Compatibility Studies on Selective Insecticides, Fungicides and Water-Soluble Fertilizer Mixtures in Soybean

In present context, there is a demand for combination spray of insecticides and fungicides to manage both insect pests and diseases simultaneously in a crop season. However, tank mixing of incompatible combinations can reduce the effectiveness of the chemicals, cause phytotoxicity or development of insecticide resistance in pests. Hence, a laboratory experiment was conducted at Agricultural Research Station (UAS, Dharwad), Sankeshwar, Karnataka to study the physical, chemical and phytotoxic compatibility of selective insecticides, fungicides and water-soluble fertilizer mixtures at their recommended dose in soybean by jar compatibility method. Out of eighteen different combinations tested emamectin benzoate 5 SG (0.3 g l-1) in combination with propiconazole 25 EC (1 ml l-1) and 19:19:19 (N:P:K @ 5 g l-1), as well as lambda cyhalothrin 4.6 + chlorantraniliprole 9.3 ZC (0.4 ml l-1) in combination with propiconazole 25 EC (1 ml l-1) and 19:19:19 (5 g l-1) exhibited sedimentation levels of 1 ml l-1 which was less than the limits of 2 ml 100 ml-1 as specified in 1973 by Indian Standard Institute. The pH of agrochemicals both alone and combinations in all solutions test ranged from 6.02 to 8.39 and none of the solutions found extremely acidic nor alkaline. No phytotoxic symptoms were observed in combination treatments at 5 and 10 days after spraying. All test combinations were physically, chemically and biologically compatible hence, tank mixing of these chemicals can be recommended in soybean for managing of insect pest and diseases.