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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.

The study was conducted with the objectives to prepare and formulate a multi nutrient stick and to evaluate and compare its effect on oriental pickling melon with fertigation. The investigation was carried out in two parts: formulation of nutrient stick and field experiment using oriental pickling melon. The trials were conducted at College of Agriculture, Padannakkad and Regional Agricultural Research Station, Pilicode during 2016-18. The nutrient stick was formulated as per the nutrient requirement of oriental pickling melon. The nutrient release studies conducted using nutrient stick proved it to be suitable for soil application. A field experiment was carried out in randomized block design with nine treatments and three replications. The treatment combination with foliar silicon spray was found to be highly effective to the crop in terms of quality and yield parameters. The residual available soil nutrients especially nitrogen, phosphorus and potassium were higher in treatments with fertigation as compared to fertilizer application in the form of nutrient stick, which indicated better efficiency of nutrient sticks. These results clearly indicated the suitability of fertilizer application in the form of nutrient stick along with drip irrigation.

Chlorpyrifos is a widely used organophosphorus insecticide and there are concerns on soil health due to excessive use in agriculture. An attempt was made to understand the effect of chlorpyrifos degradation under natural conditions and as affected by different treatments in coarse textured laterite soil of Kasaragod, Kerala, India. Results from the study revealed that chlorpyrifos content was reduced by 34.76% within 60 days of incubation period under natural conditions. Effect of physical, chemical and biological treatments on fastening the process of chlorpyrifos degradation was evaluated. Biological treatment with microbial inoculants (combination of Pseudomonas fluorescens and Trichoderma viride) showed maximum degradation (74.99 %), followed by individual application of Pseudomonas fluorescens (69.94 %) and Trichoderma viride (66.35 %) during the 60 days period of incubation. Soil enzymes such as dehydrogenase, phosphatase and urease showed significantly higher activities in treatments with Pseudomonas fluorescens and Trichoderma viride either single or combination on comparison with control. Microbial biomass carbon increased to 99.16 µg g-1 in treatment with a combination of Pseudomonas fluorescens + Trichoderma viride while control showed only 83.77 µg g-1. Degradation products of chlorpyrifos such as phosphate ions was significantly highest in biological treatment. Chlorides, sulphates and nitrate content also recorded highest values in treatment with microbial combination. Among the different agents, application of microbial combination of P. fluorescens and T. viride resulted in faster degradation of chlorpyrifos with no significant changes on chemical and biological properties of soil.

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