Twenty spring wheat varieties were studied to find out genetic variability and genetic association for grain yield and its component characters. Both genotypic and phenotypic variances were highly significant in all the traits with little higher phenotypic variations as usual. Similarly, the low differences between the phenotypic and genotypic coefficients of variations indicated low environmental influences on the expression of these characters. High heritability coupled with high genetic advance were obtained with plant height, grains per spike, 100-grain weight, harvest index and grain yield. Genotypic correlation coefficients were higher than the corresponding phenotypic correlation coefficients in most of the traits. Spikes per plant, grains per spike, spike length, 100-grain weight and harvest index were the most important characters which possessed positive association with grain yield. Path coefficient analysis revealed that among the different yield contributing characters spike per plant, grains per spike, 100-grain weight and harvest index influenced grain yield per plant directly. The direct effects of these characters on grain yield were positive and considerably high. Moreover, harvest index, days to maturity and spikes per plant had positive and higher indirect effect on grain yield through grains per spike. Thus selection for yield in spring wheat through these characters would be effective.

The genetic divergence was assessed in 60 mango genotypes through D 2 -statistics and principal component analysis. The genotypes under study were grouped into eight clusters and the diversity was influenced by the morphological characters, not by the geographical distribution of the genotypes. The clustering pattern revealed that the genotypes collected from the same region did not fall in the single cluster. The maximum inter cluster distance was noticed between cluster II and cluster VIII, and the lowest between clusters VII and cluster VIII. From the cluster means, cluster I was high yielding and ranked first in terms of number of secondary branches per inflorescence, percent fruit set per inflorescence, and yield per plant. Cluster VIII had only one genotype which produced the highest percentage of flowering shoots, % perfect flowers, number of fruits per plant, and %TSS. The genotypes of cluster VII produced the biggest sized fruits. The first nine characters of the principal component axes with eigen values above unity accounted for 88.3% of the total variation among the fifteen characters. Weight of harvested fruits per plant (0.990 and 0.181), number of fruits per plant (0.101 and 0.607) and individual fruit weight (0.027 and 0.107) for both the vectors were positive across two axes indicating the important components of genetic divergence. The genotypes belonging to clusters I, VII and VIII with high to moderate genetic distances might be recommended for use in crossing programs to produce new recombinants with desired traits.

Sixty mango genotypes were studied to find out their variability, heritability, and genetic advance. Significant variations were observed in 20 characters. There were also considerable differences between the genotypic and the phenotypic coefficients of variation for almost all the characters which indicated the influence of environment on the expression of these traits. Among the studied characters, GCV and PCV were high for weight of harvested fruits per plant, % fruit harvest per inflorescence, % initial fruit set per inflorescence, number of fruits per plant and number of main branches per inflorescence. All the characters showed considerably high heritability which ranged from 56.21 to 98.24% and the genetic advance (as % of mean) was high for the maximum traits. High heritability coupled with high genetic advance was observed in weight of harvested fruits per plant, % initial fruit set per inflorescence, % of flowering shoot, number of inflorescences per shoot, percent fruit harvest per inflorescence, number of main branches per inflorescence, number of fruits per plant, number of inflorescences per shoot, plant height (cm), and percent perfect flowers which indicated that these characters were less influenced by environment confirming predominance of additive gene action and therefore, selection in favour of these characters would be feasible for yield improvement of mango. DOI: http://dx.doi.org/10.3329/bjar.v37i4.14393 Bangladesh J. Agril. Res. 37(4): 683-690, December 2012

Sixty diverse genotypes of mango were selected from the Germplasm Centre of BAU during December 2007–August 2009 to determine the genotypic and phenotypic correlation along with their direct and indirect effects through path coefficients analysis in mango as to estimate the contribution of most important characters towards yield. It appeared that in most of the cases, the genotypic correlation values were higher than their corresponding phenotypic values. This suggests that there were strong inherent relationship between the traits. Percent flowering shoot had significant positive correlation with inflorescence per shoot, percent perfect flower, percent initial fruit set, number of fruits per plant and fruit weight both at phenotypic and genotypic levels. Fruit yield is determined by some components. The residual effects of genetic and phenotypic path analysis were 0.209 and 0.385, respectively, revealed higher genetic variability and also proved lower percent of environmental influence on the selected ten characters. In genotypic path analysis, number of fruits per plant had the highest positive direct effect (0.899) on yield. Higher positive direct effects were also observed for the characters inflorescence per shoot (0.539), percent perfect flower (0.816), and percent initial fruit set (0.292), and fruit weight (0.324). Leaf area, percent flowering shoot, number of fruits per plant, and fruit length showed negative direct effects towards yield. In phenotypic path analysis, except percent flowering, shoot per plant and fruit length and other characters also exhibited similar trend on yield as genotypic path coefficient. In combination with correlation coefficient and path analysis, it was found that number of fruits per plant and percent perfect flower gave significant positive correlation coefficients with yield and also produce the high positive direct effect. Thus, it was clear that plant height, inflorescence per shoot, percent perfect flower, percent initial fruit set per inflorescence, and fruit weight are the major component of fruit yield in mango. Bangladesh J. Agril. Res. 37(3): 493-503, September 2012 DOI: http://dx.doi.org/10.3329/bjar.v37i3.12126

An experiment was carried out at the Horticulture Farm, Bangladesh Agricultural University, Mymensingh during rabi season of 2006-2007 to study the effects of different thickness of water hyacinth mulch and tillage on the storage life of garlic. The experiment was consisted of five depths of water hyacinth mulch (0, 6, 8, 10, and 12 cm) and two methods of tillage (conventional and zero). It was laid out in the split plot design with three replications. The study revealed that the bulbs from the zero tillage showed the highest storage quality resulting in the lowest weight loss (8.45%), insect infested bulbs (6.67%) as well as rotten bulbs (2.44%) after 150 days of storage. In contrast, bulbs grown under conventional tillage with no mulch and 6 cm thick mulch had the lower storage quality compared to those of other treatment combinations. The result showed that garlic production under zero tillage with 12 cm mulch could be used for better storability.

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An experiment was conducted at the field of USDA-Alliums project, Bangladesh Agricultural University, Mymensingh to study the effect of tillage and mulches on the growth and yield of garlic. The experiment consisted of three tillage conditions (conventional, puddling and zero tillage) and four mulches (control, rice straw, water hyacinth and Curcuma amada leaf). The results revealed that different mulches had remarkable contributions on the growth and yield of garlic. The highest values of growth parameters as well as bulb yield were obtained from rice straw mulch identical with that of water hyacinth mulch. Different tillage also had significant influence on yield and yield contributing traits of garlic. Garlic cultivated under zero tillage showed remarkable variation in terms of percent emergence. Puddling and zero tillage practices resulted in higher yield compared to the conventional tillage. It was also noticed that both the tillage conditions as well as mulches showed profound effects on the yield and yield contributing parameters. Moreover, the highest net return (196647Tk. /ha) and the highest BCR of 2.90 was obtained from zero tillage with rice straw.Bangladesh J. Agril. Res. 41(1): 53-66, March 2016

Abstract.Majumder DAN, Nath SC, Kabir MA, Majumder S. 2016. Effect of mulching materials on mini tuber production of potato from in vitro plantlets. Nusantara . This paper describes the effectiveness of organic and plastic mulching for potato mini tuber production in Bangladesh. The field experiment was carried out during the Rabi season of 2013-2014 to 2014-2015 with virus free in vitro cultured plantlets of var. Diamant. The mulching materials of water hyacinth mulch (WHM), rice straw mulch (RSM) and black polythene mulch (BPM) were compared with no-mulching (control) to find out suitable mulching material (s) for obtaining higher tuber yield. During the whole production period morphological characters, yield characters as well as of soil temperature and soil moisture were assessed. The results showed that WHM (5.28 t/ac) and RSM (4.59 t/ac) had a positive effect on increased the proportion of tuber size above 28 mm and on increasing of tuber yields by 54.0% to 77.2% compared with control (2.98 t/ac). Higher soil temperatures were recorded with plastic mulch caused lower potato tuber yield (3.04 t/ac) while WHM and RSM decreased soil temperatures and increased the moisture percentage. The mulching of mini tubers had negative effect on tubers quality in regards of scab, green tuber and weed biomass.