Silicon and growth regulator induced defence against maize fall armyworm, Spodoptera frugiperda (J.E. Smith)

A microplot field experiment was conducted to study the effect of silicon sources and growth regulator against maize fall armyworm, Spodoptera frugiperda at Thoppur village of Virudhunagar district during Rabi, 2021-22. Basal application of different doses of calcium silicate and foliar application of silicic acid and potassium silicate were carried out. The results revealed that 150 kg of calcium silicate/ha + 0.2% silicic acid at 15 d after sowing (DAS) + 50 ppm GA at 30 DAS was found to be effective in reducing fall armyworm (FAW) population (1.23 larvae/plant) followed by treatment with 75 kg of calcium silicate/ha + 0.2% silicic acid at 15 DAS + 50 ppm GA at 30 DAS (1.27 larvae/plant). Regarding leaf and cob damage, the treatment with 150 kg of calcium silicate/ha + 0.2% silicic acid at 15 DAS + 50 ppm GA at 30 DAS was found to be most effective and significantly superior over all other treatments by recording lowest mean leaf damage score of 1.63/plant and mean cob damage score of 1.13/plant followed by the treatment with 75 kg of calcium silicate/ha + 0.2% silicic acid at 15 DAS + 50 ppm GA at 30 DAS with 1.66 leaf score/plant and 1.35 cob score/plant.