Gordon Johnson Extension Fruit & Vegetable Specialist; gcjohn@udel.edu
Due to the wet fall in 2009, many vegetable growers on Delmarva were not able to plant small grain windbreaks such as winter rye in fields slated for watermelons, cantaloupes, and other vegetable crops in spring of 2010. A special edition of the Weekly Crop Update was issued on January 25, 2010 (http://extension.udel.edu/weeklycropupdate/?p=1649) with some options for spring planted windbreaks.
Snow melt and continued wet weather has caused further delays for potential spring plantings. The following are some updated recommendations for spring windbreaks when the weather breaks (hopefully in the next 2 weeks).
Windbreaks most commonly are planted between groups of 3 or more beds to reduce wind damage and sandblasting on young crops. Some growers have windbreaks between every bed to help trap heat and provide additional protection on early transplanted crops.
By mid-March, winter rye, wheat, or barley are not good windbreak options because they will probably not vernalize and produce stems. They will remain vegetative or short.
March-planted alternatives for windbreaks are spring oats, annual ryegrass, and tall mustards.
Spring oats, planted as early as possible, is probably the best option for March plantings. Use a high seeding rate (120 pounds per acre or more). Oats will provide good ground cover and will head in late spring. It will start to elongate in mid-May. While still not an answer as a full windbreak for early plantings it will reduce sandblasting and provide protection for later plantings. Height will be over 3’ at heading
Annual ryegrass will also produce significant growth from a March planting and provide soil cover. Plant seeds at a rate of 30 pounds per acre. Annual ryegrass can get as high as 3’ when producing seed heads but provides less of a windbreak. One concern is with annual ryegrass is that if it goes to seed it has the potential to become a weed problem in the future.
There are several tall mustard varieties that merit considerations as windbreaks from March plantings. As these mustards produce a flower stalk, they can reach a height of over 4’. They are often used as biofumigant cover crops. Varieties of these tall mustards include ‘Idagold’, ‘Pacific Gold’,’ Caliente 119’, and ‘Caliente 99’. These mustards flower 50-60 days after planting and can be over 4’ in height. Plant at 10-15 pounds per acre.
Mixtures containing 2 or more of the crops mentioned above (spring oats, annual ryegrass, tall mustards) may be more desirable as a late winter or early spring planted windbreak. Reduce seeding rates of each component by 1/3 in mixtures.
The University of Delaware Vegetable Extension Program will be doing research on windbreak alternatives for late-winter or early-spring planting in 2010. We are seeking on-farm cooperators. If you are interested, contact information is given below:
Gordon C. Johnson
Extension Vegetable and Fruit Specialist
University of Delaware, Carvel Research and Education Center
16483 County Seat Highway
Georgetown, DE 19947
General Phone: (302) 856-7303
Direct Phone: (302) 856-2585 x 590
Cell Phone: (302) 545-2397, Fax: (302) 856-1845
Email: gcjohn@udel.edu