Japan Agricultural Research Quarterly: JARQ
Online ISSN : 2185-8896
Print ISSN : 0021-3551
ISSN-L : 0021-3551
Volume 50, Issue 3
Displaying 1-13 of 13 articles from this issue
REVIEWS
Crop Science
  • Yoshiro MANO, Fumie OMORI, Hiroyuki TAMAKI, Shohei MITSUHASHI, Wataru ...
    2016 Volume 50 Issue 3 Pages 175-182
    Published: July 01, 2016
    Released on J-STAGE: August 01, 2016
    JOURNAL FREE ACCESS

    Flooding due to worldwide climate change can drastically affect crop production. To overcome the detrimental effects of flooding during maize growth, we have been developing flooding-tolerant maize via DNA marker-assisted selection using a flooding-tolerant teosinte, Zea nicaraguensis, as a donor parent. Over the last decade, quantitative trait locus (QTL) information on flooding-tolerance-related traits in Zea species has been obtained at the NARO Institute of Livestock and Grassland Science, and near-isogenic lines containing one or more QTLs have been developed for several flooding-tolerance-related traits, such as the capacity to form constitutive aerenchyma, tolerance to flooding under reducing soil conditions, and ability to form adventitious roots at the soil surface. In field trials, we have been accumulating data demonstrating the effectiveness of teosinte-derived QTLs on flooding tolerance, and are preparing to release a flooding-tolerant F1 maize hybrid within a few years. In addition, we have just started a project to clone Qft-rd4.07-4.11 by using next-generation sequencing, which would make it possible to extend the use of this QTL to other upland crops.

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  • Tomoko KONYA, Hideo KAINUMA, Osamu FUJIOKA, Hiroyuki TANAKA
    2016 Volume 50 Issue 3 Pages 183-186
    Published: July 01, 2016
    Released on J-STAGE: August 01, 2016
    JOURNAL FREE ACCESS

    We have previously reported on the design of individual packaging containers for strawberries to prevent the degradation of quality. The container is bivalve-shaped and the two “shells” of the bivalve grip the peduncle of the fruit, thereby allowing packaging without the fruit coming into contact with the packaging material. We observed that the rate of weight loss and the extent of damage were lower for strawberries packed in individual containers than for strawberries packed in conventional packages. Thus, these containers preserve the quality of strawberries more efficiently (Konya et al. 2015). This review reports on the development of a practical-type container with improved shape and material. We measured the container’s basic performance, such as temperature following capability and peduncle grip force, and also conducted vibration and dropping tests to examine its practical utility. As a result, we observed that the practical-type container is resistant to vibration during transport, but vulnerable to dropping when the peduncle is positioned at the top. Thus, in case of long haul or transshipment transportation, the peduncle should be positioned at the bottom.

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Agricultural Environment
  • Akinori MORI
    2016 Volume 50 Issue 3 Pages 187-190
    Published: July 01, 2016
    Released on J-STAGE: August 01, 2016
    JOURNAL FREE ACCESS

    This review summarizes research on greenhouse gas (GHG) exchange between the atmosphere and grasslands in Japan, identifi es research need, and contributes to advances in the research field of GHG mitigation in grassland ecosystems. Applications of farmyard manure (FYM) and synthetic fertilizers do not reduce the ability of intensively managed grassland soils to oxidize methane (CH4). On the one hand, the use of synthetic fertilizers alone reduces the net ecosystem carbon balance (NECB) of mowed grassland ecosystems. On the other hand, the application of FYM with supplemental synthetic fertilizers at rates determined from the mineralization of FYM increases the NECB at the same yields, due mainly to C brought into the ecosystem as FYM. It also limits further emissions of nitrous oxide (N2O). Precipitation before and after fertilization in the summer months is the key driver of interannual variation in N2O emissions. These findings collectively suggest that the application of FYM with the appropriate reduction in supplemental synthetic fertilizers can maintain soil organic C and maximize the net GHG balance of mowed grassland ecosystems in Japan. Studies on organic matter inputs through root growth and turnover, and models to predict large N2O fluxes are needed to enhance our understanding of the NECB and net GHG balance of grassland ecosystems.

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ARTICLES
Crop Science
  • Xiaomei YANG, Changbin YIN, Hsiaoping CHIEN, Guichun LI, Fujio NAGUMO
    2016 Volume 50 Issue 3 Pages 191-199
    Published: July 01, 2016
    Released on J-STAGE: August 01, 2016
    JOURNAL FREE ACCESS

    In North China where the main crops are winter wheat and summer corn, current agricultural practices involve minimum tillage for corn and full tillage for corn or wheat, and require large amounts of irrigation water, especially during the wheat growing season. Conservation tillage (CT) is a promising method of water conservation, but local farmers still question whether it will affect the yield of winter wheat. We conducted fieldwork during 2011-2014 in Xushui, Hebei, China, in order to compare the effects of various methods of tillage, mulching, and irrigation on the yield, soil moisture, and soil temperature under a summer corn/winter wheat double cropping system. Wheat grain yield in 2012-2013 did not differ significantly because of tillage, residue, and irrigation treatments. This means that reduced irrigation did not affect grain yield for all the treatments. However, in 2013-2014, the yield for minimum tillage with residue mulch (MTm) was significantly higher (19.5%) than that for full tillage with residue removal (FTr). Yields for MTm with reduced irrigation were 10.2% significantly higher than FTi with reduced irrigation. The positive crop response to MTm may have been due to relatively higher topsoil moisture and soil temperature under MTm than under FTi during the winter period. Minimum soil temperature for the inter-row at the 5-cm depth under MTm remained slightly higher than that under FTi during the winter of 2012–2013, with colder weather than in 2013-2014. Hence, after our two-year field experiment, we concluded that MTm resulted in higher grain yields as compared with FTr probably due to higher topsoil water content; MTm with reduced irrigation maintained high yields despite eliminating one round of irrigation. Therefore, MTm with reduced irrigation was more beneficial for winter wheat crop production in North China.

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  • Toshiaki TAKEHARA, Sunao OCHI, Yasuo OHTO, Shigeo NAITO, Hiroyoshi INO ...
    2016 Volume 50 Issue 3 Pages 201-208
    Published: July 01, 2016
    Released on J-STAGE: August 01, 2016
    JOURNAL FREE ACCESS

    In 2004, an outbreak of Rhizoctonia aerial blight on soybeans planted after rice in paddy fields in Hiroshima Prefecture, Japan was also associated with delayed leaf senescence (DLS, or green stem/bean syndrome). The isolated Rhizoctonia solani was characterized as anastomosis group AG-1 IA, identical to that of the R. solani causing rice sheath blight. The relationship between aerial blight and soybean DLS, which are also problems in Japan, was examined through field inoculation testing of the rice sheath blight pathogen on soybean plants. In some plots, fungicides (azoxystrobin, flutolanil or validamycin A) were sprayed on the soybean foliage after inoculation, and some plots received frequent overhead irrigation to promote disease. There was a high incidence of the disease and DLS in the inoculated and frequently irrigated plots without the application of fungicide. Without fungicides, the yield from diseased soybeans was 12-35% lower than that in noninoculated control plots. The fungicide sprays described above were effective in controlling DLS and yield loss from the disease. We thus clearly showed that Rhizoctonia aerial blight of soybean caused by the rice sheath blight pathogen is at least one of the causes of soybean DLS. Frequent rainfall is likely to promote the disease and resulting DLS.

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  • Jemal Tola HORO, Toshio FUJII, Yasunori YAMASHITA, Sachie McGoey, Shin ...
    2016 Volume 50 Issue 3 Pages 209-217
    Published: July 01, 2016
    Released on J-STAGE: August 01, 2016
    JOURNAL FREE ACCESS

    The rice blast control efficacy of three genes—complete resistance gene Pib in isogenic line ‘Koshihikari Toyama BL 3’ and partial resistance genes Pb1 in near-isogenic line ‘Koshihikari Aichi SBL’ and pi21 in a variety ‘Tomohonami’—was evaluated in pot and upland trials with spray inoculation of the blast isolate Ina 86-137 (Japanese race 007.0) or Ao 92-06-2 (Japanese race 337.1). The evaluation was conducted by assessing their leaf and panicle blast severity, and then comparing their severity with that of blasticide (probenazole or tricyclazole) applied ‘Koshihikari’ and three control varieties with different levels of partial resistance to blast, including ‘Koshihikari’. ‘Koshihikari Toyama BL3’ harboring Pib showed very high levels of efficacy with few leaf and panicle blast lesions in both trials. The efficacy of ‘Tomohonami’ having pi21 to leaf blast was also high and equal to or higher than that of the blasticide-applied ‘Koshihikari’ in both trials. However, ‘Tomohonami’ had no panicle blast control efficacy in the pot trial, although it showed high panicle blast reduction in the upland trial. The panicle blast control efficacy of ‘Koshihikari Aichi SBL’ with Pb1 was moderate, while its leaf blast reduction was low to moderate in both trials. For expansion of the leaf blast lesions with punch inoculation on the uppermost leaves of rice plants in the booting stage of the pot trial, the areas (length x width) of the lesions on ‘Koshihikari Toyama BL 3’ with Pib were the smallest and significantly different from those of all other lines and varieties, including probenazole-applied ‘Koshihikari’. The results showed the blast control efficacy of the three resistance genes Pib, Pb1, and pi21, and confirmed a quantitative reduction of blast severity with partial resistance genes Pb1 and pi21.

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  • Hideyuki AOKI, Atsuko ONISHI, Masahiro MIYASHITA, Hisashi MIYAGAWA, Os ...
    2016 Volume 50 Issue 3 Pages 219-227
    Published: July 01, 2016
    Released on J-STAGE: August 01, 2016
    JOURNAL FREE ACCESS

    Pathogenic infection causes auxins to accumulate in plant cells and suppresses plant defense systems. We isolated the OsSAUR51 (Oryza sativa small auxin-up RNA 51) gene as one of the rice field resistance-related genes from a retrotransposon Tos17-tagged ‘Nipponbare’ mutant (XC20) in which field resistance was reduced against several races of bacterial blight pathogens. OsSAUR51 expression was induced by infection of the pathogen and exogenous auxin treatment, whereas the OsSAUR51 gene in the XC20 insertion mutant lost its function due to the Tos17 insertion. We transformed the OsSAUR51 gene with the 1.0 kb OsSAUR51 native promoter into XC20 for complementation analysis and also introduced the OsSAUR51 gene controlled by RexPhi, an enhanced CaMV 35S promoter, into the rice cultivar ‘Dontokoi’ to make transgenic plants with enhanced expression of the OsSAUR51 gene. The OsSAUR51-transformed XC20 recovered its bacterial blight resistance, and the RexPhi::OsSAUR51-transformed ‘Dontokoi’ showed enhanced bacterial blight resistance as compared to untransformed ‘Dontokoi’. Auxin accumulation after the bacterial blight inoculation of XC20 was comparatively higher than that of ‘Nipponbare’, but the auxin levels of OsSAUR51-transformed XC20 were lower than those of untransformed XC20. Auxin accumulation after bacterial blight infection in the RexPhi::OsSAUR51-transformed ‘Dontokoi’ plants was repressed as compared to untransformed ‘Dontokoi’. These results suggest that the OsSAUR51 gene induces a field resistance mechanism and represses auxin accumulation after bacterial blight pathogen infection.

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Agricultural Environment
  • Motoo KOITABASHI, Yuka SAMESHIMA–YAMASHITA, Takashi WATANABE, Yukiko S ...
    2016 Volume 50 Issue 3 Pages 229-234
    Published: July 01, 2016
    Released on J-STAGE: August 01, 2016
    JOURNAL FREE ACCESS

    The rate at which biodegradable plastic (BP) mulch films decompose in agricultural fields depends on environmental conditions. If degradation of used mulch film is insufficient for plowing-down, they impede agricultural work and get entangled in farm equipment. We developed a new technique to accelerate the degradation of BP mulch films in agricultural fields by applying an enzyme from a Paraphoma-like phylloplane fungus (strain B47-9). Spray treatment of the enzyme solution alone significantly accelerated film degradation, and the additional application of a moisture-retaining agent, carboxymethyl cellulose sodium salt (CMC), further accelerated decomposition. Commercially available BP mulch films started to break down one day after treatment with the enzyme solution and CMC. Within seven days of treatment, small tears in the film turned into long cracks, covering 6.2% of the total film area.

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  • Teruhiko ISHIKAWA, Taro HARADA, Fumio AKAHORI, Yasumasa SAKURAI
    2016 Volume 50 Issue 3 Pages 235-240
    Published: July 01, 2016
    Released on J-STAGE: August 01, 2016
    JOURNAL FREE ACCESS

    Following the accident at the Fukushima Daiichi Nuclear Power Plant, agricultural fields in Fukushima Prefecture were subject to severe radioactive contamination. Given the fact that radiocesium is readily transferred along the food chain and potentially poses a radiation risk to humans, effective methods of lowering the transfer of radioactivity from soil to crops are needed. We examined the effect of neutralized schwertmannite (NS) produced in the disused Yanahara mine as a new agricultural material for reducing radiocesium uptake by crops. The application of NS to soil at 1% or 5% showed inhibitory effects on radiocesium accumulation in the harvests of four upland crops (sweet potato, radish, turnip, and Chinese cabbage) and rice. Substantial amounts of radiocesium were detected in brown rice and hulls following cultivation in soil with recommended levels of exchangeable potassium (> 200 mg kg−1). Decreased levels of radiocesium were observed in both tissues following the application of 5% NS, suggesting additional effects of NS application in potassium-rich soil. Our results indicated the efficacy of NS application and suggest its practical use in minimizing the radioactivity in crops cultivated in radiocesium-contaminated soil.

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Agricultural Engineering
  • Katsushi SHIRAHATA, Shuhei YOSHIMOTO, Takeo TSUCHIHARA, Satoshi ISHIDA
    2016 Volume 50 Issue 3 Pages 241-252
    Published: July 01, 2016
    Released on J-STAGE: August 01, 2016
    JOURNAL FREE ACCESS

    This paper discusses digital low-pass filters for application to tidally fluctuated groundwater observation data. Three types of filters that are commonly used, mainly for oceanography, and newly produced filters are comparatively evaluated with a focus on their ability to eliminate major diurnal and semidiurnal tidal components. All the digital filters presented are the nonrecursive type that can easily be used with spreadsheet software. Newly produced low-pass filters are excellent tide-killer filters with a length of 241 hours applicable to hourly sampled time-series data. The new filters suppress eight major diurnal and semidiurnal tides to practically negligible magnitudes (10–8 order input), with longer-period components (longer than two days) being nearly completely preserved. High-pass filters transformed from these new tide-killer low-pass filters can separate the components of semidiurnal to diurnal tidal periods from other longer-period components, keeping approximately the same magnitude as in the input data for eight major tides. Therefore, the use of the new high-pass filters prior to quantitative analysis of major tidal components in groundwater observation data should effectively improve the accuracy of analysis.

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Agricultural Economics
  • Qianqian MAO, Wenlue WANG, Shunji ONIKI, Masaru KAGATSUME, Jin YU
    2016 Volume 50 Issue 3 Pages 253-265
    Published: July 01, 2016
    Released on J-STAGE: August 01, 2016
    JOURNAL FREE ACCESS

    This study elicits the risk preferences of rural households through a field experiment conducted in Shaanxi Province using the Holt-Laury mechanism that considers the effects of implementing the Sloping Land Conversion Program (SLCP) on the risk preferences of farmers. The program has significantly changed the structure of farmers’ productive property, which may further influence their risk attitudes. This study reveals that household geographic and demographic characteristics have a significant effect on the risk preferences of participants in the experiment. More importantly, the SLCP has had a significant effect on farmers’ risk preferences. Hence, when assessing the outcome of such public policies as the SLCP that may affect the future incomes of farmers, we should consider the socioeconomic characteristics of the households concerned and the public policies implemented in the targeted area in detail.

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  • – Simulation for eight ASEAN countries –
    Tatsuji KOIZUMI, Hideki KANAMARU
    2016 Volume 50 Issue 3 Pages 267-284
    Published: July 01, 2016
    Released on J-STAGE: August 01, 2016
    JOURNAL FREE ACCESS

    The role of agricultural investment growth in alleviating climate risks to rice production systems and rice markets was examined using a partial equilibrium model. The Rice Economy Climate Change (RECC) model covers the rice markets in 15 countries and regions. The rice yield in each economy is estimated from minimum and maximum temperatures, precipitation, and agricultural investments. The rice area harvested is estimated from rice and wheat producer prices and precipitation. We examine how future agricultural investments will affect the world rice market. The volatility of international rice prices in the baseline is expected to increase during 2010/12 to 2030 with climate change. However, a constant increase in agricultural investments in eight ASEAN countries will contribute to reducing international rice price volatility. In particular, investments in Thailand and Vietnam are most important for stabilizing international rice prices under future climate change conditions.

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Horiticulture
  • Jincai LI, Yasuyo NISHIMURA, Xiheng ZHAO, Yasufumi FUKUMOTO
    2016 Volume 50 Issue 3 Pages 285-292
    Published: July 01, 2016
    Released on J-STAGE: August 01, 2016
    JOURNAL FREE ACCESS

    To gain a physiological understanding of applying nitrogen to cucumbers (Cucumis sativus L.), three treatment plots of ‘Jinchun No. 5’ seedlings were prepared for three levels of nitrogen application using low (L, 0.0 g·kg−1), medium (M, 0.4 g·kg−1), and high (H, 0.8 g·kg−1) amounts of urea. The specified amount of urea was applied to the dry culture medium of each texting group at three time points: before planting, then at 27 and 43 days after sowing. The following indicators of active oxygen species and senescence were observed in L: soluble protein was low and malondialdehyde (MDA) high in the cotyledons on the 18th day after sowing, and active oxygen species superoxide anion (O2˙¯) and MDA were high, while soluble protein and chlorophyll were low in the 2nd and 3rd leaves on the 42nd and 52nd days. Therefore, no nitrogen application in L resulted in active oxygen generation and membrane lipid peroxidation, as well as accelerated senescence in the cucumber ‘Jinchun No. 5’ seedlings. In contrast, in H, soluble protein was high in the cotyledons on the 18th day after sowing, O2˙¯, hydrogen peroxide (H2O2), and MDA were high on the 42nd, 52nd, and 62nd days, respectively, and soluble protein and chlorophyll were high on the 52nd and 62nd days. These results indicate that an excessive application of nitrogen resulted in active oxygen generation and membrane lipid peroxidation, but also delayed senescence at the same time. The photosynthetic properties and growth of the transpiration rate (E), net photosynthesis rate (Pn), plant height, number of leaves, and shoot fresh weight decreased in L, indicating that active oxygen species, senescence, and E were associated with decreased photosynthesis and growth in the cucumber ‘Jinchun No. 5’ seedlings due to a lack of nitrogen application. Conversely, in H, a decrease in stomatal conductance (gs), E on the 42nd day, followed by an increase on the 62nd day, suggests that in the leaf mid-growth phase of the seedlings, active oxygen species and E were associated with decreased photosynthesis due to excess nitrogen application. However, delayed senescence was associated with maintaining gs, E, and Pn in the late growth phase of the leaves. Moreover, plant height, the number of leaves, and shoot fresh weight showed decreases on the 42nd, 52nd, and 62nd days, respectively, showing the adverse effects of excess nitrogen application on the growth of cucumber ‘Jinchun No. 5’ seedlings.

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