On-Farm Assessment of Melon and Cucumber Feedstocks for Downy Mildew and Bacterial Wilt

In this project I will assess resistance to both Bacterial Wilt and Cucurbit Downy Mildew among selected cucumber and muskmelon seedstocks, and move forward with an ongoing project to develop a pickling cucumber that is resistant to both diseases.

Bacterial Wilt (BW) and Cucurbit Downy Mildew (DM) have been identified by farmers (both organic and conventional) in the mid-Atlantic and Southern US as central limiting factors for production. However, resistant varieties and information on resistance to these diseases are limited. Organic farmers in particular have quite limited options for controlling Downey Mildew. Controlling Bacterial Wilt organically, while possible with row cover, is labor intensive and not always effective.

Experimental design for the variety trials includes one trial set up to expose plants to high pressure from BW, but not to high levels of DM. A second variety trial will expose plants to high levels of DM but not BW. The information gathered will be immediately useful to farmers looking for disease-resistant varieties, and will be useful for plan breeding projects that seek to create varieties that hold up to both diseases.

In the pickling cucumber breeding project I will work with third and fourth generation plants of a 3-way cross between cucumber seedstocks from China and the Philippines (both identified as DM resistant (DMR) in Twin Oaks' 2014 cucumber tiral), and the standard pickling variety 'Homemade Pickles.' This will move us closer to a 2020 targeted release date for the new variety.