Growth and yield of pickling cucumber in different soil moisture circumstances

High yield of top quality is a prerequisite for profitable production of pickling cucumber in Finland. This research was aimed at optimising water supply of pickling cucumber in open field when using drip irrigation. The objective was to determine the soil water potential at which growth and yield production of pickling cucumber would be optimal. Three water potential thresholds for starting the irrigation (−150, −300, −600 hPa) were compared in field experiments in 2001-2003. The experiments were conducted in a plastic tunnel to prevent disturbance by rainwater. Irrigation was 1.7-2.3 times higher in the −150 hPa treatment and 1.5-1.7 times higher in the −300 hPa treatment than in the −600 hPa treatment. Higher soil water potential enhanced vegetative growth, but the effect was not statistically significant each year. Variation in soil water potential had no statistically significant effect on yield in the first two seasons, but in 2003, the yield was significantly higher in the −150 and −300 hPa treatments than in the −600 hPa treatment. The yield quality was good and not affected by different soil moisture levels. Monitoring of soil water potential is recommended as the basis for irrigation. Using tensiometers, an optimal threshold for starting irrigation is between −150 and −300 hPa.