The effects of direct harvesting and drying systems on the incidence and control of neck rot (Botrytis allii) in onions

Direct harvesting, with mechanical removal of the foliage (topping), of onion crops followed by post‐harvest drying at ambient temperatures (c. 18°C) resulted in an increase in the incidence of onion neck rot (Botrytis allii). The disease was substantially reduced if topped onions were dried at 30°C with an airflow of 425 m3 air/h/tonne. The treatment was most effective if the crop was removed from the field for drying within 48 h of topping thus avoiding severe infection of the damaged green tissues of the necks of onions.