Selected Highlights of the 2020 Cranberry IPM/Weed Program
Dr. Hilary Sandler and Dr. Katherine Ghantous with support from K. DeMoranville
Program Highlights:
Moss in cranberry bogs. Moss continued to be a prevalent weed issue that is not controlled by currently available herbicides. We worked with FMC and MDAR to obtain a Special Local Needs label for Zeus XC (sulfentrazone) in April 2020. We generated research data showing efficacy for moss control and safety for application to dormant cranberry. Over 30 growers took advantage of this label to apply Zeus for moss control in the spring. We are currently surveying growers who applied Zeus to collect information on use patters, efficacy, and overall satisfaction with the product. In collaboration with our colleague in New Jersey and IR-4, we are working towards a full Section 3 label for this product. Some of this work has led to a collaborative manuscript currently under review for publication in Weed Technology.
Screened herbicides for use in cranberry. Novel herbicides are needed to control problem weeds and allow growers access to more chemical mode of actions (MoA) to enable them to rotate chemicals and practice Resistance Management. Our program screened five postemergence herbicides in field trials for crop safety and control against yellow loosestrife and moss. In addition, we collected 175 live yellow loosestrife plants and are cultivating them until spring 2021 for preemergence herbicides screening trials.
Crop safety studies with Kerb SC on new plantings. Kerb has been demonstrated to be safe on established cranberry plants, for application to new cranberry plantings established from plugs (rooted cuttings), and for one year old plantings established from disked in cuttings. The effects of Kerb on cuttings during initial rooting has not been previously evaluated. We conducted greenhouse trials to study the effect of single and multiple applications of different rates of Kerb to newly planted cranberry cuttings.
Promoting better understanding of dodder biology (with Dr. A. Caicedo, Jacob Scott and Phoebe Antonio, UMass-Amherst Biology). To date we do not know the extent of dodder species infesting cultivated bogs nor the genetic diversity present in these infestations. In 2019, generation of high-resolution genetic data began, allowing us to explore: Which dodder species occur in commercial cranberry bogs? How much genetic diversity is present in dodder infestations, and how is this diversity structured? and What is the relationship between weedy and wild dodders? Though Covid limited efforts in 2020, headway was made on rearing dodder on alfalfa in the greenhouse with greater attachment success with C. campetris compared to C. gronovii. We have identified two markers and are developing a PCR based way to distinguish C. gronovii and C. campestris. Sites on commercial farms have been identified to study overwintering of dodder haustoria.
Completed final year of long-term study on effects of herbicides on hybrid cranberry cultivars. Crop safety and current recommendations for registered herbicides have been largely based on older cultivars. Beginning in 2016, we evaluated herbicides (dichlobenil, clethodim, mesotrione (spot and chemigation application), napropamide, norflurazon (spring and fall applications), quinclorac) yearly for yield effects and injury on new hybrid cranberry varieties.
Extension Highlights:
- We obtained a renewal of Emergency Exemption permit from the U.S. EPA for the use of Kerb (pronamide) for dodder control on cranberries in MA and RI.
- We obtained a Special Local Needs (SLN or 24c) label to permit the use of Zeus XC for moss control MA cranberry farms and secured an SLN for Intensity and Intensity One for RI cranberry growers.
- We participated in 6 virtual extension meetings for MA cranberry growers and participated in 3 workshops for cranberry growers across North America.
- We collaborate with MA-DEP and SMAST to provide water sampling services for a cranberry grower under an Administrative Consent Order (ACO).
- We participate in Maximum Residue Limit (MRL) discussions with other scientists and industry representatives to review export issues and prioritize pesticides slated for review.
- ScholarWorks (digital repository). Station documents were downloaded by people from 119 different countries (total downloads=8,149). China was the 2nd most popular country for downloads; Singapore was new, coming in 4th. Cranberry Chart book: 1,867 downloads with 180 downloads of 2018-2020 version (800 >last year); Cranberry Production CP-08 Manuals: 570 copies (similar to last year); BMPs: 444 copies (56 >last year); Extension meeting presentations had 2,949 downloads (1,246 >last year); Jar test was downloaded most frequently, 398 times; Fact sheets: 880 copies (197 >last year); Physiology of cranberry yield, 266 downloads.
- UMass Cranberry Web Site (Oct 1, 2019-Sept 30, 2020): 8,936 users (+9% from 2019); 22,639 page views (similar to 2019). Top 5: How Cranberries Grow, IPM Message Alerts, Faculty/Staff page, Cranberry Chart Book, Frost Tolerance Reports.
Other Program Highlights:
- Published 1 journal article (1 accepted, 1 in review) and 10 abstracts (3 postponed due to Covid).
- Giorgio, T., L.S. Adler, and H.A. Sandler. 2020. Differential response to azoxystrobin by Colletotrichum species isolated from Massachusetts cranberries. Plant Health Progress. doi:10.1094/PHP-10-19-0075-BR.
- Ghantous K.M. and H.A. Sandler. Seasonal nonstructural carbohydrate patterns in dewberry (Rubus spp.) roots. Weed Science. accepted.
- Besancon T.E., K.M. Ghantous, and H.A. Sandler. Cranberry tolerance response to sulfentrazone rate, timing, and method of application, Weed Technology (under review).
- Led and administrated EIP grant program for UMass Extension small fruit, tree fruit, vegetable, and cranberry teams. Year 3 (of 3-year grant) monies from USDA-NIFA: $298,466.