Tropical Agriculture and Development
Online ISSN : 1882-8469
Print ISSN : 1882-8450
ISSN-L : 1882-8450
57 巻 , 4 号
選択された号の論文の5件中1~5を表示しています
Original Article
  • Tomohiro KONDO, Hirokazu HIGUCHI
    2013 年 57 巻 4 号 p. 109-113
    発行日: 2013年
    公開日: 2014/04/06
    ジャーナル フリー
    To determine the effects of excess phosphorus (P) application on fruit quality, three-year-old passion fruit plants grown in sand culture with nutrient application of sufficient P at 3.5 mM were subjected to regulated P application treatment of 0, 1.3, 2.5, or 10 mM for three months. Just after harvest, fruit weight, dimensions, and peel color were measured. After a 10-day storage, titratable acidity (TA), total soluble solids (TSS), juice content, wrinkling degree, and juice P content were measured. Leaf mineral contents and SPAD index were measured. TA was the highest and the sugar/acid ratio was the lowest at the highest P treatment where 10 mM of P was applied, although there was no relationship between TA and juice P content. TSS was the lowest at terminated P treatment. Excess P application worsened peel color, while the wrinkling degree was not affected. Fruit weight and juice content were the highest at the highest P. Leaf P content was 0.2 % at P terminated treatment, and 1.2-1.6 % at the highest P treatment. No visible signs of P deficiency or excess were observed. Leaf Ca and Mn contents were higher at higher P treatment. The SPAD index and leaf N, K, Mg, Fe, and Zn contents were not affected. These results indicated that excess P application resulted in a deterioration of passion fruit quality, both in palatability and external appearance.
  • Evans Atuti ATERA, Fumi KONDO, Kazuyuki ITOH
    2013 年 57 巻 4 号 p. 114-119
    発行日: 2013年
    公開日: 2014/04/06
    ジャーナル フリー
    Field trials on permaculture system and intercropping of maize with legumes were conducted during the long rainy seasons (December–May) of 2009 to 2011 at Dowa and Chitedze Agricultural Research Centre in Malawi, respectively, to evaluate the effect of the systems in reducing Striga asiatica incidence. There were five treatments in intercropping (maize intercropped with common bean, pigeon pea, cowpea, soybean and groundnut) and permaculture (maize planted in the same plot with soybean, bambara bean, cotton, pigeon pea and marigold) laid out in a randomized complete block design (RCBD) replicated three times. Sole maize was sown as a control in each farming system. The result showed all maize-legume intercrop plots had lower Striga counts than sole planted maize. Maize-cowpea intercrop indicated a significantly reduced Striga infestation up to 50% in maize in both years. The combined data analysis of maize-legume intercropping, however, showed there was no significant difference in grain yield of maize due to treatments. Maize supported significantly fewer number of Striga in the permaculture cropping system compared with the sole sown maize. There was higher yield of maize in permaculture than monoculture by 28.3%. This study confirmed the potential in cowpea as a food trap intercrop and permaculture as a cropping system in the management of Striga, which should be incorporated in cropping systems in subsistence farmers’ fields.
  • Hiroshi MATSUDA, Hirokazu HIGUCHI
    2013 年 57 巻 4 号 p. 120-125
    発行日: 2013年
    公開日: 2014/04/06
    ジャーナル フリー
    We determined favorable temperatures for in vitro germination of ‘Bengal’ and ‘Chakrapat’ lychee pollen, and quantified effective sucrose, boric acid, and agar concentrations for ‘Chakrapat’ germination medium. Pollen germination was high at 25–30°C in ‘Bengal’ and at 25–35°C in ‘Chakrapat’, and pollen tube elongation proceeded well at 25–30°C in both cultivars. The pollen germination percentage and pollen-tube elongation in ‘Chakrapat’ were highest on 1% agar media containing 15% sucrose and 10 ppm boric acid when incubated at 25°C. Pollen germination continued until 12 h after placement on media, and vigorous pollen-tube elongation continued until 9 h after placement.
  • Mitsuru HAMANO, Tetsuo MATSUMOTO, Kasumi ITO
    2013 年 57 巻 4 号 p. 126-137
    発行日: 2013年
    公開日: 2014/04/06
    ジャーナル フリー
    One of the key strategies for economic development and poverty alleviation, especially in rural areas of Cambodia, is brought about by adding value to local agricultural products by agro-processing. Although rural farmers traditionally produce various processed products, these productions have not yielded added value. Rice liquor, which has been traditionally produced by small-scale farmers, faces low profitability due to low prices associated with the low quality of the product. The objective of the present study was to determine modified techniques for improving rice liquor quality using the action research method. In the study, first, the causes of low quality were identified by observing the farmer’s liquor production. Thereafter modified production techniques to eliminate the causes behind the low quality by repeated trials until the problem was solved. Finally, the quality of a trial product was evaluated through consumer tests, and unfavorable smells and tastes were considerably reduced due to the improvement of the hygienic conditions and production management. Some examples of changes included the prevention of putrefaction of fermenting rice (bay sraa in Khmer), the degrease of burning problems during rice cooking and distillation, and the separation of clear and cloudy distilled liquor. The smells and tastes of the trial rice liquor were highly appreciated by the consumers, suggesting the high possibility for commercialization of the improved product. Thus the technical modifications for rice liquor production were considered to achieve an expected level of quality using traditionally based, simple, and inexpensive methods that can be applied by rural producers in Cambodia.
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