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An experiment was conducted during 2010 -2012 to find out the suitable lopping interval of gliricidia (Gliricidia sepium) on sandy loam soil. There were six treatments viz., T 1 : lopping once in 2 months, T 2 : lopping once in 4 months, T 3 : lopping once in 6 months, T 4 : lopping once in 8 months, T 5 : lopping once in 10 months and T 6 : lopping in 12 months and replicated thrice. The results showed that lopping at shorter time interval i.e once in 2 months or 4 months resulted in more number of branches, leaves, leaf weight, leaf branch ratio and increased yield. Further, early lopping resulted in succulent leaves and branches which are highly suitable for the animals to consume.

Azospirillum brasilense strains KUL-Z, KUL-X, LUDHI and Azospirillum lipoferum strain KUL-Y and their cell free extracts (CFE) enhanced the nodulation and N2-fixation when inoculated together with Rhizobium strain KUL-BH in winged bean ( Zruthuyathas et al., 1982). We also found that none of these Azospirillum strains had any effect on another winged bean Rhizobium strain RRIM-56, but the cell free extract of Azospirillum strain KUL-X, drastically reduced nodulation and N2 fixation. The study was repeated with this Rhizobium strain and the cell free extracts (at high concentration) of all the Azospirillum strains. Glutamic acid and Aspartic acid were also given as additional treatments at a concentration of M (100mVplant). The Rhizobium strain was cultured in semi solid yeast-extract mannitol broth. In the cultures of Azospirillum that were used for preparation of cell free extracts, Dobereiners' liquid malate medium was used. A week old cultures at exponential growth phase (lo9 active cells m1-l) were used while inoculum preparation. Azospirillum cultures were centrifuged at 6000rpm and the cells were separated from culture supernatant part. Cell free extracts were prepared by sonicating the supernatant free cell concentrations suspended in 7 m MK-phosphate buffer for 10 minutes by a Ultra-Turrax Type TP18" sonicator and separating the cell debris by centrifugation.The cell suspensions were kept at 0-5°C while sonicating by covering the container with ice cubes. Equal volumes of Rhizobium culture suspension and Azospirillum cell free extract were mixed and pregerminated seedlings were immersed in this mixture for 4 h before planting. At planting and 2 days affter emergence the same mixture was applied to the soil. We found that cell free extracts of all the Azospirillum strains, except strain LUDHI, and glutamic acid drastically reduced the nodulation, N2-fixation and dry matter production and subsequently the symbiotic effectiveness (Table I). These treatments also drastically reduced the root formation as indicated by root weight. Reynders and Vlmsek (1982) showed that certain strains of Azospirillum when inoculated as active organism, could inhibit root formation in springwheat. Of the various compounds that could be present in the cell free extracts of the Azospirillum strains we do not know exactly which one or more cause such inhibition in nodulation.