Tropical Agriculture and Development
Online ISSN : 1882-8469
Print ISSN : 1882-8450
ISSN-L : 1882-8450
60 巻 , 4 号
選択された号の論文の10件中1~10を表示しています
Original Article
  • Md. Enamul KABIR, Md. Mahabur RAHMAN, Kazuo ANDO
    2016 年 60 巻 4 号 p. 205-215
    発行日: 2016年
    公開日: 2017/12/09
    ジャーナル フリー

    Agroforestry homegardens are important repository of useful plants in most tropical and subtropical world. Home gardens, which are maintained by at least 20 million households, represent possible strategies for livelihood provision, environmental amelioration and perhaps more importantly biodiversity conservation in Bangladesh.Having no accessible natural forests, majority people of Satkhira District in Bangladesh are heavily depend on home gardens to meet their basic forest resources need. This study investigated the existing useful plant resources, its utilization and conservation importance of home gardens in Kalaroa Upazila of Satkhira District, Bangladesh. All useful plants were censused, totalling 270 species including four threatened from 50 randomly selected home gardens totalling 9.29 ha area. Of the 270 species, 108 trees, 53 shrubs, 67 herbs, and 42 woody and non-woody climbers. All the recorded plant species were classified into nine main usage categories where 36species were multipurpose. Home gardens accounted for about 18% of household’s total annual income. Maintaining high species richness, home gardens in the study area are representing biodiversity hotspot through use in Bangladesh. Despite the high species richness majority species in the home gardens was rare.Thus, serious effort must be taken to increase the population density of most species to determine whether home gardens indeed act as long-term source to livelihood options, climate resilience, and biodiversity conservation in Bangladesh.

  • Aki KUBOTA, Yoshiya SHINOTO, Waleed H. ABOU EL-HASSAN, Sachio MARUYAM ...
    2016 年 60 巻 4 号 p. 216-225
    発行日: 2016年
    公開日: 2017/12/09
    ジャーナル フリー

    Water is the primary limiting factor for crop production in Egypt. Two-year field experiments were conducted on Vertisols of the Nile Delta to elucidate the possibility of saving irrigation water during the cultivation of maize (Zea mays L.) by prolonging the irrigation interval in surface furrow irrigation. Maize was grown under a conventional (about 2-week interval: CI) and a prolonged irrigation interval (about 3-week interval: PI). Soil water potential, plant growth, photosynthetic parameters at the early grain-filling stage of maize plant, and grain yield were investigated. The results showed that the PI markedly affected the photosynthetic rate via stomatal closure, especially at midday, and reduced dry matter production by 49% at the early grain-filling stage. However, no significant differences were detected for the final grain yield in both years. Water use efficiency (WUE) based on dry matter production at the early grain-filling stage was higher under CI, while WUE based on grain yield was higher under PI. The absence of differences in yield under different irrigation intervals was ascribed to the availability of water within the deeper soil profile. The results suggested that the water-saving irrigation method enabled to improve the final WUE and to maintain the maize grain yield. The prolonged irrigation interval could save 8-11% of water use in the Nile Delta region, covered by heavy clayey soil. Our study also contributed to the understanding of the response of maize plant leaf photosynthesis to water-deficit.

  • Rosnaeni SAKATA, Shuzoh SHIMADA, Naho YOSHIOKA, Ryo YOSHIOKA, Hiroshi ...
    2016 年 60 巻 4 号 p. 226-235
    発行日: 2016年
    公開日: 2017/12/09
    ジャーナル フリー

    The oil palm plantations have been expanding into the different slope positions, through its association with deforestation and nitrogen fertilizer use and concerning emission of greenhouse gases. However the interactions of soil properties and topography influencing greenhouse gas fluxes are still poorly understood. Topography affects the movement of surface and subsurface water and causes the variability of soil processes, which makes the accurate estimation of greenhouse gas fluxes more difficult. This study aimed to assess N2O and CO2 emissions, measured by closed chamber method in upper, middle, and lower slope positions for a whole year from June 2012 to May 2013 in Tunggal sandy loam soil, Indonesia and to assess the dissolved N2O concentration as source of indirect emission from oil palm plantation to the atmosphere, measured by headspace method in puddle, drain, and well. N2O and CO2 fluxes showed variability with seasons and slope positions. Cumulative N2O fluxes were significantly higher in the lower position than upper and middle position, while cumulative CO2 fluxes showed no significant difference among the slope positions. Dissolved N2O concentrations varied by water sources and sampling time, sometime supersaturated than ambient equilibrated concentration. These results show that topography even in a short slope affected the spatial variability of N2O and CO2 emission, which may need to be taken into account in field measurements and estimating the whole emissions of these gases including the indirect emissions.

  • M. Amir HOSSAIN, M. A. Khaleque MIAN, M. Golam RASUL, M. Jamil HASAN, ...
    2016 年 60 巻 4 号 p. 236-241
    発行日: 2016年
    公開日: 2017/12/09
    ジャーナル フリー

    Thirteen cytoplasmic male sterile (CMS) lines were studied in Bangladesh for their genetic variability, correlation and path analysis. The rice plants were grown under medium high land condition of Bangladesh Rice Research Institute (BRRI), Gazipur, during Boro (November-May), 2009-10 season. Variability among the CMS lines was evaluated and relationship of outcrossing rate with floral traits was determined. The phenotypic coefficient of variation (PCV) values were greater than genotypic coefficient of variation (GCV), revealing a little influence of environment in trait expression. High heritability along with high genetic advance in percent of mean was observed in outcrossing rate, duration of floret opening and filament length. Outcrossing rate showed positive significant association with percent stigma exertion, angle of opened spikelet, stigma length and stigma breadth both at genotypic and phenotypic levels, though with percent panicle exertion and duration of floret opening at genotypic level only. The results suggested that higher outcrossing rate was contributed by the traits like angle of opened spikelet, percent stigma exertion, stigma length, stigma breadth and percent panicle exertion. Thus selection based on these traits for CMS lines would be effective for hybrid rice breeding program.

  • M. Amir HOSSAIN, M. A. Khaleque MIAN, M. Golam RASUL, M. Jamil HASAN, ...
    2016 年 60 巻 4 号 p. 242-250
    発行日: 2016年
    公開日: 2017/12/09
    ジャーナル フリー

    Five cytoplasmic male sterile (CMS) lines namely IR58025A, BRRI1A, D. ShanA, BRRI9A and IR73328A were crossed with three testers, viz. M.H.63R, M.H.77R and Gui99R in line × tester fashion to produce F1 hybrids and find out the best combinations related to the combining ability effects among the parents and hybrids. Analysis of variance revealed a significant difference among the genotypes and crosses. Variance due to parents was highly significant for all the characters. Variance due to interaction effect of parents and crosses was significant for all the characters except days to 50% flowering and days to maturity. Variance of sca was higher than that of gca for all the characters except number of panicles per m2, suggesting the significant role of non-additive gene action on the inheritance of this character. The relative contribution of line, tester and combinations of line × tester interaction of all characters was calculated and found that 1000-grain weight contributed the highest (61.11%) followed by number of spikelet per panicle (58.19%), plant height (53.91%), spikelet fertility (47.23%) and yield per plant (44.02%) in their hybrid. IR73328A/M.H.63R cross combination was the best specific combiner for grain yield per plant. Estimates of gca effects showed that BRRI9A was an excellent general combiner for improving eight characters viz. plant height, effective tiller per plant, days to 50% flowering, number of panicle per m2, panicle weight, number of spikelet per panicle, spikelet fertility and 1000-grain weight. The cross BRRI9A/Gui99R was found to be a good specific combiner for most of the characters. The cross between good general combiners did not always produce the best specific crosses. Moreover, the predominance of production of the best specific crosses from high × low and low × low combiners indicated the influence of non-additive and over-dominant gene action on the plant stature.

  • A Case of Gender-Based Division of Labor in Common Bean (Phaseolus vulgaris L.) Farming in Ethiopia
    Mizuki IIDA, Yoshiaki NISHIKAWA, Kiyoshi SHIRATORI, Taku SEO, Dawit AL ...
    2016 年 60 巻 4 号 p. 251-262
    発行日: 2016年
    公開日: 2017/12/09
    ジャーナル フリー

    This paper discusses the mechanism of gender-based division of labor, drawing a case of Ethiopian common bean farming with focus on production, seed procurement, and marketing in order to get a clue to gender approaches in agricultural research. In production, male-sequential farm works were confirmed in ox-drawn plowing and broadcast sowing, while female-sequential farm works were identified in row planting and some harvest and post-harvest activities such as immature harvesting, cleaning of threshing place, gleaning beans after threshing, and winnowing. They tended to have the gender-based division of labor according to their gender-based knowledge, techniques, and tools. In seed procurement, decisions on seed source only for home garden production are recognized as female-specific activity. Male and female differences in way of distributing harvest and saving places were confirmed. In marketing, both men and women tended to have large-scale marketing pattern to a different extent. But small-scale marketing was common only among women. As a principal source of the female small-scale marketing, a unique practice in Ethiopia was found, which men leave some harvest on threshing places for women to glean it. And this habit also seemed to compensate gender gaps between men and women. The study suggests gender inequality in a positive way (positive inequality) in terms of respecting male and female different potentials, supporting diversified needs among women by providing them with options, and a possibility of applying local strategies to overcome existing power relations between men and women. Finally, this paper proposes to respect local gender-based division of labor and the mechanism, and to offer them options as an alternative gender approach in agricultural research.

  • Yusufujiang YUSUYIN, Ngai Paing TAN, Mum Keng WONG, Arifin Bin ABDU, K ...
    2016 年 60 巻 4 号 p. 263-274
    発行日: 2016年
    公開日: 2017/12/09
    ジャーナル フリー

    Chemical forms and distribution of manganese (Mn), iron (Fe), copper (Cu), and zinc (Zn) in soils under oil palm cultivation were investigated at an 18-year-old oil palm field in central Pahang, Malaysia. Soils were sampled at three micro sites under different agronomic management (weeded circle, frond heap and harvest path). In the surface soils, total Mn at the frond heap was significantly higher than at the weeded circle and the harvest path, and total Zn was highest at the weeded circle. Amounts of diethylene triamine pentaacetic acid (DTPA) extractable Mn, Fe, Cu and Zn at the frond heap were higher than at the harvest path. Results of sequential fractionation indicated that Mn in the acid soluble, Mn oxide-occluded, and organically bound fractions were higher at the frond heap than at the harvest path. On the other hand, the amount of Mn in the heaped fronds was highest among the examined micronutrients. These results suggest that release of Mn during decomposition of heaped fronds increased the amounts of Mn in the above mentioned fractions, which in turn contributed to the increment of total and available Mn in the surface soil at the frond heap. It is also supposed that frond heaping practice affects the distribution of Fe, Cu, and Zn. This study shows that, as well as soil macronutrients, the dynamics of soil micronutrients in oil palm fields are influenced through the practice of frond heaping.

  • Aki KUBOTA, Sayed Ahmed SAFINA, Saad Mohamed SHEBL, Alaa El-Din Hassan ...
    2016 年 60 巻 4 号 p. 275-282
    発行日: 2016年
    公開日: 2017/12/09
    ジャーナル フリー

    Using limited water resources efficiently and increasing crop production for population growth are critical issues in Egypt. A field experiment was conducted to evaluate wheat-Egyptian clover intercropping system with the purpose of maximizing the land use and minimizing evaporation from soil surface in the Egyptian Nile Delta. An additional treatment was cutting at 15 cm from the land level at 69 days after sowing to provide animal feeds in winter. Leaf area index (LAI) and ratio vegetation index (RVI) of the canopies, SPAD values of leaves, biological yields, grain yield, land equivalent ratio (LER), and water use efficiency (WUE) were measured. LAI and RVI of monocultured wheat were improved by intercropping with Egyptian clover, which can contribute to reduction in water evaporation from the soil surface. Wheat grain yield was not affected by intercropping but significantly reduced by cutting during the vegetative stage. Egyptian clover production was notably reduced by both intercropping and cutting treatment. WUE based on the yield was 63% higher for intercrops than that for wheat monocrop. The total LER of intercropping system was 1.17. The results suggested that the cultivation of wheat intercropped with Egyptian clover has possibility to provide food both for human and animal of small-scale farmers with limited land and water resources, and also to reduce evaporation from soil surface in the Egyptian Nile Delta. The cutting treatment at early stage of crops was not effective of production of neither wheat nor clover.

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