Co-planting of Japanese Bunching Onions with Watermelon for Managing Soilborne Diseases in Watermelon

Goals / Objectives
Evaluate efficacy of co-planting watermelon and bunching onions for managing soil-borne diseases in watermelon in a field test in Manteca, CA.

Project Methods
The study will be conducted on the Van Groningen & Sons, Inc. farm, Manteca, California. The objective is to evaluate mixed-plantings of Welsh onion with seedless watermelon. The test will be planted in a field with a cropping history of watermelon where pathogens including Pythium spp. and Phytophthora capsici have been identified in prior years. The experimental design will be a randomized complete block design with four replicates of four treatments: 1) watermelon, 2) Japanese bunching onion + watermelon, 3) rice hulls + watermelon, 4) rice hulls + Japanese bunching onion + watermelon. Six-week-old greenhouse plants will be transplanted into black plastic mulched beds 1000 feet long. Watermelon fruit will be harvested and yield data (fruit counts and weights) and fruit quality traits including Brix will be recorded in each treatment plot. Harvest data will be collected by research staff of Van Groningen & Sons.