Changes in pickling cucumber yield and economic value in response to planting density

Studies on density-dependent variations in yield and economic value of crops could help identify optimum plant density. Field experiments were conducted in 2003 and 2004 using a wide range of densities (from 88000 to 330000 plants ha(-1)) of pickling cucumber (Cucumis sativus L.) grown for once-over machine harvest. Fruit set was identified as a major yield-limiting factor at low densities. When plant density decreased by 73%, fruit number only increased by 50% within the range of densities used. Total marketable yield increased with density. However, the highest yield observed at the highest density did not translate into the highest economic value. This was mainly due to the added cost of the seed under high densities. Optimum density required to maximize economic value, was between 220000 and 245000 plants ha(-1) and depended on the selling price of the fruits. Our results support the hypothesis that the density of 330000 plants ha(-1) currently used by many growers could be significantly reduced without losses in economic value of the crop. Finally we propose that seed cost be included in studies designed to identify optimum planting density of crops.