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Rhizobia isolated from root nodules of wild legumes (Macroptilium lathyroides (L.) Urb, Phaseolus atropurpureus Moc ⇐p; Sesse DC, Clitoria ternatea L., and Crotalaria verrucosa L.) were examined for cultural, biochemical, serological and symbiotic characters. The strains were characterized by their colony morphology, growth rate, alkali production, tolerance to acid or alkali, type of flagella, temperature sensitivity, resistance to antibiotics, utilization of different carbon sources, serological relatedness and ability to nodulate other host species. All of the strains had cultural characters consistent with the slow growing rhizobia of the cowpea group. Serological relatedness examined by the enzyme‐linked immunosorbent assay (ELISA) technique showed that all of the 4 strains have antigenic homology to an isolate from a wild Arachis sp. and varying degrees of relatedness to cowpea rhizobia. All strains produced effective nodules on cowpeas and pigeonpeas but not on peanuts and kidney beans.

The experiment was conducted at the farmers field of FSRD site, Elenga and MLT site Modhupur, Tangail during two consecutive years 2011-12 and 2012-13 to study the productivity, production efficiency, land use efficiency and economic return of the improved cropping pattern (Mustard -Boro -Jute -T. Aman) against the existing cropping pattern (Mustard -Boro -T. Aman) through incorporating of modern crop varieties and improved management practices. The experiment was laid out in randomized complete block design with six dispersed replications. The pooled data of improved management practice for the pattern produced significantly higher yield in Mustard and T. Aman rice respectively and also gave additional jute yield. The gross return and gross margin were higher in improved pattern compared to that of existing farmer's pattern with only 149 and 151% extra cost at FSRD site, Elenga and MLT site Modhupur, respectively. The higher benefit cost ratio (1.74 and 1.79), rice equivalent yield (22.41 and 21.82), production efficiency (40.19 and 39.48) and land-use efficiency (95.75 and 96.48) indicated the superiority of the improved pattern over the farmer's existing pattern at both sites. Higher rice equivalent yield indicates that improved cropping pattern (Mustard -Boro -Jute -T. Aman) could be suitable in Tangail region for increasing crop productivity as well as cropping intensity.Keywords: Improved cropping pattern, rice equivalent yield, land use efficiency and production efficiency.

The grain weights of normal and high-lysine cultivars were compared in field and pot experiments in which the supply of assimilate per grain was adjusted by a variety of treatments involving application of fertilizer, thinning, degraining or defoliation. The results of these experiments indicated that in normal cultivars, grain weight was affected both by the supply of assimilate from the green tissues and by internal factors in the grain which limited the accumulation of this assimilate. Some evidence suggested that physical constriction of the expanding endosperm by the surrounding husk could be one of these factors; the effects of the husk on growth of the caryopsis was not clear.The development of grain weight in the high lysine cv. Riso 1508 was initially similar to that of normal cultivars, but the cessation of growth as maturity approached was more abrupt. Increased assimilate availability resulting from the application of fertilizer, thinning or degraining treatments effectively increased grain weight in this cultivar, but to a lesser extent than in low-lysine cultivars. Conversely, decreased assimilate supply as a result of defoliation produced less marked reductions in grain weight in the high-lysine type, suggesting that the reduced starch accumulation associated with the high lysine characteristic rendered superfluous some of the photosynthetic capacity in these types.

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