Appraisal of fungi leaf spots of groundnut (Arachis hypogea) and control of Cylindrocladium blight disease using biocontrol, botanical, and chemical measures

Abstract

Groundnut is infected by 55 pathogens which adversely contribute to the low yield of groundnuts. Three sub-trials were conceived to proffer solutions to groundnut Cylindrocladium parasiticum disease. These sub-trials (using biocontrol, synthetic and botanical measures) were set up in vitro using completely randomized design with each treatment replicated thrice. Firstly, all biocontrol (Trichoderma) isolates showed a steady linear increase in the inhibition of the growth of the pathogen. There was no significant difference (P≤0.05) between the isolates of Trichoderma harzianum at 96 h after inoculation (HAI). Secondly, the synthetic pesticide Mancozeb® 100% significantly inhibited the pathogen more than all other synthetic chemical treatments, followed by Mancozeb 50%, Tandem® 100% and Tandem 50% (which were at par (at 144 HAI)). Thirdly, the botanical Parkia sp. 100% was significantly superior to other botanicals (192 HAI results). Likewise, Casuarina sp. 100% and Parkia sp. 50% were at par but performed better than other treatments except for Parkia sp. 100%. Inhibition by Casuarina sp. 50% was at par with Parkia sp. 50% but it was significantly superior to other treatments (except for Parkia sp. 100%, Casuarina sp. 100%, and Parkia sp. 50%). Finally, all trials showed that Mancozeb 100% performed better than other treatments.