Healthy Fruit 2000 Vol. 8:28

Highlights from the Great Lakes Extension and Research Fruit WorkerÕs In-service: November 29-30, 2000

Thanks to your support, I had the good fortune of attending the ÔGreat Lakes Fruit WorkerÕs In-serviceÕ meeting in Ithaca, NY during the last week of November. I have attended this meeting in previous years while a hort agent in Michigan, and it is clearly a great way for me to find out whatÕs happening in extension and research in the large fruit production states of New York and Michigan, as well as CanadaÕs Ontario province. And believe me, thereÕs a lot of good extension and research work going on! I have summarized many of the presentations by fruit workers from Cornell, Michigan State, and Ontario and thought youÕd be interested in these highlights. If you have any specific questions about any of the topics mentioned, or would like more information, please let me know--Jon Clements.

ECONOMICS AND MARKETING

The New York apple harvest situation in 2000 was outlined by Alison DeMaree, Cornell Cooperative Extension Educator. Her points on whatÕs needed to retain an apple industry in New York (but clearly applicable to Massachusetts and New England) include:

• U.S. per capita consumption of apples needs to increase.
• Every grower needs to remove every variety they cannot sell.
• Every grower needs to think about removing 25% of their lowest value production (not acreage).
• Growers need to replant consumer demanded varieties of apples at densities that allow high early production (2nd, 3rd, 4th leaf) and high quality.

To punctuate the above points, she quotes a NY processing apple grower: ÒIf apple orchards are not removed this winter -- it means that apple prices are not low enough!Ó

An Adjusted Gross Revenue (AGR) Insurance Pilot Program was explained by Charles Koines of USDAÕs Risk Management Agency. The bottom line is that growers really ought to look long and hard at this type of insurance which guarantees an income for crop loss or reduction beyond the growerÕs control -- i.e., hail, frost, wind, low market prices, etc. For 2001, AGR premiums will be partially paid by the government in Ôunder-servedÕ areas -- including all of New England -- making it an Òextremely affordable tool for managing risk on diverse horticultural farms where traditional crop insurance is either unavailable or incomplete.Ó If you need more information, contact your local Farm Services Agency (FSA) office or independent crop insurance agent, or look at the Risk Management AgencyÕs web site (http://www.rma.usda.gov/pilots/2001pilot.html).

Fruit Quality and Postharvest

Phil Schwallier, Michigan State University District Extension Agent talked about the results of his work with Apogee for vegetative growth control in apples. He saw: increased fruit set and (sometimes) decreased fruit size; a good response across the board on all varieties in terms of shoot growth reduction, ranging from 50 to 70% reduction in growth compared to untreated control; and Empire cracking observed in some orchards treated with Apogee.

According to Chris Watkins, a major Honeycrisp post harvest issue is high incidence of bitter pit and soft scald. Research is looking at regional and orchard effects; harvest delay and DPA treatment; ReTain and ethrel application; and calcium issues. He also noted Honeycrisp does not act like a ÔnormalÕ apple in terms of climacteric/ethylene concentration during the harvest period.

Jim Schupp, Cornell researcher at the Hudson Valley Lab is evaluating the use of ReTain and ethrel combinations on Honeycrisp to reduce pre-harvest drop while promoting color development. The goal is to have fewer harvest dates for Honeycrisp with minimal drop and good color. So far his results indicate a ReTain application is effective at preventing drop and evening out maturity, and a follow-up ethrel treatment may aid color development.

Randy Beaudry, Michigan State University post harvest physiologist,Ê presented results of his current research on preventing ÔsoftÕ or ÔribbonÕ scald development in Honeycrisp. This type of scald scald is a low temperature disorder, not related to the more common ÔsuperficialÕ scald common on Delicious and McIntosh. In particular, low temperature storage ( below 36 degrees F.) and advanced maturity significantly increases susceptibility of Honeycrisp fruit to soft scald development in storage. Therefore, Beaudry suggests harvesting at correct maturity (in sync with the first McIntosh harvest, perhaps as early as ÔMarshallÕ McIntosh) for fruit destined for long-term storage; DPA dips can help; and store Honeycrisp no lower than 36-38 degrees F. for the first few weeks to reduce the incidence of soft scald. Beaudry also noted a high incidence of bitter pit and rots during storage of Honeycrisp, which may be reduced with good fungicide and calcium programs during the growing season.

David Rosenberger, Cornell/Hudson Valley Lab plant pathologist gave an overview of post harvest decays: a contributor to lost sales. His results of surveys of 17-20 supermarkets in the Hudson Valley found a 10 to 40% incidence of decay in bagged Empire and McIntosh apples. He surmises factors contributing to the high incidence of rot include:

• There are predominant strains of Penicillium expansum that are resistant to post harvest benzimidazole/DPA combination treatments.
• Inoculum levels in the field and packinghouse have risen gradually since the early 1990Õs.
• Contaminated field bins are the primary source of recycling delay causing organisms.
• P. Expansum can invade Empire via stems during long-term CA storage.
• Airborne inoculum in packing-houses carries spores to apples being packed.
• Improved sanitation is essential for managing decay problems.

Art Agnello, Cornell University entomologist presented an overview of his evaluations of organic pest management tactics in apples including mating disruption; Surround application, (a kaolin clay product), and complete exclusion using various net-like fabrics. His evaluations are ongoing, so stay tuned for updates. In collaboration with Agnello, David Combs evaluated the organic tools of Surround, Orchex (an oil), and Aza-Direct (a neem derivative). Surround did a good job of controlling some insect pests (such as plum curculio) but failed at others (san jose scale). But Surround issues include cost; frequent applications; harvest residues; and higher damage levelsÊ that would need to be accepted by consumers. The other organic insecticides failed to give acceptable control of most direct fruit feeding insects.

Gary Thornton, Michigan State University Extension District Agent talked about an organic disease and insect control program for pears using lime sulfur for pear scab; Surround and Ecozin (a neem product) for pear psylla; and mating disruption for codling moth. The organic program did keep pest numbers below economic injury levels, however, weed control, fireblight, secondary pest issues, and fruit thinning are still concerns.

Organic apple thinning studies have been carried out by Cornell researchers Jim Schupp and Terence Robinson using NC99 (a calcium/magnesium brine solution) and fish oil + lime sulfur (an extremely smelly solution!). Both were applied during bloom as blossom thinners. A reduction in fruit set and yield (compared to the control) was achieved with only the fish oil + lime sulfur combination. Fruit size was increased with both fish oil + lime sulfur and NC99. But the organic thinners did cause some petal browning and mild leaf spotting.

Michael Celetti, a plant pathologist with the Ontario Ministry of Agriculture and Rural Affairs (OMAFRA) discussed his results of a nematode suppressing cover crop trial. Cover crops included Canadian Forage Pearl Millet 101; Canadian Hybrid Forage Sorghum; Marigold cv. ÔCrackerjackÕ; and a fallow control. Cover crops were planted in large blocks using grower equipment. At first it appeared the crops were ineffective at reducing lesion nematodes (with the possible exception of Pearl Millet), however, when cover crop stand density and weed exclusion were looked at too, the cover crops Pearl millet and marigolds did indeed suppress lesion nematodes. His conclusion was that in using these two cover crops, a dense stand that excludes weeds needs to happen for nematode suppression and Sorghum in fact may be a nematode host.

Michigan State University fruit worker David Waldstein gave an overview of the Michigan Apple IPM Implementation Project. Reduction in organophosphate (OP) use is the primary objective of the Project, and mating disruption is the primary tool being evaluated. Hand applied dispensers, the MSU pressurized pheromone injector, and sprayable pheromones were deployed in numerous commercial orchards for control of the common lepidopteran pests codling moth, oriental fruit moth, andÊ the leaf rollers. Although OPÕs were still needed in conjunction with the pheromones to keep insect injury at acceptable levels, reductions in OP use of up to 40% were common in many of the ProjectÕs 3,000 acres of commercial orchards in 2000.

Varieties/Rootstocks and Systems

With a peach variety update were Cornell scientist Robert Anderson, Michigan State University Extension Agent Bill Shane, and OMAFRAÕs Ken Slingerland. First, Shane and Slingerland introduced a new IQF (Individually Quick Frozen) cling peach slice and a Nabisco developed mixed stone fruit spread in Michigan and Ontario respectively. Ontario has an active stone fruit breeding program formerly under the auspices of the recently retired Neil Miles and Slingerland highlighted some of their new promising peach and nectarine cultivars, both named and numbered. Then Shane overviewed some of the peaches coming out of several breeding programs that have performed well in southwest Michigan, including: PF-1, PF-12B (formerly PF-14), PF20-007 (formerly PF-18A), PF-23, PF17, and PF27A, all from peach breeder Paul Friday; and RisingStar, RedStar (FA52), BlazingStar, CoralStar, the soon to be named FA100, AllStar, and GlowingStar, all from the Fruit Acres breeders. Anderson discussed the ÔLabor Day gap,Õ and says there are Fruit Acres varieties such as FA42, FA65, FA68, FA71, and FA32, as well as Paul FridayÕs PF25 that may help fill the gap.

A panel discussion on sweet cherry varieties and systems lead by Bob Anderson included Jim Nugent of Michigan State University and Steve Hoying, Cornell Cooperative Extension. It was first noted there is tremendous variability among sweet cherry varieties in quality and fruit set depending on where they are grown. Thus, pomologists throughout the world are actively networking and developing resources (often web based) on these differences to help growers make better decisions on what to plant in their growing area. ÔAtticaÕ and ÔReginaÕ are new sweet cherry varieties that are hot in Europe in terms of fruit quality, however, Attica appears particularly frost susceptible, and Regina is largely untested in North America. Hoying suggested berming as a technique to improve sweet cherry establishment in the heavier soils of the Northeast. He also discussed the challenge of getting young sweet cherries to branch: techniques include heading, Promalin application, notching, and bud removal (during swell, two out of every three buds removed). The best distribution of branches along young tree leaders was achieved with bud removal, however, this technique may not be the best for varieties susceptible to bacterial canker. Nugent noted the vigorous 1st and 2nd leaf growth of young sweet cherries on the dwarfing Gisela rootstocks, however, followed by heavy fruiting which must be managed so the tree does not shut down growth completely.

In Ontario, Ken Slingerland and OMAFRA colleagues are actively researching fireblight resistant pear varieties and rootstocks for high density production systems with outstanding fruit quality (dubbed ÔCanAdaptÕ). Slingerland recently attended a pear production symposium in Italy where pear growing and marketing has reached a state of perfection. Pear varieties being planted in large-scale commercial demonstrations include Harrow Gold, Harrow Crisp, and a couple of numbered selections from the Ontario breeding program. Borrowed from apples are planting and training techniques to promote early production in these pear plantings, including staking, minimal pruning, and branch spreading.

Cornell University small fruit researcher Marvin Pritts showed a video on greenhouse raspberry production, a technique he has been promoting to bring a high value crop to market during the winter season. Raspberries are a cool season crop that adapt perfectly to fruiting in pots in underutilized greenhouses during the winter, although canes are initially planted and grown outside during the previous growing season. Tulameen is the variety of choice to be grown in greenhouses, and yields have been 8-1/2 to 11 pints per plant and the economics are comparable to bedding plant production. In fact, growers are getting up to $4 per half pint for their fruit. Fruit quality is extremely high as disease and insect pest problems are minimal, however, bees do need to be brought into the greenhouse for pollination.

John Cline, OMAFRA scientist discussed the characteristics of the Ontario bred Vineland series of rootstocks including V.1 and V.3. V.1 produces an M.26Ê size tree with cumulative yields that have been superior to M. 26, as well as M.9, Budagovsky 9, and Ottawa 3. V.3 is comparable to or slightly smaller than M.9 (depending on the M.9 clone)with very high yield efficiency. Both V.1 and V.3 are cold tolerant and fireblight resistant. Ontario is introducing these high performance rootstocks to the industry, with tree availability expected in 2003. Food Safety

A morning session on food safety was highlighted by the introduction of a new Cornell University ÔGood Agricultural Practices ProgramÕ designed to help educate farmers and their employees on ways to Òreduce microbial risks to assure food safety.Ó Presenters urged growers to: learn about the risks; develop a ÔFood Safety Plan;Õ strengthen ÔGood Agricultural Practices;Õ and document your food safety activities. An excellent publication, ÔFood Safety Begins on the Farm: A GrowerÕs GuideÕ is available from the Cornell Good Agricultural Practices Program at (607) 254-5383 or e-mail eab38@cornell.edu. I highly recommend every fruit grower call and get a copy of this publication that addresses a topic of importance to ALL Massachusetts fruit growers.

Disease Control

Dr. David Rosenberger of CornellÕs Hudson Valley Lab presented some efficacy data on Flint and Sovran fungicides during the rather wet 2000 growing season. In a nutshell, both new fungicides performed very well, particularly for scab. But RosenbergerÕs advice to growers contemplating using them in their disease management program for 2001 include: careful sprayer calibration; keep trees open via good puning; and that no single timing strategy is suitable for all growers.

Michigan State University Extension District Fruit Agent Mark Longstroth described a devastating fireblight (FB) epidemic in southwest Michigan during the 2000 growing season. A prolonged bloom with high humidity and rain, FB susceptible varieties (like Gala) of dwarf plantings, a trauma hail event in mid-May, and streptomycin resistant FB bacteria combined to result in a devastating loss of orchards from 3-6 years in age. Longstroth explained 1,500 acres of apple trees (mostly young) were seriously affected with an economic loss to the industry expected to be $42 million over the course of the next few years due to tree death and loss of production.

Pre-plant incorporation of gypsum (calcium sulfate at six tons per acre) is effective at reducing the incidence of phythoptera in raspberries and dramatically improving yields on marginally wet raspberry sites according to Marvin Pritts, Cornell University small fruit researcher.

Entomology

MSU Extension District Fruit Agent Gary Thornton presented results of his plum curculio (PC) control efficacy trials on sweet cherries using the newer insecticides Actara and Calypso, as well as Provado compared to the industry standard Guthion. Only Guthion and Actara resulted in significantly fewer live PC larvae in cherry fruit than the untreated control and the Provado and Calypso treatments. Actara, Provado, Calypso, and Guthion also provided good control of cherry fruit fly, although the ÔsofterÕ pesticide Spintor resulted in some infestation. All these products are potential replacements for the OPÕs Guthion and Imidan, should we lose these to FQPA.

Pheromone disruption of oriental fruit moth (OFM) is being studied in New York peaches by Cornell University entomologist Art Agnello. Isomate M-100 twist-ties (CBC); Micro encapsulated (MEC) sprayable pheromone (3M); and Confuse-OFMÊ paraffin base liquid (Gowan) treatments suppressed OFM trap catches (an indication of efficacy) compared to non disrupted, unsprayed orchards. Shoot and fruit damage from OFM were negligible in most disrupted plots, however, tarnished plant bug and plum curculio damage to harvested fruit remained significant.

Borers were a topic of importance considering the large amount of burrknot forming roostocks (Mark, M.9, M.26) that have been planted in the East in recent years. (Estimated to be 70% of new orchards.) As there is clearly a positive correlation with extent of burrknot formation, David Kain, Cornell University entomologist has been studying the incidence and control of both american plum borer (prevalent in western New York) and dogwood borer, a pest of all eastern orchards. His recommendations to avoid dogwood borer problems in apples include:

• Keep graft union within 2Ó or less of the ground level; i.e plant as deep as you can without running the risk of scion rooting.
• Plant a more burrknot-resistant rootstock, such as G.16.
• Mounding of soil around the rootstock/graft union down the row may help but is labor intensive and may promote scion rooting.
• Paint trunks, burrknots, and exposed rootstock with white trunk paint.
• Manage weeds and avoid mouse guards if possible--shade and humidity encourage burrknot formation.
• Prebloom trunk sprays (at pink) with Lorsban 50WP may still be worthwhile and have season long efficacy against borers.

Cropload and Physiology

The subject of Honeycrisp fruit thinning was addressed by Cornell University/Hudson Valley Lab pomologist Jim Schupp. After two years of experimenting with thinning Honeycrisp using various rates of NAA, Sevin, and Accel (including combinations) his conclusions are: Honeycrisp are easy to thin--low rates of NAA (

The Effects of Kaolin Clay (Surround) Sprays on Apple Fruit Color and Soluble Solids, Belchertown, MA, 2000

To determine whether spray solutions of kaolin clay, used as an insect or disease deterrent, would have a negative effect on apple fruit quality, apples sprayed with Surround and apples sprayed with a standard fungicide/insecticide program were rated for color and soluble solids in the scab-resistant block at the UMASS Horticultural Research Center in Belchertown shortly before each cultivar was harvested (9/22-9/25).

Surround (kaolin clay) was sprayed at 10-14 day intervals starting at the pink bud stage. The industry standard consisted of Benlate & captan fungicides starting on June 15 and the insecticide Imidan starting at pink. These were applied at 14 day intervals. The scab resistant block at the UMASS Horticultural Research Center is divided into sections by cultivar. This study used three sections: 'Liberty', 'Priscilla', and a mixture of New York numbered cultivars. Each treatment plot consisted of 3 trees. Data were collected from the center tree of each plot. There were 3 sets of plots in each of the 3 cultivar sections. For color evaluation, thirty apples in each treatment plot were examined and rated for % red on a 10 point scale (10 = 100 % red). For soluble solids evaluation, thirty apples in each treatment plot were punctured with a penetrometer to collect juice. Two samples were drawn from this collection and tested for % sucrose with a refractometer.

Treatment	Cultivar	Mean RedColor	Mean % Sucrose
Surround	Liberty	8.62	10.83
Surround	Priscilla	8.14	12.33
Surround	NY No.	8.65	9.75
Benlate & captan, Imidan	Liberty	8.58	10.5
Benlate & captan, Imidan	Priscilla	8.51	12.33
Benlate & captan, Imidan	NY No.	8.51	10.17

Results: The kaolin clay material had neither a positive nor a negative effect on fruit quality. There were no statistically significant differences between the 2 treatments for either red color or for % sucrose. There were differences due to cultivar, however, in the case of sweetness. The 'Priscilla' cultivar had sweeter fruit than the trees in the other 2 sections. There were no significant interactions between treatment and culivar.

 

The Efficacy of New "Green" Materials on Fungal and Arthropod Pests, Belchertown, MA, 2000

The study described above was part of a larger trial which compared the efficacy of new, environmentally benign materials with industry standards (Benlate & captan with Imidan), and an untreated control. For the diseases sooty blotch and flyspeck, the new materials were Flint (trifloxystrobin) (sprayed twice in June as part of 2 different sequences) and Surround (kaolin clay). For arthropods the materials were Actara (thiomethoxam) for plum curculio and European apple sawfly and Surround for all arthropod pests active after pink. A full account is being prepared for 'Fruit Notes,' but a summary is provided here for quick dissemination.

For summer disease management, both sequences of Flint were as good as the industry standard. Less than 2 % of the fruit sampled from the 3 chemical treatments were infected with sooty blotch, compared with 37 % of the untreated fruit. Aproximately 6 % of the fruit sampled from the 3 chemical treatments had flyspeck while 40% of the untreated fruit were infected. Unfortunately, Surround provided no control of sooty blotch or flyspeck. This is at odds with some reports from other states.

Through May and June, Surround and both rates of Actara performed as well as the standard treatment with Imidan for control of both plum curculio and European apple sawfly. After mid-June (comparisons of Surround vs. Imidan vs. untreated), Surround offered control of all summer arthropod pests of fruit (including apple maggot, leafroller, lesser appleworm, codling moth, oriental fruit moth, San Jose scale, and stink bug) equal to that of an interval-spray Imidan program.

Upcoming Dates to Remember

Tuesday, January 30, 2001 Winter Flower Growers' Meeting, (King Farm, Inc., Townsend, MA) Co-sponsored by University of Massachusetts Extension and the Massachusetts Flower Growers' Association. Beat the winter blues by joining us in the greenhouse at this annual program. All commercial flower growers are welcome. There will be open houses at Gilson Farms (Herb grower) and Cupp & Sons (cut flowers) from 7:30 AM-10:00 AM. An educational program will follow at King Farm, Inc. beginning at 10:00 AM and ending at 3:30 PM. Featured topics will include potted herb production, managing root diseases on greenhouse crops and a tour of King Farm's new greenhouse addition. A catered lunch will be available. For a program flier and preregistration form, contact Tina Smith 413-545-5306 or Paul Lopes 508-295-2212, UMass Extension, or Bob Luczai 978-952-0116, Massachusetts Flower Growers Association.

Wednesday, January 10 and Thursday, January 11, 2001 New England Fruit Meetings & Trade Show at the Sturbridge Host Hotel and Conference Center, Sturbridge, MA.