Integrated management of stalk rot disease (Sclerotinia sclerotiorum) of cauliflower in the eastern hills of Nepal

Cauliflower is a high value cash crop for the resource-poor farmer of the eastern hills of Nepal. Non-governmental organisations are enabling resource-poor farming communities to gain a better share in economic development by facilitating input supply and helping to explore market facilities. Previous work indicated that stalk rot (Sclerotinia sclerotiorum) is an important disease of cauliflower. Currently, no single management technique provides a satisfactory level of control of stalk rot disease; therefore the management of stalk rot had to be approached in several ways in order to develop the basis for an integrated management strategy. Surveys of farmers' experience and the results of investigative work indicated that stalk rot (S. sclerotiorum) and damping-off (S. sclerotiorum., Alternaria spp., Pythium sp., Rhizoctonia spp. andFusarium spp.) are major constraints for satisfactory cauliflower production. Stalk rot is problematic for all stages of the crops. Seeds used by the farmers did not meet an acceptable standard of germination. Experimental data indicated that S. sclerotiorum and Fusarium spp. are major fungal pathogens associated with poor germination and seedling mortality after emergence. In the case of S. sclerotiorum, it is likely that sclerotial contamination of seed is the source of these problems. Farmers are generally aware of cultural practices to manage disease problems, but lack awareness of correct methods of disposal and alternative use of diseased debris. Studies on the effect of weeds on cauliflower production did not support farmers' perceptions that weeds reduce the disease incidence in the fields. Weeds did reduce curd size and yield presumably due to competition with crop plants. Some fungal antagonists of S. sclerotiorum, particularly a Trichoderma harzianum, showed promising activity but further work is necessary to translate the results on detached curds into a practical technique. Source of resistance to S. sclerotiorum were found in cv. Kathmandu Local that could be exploited in breeding varieties of cauliflower acceptable to farmers. The results are used to develop a strategy for integrated management of cauliflower diseases that could be adopted by agricultural scientists, extension workers, NGOs and farmers