Growth Improvement of Seedlings of A Tropical Forest Species, Khair (Acacia catechu Willd.), Using Beneficial Microbial Inoculant (Effective Microorganisms)

Microbial Inoculant (EM) was used to find out their effectiveness on the growth and development of seedlings of a tropical forest species; Khair (Acacia catechu Willd.), in the nursery. Effective Microorganisms (EM) are a combination of many different beneficial microorganisms in a solution. The seedlings were grown in a mixture of forest top soils and cowdung (3:1) kept in polybags. The EM solution at different concentrations (0.1,0.5,1,2,5 and 10%) was added before and after a week of sowing the seeds. Germination as well as ,physical growth parameters like, shoot and root length, vigor index, collar diameter, leaf number, fresh and dry weight of shoot and root and total biomass increment were measured. The nodulation status influenced by EM was also observed along with the measurement of chemical parameters like chlorophyll a, chlorophyll b and carotenoid. Both germination and the measured physical parameters were found significantly higher in seedlings treated with different concentrations of EM solution in comparison with control. Maximum growth was observed at 2% concentration followed by 5% and 1%. Nodulation was higher at 0.1% concentration of EM but it normally decreased with the increase of concentrations. Although there was a higher amount of pigments in leaves of the treated seedlings than the control but the variations recorded with respect to chlorophyll a, chlorophyll b and carotenoid were not significantly higher in most of the treatments. The results of the present study indicate that the Microbial Inoculant (EM) technology might be useful to improve the growth of seedlings in the nursery. These also indicate that the associated beneficial organisms along with the poly bag soils might be of value in improving the degraded soil or poor field soil for better nutrient uptake and water uptake during the initial growth of transplanted seedlings.