Optimal sowing time and seeding rate for winter-sown, rain-fed chickpea in a cool, semi-arid Mediterranean area

摘要

Chickpea (Cicer arietinum) is one of the 3 most important legume crops in West Asia and North Africa. Winter sowing of chickpea has been advocated recently in the region, but detailed research on date and rate of sowing has not been conducted. The objectives of this study were to find the optimal sowing month and to test the hypothesis that a lower than normal seeding rate is needed for winter-sown chickpea. Two series of field experiments were conducted under rain-fed conditions at the Agricultural Research and Educational Center in the Bekaa Valley of Lebanon. In the sowing-date experiment, which was conducted over 3 years, seed was sown in November, December or January and February. The seeding-rate by sowing-date experiment, which was conducted over 2 years, consisted of 3 seeding rates: 25, 40 and 55 seeds/m2, and 2 sowing dates: one each in November and March. Sowing in December or January gave similar seed yield as November sowing, and both gave higher yield than sowing in February. Sowing in December or January should be preferable than sowing in November because it is expected to give adequate time for weed control and less chance of ascochyta blight infestation. Seeding rates had no significant effects on yield, and seeding-rate by sowing-date interaction was non-significant, indicating that there is no yield advantage of a reduced seeding rate with winter sowing. However, sowing at 25 seeds/m2 yielded bigger seeds, which usually fetch higher prices. In conclusion, chickpea farmers in the semi-arid areas of the high-elevation Bekaa Valley of Lebanon or in other areas with similar environments should shift their sowing date from early spring to December or January and sow at a lower (25 seeds/m2) than normal seeding rate.