熱帯における最近の稲作技術

概要

論文の詳細を見る
Since 1950,the trend of paddy yield is increasing in irrigated and rainfed favourable lowland area and this is particularly remarkable after 1970. On the otherhand, no yield increase is noted in upland area as well as lowland with adverse environment. Increased yield in irrigated and rainfed favourable lowland area is mainly due to introduction of high yielding varieties, improved cultural practices and high production input. In irrigated area, the most common method to promote cropping intensity in paddyfield, is rice double cropping. However, paddy yield becomes unstable with an increase in rice double cropping area, due to serious pest infection, irrigation water shortage, lack of appropriate irrigation system and shortage of man power. Therfore, in double cropping area, the stabilization of yield could be attained by the establishment of cropping patterns and introduction improved varieties and appropriate cultural practices. Newly bred varieties are required to be short duration, have high yield potential and resistance to pests, especially to brown planthopper and virus deseases. Short duration varieties are primarily useful in intensified cropping, however this growth duration group has low yield potential. The low yield potential of short duration varieties can be compensated by improving cultural practices particularly narrow spacing and higher rate of basal fertilizer. For saving labour cost, direct seeding is employed. Generally, large part of direct seeding is broadcast wet seeding and dry seeding is observed only in 1st crop season in Muda area in Malaysia. Most serious problems for direct seeding are uneven crop establishment and weed injury. Research for direct seeding is now concentrated on germination of seeds and control of weeds. Direct seeding promotes the early growth and nutrient uptake at the early growth stage and increases the duration of vegetative lag phase, hence short duration varieties are preferable for direct seeding. The damage of brown plant hopper and virus diseases are most serious in double cropping area. It is very difficult to control pest and disease only by insecticides because of very high cost compared with rice price and double cropping and continuous cropping are the preferable conditions for keeping high insect population. The resistant varieties are used for avoidance of these damage, however the risk of possible development of new biotype under continuous cropping is high. It is important to decrease insect population by the removal of rice and potential host plants, and source of virus inoculum by scheduling fallow period. In Malaysia, the control of tungro disease has been successful by using combination of resistant varieties, insectides and systematic staggered cropping method preceded by 2 month fallow period.
日本熱帯農業学会の論文
1990-05-25

熱帯における最近の稲作技術

スポンサーリンク

概要

著者

関連論文

スポンサーリンク