The Effects of Plant Populations on Pickling Cucumber Canopy Dynamics and Yield

Abstract

Michigan is the national leader for pickling cucumber production. However, over the last few years growers have witnessed a considerable decline in marketable yield, mainly attributed to fruit rot caused by Phytophthora capsici. Phytophtora develops rapidly under high relative humidity, a situation commonly found with narrow rows. Growers are interested in using wider rows but would like to know if there are any associated yield reductions. This study was conducted in 2003 to measure the effects of cucumber plant populations on canopy dynamics and fruit yield. Cucumbers were grown with between-row spacing of 30.5, 45.7, 61.0, and 76.2 cm, and in-row spacing of 10.2, 12.7, and 15.2 cm. A split-plot design with four replications was used. Row spacing was the main plot factor, and in-row spacing the subplot factor. Soil covered by plant canopy was monitored throughout the growing season using digital image analysis techniques. At harvest, the number of fruits per plant and marketable yield for the different grades were measured. Cucumber canopy remained open during the major part of the growing season when wide rows (61.0 and 76.2 cm) were used. The number of fruits per plant increased from an average of 1.5 fruits at 30.5 cm to 2.0 fruits per plant at 61.0 cm. Further widening of row spacing to 76.2 cm slightly reduced the number of fruits per plant. Therefore, the optimum row spacing would be 61.0 cm if the number of fruits per plant was the only parameter being measured. Cucumber marketable yield was similar with 30.5, 45.7, and 61.0 cm spacing between the rows. With 76.2-cm rows, yield reduced slightly. These results suggest that cucumber plant density can be reduced substantial with limited yield penalty.