Prevalence, epidemiology and management of grey mould rot of strawberry

Grey mould rot is most destructive disease of strawberry resulting in yield losses up to 90 per cent. The disease was observed to occur in moderate to severe form in different strawberry growing areas of Solan, Kullu, Sirmour and Mandi districts of Himachal Pradesh; with maximum disease incidence (31.45%) in Dhaulakuan area of Sirmour district. Low to moderate temperature (15–20 ^oC) accompanied with moderate to high humidity (65–73%) and minimum sunshine hrs (4-6hrs) favoured the disease development. Disease incidence was positively correlated with relative humidity, rainfall and sunshine hours and negatively with temperature. Amongst twenty four cultivars of strawberry screened against the target disease under natural epiphytotic conditions, none of the cultivars exhibited resistant reactions and only two namely; Black Moore and Dana were moderately susceptible. All other were susceptible. Under in vitro conditions, fungicide carbendazim was most effective in inhibiting the growth of the pathogen and was followed by captan + hexaconazole, mancozeb and carbendazim + iprodione, respectively. Under field conditions, three consecutive sprays of carbendazim (0.05%) at 15days interval starting with the first appearance of disease were most effective (99.33PDC). Next best fungicides were captan + hexaconazole and hexaconazole in order. Polythene mulch combined with two sprays of carbendazim (0.05%) was equally effective (94.20%). Further, leaf water extract of Vitex negundo was most effective under in vitro conditions against the target pathogen followed by vermiwash and neem leaf water extract. Polythene mulch combined separately with water extract of Vitex leaf, neem leaf or vermiwash @ 7.5 per cent also proved effective (79.8 -86.5%).