Nematicidal efficacy and persistence of carbosulfan, fenamiphos and triazophos in chickpea following seed treatment

Abstract

Seed treatment has proved to be a low cost and effective nematode management option with minimal environmental contamination. Absorption of carbosulfan, fenamiphos and triazophos by seeds of chickpea, Cicer arietinum L., (cv. Pusa 362), following soaking in 0.1% acetonic solution of the nematicides, increased by 55, 36 and 32% of fenamiphos, carbosulfan and triazophos, respectively, compared to that in aqueous solutions. The amount of toxicant incorporated into seeds influenced the concentration of its residues in both roots and shoots. This affected the control of the root-knot nematode, Meloidogyne incognita, as well as of reniform nematode, Rotylenchulus reniformis, in the field. The residues in roots and shoots of chickpea persisted beyond 90 days but residues only occurred in green seeds at trace to non-detectable levels. The reduction in root-knot nematode population in the soil was correlated with the decrease in root galling of chickpea (r = 0.70, significant at P = 0.05). Also, root galling was negatively correlated with the nematicide concentration in the roots (r = 0.65, significant at P = 0.05). A seed concentration of 53.6 μg triazophos/g was sufficient to reduce the soil population as well as root infection. Seed treatment with triazophos at 100 μg/ml of 0.1% acetonic solution can be safely recommended for managing nematodes in chickpea.