EFFECT OF SOIL AMENDMENTS, WEEDS AND BIOPOWER APPLICATION ON MYCORRHIZAL COLONIZATION IN RICE

Abstract

A field study was undertaken to investigate the effect of weeds, soil amendments and Biopower (a commercial biofertilizer) on vesicular arbuscular mycorrhizal (VAM) colonization in rice (Oryza sativa L.) var. Basmati Super. i)- Field soil was amended with recommended doses of NPK fertilizers, ii)- half N and recommended doses of P and K fertilizers, and iii)- farmyard manure. Four common rice weeds namely Cyperus rotundus L., Echinochloa colonum (L.) Link, Paspalum paspaloides (Michx.) Scribn. and Marsilea minuta L. were planted as 1:1 weed rice plant ratios in all the three soil amendments. All the treatments were with or without Biopower application. Mycorrhizal colonization was studied after 50, 80 and 110 days of rice transplantation corresponding to various growth stages viz. vegetative, flowering/panicle and maturity, respectively. The highest mycorrhizal colonization in rice was recorded at panicle stage i.e. 80 days after transplantation. Mycorrhizal colonization in rice varied with weed species, soil amendment and growth stage of rice. Generally, weeds stimulated mycelial, arbuscular and vesicular colonization in rice roots. The highest stimulatory effect on mycorrhizal colonization was due to mixed weeds in all the three soil amendments at various growth stages of the crop. Biopower application significantly enhanced mycorrhizal colonization in weed free treatment or rice plants co-cultivated with P. paspaloides and M. minuta in one or the other soil amendment.