a1 International Centre for Agricultural Research in Dry Areas, Box 5466, Aleppo, Syria
In the Mediterranean region, chickpeas are traditionally spring-sown since humid winter conditions encourage the development of Aschochyta blight which often causes complete crop failure. Lines resistant to this blight have been selected at the International Centre for Agricultural Research in Dry Areas (ICARDA) and thus winter planting has become feasible. The best selection, ILC 482, was sown in both winter and spring at three locations in northern Syria with contrasting precipitation patterns. Crop growth and soil moisture analyses were undertaken on all treatments, and relevant meteorological data were collected at each location. At all locations maximum greenarea and dry-matter production of the winter-sown crop was nearly double that of the spring sowing. Large differences were also observed between sites, with green-area and dry-matter production decreasing with precipitation. Depth of profile recharge, amount of extractable moisture and crop evapotranspiration also decreased with precipitation, but only small differences in these moisture variables were observed between winter and spring sowing. Duration of green-area production, as determined by the onset of rapid leaf senescence, was closely related to the fraction of extractable moisture in the soil profile, rapid senescence occurring in all treatments when extractable moisture fell below 40% of its maximum value. Differences in the maximum rates of green-area production are discussed both in relation to the depth of profile recharge, hence the depth of rooting and moisture extraction and to the ambient evaporative demand. The differences observed in green-area and dry-matter production was clearly reflected in final seed yield. The components of yield, number of pods, percentage of empty pods and seed size are related to the variations in moisture stress experienced by the crop.
(Received December 03 1982)