Vol. 10, Issue 8 (2021)

Author(s):
Gaesejwe Bagwasi, CR Chinnamuthu, P Murali Arthanari, C Bharathi, P Malarvizhi and CN Chandrasekhar

Abstract:
Atrazine, a triazine herbicide is an important herbicide used in India by maize growers. Researchers have used high doses of atrazine to control weeds in maize. However, little is known about the residue dynamics in the soil of these high doses under maize-cowpea cropping system. The persistence and degradation behaviour of extreme levels of atrazine in soil under irrigated maize-cowpea cropping system was assessed. Field experiments were carried out during consecutive years of 2019-20 and 2020-21 under sandy clay loam soil. Atrazine residues were determined by Agilent High Performance Liquid Chromatography (HPLC - 1200 series). Atrazine degradation pattern followed first order kinetics in the soil. The persistence of atrazine in the soil during Kharif seasons (2019 and 2020) was more in higher doses viz. 1.50, 1.75 and 2.00 kg a.i. ha^-1 (110 days) whereas during Rabi seasons it was below detectable level (< 0.01 μg g^-1). Thus, atrazine has to be applied at the recommended rate (0.50 kg a.i. ha^-1) which has manifested shorter soil persistence (30 days) during the experimental period.