Whiteflies Already a Problem for Florida Farmers

Clint Thompson Florida, Fruit, Pests, Top Posts, Vegetables

This file picture shows whiteflies on a squash leaf.

By Clint Thompson

Between the coronavirus pandemic and decreased demand for their product, Florida’s vegetable farmers have had their share of challenges this past month. Add whiteflies to the list.

According to the South Florida Vegetable Pest and Disease Hotline, the Immokalee, Florida area in South Florida has seen hundreds of acres abandoned. This is due to irregular ripening and high incidences of tomato yellow leaf curl virus disease (TLCVD).

There’s been some reports of 50% to 80% of the disease being seen in several vegetable fields. According to Gene McAvoy, University of Florida/IFAS Regional Vegetable Extension Agent IV Emeritus and President of the National Association of County Agricultural Agents, whiteflies have been problematic in tomatoes, watermelons and other cucurbits.

“We’ve had a number of growers destroy substantial amount of acreage, even before this whole COVID-19 thing blew up. We’ve had a lot of irregular ripening because of high levels of whiteflies. Most of our growers are using a resistant (tomato) variety so that’s not an issue in the round tomatoes. But especially with the Romas that have no resistance, they’re getting tore up,” McAvoy said.

According to the South Florida Vegetable Pest and Disease Hotline, farmers have pulled up entire first plantings due to very high incidence of TYLCV.

The whiteflies’ impact on tomatoes is felt across Central Florida and on the East Coast where pressure is higher in older tomatoes. Whiteflies are also problematic in cucumber and pepper and are increasing in melons.

High incidences of whiteflies may be attributed to the mild winter. While colder temperatures don’t eliminate whiteflies, they do kill many of their wild hosts and slow population development in cultivated hosts. Warmer temperatures allow for larger whitefly populations to overwinter and become mobile earlier.

“Down here our strategy is to try to have clean fallow in the summer and not have anything for them. We usually start off pretty low but if we have a warm, mild winter like we’ve had the past couple of years where they start building in the fall, they just continue going this time of year. They basically become unmanageable,” McAvoy said.