Prevalence of okra fruit rot caused by Choanephora in North Eastern Region of India Particular to Arunachal Pradesh

Abstract

Choanephora fruit rot of vegetables is an emerging threat to vegetable growers in India. During the survey of disease incidence, okra fruit rot caused by Choanephora was noticed in Sika Tode Village, East Siang District, Arunachal Pradesh, and reported for the first time in the Northeast region. The pathogen attacks young fruits causing water soaked lesions and disintegrating the infected lesion. With the progression of infestation, the entire surface is covered with dense whitish cottony growth and turns brownish to blackish thus forming a black pinhead, the superficial sporangia. The morphological study revealed that sporangia are sub-globose in shape and brown in colour. The minimum disease incidence of 22.4% was noticed in the initiation of fruiting stage (June) and gradually reached the maximum incidence of 73.3% (August) with the growth of fruiting formation. Increase in the exposure periods of fruit rot infestation, percent disease incidence (PDI) increases resulting in great losses of okra yield. The correlation coefficient of PDI with weather parameters revealed a significant positive relationship with the maximum temperature at 5% probability (P=0.05) and a non-significant negative relationship with the relative humidity and total rainfall indicating favouring in the occurrence and spreading of the plant disease. Timely caution of the incidence of Choanephora causing fruit rot to okra and other economically important vegetable crops is the need of the hour for its judicious protection and management against this disease.