Webinar Recording: Breeding Efforts to Curb Cucurbit Downy Mildew

Edmund Frost from Common Wealth Seed Growers in Virginia has been breeding cucumbers, winter squash and cantaloupe melons to improve cucurbit downy mildew resistance while maintaining taste, fruit quality, and productivity. Learn about his methods and progress in this webinar called, “Breeding Efforts to Curb Cucurbit Downy Mildew.”

Frost began breeding cucurbits in 2011 and increased focus on breeding for cucurbit downy mildew resistance in 2014 with a research grant from Southern SARE and funding support from the Organic Farming Research Foundation.

Frost’s research process is very straightforward. A flag is placed by each plant. A research number and notes about yields and plant quality are recorded right on the flag. Seed is collected and saved from plants with the best results so they can be used in future crosses.

Frost evaluates each fruit for keeping quality, eating quality, overall yield, and how concentrated the fruit set was. Physical traits like fruit shape, size, and resistance to fruit rot were also recorded to ensure marketability.

While these breeding trials are ongoing, Frost is happy with the results of the winter squash crosses and the cucumber crosses. The winter squash variety shows very good resistance to downy mildew, along with good flavor and excellent shelf life. Work continues to improve yield and more uniform fruit development.

Two varieties of cucumber have been developed from the original crosses, including both pickler and slicer varieties.

Both have good downy mildew resistance and bacterial wilt tolerance and are sweet, thin skinned, and are not bitter even in hot and dry conditions. Breeding efforts continue to achieve earlier harvests of the pickler and uniform fruit development timing in both varieties.

Achieving downy mildew resistance and good fruit quality has taken a bit longer for the cantaloupes but is progressing. Frost expects that a new variety will be available soon. Keep up with progress on the Common Wealth Seed Growers website.