As harvest approaches for spring melons, damage from whitefly feeding should be a concern. Sooty mold contamination on cantaloupes, mixed melons and watermelons can significantly reduce fruit quality and marketability. Although whitefly numbers have been unusually low so far this spring, PCAs should not be complacent in their monitoring and sampling. With the warmer weather we are now experiencing, numbers are likely to increase rapidly in the next few weeks. Our research has shown that to prevent melon yield and quality losses, a foliar insecticide treatment should be applied when a threshold of 2 adult whiteflies per leaf is exceed. This threshold applies for the IGRs, neonicotinoids and synergized pyrethroids. More information concerning sampling, thresholds and insecticide efficacy is available below:
Spray Timing of Spiromesifen and Buprofezin for Managing Bemisia Whiteflies in Cantaloupes (PDF, 124KB)
Whitefly Management in Desert Melons (PDF, 153KB)

To contact John Palumbo go to: jpalumbo@ag.arizona.edu

For questions or comments on any of the topics please contact Marco Pena at the Yuma Agricultural Center.
College of Agriculture, The University of Arizona, Tucson, AZ.