorothalonil 500 ZN Daconil Ultrex Daconil Weather Stik Daconil Zn Docket DF Echo 720 T&O Echo Ultimate T&O Ensign 720 Ensign 82.5% Equus 500 ZN Equus 720 SST Equus DF Initiate 720 Manicure 6FL Mainsail 6.0 F Mainsail WDG |
Syngenta Crop Protection, Inc. Syngenta Crop Protection, Inc. Syngenta Crop Protection, Inc. Arysta LifeScience FarmSaver.com, LLC Syngenta Crop Protection, Inc. Syngenta Crop Protection, Inc. Syngenta Crop Protection, Inc. Syngenta Crop Protection, Inc. Sipcam Agro USA, Inc Sipcam Agro USA, Inc Loveland Products, Inc. Loveland Products, Inc. Makhteshim Agan of N. America, Inc Makhteshim Agan of N. America, Inc Makhteshim Agan of N. America, Inc Loveland Products, Inc. Lesco, Inc PROKoZ, Inc. PROKoZ, Inc. |
50534‐201‐100 50534‐188‐100 50534‐188‐100 66330‐362 66222‐150‐73220 50534‐202‐100 50534‐209‐100 50534‐211‐100 50534‐202‐100 60063‐7 60063‐3 34704‐966 34704‐965 66222‐150 66222‐154 66222‐149 34704‐881 60063‐7‐10404 72112‐6 72112‐5 |
| Chlorothalonil + Propiconazole (R) | Concert Concert II |
Syngenta Crop Protection, Inc. Syngenta Crop Protection, Inc. |
100‐1192 100‐1347 |
| Chlorothalonil + Thiophanate‐methyl (R) | Spectro 90WDG Quali‐Pro TM/C WDG |
Cleary Chemical Corporation Makhteshim Agan of N. America, Inc. |
1001‐72 48234‐7‐73220 |
| Copper Sulfate | Basic Copper 53 C‐O‐C‐S WDG Cuprofix Ultra 40 Dispersers Dragoon Dust with Copper |
Albaugh, Inc. Loveland Products, Inc. Cerexagri, Inc. Bonide Products, Inc. |
45002‐8 34704‐326 70506‐201 4‐474 |
| Copper Hydroxide | Kocide 101 Kocide 2000 Kocide 3000 Kocide 4.5LF Kocide DF Nu‐Cop 50DF Nu‐Cop 50WP |
E.I. DuPont De Nemo E.I. DuPont De Nemo E.I. DuPont De Nemo E.I. DuPont De Nemo E.I. DuPont De Nemo Albaugh, Inc Albaugh, Inc |
352‐681 352‐656 352‐662 352‐684 352‐688 45002‐4 45002‐7 |
| Copper Salts of Fatty and/or Rosin Acids | Camelot O | SePRO Corp | 67702‐2‐67690 |
| Debacarb + Carbendazim | Fungisol | J. J. Mauget Company | 7946‐14 |
| Debacarb (+ Imidacloprid) | Imisol | J. J. Mauget Company | 7946‐21 |
| Etridiazole | Terrazole 35% WP Truban 25 EC Truban 30 WP |
Chemtura Corp. Scott's‐Sierra Crop Protection Co Scott's‐Sierra Crop Protection Co |
400‐416 58185‐8 58185‐7 |
| Etridiazole + Thiophanate‐methyl | Banrot 40 WP Banrot 8G |
Scott's‐Sierra Crop Protection Co Scott's‐Sierra Crop Protection Co. |
58185‐10 58185‐23 |
| Fenarimol | Rubigan A.S. | Gowan Company | 10163‐274 |
| Flutolanil | ProStar 70 WDG ProStar 70 WG ProStar 70 WP |
Bayer Environmental Science Bayer Environmental Science Bayer Environmental Science |
432‐1477 432‐1223 432‐1223 |
| Fosetyl‐Aluminum | Aliette WDG Chipco Signature |
Bayer Environmental Science Bayer Environmental Science |
432‐890 432‐890 |
| Horticultural Oil | Ferti‐Lome Horticultural Oil Spray RTSA horticultural oil |
Voluntary Purchasing Group, Inc Rainbow Treecare Scientific Advancements |
48813‐1‐7401 74779‐9 |
| Iprodione | 26 GT Chipco 26019 Flo 18 Plus T&O Ipr o 2SE |
Bayer Environmental Science Bayer Environmental Science Lesco, Inc. Makhteshim Agan of N. America, Inc |
432‐888 432‐888 432‐888‐10404 73220‐14 |
| Iprodione + Thiophanate‐methyl | 26/36 | Cleary Chemical Corporation | 432‐1414‐1001 |
| Kresoxim‐methyl (R) | Cygnus Sovran |
BASF Corporation BASF Corporation |
7969‐124 7969‐154 |
| Mancozeb | Dithane 75DF Rainshield Dithane F‐45 Rainshield Dithane M45 4 Flowable Mancozeb Mancozeb Flowable with Zinc Fore 80WP Rainshield Mancozeb DG Manzate Pro‐Stick T&O Manzate Flowable T&O Protect DF |
Dow AgroSciences, LLC Dow AgroSciences, LLC Dow AgroSciences, LLC Lesco, Inc. Bonide Products, Inc Dow AgroSciences, LLC Lesco, Inc. Cerexagri, Inc Cerexagri, Inc Cleary Chemical Corporation |
62719‐402 62719‐396 62719‐387 62719‐396‐10404 62719‐396‐4 62719‐388 62719‐402‐10404 70506‐234 70506‐236 1001‐77 |
| Mancozeb + Copper Hydroxide | ManKocide | E.I. DuPont De Nemo | 352‐690 |
| Mancozeb + Thiophanate‐methyl | Zyban WSB | Scott's‐Sierra Crop Protection Co. | 58185‐31 |
| Mefenoxam (Metalaxyl‐m) | Quali‐Pro Mefenoxam 2 AQ Subdue GR Subdue MAXX |
Makhteshim Agan of N. America, Inc. Syngenta Crop Protection, Inc. Syngenta Crop Protection, Inc |
70252‐11‐73220 100‐794 100‐796 |
| Myclobutanil | Eagle 20EW Eagle 40 WP Hoist Myclo 20 EW Myclobutanil 20 EW T&O Rally 40WSP |
Dow AgroSciences, LLC Dow AgroSciences, LLC PROKoZ, Inc. United Turf Alliance Makhteshim Agan of N. America, Inc. Dow AgroSciences, LLC |
62719‐463 62719‐417 62719‐417‐72112 42750‐166‐86064 66222‐185 62719‐410 |
| Myrothecium verrucaria (dried solids & solubles) | Ditera DF | Valent Biosciences Corp. | 73049‐67 |
| Neem Oil | 70% Neem Oil Triact 70 Trilogy Bonide Neem Oil Green Light Neem Concentrate Natria Neem Oil Concentrate Bon Neem II |
Lawn and Garden Products, Inc OHP, Inc. Certis USA, LLC Bonide Products, Inc. Green Light Co. Bayer Advanced, LLC Bonide Products, Inc. |
70051‐2‐54705 70051‐2‐59807 70051‐2 70051‐2‐4 70051‐2‐869 70051‐2‐72155 70051‐74‐4 |
| Phosphorous Acid | Agri‐Fos Agri‐Fos Alude Organocide Plant Doctor Arborfos Arborfos HP Fosphite Quanta Rampart T&O Resist 57 |
Agrichem Lawn and Garden Products, Inc. Cleary Chemical Corporation Organic Laboratories, Inc J. J. Mauget Company J. J. Mauget Company JH Biotech, Inc Helena Chemical Company Loveland Products, Inc Actagro, LLC |
71962‐1 71962‐1‐54705 71962‐1‐1001 71962‐1‐70179 7946‐26 7946‐31 68573‐2 5905‐566 34704‐924 82940‐1 |
| Potassium Bicarbonate | Armicarb 100 Eco‐Mate Armicarb "O" |
Helena Chemical Company Helena Chemical Company |
5905‐541 5905‐541 |
| Propamocarb hydrochloride | Banol T&O Proplant T&O |
Bayer Environmental Science Sipcam Agro USA, Inc. |
432‐942‐10404 55260‐9 |
| Propiconazole | Alamo AmTide Propiconazole 41.8% Banner MAXX Banner MAXX II Dorado Fathom 14.3 MEC Fitness Honor Guard PPZ T&O Monterey Fungi‐Fighter Procon‐Z ProPensity 1.3ME Quali‐Pro Propiconazole 14.3 Propi‐Star EC Shar‐Shield PPZ Spectator T&O |
Syngenta Crop Protection, Inc AmTide, LLC Syngenta Crop Protection, Inc. Syngenta Crop Protection, Inc. Syngenta Crop Protection, Inc. PROKoZ, Inc. Loveland Products, Inc. Control Solutions, Inc. Lawn and Garden Products, Inc. Loveland Products, Inc. Sipcam Agro USA, Inc. FarmSaver.com, LLC Albaugh, Inc. Sharda USA, LLC Lesco, Inc. |
100‐741 83851‐10 100‐741 100‐1326 100‐741 72112‐3 34704‐1031 66222‐41‐53883 100‐773‐54705 34704‐879 60063‐27 66222‐41‐73220 42750‐211 83529‐22 100‐617‐10404 |
| Streptomycin Sulfate |
Ag Streptomycin Firewall 17WP |
Makhteshim Agan of N. America, Inc Nufarm Americas, Inc. AgroSource, Inc. |
66222‐121 55146‐96 80990‐4 |
| Sulfur | Kumulus DF Micro Sulf Microfine Sulfur Sulfur 6 L Yellow Jacket Wettable Sulfur II |
Arysta LifeScience Nufarm Americas, Inc. Loveland Products, Inc. Arysta LifeScience Georgia Gulf Sulfur Corp |
51036‐352‐66330 55146‐75 6325‐13‐34704 66330‐211 6325‐13 |
| Tebuconazole + Trifloxystrobin | Adament 50 WG | Bayer Environmental Science | 264‐1052 |
| Thiabendazole Hypophosphite | Arbotect 20‐S | Syngenta Crop Protection, Inc. | 100‐892 |
| Thiophanate‐methyl | 3336 F 3336 WP Fungo WSB Incognito 4.5F Incognito 85 WDG Quali‐Pro 85 WDG T‐Methyl 70W WSB Thiophanate Methyl 85 WDG Quali‐Pro TM 4.5 Topsin 4.5 FL Transom 4.5 F Transom 50 WSB |
Cleary Chemical Corporation Cleary Chemical Corporation Scott's‐Sierra Crop Protection Co Makhteshim Agan of N. America, Inc. Makhteshim Agan of N. America, Inc. Makhteshim Agan of N. America, Inc. Arysta LifeScience Makhteshim Agan of N. America, Inc. Makhteshim Agan of N. America, Inc. United Phosphorus Inc. PROKoZ, Inc. PROKoZ, Inc. |
1001‐69 1001‐63 58185‐30 66222‐134 66222‐145 66222‐145 66330‐301 66222‐145 48234‐12‐73220 73545‐13‐70506 72112‐2 72112‐1 |
| Triadimefon | Bayleton 50 WSP Bayleton Flo Strike 50 WDG |
Bayer Environmental Science Bayer Environmental Science OHP, Inc |
432‐1360 432‐1445 432‐1367‐59807 |
| Triadimefon + Trifloxystrobin | Armada 50WP | Bayer Environmental Science | 432‐1412 |
| Trichoderma harzianum var. Rifai (strain KRL‐AG2) | Root Shield HG T‐22TM HC Rootshield TM Granules Rootshield WP |
BioWorks, Inc. BioWorks, Inc. BioWorks, Inc. BioWorks, Inc. |
68539‐4 68539‐4 68539‐3 68539‐7 |
| Trifloxystrobin | Compass Compass O 50WDG Flint Gem 500 SC |
Bayer Environmental Science OHP, Inc. Bayer Environmental Science Bayer Environmental Science |
432‐1371 432‐1371‐59807 264‐777 264‐826 |
| Triflumizole | Procure 480SC Terraguard SC Tarraguard 50W |
Chemtura Corp. Chemtura Corp. Chemtura Corp. |
400‐518 400‐521 400‐433 |
Table 2 presents information about currently registered fungicide or bactericide active ingredients, including current trade names, suppliers, EPA registration numbers, and current restricted use status.
Although every effort was made to be thorough, trade name lists are provided for reference purposes only and are not necessarily comprehensive or reflective of the full range of commercially available products.
(R) denotes a material that has restricted use status in Massachusetts.
| TRADE NAME* | ACTIVE INGREDIENT(S) | SUPPLIER | 2014 EPA REG. # | RESTRICTED USE? |
| 18 Plus T&O | Iprodione | Lesco, Inc. | 432‐888‐10404 | No |
| 26 GT | Iprodione | Bayer Environmental Science | 432‐888 | No |
| 26/36 | Iprodione + Thiophanate‐methyl | Cleary Chemical Corporation | 432‐1414‐1001 | No |
| 3336 F | Thiophanate‐methyl | Cleary Chemical Corporation | 1001‐69 | No |
| 3336 WP | Thiophanate‐methyl | Cleary Chemical Corporation | 1001‐63 | No |
| 4 Flowable Mancozeb | Mancozeb | Lesco, Inc. | 62719‐396‐10404 | No |
| 70% Neem Oil | Neem Oil | Lawn and Garden Products, Inc. | 70051‐2‐54705 | No |
| Abound Flowable | Azoxystrobin | Syngenta Crop Protection, Inc | 100‐1098 | No |
| Adament 50 WG | Tebuconazole + Trifloxystrobin | Bayer Environmental Science | 264‐1052 | No |
| Ag Streptomycin | Streptomycin Sulfate | Makhteshim Agan of N. America, Inc. | 66222‐121 | No |
| Agri‐Fos | Phosphorous Acid | Agrichem | 71962‐1 | No |
| Agri‐Fos | Phosphorous Acid | Lawn and Garden Products, Inc | 71962‐1‐54705 | No |
| Agri‐Mycin 17 | Streptomycin Sulfate | Nufarm Americas, Inc. | 55146‐96 | No |
| Alamo | Propiconazole | Syngenta Crop Protection, Inc. | 100‐741 | No |
| Aliette WDG | Fosetyl‐Aluminum | Bayer Environmental Science | 432‐890 | No |
| Alude | Phosphorous Acid | Cleary Chemical Corporation | 71962‐1‐1001 | No |
| AmTide Propiconazole 41.8% | Propiconazole | AmTide, LLC | 83851‐10 | No |
| Arborfos | Phosphorous Acid | J. J. Mauget Company | 7946‐26 | No |
| Arborfos HP | Phosphorous Acid | J. J. Mauget Company | 7946‐31 | No |
| Arbotect 20‐S | Thiabendazole Hypophosphite | Syngenta Crop Protection, Inc. | 100‐892 | No |
| Armada 50WP | Triadimefon + Trifloxystrobin | Bayer Environmental Science | 432‐1412 | No |
| Armicarb 100 | Potassium Bicarbonate | Helena Chemical Company | 5905‐541 | No |
| Banner MAXX | Propiconazole | Syngenta Crop Protection, Inc | 100‐741 | No |
| Banner MAXX II | Propiconazole | Syngenta Crop Protection, Inc. | 100‐1326 | No |
| Banol T&O | Propamocarb Hydrochloride | Bayer Environmental Science | 432‐942‐10404 | No |
| Banrot 40 WP | Etridiazole + Thiophanate‐methyl | Scott's‐Sierra Crop Protection Co. | 58185‐10 | No |
| Banrot 8G | Etridiazole + Thiophanate‐methyl | Scott's‐Sierra Crop Protection Co. | 58185‐23 | No |
| Basic Copper 53 | Basic Copper Sulfate | Albaugh, Inc. | 45002‐8 | No |
| Bayleton 50 WSP | Triadimefon | Bayer Environmental Science | 432‐1360 | No |
| Bayleton Flo | Triadimefon | Bayer Environmental Science | 432‐1445 | No |
| Bon Neem II | Neem Oil | Bonide Products, Inc. | 70051‐74‐4 | No |
| Bonide Neem Oil | Neem Oil | Bonide Products, Inc | 70051‐2‐4 | No |
| Bravo Ultrex | Chlorothalonil | Syngenta Crop Protection, Inc. | 50534‐201‐100 | Yes |
| Bravo Weather Stik | Chlorothalonil | Syngenta Crop Protection, Inc. | 50534‐188‐100 | Yes |
| BSP Lime‐Sulfur Solution | Calcium Polysulfide (Lime Sulfur) | AG Formulators, Inc. | 66196‐2‐72 | No |
| BSP Sulforix | Calcium Polysulfide (Lime Sulfur) | AG Formulators, Inc. | 66196‐3‐72 | No |
| Camelot O | Copper Salts of Fatty and Rosin Acids | SePRO Corp. | 67702‐2‐67690 | No |
| Chipco 26019 Flo | Iprodione | Bayer Environmental Science | 432‐888 | No |
| Chipco Signature | Fosetyl‐Aluminum | Bayer Environmental Science | 432‐890 | No |
| Chloronil 720 | Chlorothalonil | Syngenta Crop Protection, Inc. | 50534‐188‐100 | Yes |
| Cholorthalonil 720 SC | Chlorothalonil | Arysta LifeScience | 66330‐362 | Yes |
| C‐O‐C‐S WDG | Basic Copper Sulfate | Loveland Products, Inc | 34704‐326 | No |
| Compass | Trifloxystrobin | Bayer Environmental Science | 432‐1371 | No |
| Compass O 50WDG | Trifloxystrobin | OHP, Inc | 432‐1371‐59807 | No |
| Concert | Chlorothalonil + Propiconazole | Syngenta Crop Protection, Inc. | 100‐1192 | Yes |
| Concert II | Chlorothalonil + Propiconazole | Syngenta Crop Protection, Inc. | 100‐1347 | Yes |
| Cuprofix Ultra 40 Dispersers | Basic Copper Sulfate | Cerexagri, Inc | 70506‐201 | No |
| Cygnus | Kresoxim‐methyl | BASF Corporation | 7969‐124 | Yes |
| Daconil Ultrex | Chlorothalonil | Syngenta Crop Protection, Inc | 50534‐202‐100 | Yes |
| Daconil Weather Stik | Chlorothalonil | Syngenta Crop Protection, Inc. | 50534‐209‐100 | Yes |
| Daconil Zn | Chlorothalonil | Syngenta Crop Protection, Inc. | 50534‐211‐100 | Yes |
| Ditera DF | Myrothecium verrucaria (dried solids & solubles) | Valent Biosciences Corp | 73049‐67 | No |
| Dithane 75DF Rainshield | Mancozeb | Dow AgroSciences, LLC | 62719‐402 | No |
| Dithane F‐45 Rainshield | Mancozeb | Dow AgroSciences, LLC | 62719‐396 | No |
| Dithane M45 | Mancozeb | Dow AgroSciences, LLC | 62719‐387 | No |
| Docket DF | Chlorothalonil | Syngenta Crop Protection, Inc. | 50534‐202‐100 | Yes |
| Dorado | Propiconazole | Syngenta Crop Protection, Inc. | 100‐741 | No |
| Dragoon Dust with Copper | Basic Copper Sulfate | Bonide Products, Inc. | 4‐474 | No |
| Eagle 20EW | Myclobutanil | Dow AgroSciences, LLC | 62719‐463 | No |
| Eagle 40 WP | Myclobutanil | Dow AgroSciences, LLC | 62719‐417 | No |
| Echo 720 T&O | Chlorothalonil | Sipcam Agro USA, Inc. | 60063‐7 | Yes |
| Echo Ultimate T&O | Chlorothalonil | Sipcam Agro USA, Inc. | 60063‐3 | Yes |
| Eco‐Mate Armicarb "O" | Potassium Bicarbonate | Helena Chemical Company | 5905‐541 | No |
| Ensign 720 | Chlorothalonil | Loveland Products, Inc. | 34704‐966 | Yes |
| Ensign 82.5% | Chlorothalonil | Loveland Products, Inc. | 34704‐965 | Yes |
| Equus 500 ZN | Chlorothalonil | Makhteshim Agan of N. America, Inc | 66222‐150 | Yes |
| Equus 720 SST | Chlorothalonil | Makhteshim Agan of N. America, Inc | 66222‐154 | Yes |
| Equus DF | Chlorothalonil | Makhteshim Agan of N. America, Inc | 66222‐149 | Yes |
| Fathom 14.3 MEC | Propiconazole | PROKoZ, Inc. | 72112‐3 | No |
| Ferti‐lome horticultural oil spray | Horticultural Oil | Voluntary Purchasing Group, Inc. | 48813‐1‐7401 | No |
| Firewall 17WP | Streptomycin Sulfate | AgroSource, Inc. | 80990‐4 | No |
| Fitness | Propiconazole | Loveland Products, Inc. | 34704‐1031 | No |
| Flint | Trifloxystrobin | Bayer Environmental Science | 264‐777 | No |
| Fore 80WP Rainshield | Mancozeb | Dow AgroSciences, LLC | 62719‐388 | No |
| Fosphite | Phosphorous Acid | JH Biotech, Inc. | 68573‐2 | No |
| Fungisol | Debacarb + Carbendazim | J. J. Mauget Company | 7946‐14 | No |
| Fungo WSB | Thiophanate‐methyl | Scott's‐Sierra Crop Protection Co | 58185‐30 | No |
| Gem 500 SC | Trifloxystrobin | Bayer Environmental Science | 264‐826 | No |
| Green Light Neem Concentrate | Neem Oil | Green Light Co. | 70051‐2‐869 | No |
| Heritage | Azoxystrobin | Syngenta Crop Protection, Inc. | 100‐1093 | No |
| Hoist | Myclobutanil | PROKoZ, Inc. | 62719‐417‐72112 | No |
| Honor Guard PPZ T&O | Propiconazole | Control Solutions, Inc. | 66222‐41‐53883 | No |
| Imisol | Debacarb (+ Imidacloprid) | J. J. Mauget Company | 7946‐21 | No |
| Incognito 4.5F | Thiophanate‐methyl | Makhteshim Agan of N. America, Inc. | 66222‐134 | No |
| Incognito 85 WDG | Thiophanate‐methyl | Makhteshim Agan of N. America, Inc. | 66222‐145 | No |
| Initiate 720 | Chlorothalonil | Loveland Products, Inc. | 34704‐881 | Yes |
| Ipro 2SE | Iprodione | Makhteshim Agan of N. America, Inc. | 73220‐14 | No |
| Kocide 101 | Copper Hydroxide | E.I. DuPont De Nemo | 352‐681 | No |
| Kocide 2000 | Copper Hydroxide | E.I. DuPont De Nemo | 352‐656 | No |
| Kocide 3000 | Copper Hydroxide | E.I. DuPont De Nemo | 352‐662 | No |
| Kocide 4.5LF | Copper Hydroxide | E.I. DuPont De Nemo | 352‐684 | No |
| Kocide DF | Copper Hydroxide | E.I. DuPont De Nemo | 352‐688 | No |
| Kumulus DF | Sulfur | Arysta LifeScience | 51036‐352‐66330 | No |
| Mainsail 6.0 F | Chlorothalonil | PROKoZ, Inc. | 72112‐6 | Yes |
| Mainsail WDG | Chlorothalonil | PROKoZ, Inc. | 72112‐5 | Yes |
| Mancozeb DG | Mancozeb | Lesco, Inc. | 62719‐402‐10404 | No |
| Mancozeb Flowable with Zinc | Mancozeb | Bonide Products, Inc. | 62719‐396‐4 | No |
| Manicure 6FL | Chlorothalonil | Lesco, Inc. | 60063‐7‐10404 | Yes |
| ManKocide | Mancozeb + Copper Hydroxide | E.I. DuPont De Nemo | 352‐690 | No |
| Manzate Flowable T&O | Mancozeb | Cerexagri, Inc. | 70506‐236 | No |
| Manzate Pro‐Stick T&O | Mancozeb | Cerexagri, Inc. | 70506‐234 | No |
| Micro Sulf | Sulfur | Nufarm Americas, Inc. | 55146‐75 | No |
| Microfine Sulfur | Sulfur | Loveland Products, Inc. | 6325‐13‐34704 | No |
| Monterey Fungi‐Fighter | Propiconazole | Lawn and Garden Products, Inc. | 100‐773‐54705 | No |
| Myclo 20 EW | Myclobutanil | United Turf Alliance | 42750‐166‐86064 | No |
| Myclobutanil 20 EW T&O | Myclobutanil | Makhteshim Agan of N. America, Inc. | 66222‐185 | No |
| Natria Neem Oil Concentrate | Neem Oil | Bayer Advanced, LLC | 70051‐2‐72155 | No |
| Nu‐Cop 50DF | Copper Hydroxide | Albaugh, Inc. | 45002‐4 | No |
| Nu‐Cop 50WP | Copper Hydroxide | Albaugh, Inc. | 45002‐7 | No |
| Organocide Plant Doctor | Phosphorous Acid | Organic Laboratories, Inc. | 71962‐1‐70179 | No |
| Pristine | Boscalid + Pyraclostrobin | BASF Corporation | 7969‐199 | No |
| Procon‐Z | Propiconazole | Loveland Products, Inc. | 34704‐879 | No |
| Procure 480SC | Triflumizole | Chemtura Corp. | 400‐518 | No |
| ProPensity 1.3ME | Propiconazole | Sipcam Agro USA, Inc. | 60063‐27 | No |
| Propi‐Star EC | Propiconazole | Albaugh, Inc. | 42750‐211 | No |
| Proplant T&O | Propamocarb Hydrochloride | Sipcam Agro USA, Inc. | 55260‐9 | No |
| ProStar 70 WDG | Flutolanil | Bayer Environmental Science | 432‐1477 | No |
| ProStar 70 WG | Flutolanil | Bayer Environmental Science | 432‐1223 | No |
| ProStar 70 WP | Flutolanil | Bayer Environmental Science | 432‐1223 | No |
| Protect DF | Mancozeb | Cleary Chemical Corporation | 1001‐77 | No |
| Quadris | Azoxystrobin | Syngenta Crop Protection, Inc. | 100‐1098 | No |
| Quali‐Pro 85 WDG | Thiophanate‐methyl | Makhteshim Agan of N. America, Inc. | 66222‐145 | No |
| Quali‐Pro Chorothalonil 500 ZN | Chlorothalonil | FarmSaver.com, LLC | 66222‐150‐73220 | Yes |
| Quali‐Pro Mefenoxam 2 AQ | Mefenoxam (Metalaxyl‐m) | Makhteshim Agan of N. America, Inc. | 70252‐11‐73220 | No |
| Quali‐Pro Propiconazole 14.3 | Propiconazole | FarmSaver.com, LLC | 66222‐41‐73220 | No |
| Quali‐Pro TM 4.5 | Thiophanate‐methyl | Makhteshim Agan of N. America, Inc. | 48234‐12‐73220 | No |
| Quali‐Pro TM/C WDG | Chlorothalonil + Thiophanate‐methyl | Makhteshim Agan of N. America, Inc. | 48234‐7‐73220 | Yes |
| Quanta | Phosphorous Acid | Helena Chemical Company | 5905‐566 | No |
| Quilt Xcel | Azoxystrobin + Propiconazole | Syngenta Crop Protection, Inc. | 100‐1324 | No |
| Rally 40WSP | Myclobutanil | Dow AgroSciences, LLC | 62719‐410 | No |
| Rampart T&O | Phosphorous Acid | Loveland Products, Inc. | 34704‐924 | No |
| Resist 57 | Phosphorous Acid | Actagro, LLC | 82940‐1 | No |
| Rex Lime Sulfur Solution | Calcium Polysulfide (Lime Sulfur) | OR‐CAL, Inc. | 71096‐6‐7401 | No |
| Root Shield HG | Trichoderma harzianum var. Rifai (strain KRL‐AG2) | BioWorks, Inc | 68539‐4 | No |
| Rootshield TM Granules | Trichoderma harzianum var. Rifai (strain KRL‐AG2) | BioWorks, Inc | 68539‐3 | No |
| Rootshield WP | Trichoderma harzianum var. Rifai (strain KRL‐AG2) | BioWorks, Inc | 68539‐7 | No |
| RTSA horticultural oil | Horticultural Oil | Rainbow Treecare Scientific Advancements | 74779‐9 | No |
| Rubigan A.S. | Fenarimol | Gowan Company | 10163‐274 | No |
| Shar‐Shield PPZ | Propiconazole | Sharda USA, LLC | 83529‐22 | No |
| Sovran | Kresoxim‐methyl | BASF Corporation | 7969‐154 | Yes |
| Spectator T&O | Propiconazole | Lesco, Inc. | 100‐617‐10404 | No |
| Spectro 90WDG | Chlorothalonil + Thiophanate‐methyl | Cleary Chemical Corporation | 1001‐72 | Yes |
| Strike 50 WDG | Triadimefon | OHP, Inc. | 432‐1367‐59807 | No |
| Subdue GR | Mefenoxam (Metalaxyl‐m) | Syngenta Crop Protection, Inc. | 100‐794 | No |
| Subdue MAXX | Mefenoxam (Metalaxyl‐m) | Syngenta Crop Protection, Inc. | 100‐796 | No |
| Sulfur 6 L | Sulfur | Arysta LifeScience | 66330‐211 | No |
| T‐22TM HC | Trichoderma harzianum var. Rifai (strain KRL‐AG2) | BioWorks, Inc. | 68539‐4 | No |
| Terraguard 50W | Triflumizole | Chemtura Corp. | 400‐433 | No |
| Terraguard SC | Triflumizole | Chemtura Corp. | 400‐521 | No |
| Terrazole 35% WP | Etridiazole | Chemtura Corp. | 400‐416 | No |
| Thiophanate Methyl 85 WDG | Thiophanate‐methyl | Makhteshim Agan of N. America, Inc. | 66222‐145 | No |
| T‐Methyl 70W WSB | Thiophanate‐methyl | Arysta LifeScience | 66330‐301 | No |
| Topsin 4.5 FL | Thiophanate‐methyl | United Phosphorus Inc. | 73545‐13‐70506 | No |
| Transom 4.5 F | Thiophanate‐methyl | PROKoZ, Inc. | 72112‐2 | No |
| Transom 50 WSB | Thiophanate‐methyl | PROKoZ, Inc. | 72112‐1 | No |
| Triact 70 | Neem Oil | OHP, Inc. | 70051‐2‐59807 | No |
| Trilogy | Neem Oil | Certis USA, LLC | 70051‐2 | No |
| Truban 25 EC | Etridiazole | Scott's‐Sierra Crop Protection Co. | 58185‐8 | No |
| Truban 30 WP | Etridiazole | Scott's‐Sierra Crop Protection Co. | 58185‐7 | No |
| Yellow Jacket Wettable Sulfur II | Sulfur | Georgia Gulf Sulfur Corp. | 6325‐13 | No |
| Zyban WSB | Mancozeb + Thiophanate‐methyl | Scott's‐Sierra Crop Protection Co. | 58185‐31 | No |
Table 3 is a list for cross-referencing active ingredients by trade name. Includes supplier, EPA registration number and current restricted use status.
As mentioned above, this list is not necessarily comprehensive or reflective of the full range of commercially available products.
| ACTIVE INGREDIENT(S) | DESCRIPTION |
| Azoxystrobin | Azoystrobin has the broadest spectrum of any current fungicide. It has both preventative and curative effects with locally systemic properties in the strobilurin class of fungicides. Fungicides with this active ingredient can have utility against several types of cankering and anthracnose fungi. Azoxystrobin is highly phytotoxic on certain apple, crabapple and cherry varieties. Follow label instructions regarding the development of fungicide resistance over time. |
| Azoxystrobin + Propiconazole | Both chemicals are broad spectrum and have protectant, systemic and curative activity. Because reistance to azoxystrobin by fungal pathogens can develop over time, propiconazole can help to ameliorate this issue through a different mode of action. Mostly used for persistent cankering and anthracnose pathogens. |
| Boscalid + Pyraclostrobin | Broad spectrum fungicide used mostly for high‐value fruit and nut trees. Helps to control powdery mildew, foliar and shoot blight pathogens, including anthracnose. The risk of resistance development is high for both active ingredients. |
| Calcium Polysulfide (Lime Sulfur) | Inorganic compound used as a fungicide as well as an insecticide (for scales). Often used during the dormant season or just before buds open to reduce over‐wintering inoculum. Do not use within 14 days of horticultural oil spray or when temperatures are above 75°F. |
| Chlorothalonil (R) | A broad‐spectrum, protectant fungicide that is effective against numerous anthracnose, needle cast, foliar and shoot blight diseases. Although fungicides with this active ingredient are widely available, chlorothalonil is a restricted use chemical in Massachusetts and should never be used on plants near water sources because of its toxicity to fish and aquatic invertebrates. |
| Chlorothalonil + Propamocarb Hydrochloride (R) | Broad spectrum contact plus systemic fungicide combination product used to treat both foliar blight and soilborne pathogens. Chlorothalonil is a restricted use chemical in Massachusetts and should never be used on plants near water sources because of its toxicity to fish and aquatic invertebrates. |
| Chlorothalonil + Propiconazole (R) | Broad spectrum combination product that has utility against a wide array of fungal pathogens, including anthracnose, needlecasts, rusts, foliar blights and stem cankers. Chlorothalonil is a restricted use chemical in Massachusetts and should never be used on plants near water sources because of its toxicity to fish and aquatic invertebrates. |
| Chlorothalonil + Thiophanate‐methyl (R) | Broad spectrum contact plus systemic fungicide combination used to control a broad array of pathogens causing foliar and flower blights, stem cankers, rusts and powdery mildew. Chlorothalonil is a restricted use chemical in Massachusetts and should never be used on plants near water sources because of its toxicity to fish and aquatic invertebrates. |
| Copper | Copper compounds are toxic to both fungi and bacteria and are used as protectant fungicides and bactericides. Some products are compatible with other fungicides or insecticides and may leave a residue. Copper compounds may injure plants when used at temperatures below 50°F or during periods of high humidity. Phytotoxic when applied in spray solutions having a pH less than 6.5. |
| Debacarb (+ Imidacloprid) | Broad spectrum fungicide with broad spectrum insecticide applied by microinjection into the vascular system. Used to control a wide array of insect pests and fungal pathogens. Best used on trees that have a complex of chronic insect and disease problems. |
| Debacarb + Carbendazim | Broad spectrum combination product applied by microinjection into the vascular system. Used to help control vascular wilt diseases (Dutch elm disease and verticillium wilt), stem cankering pathogens, and certain anthracnose diseases. Best used preventatively for wilt diseases, but has theurapeutic effects. |
| Etridiazole | A seed and soil fungicide that is used to control Pythium and Phytophthora . May not be compatible with other pesticides. |
| Etridiazole + Thiophanate‐methyl | Broad spectrum contact plus systemic fungicide used to manage soil‐borne diseases. Formulated as a soil drench or side dressing. |
| Fenarimol | Sterol inhibitor that's a locally systemic foliar fungicide with protective and curative actions. Primarily used to control powdery mildew fungi. |
| Flutolanil | A systemic fungicide used as a preventative and curative to manage rusts and species of Rhizoctonia . In the benzanalide chemical group. |
| Fosetyl‐Aluminum | A narrow‐spectrum compound that is used as a fungicide and bactericide. Alternative material for treating Pythium and Phythophthora root rots. Moves both upward and downward in the transpiration stream. May not be compatible with foliar fertilizers or copper‐based fungicides. Do not use with spreader‐stickers. |
| Horticultural Oil | Useful for the management of powdery mildews on certain plants. When using horticultural oil, conduct a small‐scale test spray on an inconspicuous part of the plant to check for sensitivity to the oil treatment. Greenhouse grown plants tend to be more sensitive to oil treatments. The following environmental conditions increase plant sensitivity to horticultural oil: high humidity, heavy overcast, extended rain, inadequate air movement, intense sun and/or heat build‐up that stresses plant, darkness, plants experiencing water shortage, and prior to, during or following unusually cold or freezing temperatures. Check product label for compatibility information regarding the use of oil treatments with other chemicals. |
| Iprodione | A broad‐spectrum foliar fungicide with mostly preventive but some early curative effects. Locally translocated in the plant. Also used as soil drench or dip. Some chance of short term fungicide resistance. |
| Iprodione + Thiophanate‐methyl | Broad spectrum contact plus systemic fungicide used to control a wide array of foliar blight pathogens. |
| Kresoxim‐methyl (R) | A foliar fungicide for use on ornamentals in nurseries and non‐residential landscapes. Provides protective and curative activity against powdery mildew, as well as protective activity against certain leaf spot, rust, anthracnose, and downy mildew diseases. It is most effective when a protective barrier is established and maintained on the plant surface. Kresoxim‐methyl is a restricted use chemical in Massachusetts and should never be used near water sources. |
| Mancozeb | A broad‐spectrum contact dithiocarbamate fungicide also used as a soil drench for particular diseases. Surfactants can be used for maximum coverage and retention in wet weather. A coordination product of zinc ion and manganese ethylene bisdithiocarbamate. |
| Mancozeb + Copper Hydroxide | Broad spectrum, contact fungicide and bactericide product used to control fire blight, anthracnose diseases and needle cast. |
| Mancozeb + Thiophanate‐methyl | Broad spectrum contact plus systemic fungicide. |
| Mefenoxam | Used for damping off, root and stem rot caused by Pythium and Phytophthora . Apply as a soil drench, soil surface spray, or incorporate into soil mix. May develop resistant strains of the target pathogen. Earlier formulations of Subdue (metalaxyl) are chemically related to mefenoxam. |
| Myclobutanil | Protectant and curative fungicide for foliar diseases with locally systemic properties. Compatible with most other pesticides and horticultural materials. Spreader‐stickers are recommended. Overdosage can result in shortened internodes and excessive foliar greening. |
| Myrothecium verrucaria | This biological nematicide suppresses a number of parasitic plant nematodes. Incorporate Myrothecium verrucaria into the soil as a dry granule, ground spray, or using approved irrigation systems. |
| Neem Oil | A fungicide for the prevention of black spot on rose, powdery mildew, Botrytis blight, anthracnose, rust, and scab on a number of plants. Follow label directions to avoid phytotoxicity. |
| Phosphorous Acid | A systemic fungicide for the prevention of diseases caused by Phytophthora , Pythium and downy mildew on specific labeled host plants. Increasingly being used to treat many other types of diseases. In addition, it suppresses certain bacterial blights on particular labeled hosts. |
| Potassium Bicarbonate | Broad‐spectrum contact fungicide to suppress powdery mildew, Botrytis blight, and some leaf spot diseases. |
| Propamocarb Hydrochloride | Applied as a soil drench, seed treatment and soil surface spray for prevention of root rot and damping‐off by species of Phytophthora and Pythium. Systemic activity is primarily upward in the plant. Compatible with other fungicides. For use on greenhouse crops and field‐grown ornamentals. |
| Propiconazole | Widely used, sterol inhibitor fungicide that has protectant, systemic and curative activity. Mostly used for its long‐term protectant and eradicant activity against foliar blights and anthracnose. Formulated as foliar spray or trunk injection. |
| Streptomycin Sulfate | Antibiotic used as a bactericide. Some practitioners recommend adjuvants that increase the uptake of the Streptomycin sulfate. The extent to which antibiotics should be used for fireblight depends on three things: (1) Susceptibility of the plant: Highly susceptible plants are obviously more at risk. Treating a plant that is not moderately to highly susceptible to fireblight is not recommended. (2) History of fireblight on a site: If there is no history of fireblight, there is little inoculum to cause a problem. This can change quickly if conditions are just right, though. In addition, low levels of fireblight are not very noticeable, so in some cases the disease is present but it is not known. (3) Environmental conditions: Fireblight prediction models track environmental conditions and can indicate when the risk of fireblight infection is high. Contact the UMass Extension Tree Fruit Program at 413‐323‐4208 during the growing season for ongoing monitoring information, or go online to: extension.umass.edu/fruitadvisor. |
| Sulfur | Inorganic element or compound used as a foliar fungicide as well as an insecticide. May cause plant injury if used when temperatures are above 75°F. Do not use within two weeks of oil sprays. Primarily used for powdery mildew and foliar diseases of rose. |
| Tebuconazole + Trifloxystrobin | Limited spectrum contact and systemic combination fungicide with utlility against anthracnose, powdery mildew and foliar/ blossom/ fruit blight diseases of fruit trees. |
| Thiabendazole Hypophosphite | Broad‐spectrum systemic fungicide, used preventively as well as therapeutically in the early stages of disease. |
| Thiophanate‐methy | A broad‐spectrum systemic fungicide for foliar applications and soil treatments. Use of spreader‐sticker or wetting agent recommended. Do not mix with copper containing materials. |
| Triadimefon | Sterol inhibitor systemic fungicide with both curative and protective action. |
| Triadimefon + Trifloxystrobin | Both chemicals are systemic and both curative and protective modes of action. Used to control anthracnose, powdery mildew, rusts and some foliar blight pathogens. |
| Trichoderma harzianum var. Rifai | A preventative biological fungicide for management of soilborne root diseases. When applied properly to soil mix or in backfill with transplants the microbe grows into developing plant roots and protects them against root diseases such as Pythium , Rhizoctonia , Fusarium , Cylindrocladium , and Thielaviopsis. |
| Trifloxystrobin | A strobilurin type fungicide with contact and systemic activity. Follow label instructions for minimizing resistance. |
| Triflumizole | Protectant fungicide with locally systemic activity. Used as a foliar spray, soil drench or as a soak for propagation. Also used as eradicant. |
Table 4 includes descriptions of fungicides and bactericides covered in this guide, organized by active ingredient.
(R) denotes a material that has restricted use status in Massachusetts.
About the information in this guide
The predceding information is meant only to be a guide, and is not presented as recommendations but rather as research-based and expertly audited knowledge intended to help practitioners make informed decisions. The authors make no guarantees and assume no liability as to the effectiveness of outlined practices or listed materials. The user of this information assumes all risks and liability for personal injury and property damage.
About pesticides referenced in this guide
When using pesticides, applicators must read and strictly follow all directions on the pesticide label. The pesticide label is the law. In the event that pesticide label information is in conflict with information contained in this guide, the label shall take precedence.
Pesticide trade names are used for identification and reference purposes only. No product endorsement is indicated or implied, nor is discrimination intended against similar materials. No claims are made with regard to the actual efficacy of referenced pesticide materials. It is the responsibility of the applicator to determine the efficacy of any material against the target pathogen(s).
All pesticides listed in this guide are registered and approved for indicated uses in Massachusetts according to the best available information at the time of publication, but not all compounds listed are necessarily registered for use other states. Local, state and federal laws and regulations pertaining to pesticides vary and are subject to change. Pesticide applicators are advised to stay current with both state and federal laws and regulations governing pesticides and their use. To check the registration status of a material in your state, see Pesticide Resources. It is unlawful to use any pesticide in any manner other than the registered use.
In Massachusetts, anyone applying pesticides to the property of another or areas to which the public has access, both indoors and outdoors, must be licensed. It is the responsibility of the applicator to know and adhere to the licensing requirements of each state in which they work. For information in regard to licensing in Massachusetts, go to Pesticide License Information.
Some pesticides referred to herein may be classified “for restricted use only” in accordance with federal and/or state regulations. Persons purchasing and using “restricted use” pesticides must be licensed and certified applicators.
