Role of nutrients in inducing rust resistance in soybean

A field experiment was conducted at University of Agricultural Sciences, Dharwad, during kharif 2000 and 2001 to study the role of nutrients in inducing resistance against the incidence of rust in soybean. Results revealed that among different nutrients, Manganese sulphate (MnSO₄) and boric acid (H₃BO₃) treatments recorded lower PDI (per cent disease index) of 33.7 and 45.7 respectively as compared to control (89.6). The seed yield due to MnSO₄ and fungicide treatment did not differ significantly. In general, the phenol content and peroxidase activity increased from 45 to 65 days after sowing (DAS) for all the treatments, except due to the foliar application of MnSO₄ (0.3%) and fungicide, thereby indicating the operation of different mechanisms of disease control in MnSO₄. Considering the effect of MnSO₄, both in terms of yield advantage and environmental friendly, it is suggested to replace traditional fungicide application with MnSO₄.