Effects of day and night humidity on yield and fruit quality of glasshouse eggplant(Solarium melongenaL.)

Abstract

A spring and an autumn crop of eggplant (Solanum melongena) were grown under natural light conditions in a glasshouse at different day and night humidities. A high or low humidity by day was combined with either a high or low humidity by night. Vapour pressure deficits (VPD) achieved over the period in which the treatments were applied ranged from 0.44 to 1.18 kPa by day, from 0.24 to 0.91 kPa by night, with a 24 h mean from 0.34 to 0.99 kPa. The rate of plant development was unaffected by humidity. Fruit yields were reduced by continuously low VPD compared with the other treatments. The yield reduction could be attributed to fewer fruits being picked. Mean fruit weight was higher at high humidity by day. Continuously high VPD increased calyx withering, low VPD had no detrimental quality effects but promoted the incidence of Botrytis cinerea.