Morphological Characterization of Powdery Mildew of Pumpkin (Cucurbita moschata Duch.), in Two Agro-Climatic Regions of Arunachal Pradesh, India

Pumpkin is an important vegetable crop grown in tropical and subtropical regions of the world.One of the most prevalent diseases common to pumpkin is powdery mildew, a widespread fungal disease leading to significant yield loss.To determine, the occurrence of powdery mildew disease and the morphology of the causal organism, a phytopathological survey was conducted in two agro-climatic regions namely: Ziro (1500 m) and Medo (250 m) in Arunachal Pradesh during October 2022.The mean temperature of Ziro and Medo ranged between 19-21 and 24-26 coupled with mean relative humidity ranging from 66-77 % and 90-96 % respectively.Occurrence of powdery mildew was encountered in open field conditions of both the sampling fields representing different agro-climatic zones.Microscopic study was performed to examine the anamorph and teleomorph of the causal organisms.Two types of conidial shapes were observed, three types of germ tubes were observed and the cleistothecia was observed at initial to mature stages.This morphological elucidation provided a convincible insight on presence of Podosphaera xanthii and Erysiphe cichoracearum as the causal organisms of powdery mildew of pumpkin in the natural field conditions of both the study sites ranging from subtropical to tropical Zones of Arunachal Pradesh, India.