EFFECT OF HUSBANDRY PRACTICES AND WATER APPLICATIONS DURING FIELD CURING ON THE INCIDENCE OF BACTERIAL SOFT-ROT OF ONIONS IN STORE

The incidence of bacterial soft rot of onions in store was greater in bulbs of plants that were provided with overhead irrigation during the field-curing period than in bulbs of onions not receiving additional water. In the non-irrigated treatment, bulbs lifted at 50-70% top-down had more rots than bulbs lifted at >90% top-down. When additional water was applied during curing the number of rotted bulbs did not significantly differ between onions lifted at 50-70% top-down and >90% top-down. The length of the curing period generally had no effect on levels of soft rot incidence in both water treatments except in bulbs lifted at 50-70% top-down and subjected to additional water. In this treatment onions field-cured for 15 days had less soft rot than onions that had been cured for 28 days. Aeration, by raking bulbs at 7-day intervals during curing, did not affect the incidence of soft rot in both water treatments. Modification of husbandry practices, monitoring of the weather during harvest, and introduction of artificial drying of bulbs are recommended as measures to reduce the incidence of bacterial soft rot of onions in store.