2014 ASHS Annual Conference

The majority of the tomato (Solanum lycopersicum) varieties grown for the Florida fresh-market are hybrids with a determinate upright growth habit that require staking, tying, pruning, and manual harvest. These cultural practices account for as much as 55% of the total tomato production cost estimated at $14,000/acre. Mexico is the major Florida competitor for fresh-market tomatoes in the U.S. and its ability to produce tomatoes at lower cost per unit forces the Florida industry to implement new production systems to reduce cost and/or to increase yields and fruit quality. Compact growth habit (CGH) tomatoes are determinate hybrid varieties that have shortened internodes and strong side branching due to the brachytic gene (br), and can grow prostrate or upright due to unidentified gene(s). This two-trait combination results in a low-growing, spreading tomato plant with no staking, tying, or pruning requirements. Therefore, the objective of this study was to evaluate six CGH tomato breeding lines on yield and postharvest fruit quality. The CGH tomato breeding lines were provided by the University of Florida Tomato Breeding Program (UF-TBP). The experiment was conducted in a commercial tomato field in Immokalee, FL, during spring 2013. The experimental design was a randomized complete block with four replications. The bed-shoulder slope was modified to allow improved drainage. Fruit were harvested two times at the mature-green stage and graded into marketable yield size categories and unmarketable culls (sunscald, off-shape, and other defects). Postharvest evaluation included subsampling fruit at first harvest, ripening with ethylene gas, and measuring fruit firmness, color, total soluble solids, and pH. Breeding line 8916 had the highest extra-large marketable fruit yield in the first and total season harvests. Breeding line 8834 had the lowest first and total season harvest yields. Extra-large fruit yields decreased in the second harvest for all breeding lines. The most commonly observed defects were sunscald and off-shape with 41% and 36% of the total unmarketable fruit category, respectively, or 11% and 9% of the average total fruit harvested. There were no differences in postharvest quality among the six breeding lines tested except for pH. Compact growth habit tomatoes may be a viable option for the Florida mature-green fresh market based on yield and fruit quality.