Role of environmental factors on development of cumin wilt incited by Fusarium oxysporum f. sp. Cumini

Abstract

Wilt of cumin incited by Fusarium oxysporum f. sp. cumini is one of the important diseases and a big constraint in successful cultivation. Disease occurs at all the stages of crop growth. The fungus produces toxic substances that are responsible for inducing wilt symptoms in susceptible cultivars. Keeping in view of the above, present study was undertaken to study correlation of disease with environmental factors. The relationship of various environmental factors viz. maximum and minimum temperature, morning and evening relative humidity, rainfall and sunshine hours on the disease development was studied during Rabi 2014–15 and 2015–16. The disease first appeared during second week of January, conspicuous from third week of January to last week of February and declined from first week of March. Correlation coefficients of per cent disease incidence with meteorological factors were worked out and regression equation were formulated. Correlation analysis of per cent disease incidence with weather parameter indicated that maximum (18.2 to 35.5°C) and minimum (2.4 to 18.7°C) temperature had significant positive correlation, while morning (65–91 per cent) relative humidity had negative significant correlation during both the years and evening (25–73 per cent) relative humidity had negative non-significant correlation during both the years. However, statistical analysis between rainfall and disease incidence showed a positive correlation but non-significant.