Leaf reddening significantly reduced with higher dose of NPK fertilizers and also with foliar sprays of MgSO4 +KNO3, MgSO4 +19:19:19 and MgSO4 thrice combined with initial soil application of MgSO4 @ 25 kg ha−1. The extent of reduction with 125 and 150 per cent RDF was 15.4 and 30.1 per centre spectively. It was 2.52 per cent with 100 per cent RDF, while 18.7 and 16.2 per cent with three foliar sprays of MgSO4 +KNO3 and MgSO4 +19:19:19 respectively, along with soil application of MgSO4 as compared to control (2.40 per cent). Sucking pests populations like aphids, thrips and leaf hoppers populations alsoincreased with soil and foliar application of fertilizers, but higher nutrient sources can develop resistance against populations of sucking pests which interm will not cause any yield reduction in irrigated Bt cotton.