Plant Density and Shoot Pruning on Yield and Quality of a Summer Greenhouse

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 plant·m-2, as function of in-row plant spacing: 66.5, 44.3 and 33.3 cm, respectively), and shoot pruning (1, 2 and 4 main stems) was studied for effects on fruit yield, fruit quality and plant growth of greenhouse grown sweet pepper (Capsicum annuum L. cv. Robusta) during Summer 1998 in Gainesville, Florida. Plants were grown in perlite bags and irrigated with a nutrient solution. Red fruits were harvested 84 and 118 days after transplanting (Apr. 14th). Additional fruit set was inhibited due to the high temperatures. Marketable yield (number and weight) per m2 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 m2 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 2 plant·m-2. 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 than in single-stem plants. Total stem weight in four-stem plants increased linearly with the decrease of plant density. Results indicated that 4 plant•m-2 pruned to four stems increased marketable and extra large fruit yield in a short harvest period of a summer greenhouse sweet pepper crop in Northcentral Florida