Field Screening for Powdery Mildew Resistance (Erysiphe polygoni DC) in Cowpea

Abstract

Aim: The present study was conducted to identify the cowpea genotypes resistant to powdery mildew. Study Design: One hundred and nine cowpea genotypes were laid out in Augmented Block Design in a single row plot of 4m length and 60cm distance between the rows. Place and Duration of Study: In total 109 genotypes of cowpea were screened for powdery mildew under field conditions during winter 2018 and winter 2019. Methodology: All these genotypes were screened under field conditions along with susceptible line VRCP-1444-5 as infector row. Results: During winter powdery mildew incidence in cowpea was high under Varanasi conditions when cowpea is under maturity stage. Powdery mildew incidence was severe in winter months especially from second fortnight of November to January. Each genotype was grown in a single row. Scoring was done in 0-5 scale. The genotypes that had shown resistance to powdery mildew during winter 2018 were sown again in 2019 for identifying suitable resistant genotypes. Results showed that, 2 genotypes namely IC202280 and EC528412 were completely free from disease during both the seasons of screening and they falls under the category of immune. Conclusion: Hence these genotypes may be used as resistant donor for development of varieties/lines resistant to powdery mildew.