Spanish pepper trellis system and high plant density can increase fruit yield, fruit quality, and reduce labor in a hydroponic, passive ventilated greenhouse

The production and quality of red bell pepper (Capsicum annuum L. cv. 'HA3378') fruits were evaluated in a hydroponic system in a passive-ventilated greenhouse during spring and summer 2000 in Gainesville, FL, USA. Two plant growing systems were used: a) "V" trellis system (plants pruned to two stems, individually and vertically trained); and b) "Spanish" system (plants not pruned, with lateral horizontal strings for vertical canopy support). Plants were grown in flat bags or in polyethylene pots, both filled with perlite. Plant population densities were 1.5, 1.9, 3.0, and 3.8 plants per m. Marketable fruit yields were similar with both growing systems although production of extra-large fruit grade was greater with non-pruned than with pruned plants. Marketable fruit yield per m(2) increased linearly with plant density from 3.5 kg.m(-2) (1.5 plant/m(2)) to 7.4 kg.m(-2) (3.8 plant/m(2)). Plants grown in bags and pots produced similar marketable yields. Non-pruned plants had a lower percentage of fruits with blossom-end rot than pruned plants (32 vs. 62%). Non-pruned plants grew to 105 nodes that supported flower buds while pruned plants grew only to 59 nodes. The total fruit that set was lower in non-pruned plants than in pruned plants (34 vs. 50% of the total number of flowers). Fruit set per plant decreased linearly as plant density increased. The "Spanish" trellis system with a density of 3.8 plant/m(2) required less labor (25% of the labor needed for the "V" system) and resulted in greater yields of extra-large fruits than with the "V" system during a spring production season in a passive ventilated greenhouse.