Cranberry Station Newsletter 2024 Vol. 25:6

Bogside Workshop/Field Day

By Giverson Mupambi

We have scheduled a Bogside Workshop and Field Day (in-person) on September 12, 2024, from 9:00-11:00 AM and there is no charge to attend. We will meet in the AD Makepeace room and then move to the bog for a field tour of new plantings. You will earn 1 pesticide credit for this workshop. To attend or for more information please contact Giverson Mupambi at 508-970-7638 or gmupambi@umass.edu.

 TENTATIVE AGENDA 

Pesticide Credit Presentations, AD Makepeace Room

• 9:00 Entomology-Marty Sylvia
• 9:20 Pathology-Leela Uppala and Salisu Sulley
• 9:40 Weed Science-Katie Ghantous
• 10:00 Updates on the Cultivar Evaluation-Giverson Mupambi
• 10:10 New Plantings Field Tour-Giverson Mupambi

News from the IPM/Weed Lab

By Katie Ghantous

IPM AND WEED LAB NOTES

We had some grower reports of localized hail damage from the storm on August 15 (both fruit knocked off the vines and fruit on the vines being damaged from hail impact). There was another hail event in some growing areas on August 26. Fruit rot pathogens enter the fruit during the bloom period, and under normal circumstances fungicides after bloom do not offer additional fruit rot protection. There is debate about whether fungicide application after hail damage can mitigate the onset of fruit rot in injured fruit. In a recent conversation with Frank Caruso, I asked him his thoughts on this topic. Many years back in the 1990s, Frank was unable to show that plots treated with Kocide after a hail event were better off than untreated areas – but that work was with small fruited Early Black plants (damage occurred in early August and fruit was evaluated a month later). He mused that things could be different with the newer, larger fruited varieties!

NONIONIC SURFACTANTS VS LI 700 AND USING THESE ADJUVANTS IN CHEMIGATION APPLICATIONS

An adjuvant is a substance that can be added to a spray solution to enhance the performance or properties of the pesticide. There are many different types of adjuvants with various properties, but the most commonly used ones in MA cranberry production are nonionic surfactants aka NIS (such as FS AquaSupreme and Activator 90) and LI700 which is a nonionic penetrating surfactant (has qualities of both a surfactant and a penetrant).

Most, if not all, adjuvant labels do not have chemigation instructions. They are written for spray systems that use much smaller volumes of water (e.g. boom or aerial applications going out in 10-30 gallons of water per acre). The instructions are expressed on a per-100 gallon/liter basis or expressed as a percentage of the finished spray solutions (e.g. 0.25% volume:volume). When we apply by chemigation, the spray solution reaching the bog is between 400-600 gallons of water per acre.

 If we simply scaled up the regular label rates for chemigation, this could be a gallon (or more) of adjuvant per acre – not economical or feasible! Our recommendation is to use 1 - 4 pt/A of NIS for chemigation.

 Not all pesticides need adjuvants. For example, we do not use them with preemergence herbicides like Devrinol. On the other hand, some pesticides like clethodim products do not work well without them being added. Each pesticide label usually includes some information about adjuvants.

Marty Sylvia stands by 1 pt/A of adjuvant for chemigation of insecticides.  It’s what is typically used, and it seems to work.  It is especially needed with insecticides like Altacor, Intrepid/Invertid, and Delegate.  Avaunt, Actara and Fanfare also likely are improved with the addition of an NIS/LI 700 adjuvant.

For herbicides, a higher rate of adjuvant may be beneficial - especially with herbicides like Intensity One that really needs an adjuvant to be effective, and QuinStar (use postemergence) where we are substituting NIS/LI 700 for crop oil.

 LI700 and chemigation. Although LI 700 works a little differently than NIS, the recommendation is still the same! 1 – 4 pt/A.

We have been hearing from some growers that they are using as little as 4 oz/A (only 1/4 pt) of LI 700. This is a rate on the label based 100 gallons of water. This is not enough to be effective for chemigation volumes of water!!!

 There is a wide range of rates on the LI 700 label for different uses (with herbicides, as a replacement for crop oil, with insecticides, etc.). I talked to the adjuvant expert at Loveland to ask about chemigation rates for LI 700. He agreed that sticking with the 1-4 pts/A adjuvants for chemigation in cranberry is reasonable.

 Note that LI700 is advertised as “Formulated for use as a Surfactant, Penetrant, Acidifying Agent & to assist with drift management.” Since it is an acidifying agent, it should not be used with pesticides like Rampart that specify NOT to use with acidifying agents!

CRANBERRY PLANT TISSUE AND SOIL TESTING

Soil and tissue tests can be used to diagnose deficiencies of mineral elements, monitor soil pH, and aid in the making decisions for fertilizer. These tests are also required for Nutrient Management record keeping.  A soil test alone is virtually useless in determining a fertilizer recommendation for cranberry. We recommend testing soil every 3-5 years to monitor any change in soil pH. We recommend tissue sampling every 2 ‑ 4 years. Regular tissue testing meets the mandate for testing in the Massachusetts Nutrient Management Regulations since this is the UMass recommended testing for cranberry.

Because soil test results for phosphorus are difficult to interpret for cranberry soils, tissue tests are more useful for setting target fertilizer ranges than soil tests. Because levels within the cranberry plant can fluctuate throughout the growing season, research has identified the time between Aug 15 and Sept 15 as the period when nutrient levels are most stable - and therefore the best time to collect tissue samples.

Collect one composite sample for each management. A management unit may vary in size but will generally be a single variety that is treated uniformly. For routine analysis, usually one sample per bog is adequate. If your acreage is more than 10 acres or is of varied productivity or differing varieties, taking more than one sample may provide more specific information.

The best time to sample cranberry bogs is when the soil is not waterlogged. Wet soils give falsely high P values. Soil samples may be collected with tissue samples in the late summer if no sanding is planned. Otherwise, sample soil in the spring.

Tissue samples: Samples for cranberry tissue analysis should include upright tips only (do not strip off the leaves) and should NEVER contain roots, soil, runners, fruit, or trailing woody stems. Do not collect samples when plants are wet. Collect no more than the top 2 inches of new growth (mix flowering and vegetative uprights). As you walk a transect across the bog, collect enough material to make about 1 – 1.5 cups (at least 50 upright tips). Always request nitrogen determination. This increases the test cost, but nitrogen levels in the tissue test are an important indicator of plant status and the success of fertilizer programs.

Soil samples: Samples for analysis of soil nutrients should NOT contain stems, leaves, or the surface duff layer (trash). These are all organic contaminants and will bias the organic matter (OM) determination for the sample. The inclusion of some roots is generally unavoidable. Use a soil probe with a 1–2-inch diameter to collect cores of 4–6-inch depth. Minimum requirements: 4 cores for up to 1 acre; and 1 core for each additional 2 acres up to a total of 10 cores/management unit. After the trash layer on the surface of each is discarded, these cores are combined to make a sample. Collect enough soil to fill a 1 qt plastic bag about ¾ full. At home, open the bags and dry the soil at room temperature for a day or two. Clearly mark each sample bag with identifying information required by the tester. OM determination (usually an additional charge) is often useful.

Methods of analysis vary by lab – so it is best to pick a lab and stick with it over the years. For phosphorous, the UMass Soils Lab uses the Morgan test. However, the Bray test for soil P is the most commonly used in other labs for samples from the eastern United States. Standard P ranges for both methods are provided in the Chart Book.

News from the Physiology/Nutrition Lab

By Peter Jeranyama

MODERN WAYS OF FERTILIZER APPLICATION AND NUTRIENT MONITORING ON A CRANBERRY BED

There are various fertilizer application methods that a growers can consider. The four main types of application methods consist of broadcasting, foliar, placement, and fertigation. Broadcasting application means to uniformly distribute fertilizer over an entire field. In MA cranberry production, broadcast applications of granular fertilizer are typically made by hand-cranking or by helicopter.

Foliar application means to apply liquid fertilizer in a spray so that it settles on leaves of plants. Placement application means to only apply the fertilizer near the plant.

Although both deliver nutrients in water, fertigation is an entirely different type of application method than foliar fertilizer. It is the addition of fertilizer into irrigation water that is applied through the sprinkler irrigation system. Nutrients are taken up by the plant from the soil through the roots. With fertigation, growers can save money, time, labor, and water because they have more control over what is fertilized and what is not. Healthier plants are less likely to contract diseases.

Drones: Fertilizer is a critical component for the development of crops. A drone can be used to automate fertilizer application and field tracking. Drones are also used for many applications such as search and rescue, police, code inspections, emergency management, and fire control. Other advantages of drones include their fast maneuverability, improved payload, high lifting power, and stability. Drones can be equipped with specialized equipment for spraying liquids and/or dispensing granular material. Drones are operated remotely, making it easier for farmers not to be exposed to contact with chemicals, thus potentially increasing applicator safety. Agricultural drones have a robust design with low maintenance cost, while simplifying the replacement or adaptation of parts.

Improvements in efficiency and effectiveness are not only limited to crop maintenance tasks but extend to increased productivity of the land. Fertilizing, early pest detection, moisture level of all field areas or automatic spraying are the main benefits and advantages of using drones in agriculture over traditional methods.

Precision agriculture is a crop management approach that attempts to match the type and quantity of inputs with the actual crop needs for small areas within a farm field. It has the potential to revolutionize the way food is produced, making farming more sustainable, efficient, and productive. This method uses satellite imagery, GPS, and sensors to determine the nutrient needs of individual plants and applies fertilizer only where and when it is needed. This reduces fertilizer waste and can increase crop yields. Precision agriculture is a modern farming method that uses advanced technologies such as GPS, drones, and sensors to collect data on soil, weather, and crop health, among other things. This data is then analyzed to improve the efficiency and precision of farming operations, such as planting, fertilizing, and harvesting, and to optimize crop yields. The goal of precision agriculture is to increase agricultural productivity while reducing costs, conserving resources, and minimizing the impact on the environment. Precision agriculture technologies include yield monitors, GPS-based mapping and field analysis, remote sensing (such as using drones or satellites), variable rate technology for applying seeds, fertilizers, and pesticides, and precision irrigation systems. By using these tools, farmers can make more informed decisions about their operations, such as determining the optimal time to plant or harvest a crop, the amount of fertilizer and water to use, and where to direct their resources for maximum efficiency and profitability. However, the adoption of these technologies can be expensive and requires specialized training, so widespread adoption may take some time.

Nutrient status monitoring: Plants need the appropriate levels of nutrients in order to thrive and produce a strong yield. The appropriate levels of nitrogen will ensure strong growth of vegetation and foliage, appropriate levels of phosphorous are required for strong root and stem growth and appropriate levels of potassium are necessary for improving of the resistance to disease and also to ensure a better quality of crop. If soil lacks any of these nutrients, the plant will become stressed and will struggle to thrive. NDVI Index mosaics offer the possibility to identify exactly which areas of the crops are stressed or struggling and to target directly these areas. The NIR/multispectral imagery provided by the UAVs can identify these management zones long before the problem become visible to the naked eye. This means that these management zones can be targeted before crop development and yield is affected.

Currently, the most common way to determine the nutritional status is visually, by means of plant color guides that do not allow quantitatively rigorous assessments. More accurate evaluations require laboratorial leaf analyses, which are time consuming and require the application of specific methods for a correct interpretation of the data. There are some indirect alternatives available for some nutrients, such as the chlorophyll meter (Soil-plant analyses development (SPAD) for nitrogen predictions, but this is a time-consuming process, and the estimates are not always accurate. Thus, considerable effort has been dedicated to the development of new methods for the detection and estimation of nutritional problems in plants. Nitrogen is, by far, the most studied nutrient due to its connection to biomass and yield. Potassium and sodium have also received some attention.

Multispectral images have been the predominant choice for the extraction of meaningful features and indices, but RGB and hyper spectral images are also frequently adopted. Data fusion combining two or even three types of sensors (multispectral, RGB, and thermal) has also been investigated. The vast majority of the studies found in the literature extracts vegetation indices (VI) from the images and relates them with nutrient content using a regression model (usually linear). Although less common, other types of variables have also been used to feed the regression models, such as the average reflectance spectra, selected spectral bands, color features, and principal components. All of these are calculated from hyper spectral images, except the color features, which are calculated from RGB images.

If you have any questions, please contact Peter Jeranyama at 508-970-7636 or peterj@umass.edu.

News from the Entomology Lab

By Marty Sylvia

NEXTER RATE (FOR SOUTHERN RED MITES) IS LOWER FOR CHEMIGATION!

If chemigating Nexter or Nexter SC to manage southern red mites, please observe the labeled chemigation rate!  The range listed in the Chart Book is for ground application.

Specifically, upon review of the Gowan label, rates for chemigation are lower than rates for ground application.   Note that this is not in the Chart Book!  With both formulations of Nexter, there is a lower rate range for chemigation, and a higher range for ground applications.  We’ve never seen this before.  But the label is the law, so for “regular” Nexter, ground apps have a 4.4-10.67 oz rate and chemigation has a 3.5-7 oz rate.  For Nexter SC, ground apps have a 7.5-17 oz rate and chemigation has a 5.6-11.2 oz rate.

Nexter pyridaben	* 3.5 -7.0 oz/A by chemigation (4.4 – 10.67 oz/A by boom or other ground rig)	2 apps/season.  Ground and chemigation only – no aerial application.  Hold water for 3 days after application.  No flow-through bogs.  5 hours of drying time required.
Nexter SC pyridaben	*5.6 – 11.2 oz/A by chemigation (7.5-17.0 oz/A by boom or other ground rig)

Southern red mite is tiny and new outbreaks have only been reported recently, probably after use of the broad-spectrum Fanfare and the many days of hot weather. Mite injury appears as stippling on the leaf’s upper surface.  It has been some time since we have seen red mite outbreaks. Here is a link to the quarter-century-old fact Cranberry Station fact sheet

https://ag.umass.edu/sites/ag.umass.edu/files/fact-sheets/pdf/southernredmite-ua.pdf.

Station News

By Robyn Hardy

NEW EXCAVATOR

The Cranberry Station is pleased to announce the arrival of a new excavator! CAFE was able to secure grant funding to purchase this much needed piece of equipment for our facility. Rick and Jesus are thrilled to finally have a working excavator to take care of the ditches around the bogs!

A SPECIAL THANKS TO BILL SCOTT  

The Cranberry Station has been struggling with broken equipment all summer!  With our tractor out of commission, we have been unable to mow our dikes. Our neighbor Bill Scott very generously offered to help us out. He brought over his equipment and spent several hours mowing to help us get the farm back under control. We are so fortunate to have a wonderful community of cranberry growers that help keep the Cranberry Station afloat!

FAREWELL TO SUMMER STUDENTS!

Our summer students have returned to campus, and we would like to wish them a great fall semester.  We enjoyed having them here and we hope that they had a wonderful experience learning about cranberries.

DIRECTOR SEARCH

The Director search will be wrapping up with our third candidate interviewing next week. The search committee will be submitting their recommendations to the hiring authority on campus soon after. We would like to extend a warm thank you to all those who have been participating in the search process.