Evaluation of physical and chemical compatibility of insecticides with fungicides and water-soluble fertilizer mixtures in soybean

Abstract

In present context, there is a demand for combination spray of insecticides and fungicides to manage both insect pests and diseases in a crop season. However, tank mixing of incompatible combinations can affect the effectiveness of the chemicals, cause phytotoxicity or development of insecticide resistance in pests. To address few of these issues, a lab experiment was conducted at Agricultural Research Station (UAS, Dharwad), Sankeshwar, Karnataka to study compatibility of selective insecticides, fungicides and watersoluble fertilizer mixtures at their recommended doses in soybean. Three insecticides (diafenthiuron 50 WP at 1.25 g/l, dinotefuran 20 SG at 1 g/l and spiromesifen 22.9 SC at 1 ml/l), two fungicides (hexaconazole 5 EC and tebuconazole 25.9 EC at 1 ml/l) and one water-soluble fertilizer (19:19:19, N:P:K at 5 g/l) were evaluated using a jar compatibility test. Among different combinations tested, the combination of diafenthiuron 50 WP, hexaconazole 5 EC and water soluble fertilizer 19:19:19 showed a sedimentation level of 2 ml/l. The combinations of dinotefuran 20 SG, hexaconazole 5 EC and 19:19:19; diafenthiuron 50 WP, tebuconazole 25.9 EC and 19:19:19; and dinotefuran 20 SG, tebuconazole 25.9 EC and 19:19:19 showed sedimentation levels of 1 ml/l, which were below the limit of 2 ml/100 ml specified by Indian Standards Institute, 1973. All the test solutions were tested using a digital pH meter and had pH values ranging from 6.13 to 8.34. This indicated that none of the solutions were excessively acidic or alkaline. Hence, the combinations treatments were found to be physically and chemically compatible.