Dissipation Kinetics of Metribuzin in Sugarcane and Soil Under Sub-tropical Conditions of Punjab in India

Metribuzin is a systemic herbicide having translaminar flow in the plant. Therefore, there are chances of movement in the leaves, immature cane and juice. Work has been done on the residues of metribuzin in soil but no literature is available on the residues in immature cane. Therefore, present work is undertaken to check the dissipation pattern in immature cane, juice and soil. A two-year trial was conducted to study the residues of metribuzin after application @ 1400 and 2800 g a.i. ha−1. In immature cane, the initial residues were 11.73 and 20.89 mg kg−1 during 1st year and 12.78 and 26.09 mg kg−1 during 2nd year which declined below the limit of quantification of 0.05 mg kg−1 in 15 days at single and double dose, respectively. In soil, initial residues were 0.87 and 2.56 mg kg−1 during 1st year and 0.94 and 2.83 mg kg−1 during 2nd year at single and double dose, respectively, which decreased below the limit of quantification after 10 and 15 days of application during both years @ 1400 and 2800 g a.i. ha−1, respectively. The total residues followed kinetics of first order with correlation coefficient (R2) of 0.98 and 0.99. Sugarcane juice did not show the residues of metribuzin at harvest time. No residues were found in sugarcane, its juice and soil at harvest time; therefore, it can be concluded that the application of metribuzin @ 1400 and 2800 g a.i. ha−1 is safe from consumption point of view and environment point of view.