生物と気象
Online ISSN : 2185-7954
Print ISSN : 1346-5368
ISSN-L : 2185-7954
最新号
選択された号の論文の4件中1~4を表示しています
研究論文
  • 小南 靖弘, 井上 聡, 山口 高志
    2023 年 23 巻 p. 1-8
    発行日: 2023/01/10
    公開日: 2023/01/10
    ジャーナル フリー
     In order to estimate the field moisture in early spring in Hokkaido, in response to global environmental changes, a simplified snow cover model that calculates daily snow water content from daily mean temperature and daily precipitation was developed and applied to the future climate projection dataset on The Agro-Meteorological Grid Square Data, NARO. The last day of the long-term snow cover period is not significantly different from the present climate at many locations in the RCP 2.6 scenario throughout the 21st century, but the RCP 8.5 scenario shows a significant advance in the latter half of the 21st century. The RCP 8.5 scenario projection for liquid water, which is a combination of snowmelt and rainfall, shows an increase in February and March and a decrease in April from the middle to the latter half of the 21st century. Especially for February, the snow cover is dry almost all over Hokkaido under the current climate, but the western coast is projected to become a wet snow area by the end of the 21st century. The snowmelt intensity at the end of the snowmelt season tends to increase compared to the present climate until the middle of the 21st century, suggesting an increased risk of snowmelt floods and other hazards.
  • 舛谷 悠祐, 熊谷 悦史, 屋比久 貴之, 安江 紘幸, 大久保 さゆり, 田中 洋貴, 伊禮 凪沙, 安次 富厚, 大野 豪, 藤岡 智明 ...
    2023 年 23 巻 p. 51-60
    発行日: 2023/07/10
    公開日: 2023/07/10
    ジャーナル フリー

     The demand for ready-made meals is growing rapidly. Low-amylose rice is preferred for its stickiness and softness after cooking and cooling. In addition, processors demand a stable amylose content for reliable production. However, existing low-amylose cultivars have variable amylose contents and low yields. A Waxy allele, Wx-mq, which confers a stable low amylose content, has been used in low-amylose cultivars such as ‘Kiraho’, from which ‘Iwate 144’ and ‘Iwate 147’, with improved yield performance, have been developed. To identify suitable growing regions, we developed an equation using Ridge regression to predict amylose content from alleles at the Wx locus and weather conditions during the grain filling stage. The equation can predict amylose content with RMSE = 1.1 % and R2 = 0.992 of lines with both Wx-b (middle-amylose) and Wx-mq (low-amylose) alleles. The equation was combined with a rice development model and applied to the Tohoku region of northeastern Japan. Using 30-year-average amylose content and stability, the equation identified northern Iwate Prefecture and northeastern Aomori Prefecture as suitable for growing the variety. Simulations conducted for later-maturing low-amylose cultivars currently under development suggested that these cultivars would have a higher amylose content than ‘Iwate 144’ and ‘Iwate 147’. Thus, cultivars with a wide range of maturities will contribute to increased production through the expansion of suitable locations. We conclude that selecting the appropriate maturity group according to climate is important to meeting the requirements for stable amylose content and high yield of low-amylose cultivars, and will contribute to large-scale planting of new low-amylose cultivars with reliable amylose content.

  • -山梨県中山間地での露地栽培事例-
    伊藤 治, 今村 有希, 堀内 正郎, 窪田 今朝富, 深沢 政彦, 中澤 恒夫, 中沢 誠二, 小林 実, 荻原 ...
    2023 年 23 巻 p. 90-98
    発行日: 2023年
    公開日: 2023/10/10
    ジャーナル フリー

     The green papaya (Carica papaya L.) is now being cultivated from Okinawa to Kanto regions in Japan. Because of its low susceptibility to damages by birds and animals, it has started to be cultivated in hilly suburban areas where abandoned farmlands are increasing. In order to evaluate possibility of adaptation of green papaya into these areas of Japan, field experiments were conducted for 3 years from 2017 at an upland field on the slope facing Kofu basin. As growth indicators for papaya, plant height, stem diameter, leaf number and number of buds, flowers and fruits were measured. As meteorological parameters, average daily temperature, daily solar radiation and daily rainfall were used to consider with the growth indicators. The growth indicators were fitted into logistic function to convert them into daily basis. The daily changes of each growth indicator showed high multiple correlations with cumulative changes of the three meteorological parameters. Fruit weight harvested from a plant in 2017 also showed statistically significant multiple correlation with four growth indicators. The fruit yields for 22 years from 1998 were estimated from those multiple regression equations and meteorological data of each year. The predicted yields fell into a range from 1.4 to 12.0 kg plant-1 with an average of 8.2 kg plant-1 and coefficient of variation of 0.39. In the mountainous regions within the Kofu Basin, one of Japanʼs hottest areas, it was anticipated that situations such as low yields or complete crop failure, similar to what was observed in 2018, would occur at a frequency of about once every five years. This is suggested to be related to the inhibition of pollen germination due to high temperatures during the flowering period. When introducing green papaya cultivation in these mountainous areas, it is essential to acknowledge the associated risks and explore technical solutions to address them.

短報
  • 井上 聡, 小南 靖弘
    2023 年 23 巻 p. 29-34
    発行日: 2023年
    公開日: 2023/04/10
    [早期公開] 公開日: 2023/02/28
    ジャーナル フリー
     With its cold climate, Hokkaido grows early- to middle-maturing cultivars of apple. ‘Fuji’, a late-maturing cultivar, is the most popular apple in Japan, but it is not grown in Hokkaido. Warming due to climate change could make Hokkaido suitable for growing ‘Fuji’. We estimated the lower temperature limit for ‘Fuji’ from annual and seasonal (April to October) mean temperatures collected as mesh data in apple orchards in Hirosaki city from 1982 to 1991. The coastal region of western Hokkaido is predicted to become suitable for ‘Fuji’ by about 2050 under the MIROC5 RCP8.5 and RCP2.6 scenarios, and the inland of Hokkaido is predicted to become suitable under RCP8.5. It will be necessary to select appropriate apple cultivars for each cropping region in Hokkaido on the basis of anticipated future Greenhouse Gas emission trends or climate conditions.
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