Editor's note: This is the Immokalee Report, a regular column written by researchers at the University of Florida's Southwest Florida Research and Education Center in Immokalee. This column appeared in the September-October 2011 issue of Citrus + Vegetable Magazine.

In tomatoes, variety trials have being conducted since 2006 on varieties resistant to tomato yellow leaf curl virus (TYLCV) and since 2009 on varieties resistant to Fusarium crown rot (FCR). The trials also included grafted varieties.

The testing program provided recommendation under low and high TYLCV pressure.

Although the trials demonstrated that TYLCV can be managed with resistant varieties, the lack of consistent fruit quality s was a big reason why the many of the state’s tomato growers didn’t adopt the TYCLV-resistant varieties.

On the other hand, the industry has widely adopted Fusarium crown rot-resistant varieties. But testing continues, since new varieties continue to be released annually.

A growing interest in grafted tomatoes stems from continuing disease problems, lack of land for ideal crop rotation periods, increasing markets for specialty varieties that do not have disease resistance, imperfection of soil fumigation and the pending loss of methyl bromide.

Testing grafted rootstocks will continue, thanks to a $2.2 million U.S. Department of Agriculture Specialty Crop Research Initiative Grant designed to improve the sustainability and competitive of the U.S. fruiting vegetable industry.

Several states in addition to Florida are participating in the research.

Pepper varieties resist bacterial spot

Bell pepper yields have been increased dramatically recently due to continued introduction of new varieties resistant to bacterial spot. Losses from this disease can be attributed to both defoliation and spotting or rotting of fruit.

Ten races of Xanthomonas euvesicatoria, the scientific name for bacterial spot, have been identified worldwide. A race (identified by numbers 1, 2, 3, etc.) is defined by how it can survive and grow on varieties with or without specific genes for resistance. 

Over the years, genes resistant to various races of X. euvesicatoria have been identified and introduced into commercial bell pepper vareities. That’s why variety trials are conducted over multiple years, locations and seasons. 

Variety trials demonstrate that cultivars containing the added resistance to races 4, 5 and/or 6 reduced bacterial spot infection rates and increased yields compared with varieties with only resistance to bacterial spot races 1, 2 and 3 under natural disease pressure.
Hybrid radishes have higher yields

The Florida bunch radish is one of America’s most popular garnishes and is available fresh from October through June. Growers rely on non-hybrid varieties, which offer low yield and quality.

Therefore, a variety trial was conducted during the 2009-10 fall, winter and spring seasons with 21 (hybrid and non-hybrid) varieties assessing yield and quality. Results indicate that hybrid varieties can increase radish yields and quality for Florida growers.

Snap bean yield, color rank high
Florida ranks first nationally in production, acreage and total fresh market value in snap beans. Most of the state’s snap bean crop is produced for the fresh market, with only a small percentage going to processing.

Growers rely on new varieties to increase bean yields and quality and to remain competitive in the U.S. market.

Preliminary results of a variety trial conducted during the 2010 winter with 13 varieties in two locations showed yield and color were the most important attributes for Florida bean growers. Yields followed closely behind.

View the results of these trials as well as others on the SWREC’s vegetable testing ebsite, http://bit.ly/pWX6hg.
Monica Ozores-Hampton is an assistant professor and vegetable specialis at the Southwest Florida Research and Education Center in Immokalee. She can be reached at ozores@ufl.edu or (239) 658-3400.