Tropical Agriculture and Development
Online ISSN : 1882-8469
Print ISSN : 1882-8450
ISSN-L : 1882-8450
60 巻 , 2 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
  • Sota KOEDA, Elly KESUMAWATI, Yuri TANAKA, Munetaka HOSOKAWA, Motoaki D ...
    2016 年 60 巻 2 号 p. 59-64
    発行日: 2016年
    公開日: 2016/10/21
    ジャーナル フリー

    Hot peppers (Capsicum spp.) are essential spice in Indonesian meal. Recently, diseases caused by viruses are emerging as serious problems in pepper production at northern Sumatra. Viruses are destabilizing farmers’ incomes and the prices of spice used daily by the consumers. In the present study, to obtain the fundamental knowledge of severe damage in pepper production, field research and molecular study were conducted to assess the genetic identity and diversity of pepper-infecting viruses. Five local farmers’ fields located at the suburbs of Banda Aceh were chosen for the study. At each field approximately 500 to 3,000 plants of C. annuum were cultivated. The yellow leaf curl symptoms were observed in more than 81 % of plants in all the fields, and symptoms reached 100 % at four fields out of five. As yellow leaf curl symptoms are often caused by begomoviruses, DNA-A full-length sequences were determined and clarified that Pepper yellow leaf curl Indonesia virus (PepYLCIV), Tomato yellow leaf curl Kanchanaburi virus (TYLCKaV), and Ageratum yellow vein virus (AYVV) were infecting pepper plants. By detecting three different begomoviruses independently using specific primers, it was suggested that most of pepper plants were infected with two to three viruses. The present study inferred that mixed infection of begomoviruses is associated with the serious virus problems in pepper production at northern Sumatra, Indonesia.

  • Examples of Several Products in Indonesia Including Organic Rice
    Nobuo SAKAGAMI, Fumitaka SHIOTSU, Nurwulan AGUSTIANI, Masakazu KOMATSU ...
    2016 年 60 巻 2 号 p. 65-70
    発行日: 2016年
    公開日: 2016/10/21
    ジャーナル フリー

    Recently, changes in dietary life and rising awareness of agricultural food safety and health driven by economic growth have enhanced popular interest in organic rice production in Indonesia. Farmers are also showing a growing interest in organic rice cultivation since it can be sold at higher prices. In meeting such new demands, knowledge of chemical properties of rice is beneficial as fundamental information. Therefore, palatability-related characteristics, vibrational spectra and contents of water, ash, total C, total N and metal elements of milled rice that is popular in Indonesia, adding milled Japonica rice as control, were investigated in this study. The palatability scores of Indica rice were generally low, but those of organic rice varieties were slightly higher than conventional rice. No definite difference for FT-IR spectra was found between Japonica rice and Indica rice. Regarding total nitrogen content, organic rice showed low values, presumably reflecting reduced nitrogen input because of the use of organic fertilizers. Japonica rice showed higher contents of magnesium, silicon, iron, and copper and lower contents of rubidium and molybdenum compared to Indonesian rice. Organic rice varieties showed clearly lower contents of iron and zinc. It seems clear that if conversion to organic farming proceeds, then it will alter the dynamics of inorganic nutrients as well. Future research undertaken to do detailed content analysis pertaining to quality and palatability of Indica rice is needed, taking note of different cultivation methods.

  • Yoshinori YAMAMOTO, Kazuki OMORI, Youji NITTA, Kenichi KAKUDA, Yulius ...
    2016 年 60 巻 2 号 p. 71-80
    発行日: 2016年
    公開日: 2016/10/21
    ジャーナル フリー

    The differences in dry matter production and its distribution between the two folk varieties of sago palm with higher (Molat) and lower (Rotan) starch productivity were clarified in Kendari, Southeast Sulawesi, Indonesia. The fresh and dry matter weights of whole shoots of the two varieties increased exponentially with age after trunk formation and these differences were 2.7 times higher in Molat than in Rotan at the harvesting stage. Differences were not found between the two varieties after trunk formation in the ratios of whole leaf, whole trunk, and the harvested trunk (from the trunk base to the node of the lowest living leaf) dry weights to the whole shoot weight and the ratio of pith dry weight to the harvested trunk dry weight. The difference in whole shoot weight between the two varieties might be caused by the difference in leaf area per palm (2.9 times difference) observed in the previous report. These results suggested that the difference in starch productivity between Molat and Rotan resulted from the difference in dry matter production, but not from the difference in the distribution of the dry matter to the harvested trunk.

  • Ayaka UKE, Godfrey ASEA, Keiko T. NATSUAKI
    2016 年 60 巻 2 号 p. 81-88
    発行日: 2016年
    公開日: 2016/10/21
    ジャーナル フリー

    Rice yellow mottle virus (RYMV) is a major rice (Oryza spp.) virus found only in Africa. In the present study, we collected samples of rice mainly from Eastern Uganda showing RYMV symptoms. The presence of RYMV was confirmed using ELISA and PCR. Some RYMV isolates in Uganda were sequenced and showed high homology levels with the Madagascar RYMV strain. They were grouped into S4ug strain in the East African lineage, showing high homology levels with isolates from neighboring countries. Serotyping based on the amino acid sequences of a RYMV coat protein gene fragment enabled to classify the Uganda isolates into Ser 4, in accordance with a previous serotyping report of other Ugandan isolates, using monoclonal antibodies. The present study revealed the widespread occurrence of RYMV in Uganda with a low diversity, irrespective of the origin of location and the rice varieties, as well as the first serotyping of Ugandan RYMV based on the amino acid sequences but not on monoclonal antibodies.

  • Naoto ISHIKAWA, Miho SUZUKI, Alaa MOHAMED, Magdy Abou EL-FADEL, Ahmed ...
    2016 年 60 巻 2 号 p. 89-92
    発行日: 2016年
    公開日: 2016/10/21
    ジャーナル フリー

    Effects of temperature and soil moisture on ruminal fiber digestibility of maize (Zea mays L.) were evaluated in controlled environmental facility. Plants were cultivated at lower (28 °C for 14 h, day and 19 °C for 10 h, night: L) or higher (35 °C for 14h, day and 27 °C for 10 h, night: H) temperature with three soil moisture conditions (pF: 1.7, 2.5 or 2.7). Dry matter (DM) production, plant height, fiber fractions and in situ digestibility of neutral detergent fiber (aNDFom) of plants at the 13th leaf stage were analyzed. Temperature affected aNDFom digestibility which was lower at H than at L regime. Lower aNDFom digestibility at temperature H might be due to the increased lignin (ADL) content and decrease in digestibility of acid detergent fiber (ADFom) content exept for ADL. However, soil moisture did not affect aNDFom digestibility. It was also demonstrated that digestible aNDFom yield of maize decreased under high temperature with drought due to reduced yield combined with reduction in digestibility.

  • An Ethnobotanical Study of Local Names and Uses
    Yumi UEDA, Hirokazu HIGUCHI, Eiji NAWATA
    2016 年 60 巻 2 号 p. 93-102
    発行日: 2016年
    公開日: 2016/10/21
    ジャーナル フリー

    Mangifera species are fruit trees distributed throughout Thailand, some of which are protected or even cultivated by local people. We explored Mangifera trees, and recorded their local names and uses to understand their current utilization in North Thailand. M. caloneura and M. pentandra occurred frequently. M. sylvatica and M. linearifolia were also observed although they were quite rare. Average fruit weight of M. caloneura and M. pentandra varied widely among trees (22.2–93.0 g and 37.5–77.0 g, respectively). M. caloneura had five major local names, while M. pentandra had three. Intraspecific variation was not clearly recognized although fruit morphological traits varied, and neither intentional conservation nor cultivation of superior varieties was observed. People–plant relationships regarding wild Mangifera species in North Thailand were relatively tenuous compared to those in Northeast Thailand.

  • Yumi UEDA, Hirokazu HIGUCHI
    2016 年 60 巻 2 号 p. 103-108
    発行日: 2016年
    公開日: 2016/10/21
    ジャーナル フリー

    Local names and uses of non-indica mangoes in South Thailand were investigated. A total of 49 trees were identified and classified as 35 Mangifera foetida, 12 M. odorata, and 2 trees of other Mangifera species. The majority of trees were planted in homegardens and in the vicinity of settlements. The popular use of M. foetida and M. odorata was fruit consumption, similar to M. indica, except for use of the mature-green fruits in curries. No cultivars were established in South Thailand; however, M. foetida in Trang was distinguished into mud khaa khwaai with larger fruit and mud phrik with smaller fruit. M. odorata had two kinds of names; mud muang, a combined name of M. foetida (mud) and M. indica (muang), and kuainii or kuainii-like name, probably originating in kewini, a Malay name of M. odorata. M. odorata was clearly distinguished from M. foetida and believed as an intermediate of M. foetida and M. indica. M. foetida and M. odorata were all cultivated in South Thailand; utilization of non-indica mangoes is more developed than any other regions in the country. M. foetida and M. odorata were likely cultivated due to their good productivity under wet conditions and their use as ingredients in curries for their pronounced aroma.

  • Nhung Thi Hong NGUYEN, Susumu ARIMA, Tenji KONISHI, Yuko OGAWA, Xuan D ...
    2016 年 60 巻 2 号 p. 109-118
    発行日: 2016年
    公開日: 2016/10/21
    ジャーナル フリー

    Hemerocallis fulva var. sempervirens is a perennial medicinal plant, containing oxypinnatanine (OPT), which has well shown sedative and sleep-improving effects. We performed two pot experiments examining the growth, yield and OPT accumulation of this plant in three soil types in Okinawa, Japan, (dark-red, gray, and red soils), and eight quantitative combinations of N, P, K at 0.0–0.6 g pot -1 in dark-red soil. It was found that dark-red soil was the best for plant growth and yield, next by gray soil. The plants in red soil accumulated the significantly more OPT (2.19 g mg g -1 fresh leaf) than those in gray soil (1.85 mg g -1), and similar to plants in dark-red soil (2.16 mg g -1), but their growth and yield were lower than those in the other soils. Consequently, dark-red soil is advised to use for cultivation of this plant. In dark-red soil, the growth and leaf yield of this plant were proportional to the applied N, P, K quantity, especially N amount, whereas the flower yield and OPT concentration were not. The N amount at 0.6 g pot -1 promoted the leaf yield better, at 0.3–0.4 g pot -1 was better for flower yield, and the combinations of 0.3–0.4 g N with 0.3 g P, and K per pot were ideal for OPT accumulation. The results suggested the N, P, K combination at 0.4 g pot -1 is the best for cultivation H. sempervirens in dark-red soil to obtain OPT.

  • -Farmer’s Perspectives and Soil Physicochemical Properties-
    Satoshi NAKAMURA, Roland N. ISSAKA, Joseph A. AWUNI, Israel K. DZOMEKU ...
    2016 年 60 巻 2 号 p. 119-131
    発行日: 2016年
    公開日: 2016/10/21
    ジャーナル フリー

    Low soil fertility, particularly in the lowlands, has been identified as a major factor limiting rice yields in Sub-Saharan Africa (SSA). A comparative study was therefore conducted in Ghana on soil fertility and farmers’ perspectives of soil fertility management in the two major rice growing agro-ecological zones: the Guinea Savanna (GS) and the Equatorial Forest (EF), to examine farmers’ perspectives on soil fertility, how farmers manage fertility, and to suggest proper soil fertility management for lowland rice farming. Principal component analysis was used to analyze farmers’ perspectives and soil fertility characteristics of the two zones. Results show that soils characteristics vary both within and between the two agro-ecological zones. While soils in the EF zone are relatively fertile, soils of both agro-ecological zones are infertile. The soils are low in organic matter and available phosphorus. Farmer’s perspectives on soil fertility management differed across the agro-ecological zones, and could be categorized into three major groups: (a) farmers having high motivation to improve soil fertility, and high awareness of soil drought; (b) farmers who have high motivation to improve soil fertility, but low awareness of the vulnerability to drought; and (c) farmers having weaker interest in soil fertility management, and preferring extensive management to proactive soil fertility management. On the basis of farmers’ perspectives, the utilization of local materials would be effective in soil fertility improvement or maintenance in both agro-ecological zones, due to its high applicability for farmers.

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