Production and quality of bell pepper (Capsicum annuum) fruit were evaluated in a passively ventilated greenhouse, in soilless media trellised to a “V” system (two-stempruned plants) or the “Spanish” system (nonpruned plants) in flat bags or nursery pot containers; and densities of 1.5, 1.9, 3.0, and 3.8 plants/m2 (0.14, 0.18, 0.28, and 0.35 plants/ft2), in a winter-to-summer-crop in Gainesville, Fla. The trellis systems did not affect total marketable fruit yields but production of extra-large fruit was higher (38%) in non-pruned than in pruned plants. Marketable fruit yields were similar in plants grown in bags and pots, and had positive linear responses to increased plant density. Not pruning reduced by half the percentage of fruit with blossom-end rot. Pruned plants produced 50% fewer flower bud supporting nodes than non-pruned plants but had a greater percentage of fruit set. Regardless of trellis systems, fruit set per plant decreased linearly as plant density increased. Overall, the “Spanish” trellis system at a density of 3.8 plants/m2 resulted in greater yields of extra-large fruit and required 75% less labor than the “V” system to prune and support the plant canopy.

In greenhouse crops, fruit yield and quality can be increased by managing shoot pruning and plant density. The effect of plant population density (2, 3, and 4 plants/m2 as function of in-row plant spacings of 66.5, 44.3, and 33.3 cm, respectively), and shoot pruning (one, two, and four main stems) was studied for effects on fruit yield, quality and plant growth of greenhouse-grown sweet pepper (Capsicum annuum L. cv. Robusta) during Summer 1998 in Gainesville, Fla. Red fruit were harvested 84 and 118 days after transplanting (14 Apr.). Additional fruit set was inhibited due to the high temperatures. Marketable yield (number and weight) per square meter increased linearly with plant density and was greater on plants with four stems than in those with two or one stem. Extra-large fruit yield per square meter was not affected by plant density, but was higher in four-stem plants. Total marketable yield and extra-large fruit yields per plant were greatest in the four-stem plants at two plants per square meter. The stem length and the number of nodes per stem increased linearly with the decrease in plant spacing. Stem length and number of nodes per stem were greater in single-stem than in four-stem plants. Number and dry weight of leaves, stem diameter, and total plant dry weight were higher in four- and two-stem plants than in single-stem plants. Results indicated that four plants per square meter pruned to four stems increased marketable and extra-large fruit yield in a short harvest period of a summer greenhouse sweet pepper crop in north central Florida.

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Abstract:Florida produces $1.8 billion (United States dollar) of vegetables on 160,000 ha of land. All of this production is destined for the fresh market and most of the produce is shipped to Northern United States markets. Most of this vegetable production is grown in the field out of season in the winter months, thus requiring land not prone to freezes. Unfortunately, Florida is becoming highly urbanized with the population exceeding 15.3 million in 2000. The major impact of urbanization has been a loss of Florida's warmest and most productive lands for winter vegetable production. In 1997, a Florida and Israeli Protected Agriculture Project was initiated in order to take better advantage of land distal from the urbanized coastline. An 8-m high passive-ventilated Israeli-style greenhouse was constructed in north Florida, a minimum of 85 km from either coast. Successful pepper, tomato, cucumber and muskmelon crops were grown as fall-winter and springsummer crops. With proper shading, heat-sensitive crops could be produced throughout the summer. Moreover, a class of high-quality vegetable crops which could not be produced under typical field conditions in Florida's climate were produced. These included Galia-type muskmelon, Beit alpha cucumber, cluster tomato, and high-quality colored peppers. Yields from greenhouse crops are generally 10 times more than comparable field-produced crops.

The increase in U.S. demand for colored bell peppers (Capsicum annuum) has been satisfied with increased supplies from imports and increased domestic production. Greenhouse-grown peppers of red, orange, and yellow colors were imported during the period 1993–2002 at wholesale fruit market prices that were three to five times greater than field-grown fruits. With high market prices and a suitable environment for growing colored peppers under inexpensive greenhouse structures [<$40/m2 ($3.7/ft2)], up to 14 ha (34.6 acres) of greenhouses produced bell peppers in Florida in the year 2002. To estimate the profitability of a bell pepper greenhouse enterprise, a budget analysis was used to calculate the returns to capital and management. Production costs of greenhouse-grown peppers were estimated assuming the use of current technology applied in commercial greenhouse crops in Florida and in experimental crops at the University of Florida. Production assumptions included a crop of nonpruned plants grown in soilless media in a highroof polyethylene-covered greenhouse [0.78 ha (1.927 acres)] located in north-central Florida. For a fruit yield of 13 kg·m–2 (2.7 lb/ft2), the total cost of production was $41.09/m2 ($3.82/ft2), the estimated return was $17.89/m2 ($1.66/ft2), and the return over investment was 17.1%. A sensitivity analysis indicated that fruit yields should be greater than 7.8 kg·m–2 (1.60 lb/ft2) in order to generate positive returns based on a season average wholesale fruit price of $5.29/kg ($2.40/lb). For this price, a range of possible fruit yields [5–17 kg·m–2 (1.0–3.5 lb/ft2)] led to returns ranging from –$9.52 to 30.84/m2 (–$0.88 to 2.87/ft2), respectively. The estimates indicate that production of greenhouse-grown peppers could represent a viable vegetable production alternative for Florida growers.