the Symposium on Wheats for More Tropical Environments - cimmyt

257Wheat Production Constraintsand Management in BangladeshM. GuIer, Wheat Program, CIMMYT, Joydebpur, Dhaka, BangladeshAbstractThe average temperature is quite similar in all of<strong>the</strong> wheat-growing areas ofBangladesh. The amount and distribution of <strong>the</strong> monsoon rains and <strong>the</strong>differences in soil texture and elevation affect <strong>the</strong> flood situation. which in turnaffects <strong>the</strong> selection ofcropping systems by <strong>the</strong>farmers; <strong>the</strong> cropping systemhas a great effect on wheat yields. The main management problems of wheatfarmers are <strong>the</strong>jitting ofwheat into <strong>the</strong> system, land preparation. time ofseeding andfertilization.A study of <strong>the</strong> climatic conditions of <strong>the</strong>different wheat-growing areas ofBangladesh would reveal no greatdifferences in average dailytemperature, but significant differencesin <strong>the</strong> amount of average annualrainfall and its distribution. Table 1shows total annual rainfall and that of<strong>the</strong> wheat-growing season.Although <strong>the</strong> annual rainfall is veryhigh in all locations, ranging fromabout 1600 mm in <strong>the</strong> west to 2300mm in <strong>the</strong> east. only a small portion ofthis amount falls during <strong>the</strong> wheatseason. However, <strong>the</strong> amount and <strong>the</strong>distribution of rainfall in <strong>the</strong> monsoonseason in different locations affects <strong>the</strong>time of planting and harvesting of <strong>the</strong>preceding rice crop; this. in turn, affects<strong>the</strong> seeding time of wheat.Ano<strong>the</strong>r important ecological factor forwheat growth is soil texture. InBangladesh, wheat is grown in almostall soils except <strong>the</strong> very heavy-texturedsoils. Textural differences in soils causedifferences in soil moisture, which inturn affects <strong>the</strong> timing and intensity oftillage operations. as well as <strong>the</strong> wheatyield level.Ten percent of <strong>the</strong> wheat-growing areaof Bangladesh is classified as upland.with rice being grown without wetlandpreparation or transplanting and withcomplete dependence on rainfall formoisture (2). In <strong>the</strong>se areas. <strong>the</strong>favorable wheat-seeding date rangesbetween mid-November and earlyDecember; because of <strong>the</strong> croppingsystem chosen by <strong>the</strong> farmers, whichTable 1. Rainfall in six locations, BangladeshLocationAverage rainfall (mm)Annual Wheat season(Nov-March)Dinajpur (northwest)Bogra (west)Ishurdi (west)Jessore (southwest)Jamalpur (north)Comilla (east)Source: Manalo (1)177817561585165222412298537675104115151