Abstract
The influence of number and arrangement of missing plants on tomato (Lycopersicon esculentum Mill.) yields was measured in commercial fields during the spring and autumn seasons of 1981. Cultivar 'Duke' was planted at 61 cm within-row spacing in the spring and 'Sunny' was planted at 46 cm within-row spacing in the autumn. Treatments, designed to accommodate six plants, consisted of a control (no missing plants) one missing plant, and three different arrangements of two missing plants. Treatments were initiated at the vegetative, anthesis, and fruit maturation growth stages. Reduction in marketable fruit weight in plots with one missing plant and three different arrangements of two missing plants were 19, 30, 21, and 31% in the spring and 7, 23, 22, and 18% in the autumn, respectively. In the autumn planting, marketable fruit weight and number per plant in the missing plant plots were significantly higher than the control. Mean marketable fruit size did not differ among treatments in both trials. No significant treatment x growth-stage interaction occurred for any measured variable in either season. Results suggest that yield compensations by remaining plants were insufficient to bring yield to the control plot level, regardless at which growth stage the regimes of missing plants were initiated.
