Effect of Environmental Factors in the Development of Powdery Mildew in Okra [Abelmoschus esculentus (L.) Moench]
Ruparani Diwakar *
Department of Plant Pathology, College of Agriculture, Indira Gandhi Krishi Vishwavidyalaya, Raipur, 492012 (C.G.), India.
Ashulata Kaushal
Department of Plant Pathology, College of Agriculture, Indira Gandhi Krishi Vishwavidyalaya, Raipur, 492012 (C.G.), India.
C. P. Khare
Shamsher Alam
College of Horticulture and Research Station, Arjunda, Balod, 491225 (C.G.), India.
Sudha Kiran Tigga
Department of Plant Pathology, College of Agriculture, Indira Gandhi Krishi Vishwavidyalaya, Raipur, 492012 (C.G.), India.
Shanta Sahu
Department of Plant Pathology, College of Agriculture, Indira Gandhi Krishi Vishwavidyalaya, Raipur, 492012 (C.G.), India.
Rohit Kumar Mishra
ICAR- National Institute of Biotic Stress Management, Baronda, Raipur, 493225 (C.G.), India.
*Author to whom correspondence should be addressed.
Abstract
In order to study the effect of environmental factors in the development of powdery mildew in okra [Abelmoschus esculentus (L.) Moench] an experiment was carried out at the College of Agriculture, IGKV, Raipur, Chhattisgarh during kharif (2019-20). The correlation analysis revealed that the age of the crop was significantly, positively correlated and T max, T min and morning RH were significantly, negatively correlated with the disease severity. In addition to this by linear regression analysis, it was observed that plant age (69%), maximum temperature (62%), minimum temperature (60%) and morning relative humidity (46%) contributed in percent disease severity. Based on the proportional measures of extent of infection at different times the apparent rate of infection was found maximum during 70-84 DAS. At this time when the disease progress the average maximum temperature was 29.3℃, minimum temperature 14.9℃, morning relative humidity 87.6% and evening relative humidity 38.33%.
Keywords: Powdery mildew, environmental factors, percent disease index, okra, correlation, simple linear regression, rate of infection