Integrated approach for the management of common bean rust (Uromyces appendiculatus) under field conditions

Abstract

A field experiment was conducted to test the efficacy of different management practices and fungicide application timings for common bean rust management in Chitwan, Nepal. It was conducted in a randomized complete block design (RCBD) with two factors: management practices (Azoxystrobin, Trichoderma viride, maize intercropping + Trichoderma viride, Neem + Garlic extracts, and inoculated and untreated controls) and fungicide application timings (8 days after inoculation and 3 days after inoculation), each with three replications. The minimum disease severity was found with azoxystrobin, which was at par with neem + garlic extract and maize intercropping + Trichoderma at 50 days after inoculation (DAI). The maximum number of rust pustules per cm2 was observed in the control plots (7.56), followed by Trichoderma (4.79) at 50 DAI. The maximum necrotic colonies (%) were observed with the control (36.88%), followed by Trichoderma (25.15%), while the effects of other treatments were at par at 40 DAI. Maize intercropping with Trichoderma resulted in a maximum plant height (201.56 cm), which was at par with azoxystrobin (197.81 cm). The plants treated with azoxystrobin showed maximum green pod yield at one picking (2411.35 g) which was at par with maize intercropping + Trichoderma and neem + garlic extracts. Rust was controlled more effectively when the fungicides were sprayed at 4 DAI than 8 DAI. The maximum disease control was observed with Azoxystrobin; however, as other treatments also had comparable effects, an integrated approach could be adopted for the sustainable management of common bean rust.