Effect of foliar application of liquid organic and inorganic fertilizers along with NAAon cowpea (Vigna unguiculata)

Abstract

Cowpea (Vigna unguiculata) is popularly known as lobia in India, now cultivated throughout the tropics and sub-tropics and used as pulse, green vegetable, fodder, green manure and its productivity is 683 kg ha -1.Vermiwash is a liquid leachate that is collected after the passage of water through the column of worm action. It is a collection of excretory products and mucous secretion of earthworms along with micronutrients from the soil organic molecules. This bio-liquid is rich in nutrients, microorganisms, enzymes, vitamins and plant growth hormones which increase the resistant power of crops against various diseases and enhances the productivity of crops.. The nutrients present in vermiwash are in water-soluble form and meet the immediate requirements of crop plants. Further, it contains nitrogen fixing and nutrient solubilizing bacteria. Generally, foliar spray of vermiwash of vermicomposting supplies nutrients to higher plants more rapidly than soil and root application methods. Vermiwash spray persists on leaf surface and resulted in leaf thickness, increase in photosynthetic activity, internode growth, improved plant physiology and finally increased the yield (Selladuraiet al., 2009). Humic acid is a commercial product containing many elements which improve the growth and yield of cowpea. The fermented organic liquid fertilizer panchagavya contains nutrients, plant growth regulators and microorganisms which help in plant growth, yield, metabolic activities and gives resistant to pest and diseases. The commercial seaweed extract contains major and minor nutrients, amino acids, vitamins and other growth promoting substances. DAP is a complex fertilizer containing 18 % nitrogen and 46 % phosphorus. The Naphthalene acidic acid is a auxin and very effective in promoting growth and yield of pulses. It may be concluded from the results that the foliar application of 2 % DAP along with 40 ppm NAA is recommended to cowpea to enhance the yield and to obtain higher returns.