Row Arrangement, Plant Spacing, and Nitrogen Rate Effects on Zucchini Squash Yield

Abstract

Abstract Two field studies were conducted in Fall 1982 and Spring 1983 to evaluate two row arrangements (single vs. double rows per bed), four within-row plant spacings (0.30, 0.45, 0.60, and 0.75 m), and three N rates for zucchini squash (Cucurbita pepo var. melopepo L.) grown on sandy soils. Rates of 67, 134, and 202 kg N/ha were used in the fall, while 134, 202, and 268 kg N/ha were used in spring to determine the optimum levels of N for the higher population densities. Early and total marketable yields were higher with double rows in the spring experiment. Decreasing in-row plant spacing from 0.75 to 0.30 m increased total yield in both experiments, but decreased early yield in the fall experiment. Total yields increased as the N rate increased from 67 to 202 kg·ha-1, but then decreased at 268 kg·ha-1. Combinations of row arrangements and within-row plant spacings allowed testing of seven populations ranging from 11,111 to 55,556 plants/ha. The overall response of yield to increasing plant densities was linear in the fall, but quadratic in the spring, when the higher rates of N were used.