Winter versus spring sowing of rain-fed safflower in a semi-arid, high-elevation Mediterranean environment

An optimal sowing date will lead to increased crop yield, but little research on safflower sowing date has been conducted in West Asia and North Africa. The present study aimed to find the optimal sowing month for rain-fed safflower in a semi-arid, high-elevation Mediterranean site. Field trials were conducted for 4 years (1998-1999 to 2001-2002) at the Agricultural Research and Education Center in the Bekaa Valley of Lebanon. There were five monthly sowing dates from November to March. The trials were in randomised complete block designs using a productive Turkish safflower accession, PI301055. Plants m(-2), days-to-bud initiation, flowering, and maturity, shoot dry matter at bud initiation, flowering, and maturity, plant height, seed yield, and oil percentage in seed were recorded. Safflower oil and seed yield were higher (59-169%) in November, December, and January (fall or early winter) sowings than in the February and March (late winter or early spring) sowings, but yields did not differ significantly between the November, December, and January sowings. There were no significant sowing-date-by-year interaction and year effect on oil and seed yield. December and January sowings gave higher oil percentages than the other months. Averaged over years, each monthly delay in sowing resulted in a decrease in straw yield. These findings showed clearly that Lebanese farmers in the Bekaa Valley should shift the sowing time for safflower from the spring to the winter. Although sowing in November, December or January gave similar seed yield, farmers should sow safflower as soon as possible after preparation of a weed-free field in order to give the maximum straw yield and environment protection. (c) 2006 Elsevier B.V. All rights reserved.