Postharvest Physicochemical Quality Assessment of Greenhouse Produced Soilless Cucumbers in Relation to Differential Fertigation

A study was undertaken to investigate the physico-chemical quality of cucumbers produced in soilless media under naturally ventilated greenhouse microclimatic conditions. The monitored microclimatic parameters included mainly air temperature, relative humidity and solar radiation. The air temperature varied in the range of 19.1-29.3°C and 22.6-32.4°C during season 1 and season 2, respectively. Relative humidity varied in the range of 55.0-91.5% and 59.3-85.3% during season 1 and season 2, respectively. Solar radiation varied in the range of 80-147 W.m^-2 and 97-172 W.m^-2 during season 1 and season 2, respectively. The quality of cucumber was significantly affected by growing seasons, crop varieties, and fertigation levels. The vitamin C content, total phenolic content, and total chlorophyll content were significantly higher for PBRK-4 variety compared to Kafka and Multistar during both growing seasons, mainly due to varietal differences. Fruit firmness was also highest for PBRK-4 variety for both growing seasons at 100% level of fertigation. The vitamin C content, total phenolic content, antioxidant capacity, chlorophyll content, and firmness of cucumber fruit were in the range of 3.29-5.52 mg.100 g^-1, 0.550-1,724 mg.100 g^-1, 12.7-21.8%, 117.09-129.97 mg.100 g^-1, and 30,960-34,030 gf, respectively. The partially controlled growing conditions helped in improving the physico-chemical quality of cucumber to a great extent compared to open field conditions.