Field evaluation of cluster bean (Cyamopsis tetragonoloba (L.) Taub) genotypes against powdery mildew under natural epiphytotic conditions

Abstract

Powdery mildew is an important foliar disease of cluster bean in Karnataka which results in huge economic loss. Disease first appears on the lower leaves at thirty days after sowing and continue to produce white mycelial growth on various aerial plant parts upto the harvest. Fungicides have been recommended for the control of the disease however, use of fungicides is expensive and not eco-friendly. The best approach to control the disease is by using resistant genotypes. Hence, in this study 41 genotypes were screened against powdery mildew disease under natural epiphytotic conditions in the field to identify the resistance source. The results revealed that none was found to be immune or resistant. However, two genotypes viz., Samrat and Usm Deepti were found moderately susceptible and thirty seven genotypes were found susceptible. The remaining two genotypes viz., Dhanshree and Naveen were found highly susceptible with maximum grade nine in (0-9) scale.