Optimization of cover crop strategies for pumpkin production in the mid-Atlantic

Optimization of cover crop strategies for pumpkin production in the mid-Atlantic

Summary

Many vegetable and field crop producers grow pumpkins to diversify their operations and provide an alternative source of revenue. The use of cover crops and no-till planting reduces diseased fruit, soil erosion, weed pressure, and nutrient loss. However, several concerns have prevented the wide-scale adoption of no-till methods for pumpkin production. These are: concern about carryover seed from the hairy vetch causing a weed problem in subsequent years; weed management in a no-till system; and a potential increase in Fusarium rot. In addition, farmers have requested help identifying cover crops that can be used after the pumpkin harvest.

This 3-year project is designed to address research needs expressed by pumpkin growers. We propose to 1) develop at least 2 cover crop schemes that maximize profits of pumpkin producers while minimizing disease development, and 2) improve the understanding of how cover crops affect pumpkin diseases, fungicide use and the cost of pumpkin crop production. We will examine cover crops to precede or follow the pumpkin crop; the effect of the cover crops on yield, fruit quality; incidence and severity of pumpkin diseases; and management options for diseases.

Pumpkin growers will be active participants in this project through feedback on our research and by conducting on-farm trials and demonstrations. Farmers will learn about cover crops and will provide us with feedback and suggestions on our project. Growers will attend twilight meetings and see results of replicated research non-replicated on-farm demonstrations. We will work directly with interested farmers to help them implement the new technology.

Objectives/Performance Targets

Of the 150 mid-Atlantic pumpkin growers participating in this SARE project, 12 will either initiate cover crop use or improve their cover crop selection and management within 3-5 years of the start of this project. Alternatively, the research may determine that a particular cover crop/pumpkin production strategy is not profitable and we will demonstrate to 150 growers to not adopt this production practice thus avoiding lost income for these growers.

To help us achieve this goal, we will produce written descriptions of at least 2 cover crop schemes that maximize the profits of pumpkin producers while minimizing disease development. These descriptions will include information on cover crop management and their effects on pumpkin diseases and management. These products will help farmers adopt new practices even after the project has concluded.

Accomplishments/Milestones

• 75 pumpkin growers will give feedback on cover crop selection and problem identification (30 in calendar year 2004, 45 in 2005). Surveys were distributed, asking about priority problems to the industry. There were 193 and 75 surveys distributed in 2004 and 2005, respectively. Surveys also were distributed at the University of Maryland WyeREC pumpkin twilight tour in 2006. Outreach activities included talks at the New Jersey Vegetable Growers meeting, the Central Maryland Vegetable Growers Meeting and the UM WyeREC Pumpkin Twilight Tour.
• Farmer cooperators will be identified for the on-farm replicated experiments (3-4 farms) and of demonstration plantings (at least 3 farms per year). (June/July, 2003 and June/July, 2004).
• Demonstration plantings were conducted on 3 farms each in 2003-2004 and 2004-2005. In 2006 we also planted demonstration plots at the University of Delaware Research and Education Center near Georgetown.
• During the three-year period, 150 farmers will learn about using and managing cover crops, including the effect of cover crop selection on pest and disease management. They will learn this by attending one or more meetings that include the topic of cover crop use with pumpkins. In 2006, 165 farmers learned about this project including 20 who visited the experimental site at the WyeREC pumpkin twilight tour.
• Approximately 20 farmers will attend each of the 2-3 annual meetings that include this topic (calendar years 2003, 2004, 2005). In 2006, 165 farmers attended three meeting that taught about pumpkins and cover crops.
• 12 pumpkin farmers will have either initiated cover crop use or improved their cover crop selection and management within 2 years of the end of the project. One farmer has begun to grow pumpkins following a crimson clover cover crop.

Impacts and Contributions/Outcomes

In 2004 and 2005 we identified winter wheat and crimson clover cover crops as the best alternatives to hairy vetch or rye. Winter wheat and crimson clover were alternatives for growers that had concerns about carry over seed from hairy vetch, or increased disease. Experiments to determine the optimum fungicide disease management program for each of the five systems (pumpkins produced on bare ground, winter wheat, rye, crimson clover, or hairy vetch) were conducted at two locations in Maryland. The disease management programs were conventional fungicides applied every 7 days, conventional fungicides applied every 14 days, a program where the biofungicide Serenade was alternated with conventional fungicides, or no fungicide was applied (nontreated). Powdery mildew was the most severe disease at both locations and Plectosporium blight (aka Microdochium blight) was present at UM Lower Eastern Shore Research and Education in Salisbury. These experiments will be repeated in 2007.

Outreach

At the 2006 Pumpkin Twilight, several conclusions from Alyssa A. Collins’ dissertation (University of Delaware, July 2006) were presented. She examined pumpkins grown on four cover crop treatments and bare ground for disease development, yield and quality. The cover crop treatments were fall planted rye (120 lbs/A), hairy vetch (40 lbs/A), rye plus hairy vetch (20 lb hairy vetch/A and 30 lbs rye/A), and spring planted oats (4 bu/A).

Ground cover was the greatest in plots of fall planted rye, rye plus hairy vetch, followed by hairy vetch alone. The least amount of ground cover remained where oat was spring planted and in bare ground plots. Where ground cover was higher, rain driven soil splash was the lowest. In 2005, Plectosporium blight was lower in pumpkins grown on fall planted cover crops. Fruit rot was lower in plots where the ground cover was the highest, although other factors also influenced fruit rot. There was a stronger correlation between edema and ground cover, where edema was lowest in pumpkins planted into a rye, hairy vetch plus rye, and hairy vetch cover crop.

These results suggest that planting pumpkins into a no-till cover crop which produces good biomass will reduce edema, fruit rot and Plectosporium blight.

Collaborators: