Influence of weather variables on the development of pearl millet downy mildew

Ashlesha Atri Ashlesha Atri,Harpreet Singh Harpreet Singh

doi:10.54386/jam.v21i1.209

Ashlesha Atri Ashlesha Atri, Harpreet Singh Harpreet Singh

Open Access

https://doi.org/10.54386/jam.v21i1.209

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Abstract

The present study was undertaken during 2016 to 2018 to find out the effect of different weather variables on the initiation and development of downy mildew in pearl millet in Punjab. The maximum temperature ranged from 32.8ºC to 36.9ºC and minimum temperature ranged from 17.2ºC to 27.8ºC during the crop season. The correlation analysis showed significant negative correlation of maximum temperature (r = -0.665*), minimum temperature (r = -0.776**), wind speed (r = -0.898**), rainfall (r = -0.625**) and non-significant negative correlation of evening relative humidity (r = -0.523) with downy mildew incidence. The positive correlation with morning relative humidity (r = 0.871**) was significant and sunshine hours (r = 0.321) were non-significant with per cent disease incidence. A multiple regression model was developed using two years (2016 and 2017) data to predict the occurrence of downy mildew with R2 = 0.981, indicating that all weather parameters contributed 98.1 per cent towards disease development. The model was validated with 2018 data which shows that equation can be used in the disease forecasting for taking timely actions for control measures.

Highlights

Pearl millet is a major cereal and fodder crop grown all over the world and in India
A good deal of work has been done on the influence of temperature and relative humidity on the development of downy mildew in other states (Singh and Gopinath, 1990), but relatively limited studies have been conducted on the influence of these environmental factors on downy mildew especiallyin pearl millet growing areas of Punjab
It is evident that downy mildew incidence was observed from 28th to 42nd standard meteorological week (SMW) in both the cropping seasons (Table1)

Summary

Introduction

Observations on the appearance and progress of downy mildew in pearl millet were recorded at weekly intervals starting with the onset of disease until the occurrence of maximum disease incidence. The weather data like maximum and minimum temperatures, morning and evening relative humidity, rainfall, sunshine hours per day and daily wind speed in km h-1 were recorded from School of Climate Change and Agricultural Meteorology, PAU, Ludhiana for the period of experimentation.

Results

Conclusion