In October 2022, South Carolina Cooperative Extension agents reported on hurricane damage and pest damage on cucurbit and other crops.
October 10: CDM has been confirmed on butternut squash in PA.;October 5 CDM has been confirmed on pumpkin in MS and on pumpkin in AL.
October 3: CDM has been confirmed on gourd and pumpkin in MS; on cucumberand on butternut squash in AL.
Alabama cucurbit growers are already seeing increased whitefly populations in their fall crops. Whiteflies transmit cucurbit leaf crumple virus can cause severe symptoms on infected plants includine yellowing of leaves, leaf crumpling, plant stunting and overall plant decline. Squash, zucchini, and cucumber are susceptible to viruses transmitted by whiteflies.
The South Florida Pest and Disease Hotline is a newsletter published by Florida Extension Agents. In October, the newsletter reported on crop damage caused by Hurricane Ian, whitefly observations on watermelons, Cucurbit leaf crumple virus in watermelons, and reports of gummy stem blight on watermelon in Southwest Florida.
Downy mildew on jack-o-lantern pumpkin was reported for the region. Downy mildew has also been reported on summer squash in New Jersey and watermelon on Long Island, NY. These hosts are primarily affected by clade 1 isolates of cucurbit downy mildew. Before this, downy mildew has primarily been affecting cucumber and cantaloupe, which are largely affected by clade 2 isolates.
Clemson Extension Agents Provide Crop Updates
SEPTEMBER 14, 2022. Coastal Region update: “Fall watermelons are looking good. There is some disease around, so fungicide applications remain crucial. I am finding whiteflies in a few crops, too. As we move into fall, with increasing numbers of misty mornings, scouting for diseases is going to be very important.”.
“The buildup of whiteflies is concerning since growers have planted their fall crops. Whiteflies can cause feeding injury issues in vegetables and transmit two viruses: cucurbit leaf crumple virus and cucurbit yellow stunting disorder virus. Vegetables like squash, zucchini, cucumber, cantaloupe and snap beans are most susceptible to these viruses.”
Epidemic Status of cucurbit downy mildew (Pseudoperonospora cubensis) displayed on the website map for 9-22-2022 on all Cucurbit hosts. Disease observations on cucumber, squash, and pumpkin were reported in the previous seven days.