Evaluation of Tomato Yellow Leaf Curl Virus Resistant (TYLCV-R) Varieties and Advanced Breeding Lines in Florida

Florida ranks second nationally in production of fresh market tomatoes (Solanum lycopersicum) with 29,000 acres and a value of 267 million in the 2012 season.  TYLCV is transmitted by sweetpotato whitefly (Bemisia tabaci) and contributes significantly to yield losses due to  flower abortion.  Controlling whitefly, maintaining a tomato free period and tomato TYLCV-R varieties are currently the tools available to lower the negative impacts on yields. The objective of this study was to evaluate TYLCV-R varieties and advanced breeding lines on disease incidence, fruit yield, and post-harvest fruit quality.  The trial included 10 TYLCV-R varieties and advanced breeding lines plus a susceptible control (‘FL 47’) planted on 8 Feb. 2012 under polyethylene black mulch with drip irrigation in Duette, FL.  Plants were 20 inches apart and beds were 36 inches wide at 6 ft. bed spacing (center to center).  Tomatoes were harvested twice on 2 May and 16 May 2012.  Data collection consisted of TYLCV severity and yield of X-large, large, medium and unmarketable fruit and unmarketable (zippers, cracks, scratches, odd shaped fruit and blossom end scars).  Ten tomatoes fruit per plot were collected and evaluated for post-harvest quality including fruit firmness (by fruit deformation) and color (1-6 scale, 1=green, 6=red). Weather was cool to warm with a total of 3.8 inches of rainfall.  TYLCV pressure was low with 2.5% in ‘FL 47’.  At first harvest there we no differences between the TYLCV-R and ‘FL47’ in X-large fruit and total marketable yield.  Total X-large fruit and season marketable yield (all harvests and sizes combined) was similar for all TYLCV-R varieties, except XTM 0211 and K55 which were significantly lower than ‘Fl47’.  Several TYLCV-R varieties produced a high percentage of unmarketable fruit due to zippering and off shapes compared to ‘FL47’. However, several TYLCV-R varieties had higher firmness and better color than ‘FL 47’.  Based on yield and post-harvest quality, there are several TYLCV-R varieties and advanced breeding lines with acceptable horticultural characteristics available in tomato growers, but the trial should be repeated in higher TYLCV pressure.