Rice - Rice

Japanese: イネ(稲) - イネ

The most important annual grass crop in Japan. It is the second largest producer in the world after wheat. It has been cultivated since ancient times, and it is said that it was already cultivated in India, China, and other places several thousand years before Christ. There are two types of cultivated rice: Asian rice and African rice. African rice is cultivated only in a very limited area of West Africa, in the Niger River basin, so when we say rice, we are mostly referring to Asian rice. Here, we will simply call Asian rice rice rice. [Origin] More than 20 wild species of the Oryza genus grow in the tropical regions of India and Southeast Asia. There are two theories about the origin of modern rice: the single origin theory, which says that it originated from one wild species, and the multiple origin theory, which says that cultivated rice was developed through hybridization of two or more species. At present, the most likely theory is that rice cultivation originated in the tropical to subtropical regions of Southeast Asia. From there, it was introduced to East Asia, West Asia, the Mediterranean coast, and the New World in the 17th century. It was introduced to Japan in Kitakyushu around the 1st century BCE. It gradually moved eastward after that. [Classification and varieties] There are many varieties of rice, and they are broadly divided into two types: Indica rice, which is called foreign rice in Japan and has large, thin, and easily crumbled grains, and Japonica rice, which is round, difficult to crumble, and sticky. There are non-glutinous and glutinous varieties of each. There is paddy rice, which is mainly grown in paddy fields, and upland rice, which is mainly grown in fields, but botanically they are the same. There are also early-maturing varieties (wase) and late-maturing varieties (okute). Currently in Japan, paddy rice, Japonica non-glutinous rice, accounts for almost all of the total harvest. Since the Meiji period, many varieties have been created through breeding, and the cultivation limit has rapidly moved north, making it possible to cultivate it in Hokkaido. It is believed that there have been a total of 2,000 varieties in Japan since ancient times, but in recent years, the number of varieties cultivated has tended to decrease. [Growth and cultivation] Rice cultivation is called rice cultivation, and it is carried out between 50° north and 35° south latitude, with Southeast Asia being the main production area. Direct sowing cultivation, where seeds are sown directly in the paddy field, is widely practiced in the United States and other countries because it can be mechanized throughout the process, but is rare in Japan, except for upland rice. In traditional Japanese hand-planting cultivation, seeds are generally sown in the spring seedbed, and transplanted about 40 days later. Prior to transplanting, the paddy field is plowed, basal fertilizer is applied, and the field is plowed. Traditionally, inter-row weeding was performed several times after transplanting, but due to advances in herbicides and doubts about the effectiveness of inter-row weeding, it is rarely performed today. Rice stalks split into many at the base and produce tillers. About 30 days after transplanting, the growth point at the tip of the stalk differentiates, young panicles are formed, and about 30 days later the ears emerge. Nitrogen fertilizer such as ammonium sulfate is applied as top dressing about 25 days before ears emerge. The ears produce around 100 small flowers. They have six stamens, one pistil, and a feathery stigma that splits into two. When heading, the flowers bloom in the morning and self-pollinate. The seeds are fully ripe 30 to 40 days after flowering. [Diseases and pests] Most rice diseases are caused by fungal infestations. There are several dozen known types, including blast (rice fever), wilt disease, and sclerotinia rot, but the one that causes the most damage nationwide is rice blast. To prevent these diseases, it is necessary to select varieties with strong resistance, properly control them with pesticides, and eradicate vector insects such as planthoppers. There are more than 120 known types of rice pests, including the rice stem borer, rice leaf miner, rice stink bug, and rice cutworm, as well as the rice leaf beetle, rice leaf miner, rice stink bug, and rice fall armyworm, which are particularly damaging. All of these can be eradicated with the appropriate insecticides. →Rice→Related itemsRice genome analysis research｜Early maturing

Source : Heibonsha Encyclopedia About MyPedia Information

Japanese:

日本では最も重要なイネ科の一年生作物。世界的にもコムギに次ぐ生産量がある。古くから栽培され，紀元前数千年には，すでにインド，中国等で栽培が行われていたという。栽培イネには，アジアイネとアフリカイネがある。アフリカイネは西アフリカ，ニジェール川流域のごく限られた地域にしか栽培されていないため，イネといった場合，アジアイネを指すことがほとんどである。ここでもアジアイネを単にイネと呼ぶことにする。〔起源〕　インド〜東南アジアの熱帯地方には20数種のイネ属の野生種が自生する。現在のイネの起源については，１種の野生種より生じたとする単元説と，２種以上の交雑を経て栽培イネになったとする多元説がある。イネ栽培の発祥地は現在のところ，東南アジアの熱帯〜亜熱帯説が最も有力。そこから東アジア，西アジア，地中海沿岸，17世紀に新大陸へ伝わった。日本へは前１世紀ごろ北九州に渡来。以後次第に東進。〔分類と品種〕　イネの品種は非常に多く，日本で外米といわれ，米粒が大型で細長く砕けやすいインド型（インディカ米）と，丸く砕けにくくて粘りのある日本型（ジャポニカ米）に大別され，おのおのに粳(うるち)ともち（糯）がある。おもに水田に栽培される水稲とおもに畑に栽培される陸稲とがあるが，植物学的には同一。また早生品種（わせ）と晩生品種（おくて）がある。現在日本では，水稲日本型うるち米が全収穫量のほとんどを占めている。明治以後，品種改良により多くの品種が作られ，栽培限界が急速に北進し，北海道での栽培が可能になった。日本での品種は，古来から総計すれば2000に達するとみられるが，近年では，栽培される品種が少数化する傾向にある。〔生育と栽培〕　イネの栽培を稲作といい，北緯50°〜南緯35°で行われ，東南アジアが主産地。直接本田に種子をまく直まき栽培は，一貫した機械化が可能で米国などでは広く行われているが，日本では陸稲を除けば，まれである。日本の伝統的な水稲手植栽培においては，一般に春苗代(なわしろ)に種子をまき，約40日後に田植をする。田植に先立ち本田を耕起し元肥を施し，代掻(しろか)きを行う。なお従来は田植後数回，中耕除草が行われたが，除草剤の進歩と中耕の効果が疑問視されたため，今日ではほとんど行われない。イネの茎は基部で多数に分かれ，分げつを生じる。田植後約30日で茎の先端の生長点が分化し，幼穂ができ，さらに約30日後に出穂する。出穂前25日くらいに硫安などの窒素肥料を追肥する。穂には100個内外の小花がつく。おしべ６本，めしべ１本，柱頭は羽毛状で二つに分かれる。出穂にあたっては，午前中に開花，自家受粉する。種子は開花後30〜40日で完熟。〔病虫害〕　イネの病気の大部分は糸状菌の寄生による。いもち（稲熱）病，萎縮病，菌核病など数十種が知られているが，特に全国的に被害の大きいのは，いもち病である。これらの病気に対しては，抵抗性の強い品種の選択，農薬による適切な防除，ウンカ類などの媒介昆虫の駆除が必要。イネの害虫は，特に被害の大きいニカメイチュウ，サンカメイチュウ，ウンカ類のほか，イネドロオイムシ，イネハモグリバエ，イネカメムシ，イネヨトウなど120種以上が知られている。いずれも適当な殺虫剤により駆除が可能。→米
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