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Compact growth habit (CGH) tomatoes (Solanum lycopersicum) are determinate plants with shortened internodes and strong side branching due to the brachytic gene (br) that grow either prostrate or upright as a result of unidentified gene(s). Compact growth habit tomatoes do not require staking, tying, or pruning and can potentially be mechanically harvested, lowering Florida fresh-market tomato production costs. Therefore, the objective of this study was to evaluate the effects of two planting configurations (single and double row) and breeding lines (BLs) on CGH tomato plant growth, flowering pattern, yield, and postharvest fruit quality. Two experiments were conducted in Immokalee, FL, during Spring 2013 and 2014 in a split-plot design with four replications. Planting configurations affected CGH tomato growth at midseason in 2013 but not in 2014; however, in 2014, CGH tomato vines grew outside the beds into the row middles, which is uncommon for this tomato type and undesirable. Plants of CGH tomatoes had a similar flowering pattern to a conventional upright tomato cultivar, which was unexpected. Planting configurations did not affect marketable yields in 2013, but single-row plots produced higher extra-large and total marketable yields at first and total season harvests in 2014. Total season marketable harvests ranged from 26.1 to 53.6 and 29.3 to 45.6 Mg·ha in 2013 and 2014, respectively. Fla 8916 was among the highest yielding BLs, maximizing extra-large and total season marketable yields. Unmarketable fruit ranged from 22% to 31% and 25% to 52% of the total season harvest in 2013 and 2014, respectively, and the most common defects were sunscald, off-shape, catface, and graywall. All CGH evaluated may be suitable for mature-green harvest regarding postharvest fruit quality, although fruit ripening uniformity was of concern in 2014. Average CGH total season marketable yields harvested twice were lower than expected yields of staked-upright tomato cultivars that may be harvested three times, but higher than Florida average yields. However, CGH tomato total production cost can potentially be lower than staked-upright cultivars making CGH tomatoes a viable alternative for the Florida mature-green fresh-market industry to remain sustainable. Nationally, Florida ranks first in fresh-market tomato (Solanum lycopersicum) production value with U.S. $455 million in the 2013 season [U.S. Department of Agriculture (USDA), 2014]. In 2013, Florida had the largest fresh-market tomato area in the United States with 13,760 ha harvested and an average yield of 29.7 Mg·ha resulting in 408,397 Mg of tomato fruit (USDA, 2014). The majority of the tomato cultivars 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 (Davis and Estes, 1993), estimated at $34,595·ha (G. McAvoy, personal communication). Mexico is the main Florida competitor for fresh-market tomatoes in the United States with the ability to produce tomatoes at lower cost per unit, which forces the Florida industry to seek new production systems to reduce cost and/or increase yields and fruit quality (McAvoy and Ozores-Hampton, 2011). CGH tomatoes, which are determinate plants with a unique architecture, may be the basis of an alternative production system for Florida tomatoes. These tomato plants have low growth and spreading characteristics, forming compact vines that hold fruit above the ground as a result of their short branches and do not require staking, tying, or pruning (Kemble et al., 1994). When in the field, these tomato plants will cover the polyethylene-mulched bed but will not grow into the row middles, holding most of the fruit above the bed surface (Scott et al., 2010). As a result of the plant architecture of CGH tomatoes, they may be grown in a higher plant density than the currently used tomato cultivars, which may recover the losses of vertical space use. Studies with the CGH tomato line NC 13G-1, evaluated in North Carolina, planted in single or double rows showed that higher early and total marketable yields were produced in double rows compared with single rows (Gardner and Davis, 1991; Kemble, 1993). When NC 13G-1 in double rows was compared with the staked-upright tomato ‘Mountain Spring’ (Syngenta, NC) in a single row, NC 13G-1 produced 48% higher yield, although the staked-upright tomato cultivar had higher individual fruit weight than the NC 13G-1 line (Kemble, 1993). Compact growth habit cultivars that have the jointless pedicel characteristic ( j or j-2 genes) may be once-over mechanically harvested, eliminating the need for expensive hand-harvest labor (Scott et al., 2010). Because CGH tomatoes have in general a concentrated fruit set, they can be harvested once or twice (if manually harvested), reducing the harvesting cost when compared with the currently grown staked-upright tomatoes, which are generally harvested three or more times. Production costs would also be reduced because the time from transplant to final harvest in CGH tomatoes may be 2 to 4 weeks shorter than the currently grown cultivars (Ozores-Hampton et al., 2013a). The development of a concentrated fruit set that is generally early in maturity in CGH plants compared with currently grown staked-upright tomato cultivars (Ozores-Hampton et al., 2013a; Scott et al., 2010) will be critical to enable once-over mechanical harvest (George and Berry, 1992). In processing tomatoes, which are mechanically harvested, plants set fruit and the fruit reaches maturity in a Received for publication 25 July 2014. Accepted for publication 20 Oct. 2014. We thank The Florida Tomato Committee and Pacific Tomato Growers for providing monetary or in-kind support to this project. Mention of product or manufacturer names are for documentation purposes only and do not imply endorsement by the authors or the University of Florida Institute of Food and Agricultural Sciences. To whom reprint requests should be addressed; e-mail ozores@ufl.edu. HORTSCIENCE VOL. 49(12) DECEMBER 2014 1529 concentrated time period, which maximizes the harvest while maintaining fruit quality (George and Berry, 1992). For the freshmarket, mature-green tomato industry, a concentrated fruit set will maximize the amount of mature-green fruit at the time of harvest and enable the use of exogenous ethylene application, which is currently used by this industry. Compact growth habit tomatoes with jointless pedicels that would be commercially acceptable have not been completely developed for the Florida market at this time, but progress is being made by the University of Florida Tomato Breeding Program (UF/TBP). Evaluation of the performance of new CGH tomato BLs and appropriate cultural practices to maximize yields at different locations will be crucial in the process of selecting lines that are suitable for the target market. Therefore, the objective of this study was to evaluate the effects of two planting configurations (single and double row) and BL on CGH tomato growth, flowering pattern, yield, and postharvest quality. Materials and Methods Two experiments were conducted on a commercial farm in Immokalee, FL, during Spring 2013 and Spring 2014. On 12 Nov. 2012 and 21 Nov. 2013, beds were formed 1.8 m center to center, being 20 cm high in the middle, 18 cm high on the edges, and 81 cm wide. After bed formation, beds were fertilized, fumigated with 1,3-dichloropropene and chloropicrin (40:60) at a rate of 123 and 134 kg·ha in 2013 and 2014, respectively (Intergro, FL), and covered with virtually impermeable film, black in 2013 and metalized in 2014 (TriEst Ag Group, NC). In both years, pre-plant dry fertilizer was broadcast as a ‘‘bottom mix’’ and applied on two fertilizer bands on the bed shoulders as the ‘‘top mix’’ (Olson et al., 2010) for a total nitrogen–phosphorus–potassium (N–P–K) of 207–49–344 kg·ha. Sources of dry fertilizer were ammonium nitrate, triple superphosphate, and potassium sulfate plus micronutrients. Fertigation was used to supplement the pre-plant fertilizer with 112–0–167 kg·ha N–P–K from tomato flowering to first harvest. The polyethylene-mulched beds slope was modified from 70.4 to 63.4 or 10% steeper slope manually by rolling a polyvinyl chloride pipe on the shoulders of the beds to enable improved drainage. In 2013, six CGH tomato BLs (Fla 8914, Fla 8915, Fla 8916, Fla 8916a, Fla 8916b, and Fla 8834) from the UF/TBP were planted with two planting configurations (PCs), as single and double rows. In 2014, the CGH BL Fla 8924 and the normal growth habit, upright tomato cultivar Florida-47 (FL 47) (Seminis Vegetable Seeds, Inc., MO) were planted in addition to the six BLs evaluated in the previous year. All CGH BLs have the jointless (j2) gene, the light green shoulders (u) gene, and produce flat, round tomato fruit. Tomato seedlings were planted on 18 Dec. 2013 and 19 Dec. 2014 as 6-week-old transplants grown in 200-cell Styrofoam trays produced by Redi Plants Corp. (Naples, FL). Plots were 6 m long, composed of 10 plants for single-row and 14 plants for double-row plots. Single-row plots had an in-row spacing of 61 cm (9108 plants/ha) and double rows were planted in an alternated pattern with a diagonal spacing between plants of 48 cm (11,575 plants/ha). Plants in the double-row arrangement were located 15 cm from the dry fertilizer band on the bed shoulders and the drip irrigation tape was moved to the middle of the bed between the two tomato rows. Tomato plants were not staked, tied, or pruned. The experimental design was a split plot with four replications, where PCs were the main plots and the BLs were the sub-plots. The crop was irrigated by a hybrid system of seepage (Ozores-Hampton et al., 2012a) and drip irrigation, which allowed for fertigation. Pesticide applications were performed as needed according to regular

Effect of Plant Population and Breeding Lines on Fresh-market, Compact Growth Habit Tomatoes Growth, Flowering Pattern, Yield, and Postharvest Quality