Effects of ozone phytotoxicity in reducing the yield and nutritional quality of chilli (Capsicum annuum L.)

This study was designed to assess the effects of tropospheric ozone (O3) on the yield and nutritional quality of chilli (Capsicum annuum L. cv. Pusa Jwala) using ethylene diurea (EDU) under field conditions in Peshawar, Pakistan. Average O3 concentration ranged between 38 and 68 ppb which is high enough to cause phytotoxic effects. Accumulated ozone exposure over a threshold of 40 ppm h (AOT40) value calculated for 3-month period was found to be substantially higher, i.e., 7.3 ppm h. Various growth and yield parameters analyzed on weekly basis showed that the plant height (6.3%), number of flowers (15%), fruits (36%), and total dry biomass (30%) and its nutritional quality parameters such as mean crude protein, fat, and fiber showed 24%, 100%, and 12% better results in EDU-treated plants as compared with control, respectively. However, mineral contents showed no significant difference (p < 0.05) for both the groups. The results of this study concluded that ambient O3 is a threat to the selected plant species thus affecting its quality and yield and EDU remains successful in protecting the chilli (Capsicum annuum L.) against the negative effects of tropospheric ozone.