Watermelon Yield as Affected by Plant Density and Spatial Arrangement

Abstract

Watermelons are grown at many different row widths and in-row spacings, but an ideal plant density has not been established. Experiments were conducted at one location in 1993 and at two locations in 1994 in southeastern Oklahoma. Effects of plant density and spatial arrangement on `Allsweet' and `Sangria', two standard-sized watermelons, were evaluated. Beds 0.3 m wide were formed on 0.91-, 1.83-, 2.74-, and 3.66-m centers. Various in-row spacings that ranged from 0.30 to 2.44 m were established at each row width. This resulted in various spatial arrangements of plants with densities of 1500, 3000, 6000, and 12,000 plants/ha. With 1500 and 3000 plants/ha, about one melon was harvested from each plant, and less than one melon was harvested from each plant when the density reached 12,000 plants/ha. Yield (weight/ha) increased with plant density and reached a maximum at 12,000 plants/ha. Isometric spatial arrangements did not produce greater yields than did the more-rectangular arrangement. Weight per melon decreased with increasing plant densities in two experiments, but the decrease was small relative to the increased number of melons/ha.