Persistence and Degradation of Propineb in Different Soils and Moisture Regimes

A study was undertaken under laboratory condition to determine the persistence and degradation of propineb residues in two soils (Mandya and Shimoga) following application at two different doses (10 and 25 μg g⁻¹) and at two moisture regimes (field capacity and submergence). Persistence of propineb was slightly increased with higher rate of application and residues persisted more in Shimoga soil than Mandya soil irrespective of treatments. The propineb residues persisted up to 21 to 30 days and 30 to 60 days at field capacity and submerged conditions under both the application rates. The dissipation of propineb follows first order reaction kinetics. The half-life of propineb ranges from 5.3 to 7.3 days under field capacity and submergence in Mandya soil whereas in Shimoga soil, it ranged from 6.0 to 13.0 days at both the application rates. The degradation kinetics [K_(deg)] of propineb residues was faster under field capacity (72.4x10⁻³day⁻¹-130.5x10⁻³ day⁻¹) than under submergence (53.3x 10⁻³ day⁻¹-103.4x10⁻³ day⁻¹).