EFFECT OF HUMIDITY ON GROWTH AND DEVELOPMENT OF FUNGAL PATHOGENS OF RIPENING DATES (PHOENIX DACTYLIFERA L.) AT KHAIRPUR, PAKISTAN

Abstract

Pakistan is regarded as one of the top ranked date palm cultivated regions of the world. In Sindh province of Pakistan, date palm (Phoenix dactylifera L.) is mainly cultivated in Khairpur. Date palm holds a significant position in the socio-economic development at Khairpur where several thousand peoples are associated directly or indirectly with date palm cultivation, trade and market. Date palm requires high temperature and low humidity from flowering to fruiting and no rainfall during ripening. Unfortunately, in district Khairpur, during the period of rainfall, humidity becomes very high and temperature decreases. The periods of high humidity provide favorable conditions for the growth and development of fungal pathogens which cause severe losses in yield and quality of fruits. The present study was, therefore, conducted to find out the effect of humidity on the growth and development of fungal pathogens in three cultivars of dates viz. Aseel, Kupro and Khar at ripening stage due to moisturized weather conditions at Sobho Dero Taluka of district Khairpur. The symptoms of fungal attack such as cracking, blackening, blemishes and spoilage were observed on ripened fruits. Three fungi viz. Fusarium poae, Alternaria tenuis and Aspergillus niger were isolated from infected samples of three selected cultivars. The frequencies of occurrence of these fungi were 5.66, 6.33 and 8.33 respectively. It is concluded that incidence and prevalence of fungal pathogens greatly increased during rainy season which demand stringent surveillance and control measures to minimize the damage.