SEEDING-DATE EFFECTS ON YIELD, QUALITY AND MATURITY OF SAFFLOWER

Experiments were conducted for 4 yr at Lethbridge and Brooks, Alberta, and at Morden, Manitoba, to determine the effect of seeding date, cultivar (Saffire, S-208 and Cargill-3) and location on safflower (Carthamus tinctorius L.) yield, oil content, test weight and maturity; and the effect of accumulated degree-days (DD) on yield, oil content and test weight. The early-maturing cultivar, Saffire, produced the least variable yields across seeding dates. For locations and years where fall frosts did not occur before maturity, Cargill-3 produced good yields, even with late seeding; S-208 yielded less in similar situations; however, S-208 generally outyielded Saffire. Highest yields were obtained at Brooks by seeding in late April, at Lethbridge, by seeding in late April or early May. However, at both Alberta locations, Saffire could usually be seeded to mid-May without major yield reduction. At Morden, seeding during the third week of May provided optimum yields. Seeding date had little influence on oil content. Later seeding dates tended to reduce days to maturity and test weight. Safflower matured 3 wk earlier at Morden (earliest site) than at Lethbridge (latest site), with maturity at Brooks averaging 4-8 days earlier than at Lethbridge. Plants required more DD to reach maturity at Morden than at either Alberta location. DD was positively associated with yield of S-208 at both Lethbridge and Morden; for Saffire, only at Lethbridge; and for Cargill-3, only at Morden. DD generally did not significantly affect oil or test weight.