Mineralization of aldicarb to C02 as well as formation of various metabolites and extractable and nonextractable 14C were measured in [14C] aldicarb-treated surface and subsurface soils. Surface soil samples were incubated under aerobic conditions, and subsurface soil samples were incubated under aerobic and anaerobic conditions. Total aldicarb, aldicarb sulfoxide, and aldicarb sulfone residue (TTR = total toxic residue) disappearance rates were also determined in soils held under aerobic conditions. These data were used to compute half-lives for aldicarb mineralization and TTR disappearance in soil. TTR disappearance in soils held under strict anaerobic conditions, despite slow mineralization, was more rapid than under aerobic conditions. Mineralization rates for surface soil samples were generally higher than for subsurface soil samples. Metabolites detected included aldicarb sulfoxide, aldicarb sulfone, aldicarb sulfoxide oxime, aldicarb sulfoxide nitrile, aldicarb sulfone oxime, TLC polar products, and two unknowns. Aldicarb sulfone and its hydrolysis products were not detected in soils incubated under

The movement and degradation of the pesticide aldicarb was monitored in two Florida citrus groves. One of these was a bedded grove near Oviedo and the other was located in the central ridge near Lake Hamilton. Soil core samples were collected at 0.3 or 0.6 m depth increments six times over an eight-month period and were analyzed for aldicarb and its two oxidation products aldicarb suljoxide and aldicarb suljone. These analyses showed a relatively rapid decrease of aldicarb accompanied by an increase in aldicarb sulfoxide and aldicarb suljone; the levels of these carbamate metabolites peaked after about 50 days and then began to decline. The dissipation rate of aldicarb carbamate residues in surface soils corresponded to a half-life of approximately 20 days at both jield sites. The degradation rate in subsoils appeared to be significantly longer (half-life greater than 60 days), especially at the Lake Hamilton site.Aldicarb carbamate residue concentrations measured in replicate soil analyses were highly variable, with coeflcients of variation ranging up to 300 % for samples collected at the same time and depth. These data point out the need for carefirl design of soil-sampling strategies (including numbers, timing, and location of samples) in order to obtain statistically valid results @om unsaturated zone pesticide monitoring studies. 307 Pestic. Sci. 0031-613X/88/$03.50 0 1988 Society of Chemical Industry. Printed in Great Britain EXPERIMENTAL METHODS Site descriptionThe Oviedo site was a 3.6 ha portion of an orange grove located approximately Also, 0.6 m increments were used below 0.6 m for the 49day samples. At the Lake Hamilton site, soil cores were collected to a depth of 3 m in increments of 0.6 m. For n 9. 9 * 2 s 3 -. 3 0, 0.

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Background: Micronutrient formulation is a liquid mixture of micronutrients which can be used as a fertilizer. It is a mixture of two solutions viz., solution A and solution B. Solution A is a mixture of zinc sulphate (50 gL-1), boric acid (10 gL-1), copper sulphate (20 gL-1), manganous sulphate (0.5 gL-1), ferrous sulphate (10 gL-1) and ammonium molybdate (0.5 gL-1) whereas solution B is an organic acid which act as a chelate. The mixture can be diluted to specific concentrations for application. The objective of the study was to evaluate the effect of micronutrient formulation as seed treatment and foliar nutrition. Methods: The study was conducted at College of Agriculture, Padannakkad, Kerala Agricultural University and Regional Agricultural Research Station, Pilicode during 2018–19. The investigation was carried out in three parts: (i) standardization of micronutrient formulation for cowpea (ii) seed treatment study (iii) field experiment. The proportion of mixing micronutrient formulation and the duration for seed treatment was standardized in experiment I. In experiment II, a seed treatment study was carried out in a completely randomised design with seven treatments and three replications which included seed treatment with micronutrient formulation @ 0.25, 0.50, 0.75, 1, 1.5 and 2 percent as T1, T2, T3, T4, T5 and T6 respectively. T7 (seed treatment with water) was the control. Three, a field experiment was carried out in randomized block design (factorial) with twelve treatments and three replications. The treatment consisting of combination of four levels of seed treatment - factor A [no seed treatment (S1), seed treatment with rhizobium (S2), seed treatment with best concentration from experiment 1 (S3) and second best seed treatment from experiment 1 (S4)] and three levels of foliar application of micronutrient - factor B [no foliar application (F1), one foliar application at 15 DAS (F2) and two foliar applications at 15 and 30 DAS (F3)]. Result: Through lab experiments, solution B was standardized and the formulation was developed by mixing solution A and solution B in the ratio 1:2. Duration for seed treatment was also standardized as 6 hours. Thus micronutrient formulation was standardized. In seed treatment study, seeds treated with 2% micronutrient formulation (T6) showed highest plant height at three leaf stage (24.23 cm) and seedling vigour index (2423). In the field experiment seed treatment with 2% micronutrient formulation (S3), foliar spray at 15 and 30 days after sowing (F3) and their interaction (S3F3) was found to be highly effective to the crop in terms of plant height, stem diameter, number of pods per plant, pod weight per plant, grain yield and nutrient content in grain. These results clearly indicate the role of micronutrient formulation in enhancing the growth, yield and nutrient content of cowpea.

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