EFFECTS OF PLANT POPULATION AND SEASON ON GROWTH AND DEVELOPMENT OF SAFFLOWER (CARTHAMUS TINCTORIUS L.) AS AN ORNAMENTAL PLANT

Safflower (Carthamus tinctorius L.) is a multipurpose oilseed crop grown mainly for animal feed, uses as horticultural crop (vegetables, cut flowers and medicinal), oil crop, paint and textile industry and food industry. It is one of humanity’s oldest crops, but its cultivation worldwide has remained limited, and as a result it has remained an underutilized and neglected crop. Two field trials were done to evaluate the effects of plant density on the growth and development of safflower. The results showed that plant density and season of growth had significant (P≤0.01) effects on growth and development of safflower. Increasing safflower plant density from 100,000 to 250,000 plants ha^-1 significantly reduced plant height, branch number/plant, leaf number/plant, leaf area, plant spread, root length, plant biomass, flower size and flower number/plant. The reduction in vegetative growth and yield components of safflower due to increased plant density was attributed to inter and intra-plant competition for light, nutrients and water necessary for growth and development. The differences between winter and summer grown safflower was attributed to difference in day and night temperature (DIF) and the average daily temperature, which were optimum for safflower growth in winter. It was concluded that under Botswana conditions or in semi-arid areas, safflower grown for cut-flower production should be planted at 50 × 20 cm or wider in order to maximize cut stems and allow the plants to express their maximum genetic potential.