Effect of microclimate on the performance of salad cucumber under naturally ventilated polyhouse

Abstract

A study was conducted to determine the effect of microclimate on the plant growth characteristics and fruit yield of salad cucumber grown in a naturally ventilated polyhouse at PDFC, KCAET, Tavanur, Kerela. The crop water requirement of the salad cucumber was determined using the irrigation management and planning model CROPWAT. The calculated total evapotranspiration during the crop period was 264.6 mm. The daily crop water requirement of salad cucumber obtained was 2.84 mm. The microclimate change in a naturally ventilated polyhouse was also evaluated. The results were then discussed with respect to yield of salad cucumber. It was seen that the most suitable temperature range for the optimum crop production is 22 to 33 o C and most suitable relative humidity range was 80 to 95%. The irrigation trial was carried out with four levels of irrigation viz. 50, 65, 80 and 95% of daily irrigation requirement. Under the same fertilizer amount, the highest yield was obtained for the treatment with 65% of daily irrigation requirement and the lowest yield was obtained with 50%. This may be due to the reason that plants suffer due to water deficit by limited application of water. Irrigation amount significantly affected irrigation water use efficiency (IWUE). It ranged from 150 kg/ha-mm to 359 kg/ha-mm. In the fertigation trial, the treatment which applied 100% of fertilizer requirement increased the yield significantly compared to 80, 90 and 110% under the same amount of irrigation. The fruit characteristics and quality did not vary significantly with respect to irrigation and fertigation levels.