the Symposium on Wheats for More Tropical Environments - cimmyt

Nigeria is high temperature. South oflatitude looN. between November andFebruary. maximum temperatures areconsistently above 32.5°C andminimum temperatures are mostlyabove 15°C. These temperaturesreduce <strong>the</strong> length of <strong>the</strong> growing seasonand yield potentials.InputsThe inputs necessary for wheatproduction are also lacking or in shortsupply in most instances.Fertilizers-Shortages of adequatesupplies of fertilizer dUring <strong>the</strong> plantingperiod has posed a problem to wheatfarmers. Unfortunately. <strong>the</strong> plantingtime of <strong>the</strong> crop coincides with <strong>the</strong>period when all of <strong>the</strong> importedfertilizers have been exhausted onrainfed crops. Thus. lack of initialsupplies of required nutrients reducesvigor and. subsequently. yield.Labor-The planting season for wheatin Nigeria overlaps <strong>the</strong> period whenlate-harvested. rainfed crops (sorghum.cowpea and cotton) are harvested.Since most operations (except landpreparation) are carried out manually,labor shortages tend to pose someproblems. as labor is needed forharvesting <strong>the</strong> rainfed crops. delaying<strong>the</strong> planting of wheat. Late-plantedwheat is known to yield up to 25% lessthan timely sown crops.Machinery-Most of <strong>the</strong> major landpreparation operations (except plantingand fertilizer application) are carriedout by machines from <strong>the</strong> governmentorganizedtractor hiring units (THU).After harvesting <strong>the</strong> rainfed crops.farmers await <strong>the</strong>ir turn to get <strong>the</strong>irland prepared for wheat. But, forseveral reasons. such as insufficientnumbers of tractors. inadequate spareparts and lack of operators. <strong>the</strong> farmers'fields are more often than not preparedlate. Also. during <strong>the</strong> harvesting of <strong>the</strong>crop. a lot of wheat is lost throughdamage by early rains owing to aninadequate number of threshers.Water managementDuring <strong>the</strong> wheat-growing season. <strong>the</strong>reis practically no rainfall to support <strong>the</strong>crop. An average of about 6 mm ofwater per day is lost throughevapotransporation during <strong>the</strong> cropgrowingseason. This warrants <strong>the</strong> needfor regular irrigation. At present.irrigation is scheduled on <strong>the</strong> basis oftime interval (5 to 10 days). dependingon soil type.This approach has not beensatisfactory. especially when bordercheck and basin methods of irrigationare employed; it results in excessivewater loss. Since water is a scarceresource. irrigation has to be scheduledto maximize wheat production per unitof water applied. An improvement inirrigation management is reqUired if <strong>the</strong>country is to achieve its target of700.000 tons of wheat per annum by1990.Fertilizer useMost of <strong>the</strong> work conducted on fertilizeruse in relation to wheat crops in Nigeriahas been confined to <strong>the</strong> three majornutrients. nitrogen. phosphorus andpotassium, and <strong>the</strong>ir optimum rate.timing and method of application. Theneed for balanced fertilization foroptimum wheat production on <strong>the</strong>savanna soils cannot be underestimated.No information is yetavailable on micronutrients. With <strong>the</strong>passage of time. a deficiency of <strong>the</strong>senutrients may arise. <strong>the</strong>reby limiting<strong>the</strong> production of <strong>the</strong> crop. especiallyunder intensive cultivation.Research PrioritiesThe federal government of Nigeria ispresently committed to increasingwheat production locally. It has.<strong>the</strong>refore. been encouragingcoordinated research projects between<strong>the</strong> Institl,lte for Agricultural Research.Samaru and <strong>the</strong> various River Basin