Dynamics of fluopyram in soils and its uptake by tomato (Solanum lycopersicum L.)

Abstract

The experiment entitled “Dynamics of fluopyram in soils and its uptake by tomato (Solanum lycopersicum L.)” was conducted at the Department of Soil Science and Agricultural Chemistry and the laboratory attached to the All India Network Project (AINP) on Pesticide Residues, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala during 2018-21. The main objectives of the study were to assess the persistence, movement and metabolism of fluopyram in laterite and red loam soils and its uptake by tomato. The study was conducted in the laterite and red loam soils of Kerala. The representative soil samples for analysis were collected from the respective field of laterite soil and red loam soils of Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala. The physical and chemical analysis of the soils revealed that the laterite soil was moderately acidic with pH of 5.62 and the red loam soil was strongly acidic (pH 5.01), while the values of electrical conductivity were 0.27 and 0.16 dS m-1, respectively. The organic carbon content was medium in laterite soil (0.78%) and high in red loam soil (1.67%). The laterite soil belongs to the structured category of sandy loam while the red loam soil to loamy. The cation exchange capacity was 3.41 and 4.13 cmol (+) kg-1 for laterite and red loam soils respectively. The bulk density and particle density were found to be 1.44, 2.41 Mg m-3 for laterite soil and 1.42, 2.47 Mg m-3 for red loam soil respectively. The availability of major (primary) nutrients in laterite and red loam soils were available nitrogen (197 kg ha-1, 291.6 kg ha-1); available phosphorous (106 kg ha-1, 93.72 kg ha-1); available potassium (231 kg ha-1, 176 kg ha-1) respectively. The secondary nutrients such as calcium, magnesium and sulphur were found to be 250, 42, and 43 mg kg-1 for laterite soil and 280, 102 and 31 mg kg-1 for red loam soil. A suitable method was validated for standardizing the analytical procedure for estimation of residues of fluopyram and fluopyram benzamide in soil, water, tomato fruit and leaf by QuEChERS method and liquid-liquid method partitioning using DCM. The QuEChERS method gave satisfactory