RICE RATOONING - IRRI books - International Rice Research Institute

Ratooning in Bangladesh:prospects and potentialsM. M. Hossain and A. K. M. FarooqBangladesh Rice Research Institute, Joydebpur, Gazipur, BangladeshABSTRACTAgroecological conditions in Bangladesh are divided into three distinct rice croppingseasons, with cropping patterns to fit particular agroclimatic regions. Rainfed andirrigated rice-based cropping systems have developed where monthly total rainfall isfavorable and in locations with assured irrigation. Crop intensification by ratooncultivation is one way to secure more food production in Bangladesh, but its prospectsare restricted by unfavorable weather during the boro season. However, prospects forratoon cultivation during aus, after the boro harvest, as well as during transplantedaman after aus harvest might be feasible. High-yielding, good-ratooning boro and ausvarieties are needed. Pajam II and IR50 produced good numbers of ratoons and yielded1.1-2.4 t/ha after boro and aus. Traditional deepwater rice areas are converting toirrigated boro followed by fallow, late-seeded, or transplanted deepwater rice. Ifdeepwater rice varieties with good ratooning ability could be developed, with thecapability of producing high yields for boro cultivation followed by ratooning,deepwater rice areas presently fallow could be brought into production.The cultivable land in densely populated tropical Asia is already being farmed. Infact, the agricultural land area is gradually decreasing as land is diverted tononagricultural uses. At the same time, rapid population growth is increasingday-to-day food demands. To meet these increasing demands, food production willhave to increase by intensifying land use and by increasing yields.Rice ratooning saves time and production costs and could increaseproductivity where irrigation facilities are limited or when a fallow period existsbetween crops.In recent years, farmers in many countries have begun rice ratooning. Thepractice can be successful if soil moisture is available for at least a month after themain crop harvest (7). Ratoon growth will vary with internal and external conditions(4): food reserves in the stubble, number and vigor of resting buds, number andcondition of rice plant roots, mineral nutrient status in the field, and watermanagement. External conditions, such as agroclimatic factors, also affect riceratooning capacity.CLIMATE OF BANGLADESHBangladesh is situated between latitude 20.50°N and 26.20°N and longitude 88.50°Eand 92.50°E. The significant variation in temperature, humidity, rainfall, and solar