Evaluation of flowering cover crops as an IPM tool in Northeastern hop production

2012 Annual Report for GNE12-033

Project Type: Graduate Student
Funds awarded in 2012: $14,154.00
Projected End Date: 12/31/2014
Grant Recipient: University of Vermont
Region: Northeast
State: Vermont
Graduate Student:
Faculty Advisor:
Dr. Heather Darby
University of Vermont Extension

Evaluation of flowering cover crops as an IPM tool in Northeastern hop production


New England is now home to over 200 high quality microbreweries. Public interest in sourcing local foods is extending into beverages, and the current demand for local and organic brewing ingredients is quickly increasing. The demand for locally sourced hops has reached the farming community resulting in a sharp increase in hop producers from six in 2009 to over twenty two in 2011. All of the growers in the Northeast are novices at growing hops and are turning to Extension for help and guidance. In 2011 hop producers in the region started to report serious insect pressure and damage to crop quality and yield. To avoid insect pressure putting a quick end to this fledgling industry, intercrop research and outreach began this 2012 field season between hop rows. Data have been collected and is currently being processed. Continued data collection for accurate efficacy of intercropping in hops is necessary. Preliminary observations show that intercropping will likely be one of many IPM methods incorporated into the hop pest management toolbox.

Objectives/Performance Targets

1.The first objective of this project is to work collaboratively with growers to identify arthropods among hop plants in the Northeast and create outreach materials to help farmers adopt IPM practices. Steps this year included:
-Planting of intercrops
-2012 season data collection (arthropods and harvest)
-Three field days where arthropod identification was disseminated
-Pest identification YouTube video posted
-Winter Hop Conference held in Morisville, NY where harvest data was shared

2.The second objective is to evaluate the impact of cover cropping on arthropod communities in hop production.
-Half of the 2012 arthropod collection samples have been identified to order or family level and categorized into pest, predator, and pest
-Documentation of crop development, hop yield, and hop quality data has been entered
-Data analysis for 2012 is up-coming this winter


To date, outreach dissemination has been completed for the 2012 season. Despite an additional year of growing hops under our belts, 2012 Nugget and Cascade yields in the intercropped hopyard did not increase. Yields remain low compared to Pacific Northwestern 2,000lbs/acre standard for hop production. Understanding that it may take several years to reach this high standard of poundage and quality, we also see room for improvement in hop IPM. Potato leafhoppers continued to be an economically damaging pest and our three leafhoppers to one leaf economic threshold did not prove effective for growers. Effective organic sprays for this phloem feeder have not been researched for application rate on hops. Additionally, a visual difference observed between adjacent hop variety trial and intercropped hops is the effect of spraying broad spectrum insecticides. The intercrop trial was not sprayed because I want to make sure I collect an accurate representation of all arthropods in the intercrop and on hops within the intercrop trial. We witnessed visually more healthy hop plants in the non-sprayed, intercropped hops compared to sprayed hops. We cannot compare this observation statistically due to varietal differences between the two sides of the hopyard.

Intercrop plantings were established well, yet control treatment mowing did not occur as frequently as needed and the clover treatments should be mowed every other week to suppress weeds. Weeds took over much of the yard as expected and we plan to trial the use of a “steamer” which uses hot steam to cut back weed growth. Intercrop measurements could also have been collected more thoroughly using a quadrant. This coming season I will be taking three 1ft x 1ft quadrants into the field to collect intercrop composition and phenological stage. This is different from the methods used last year where intercrop composition was estimated in their entirety.

Impacts and Contributions/Outcomes

The Northeast Hop Alliance Fall Conference held this November sold out for the second consecutive year, and we are gearing up for a fourth sold out UVM Extension Winter Hops Conference on February 22nd. The interest in this crop continues to be phenomenal. Of the 31 respondents to the UVM Extension online hop grower survey, 92% percent of participants identified insect and/or disease control strategies as an important barrier to their hop operation’s success. Through a Partnership Grant awarded by the Northeastern IPM Center in 2012, we worked to develop resource material that helps growers identify arthropods in hopyards, and to identify suitable control options. A YouTube video developed as a part of this project, entitled “Scouting a Hopyard for Insects and Diseases”, http://youtu.be/iZ2FbHPSCBI, was posted in September, and has received a total of 436 views as of Dec. 12, 2012. As a result of 2012 work on this project, 91% of respondents to a survey handed out at an August 2012 field day in Gilbertville, MA focusing on pest identification stated that UVM Extension has helped them improve their scouting, increasing their pest identification knowledge. At a similar field day in Addison, VT, 100% of respondents stated that the field day helped them improve their scouting and increased their pest identification knowledge. This outreach is a direct improvement to hop IPM practices. As growers scout their hopyards for pest presence, they begin to understand the level of certain pests and beneficials. This practice directly decreases the number of chemical pesticide applications.


Heather Darby

Extension Agronomist
278 South Main St.
Burlington , VT 05478
Office Phone: 8027826054