the Symposium on Wheats for More Tropical Environments - cimmyt

255Alternative locations-An evaluation ofmore suitable areas, those with lessacid soils, is being undertaken forgrowing rainfed wheat in Zambia.Twenty sites from Magoye in <strong>the</strong> southand Mbala and Nakonde in <strong>the</strong> northhave been planted at two seeding datesand with <strong>the</strong> best available varieties.The preliminary results indicatepromising areas near Nakonde andMpika and also between Serenje andMpika. These areas are now being,fur<strong>the</strong>r surveyed to determine <strong>the</strong>extent of <strong>the</strong> potential areas.ConclusionsYields of about 2.5 tlha are nowbeing obtained in rainfed wheat trials inZambia. These have been achieved bycombining <strong>the</strong> use of varieties tolerantto aluminum and resistant to diseaseswith liming (at about 2 tlha on acidsoils) or growing on soils with a pH(CaCI2) of about 5.0, where aluminumtoxicity is very much reduced orabsent. Currently recommendedfertilizer rates are approximately 20 kgNlha (basal), 100 kg Nlha (top dressing).54 kglha phosphorus, 36 kg/hapotassium, 30 kglha sulphur and 0.3kglha boron.AcknowledgementsThe use of data of colleagues of <strong>the</strong>Zambia-Canada Wheat ResearchProject, B. Aulakh, J. Brandle,L. Hodgins, G. Musa and D. Penney. isgreatfully acknowledged. The authoralso thanks J.R. Boyer. M. Hangala,S.K. Hartley, M.M. Mwanamwenge andM. Ngwele for <strong>the</strong>ir technical assistance,as well as Mrs. S. Wateridge for typingand J. Little for preparation of <strong>the</strong>figures.2000••• •Y = -315 x +3152•" i 3Highi4 5Al + + + tolerancei6i7i8LowFigure 4. RelatioDship of wheat yields on limed soil and aluminumtolerancerating of <strong>the</strong> cultlvar. Zambia. 1983-84