A field experiment was conducted at Regional Agricultural Research Station, Vijayapur, UAS, Dharwad during rabi
-2015 to assess the phytotoxicity of different pesticides in rabi
sorghum. Totally 15 pesticides were evaluated consisting of 13 insecticides, 1 acaricide (spiromesifen), and 1 botonical (NSKE) along with control (water spray) at 3 dosages i.e.,
recommended, two times the recommended and four times the recommended dosage. The pesticides were applied at seedling (20 DAS), vegetative (60 DAS) and reproductive (90 DAS) stages of the crop growth. Observation on different phytotoxic symptoms like chlorosis, white blotches and bronzing type of symptoms were recorded based on percentage leaf damage by visual score (1-10) and later the per cent phytotoxicity was calculated. The highest mean per cent phytotoxicity index was recorded in the profenophos 50 EC @ 1.0, 2.0, 4.0 ml/litre treated plots (20.2, 44.1 and 56.1 PPI) at seedling, vegetative and reproductive stage of crop growth, respectively and was followed by spiromesifen 240 SC treated plots. Other treatments such as malathion 50 EC, methomyl 40 SP, chlorphyriphos 20 EC, cypermethrin 10 EC, alphamethrin 10 EC, imidacloprid 17. 8 SL treated plots produced the phytotoxic symptoms to a various level. Acephate 75 SP, fipronil 5 SC, carbofuron 3G, Phorate 10 G, chlorantraniliprole 18.5 SC, emamectin benzoate 0.5 SG and NSKE were found safe to the sorghum crop at recommended, two times the recommended and four times the recommended dosage of pesticides tested. The grain yield was inversely correlated with the per cent phytotoxicity index.
Ambarish S, AP Biradar, SB Jagginavar and SS Karbhantanal. Effect of Phytotoxicity of pesticides on grain yield of Rabi sorghum [Sorghum bicolor (L.) Moench]. J Pharmacogn Phytochem 2017;6(5):1850-1853.