No abstract

A field experiment was conducted during the rabi season of 2015-16 and 2016-17 at Regional Research Sub-station, Raghunathpur, Bidhan Chandra Krishi Viswavidyalaya, Purulia, West Bengal to evaluate the post emergence herbicides application for effective weed control and influence on crop yield in maize. The treatments were arranged in a Randomized Block Design with four replications. Results of this study revealed that hand weeding recorded superiority over remaining treatments with respect to reduced weed density and increased weed control efficiency. But, it required lot of man force which was not economic to the farmer's point of view. Among the herbicidal treatments 2, 4 D Ethyl Ester 38% EC @ 1.0 kg ha -1 was proved to be better in controlling weeds, increasing crop yield and microbial population in the rhizosphere. 2,4 D Ethyl Ester 38% EC @ 1.0 kg ha -1 was recommended as a postemergence herbicide in rabi maize for effective and eco-friendlycontrol of weeds and getting higher grain yield.

No abstract

Field study was conducted in during 2015 and 2016 to evaluate the efficacy of new formulation of atrazine herbicide on weed control in maize. The experiment was conducted at Research farm, kalyani of BCKV. The treatment schedule was untreated, Spraying of new formulation atrazine 50% WP @ 1 kg / ha , new formulation atrazine 50% WP @ 2 kg / ha, new formulation atrazine 50% WP@ 4 kg / ha, old formulation atrazine 50% WP @ 1 kg / ha and old formulation atrazine 50% WP @ 2 kg / ha. The spraying schedule was started on ten days after sowing. The weed complex consisted of Echinochloa colona, Brachiaria mutica, Digiteria sanguinalis, Elusine indica, Cyperus rotundus, Amaranthus viridis, Digera arvensis, Alternanthera philoxeroides, Phyllanthus niruri etc. However application of new formulation @ 4 kg/ha to maize plot gave lowest weed density, dry matter and highest WCE at 10, 20 and 30 DAA. Application of atrazine 50% WP (new source) at the higher doses i.e. @ 4 kg ha -1 gave highest grain yield (4.37 t/ha) , which was statistically at par with the recommended dose i.e. @ 2 kg ha -1 , therefore lower concentration may be preferred over higher concentration. No phytotoxic symptoms were observed in any of the doses of atrazine 50% WP (new). So atrazine 50% WP (new source) @ 2 kg ha -1 may be safely used for effective weed control and better yield of maize.

Herbal medicinal plants are in great demand for their use in food preparations, pharmaceuticals, cosmetic and beauty aids. But its availability is reduced every year due to attack of fungal disease i.e. leaf blight. Therefore an experiment was conducted to gather the knowledge about the future management aspect of this disease. Here three medicinal plants viz, Piper longum, Tylophora indica and Hibiscus subdariffa were planted and observed the disease throughout year. The characteristic symptoms of the disease along with causal organisms (Colletotrichum gloeosporioides- Piper longum, Sclerotianum rolfsii- Tylophora indica, Fusarium sp- Hibiscus subdariffa) were recorded. In the seasonal study, the lowest disease incidence and severity of the disease were observed in the month of August and higher in June. Hibiscus subdariffa showed less disease incidence (15.33%) and severity (6.11%) at initial stage (August) and 67.33% & 42.46% respectively at peak period (June). But Piper longum and Tylophora indica showed higher disease incidence and severity at the same times. All these pathogens were isolated in PDA medium from the infected parts of plants and confirmed their pathogenicity. The cultural characteristics along with their micrometric measurement of spores were recorded in four different media (PDA, CZA, OMA and MMA). Colletotrichum gloeosporioides was found to grow better in PDA (9.0 cm) along with high dry weight (1.47g) and lowest growth in maize meal medium (4.8cm). In Sclerotium rolfsii, highest radial growth (9.0cm) and dry weight (1.48g) were observed in maize meal medium but no growth in Czepek’dox. Fusarium sp showed highest radial growth (8.3 cm) and dry weight (1.34 g) in czepek dox and lowest in maize meal agar medium (4.4cm).