Efficacy of nitrogen fixing and phosphorous Solublizing bio-inoculants on growth performance of tea nursery seedlings

Abstract

Tea is one of the important plantation crops of India as well as West Bengal, contributes considerably in national economy and earns foreign exchange. During 2014-15, total production of tea in India was 1233.14 m kg, out of which only100 m kg were organic tea. Mainly due to importers demand of organic tea, there is urgent need to enhance organic production of tea crop. Indiscriminate use of inorganic agricultural inputs-fertilizers, weedicides, pesticide and fungicides and lesser use of organic matters deplete soil health, residues remain beyond MRL in processed tea, ultimately reduction in export. Tea Board provides 55% subsidy for organic tea production. For organic cultivation of tea, the planting materials should also be organically produced in nursery, which is very scanty for perennial crops in general and plantation crops in particular. With this background, the present investigation was carried out at instructional farm of the department of Plantation Crops and Processing, UBKV, Pundibari, located at 26019′86′′ N Latitude and 890 23′53′′ E Longitude at an elevation of 43 m msl with the objective to study the efficacy of N- and P-fixing bio-inoculants in the nursery plants, The experiment was conducted from 2013 to 2015 and laid out in completely randomized block design. The efficiency of nitrogen and phosphorous fixation by bio inoculants and other supplementary source of phosphorous to seed stock TS-462, a dose of 5 g rock phosphate and application of bio fertilizers produced best results, but treatment T8 i.e., dose of 3 g rock phosphate along with bio fertilizers 10g (Azotobacter+Azospirillium+PSB+VAM @2.5 g each)/sleeve proved best over other treatments to meet the standards of ideal planting materials of tea for 9-13 months.