Genotype, Planting Density and Seasonal Effects on Phenological Stages of Safflower (Carthumustinctorious L) in Sebele, Botswana

Field experiments were carried out in Botswana University of Agriculture and Natural Resources in Botswana (59o 24S, 95o 25E and 993 m above sea level) during winter and summer to evaluate the effect of genotype, plant density and growing season on phenological stages of safflower. The treatments were five safflower genotypes (Kiama, Gila-Pi 537 692, Sina-Pi 537 598, Pi 537 636 and Pi 527 710) and six plant densities (62, 500, 83, 333, 100, 000, 125, 000, 166, 666 and 200, 000 plants/ha). Increasing plant density resulted with decreased days to rossette, elongation, branching, flowering and physiological maturity even though there were inconsistencies at some planting densities. Safflower genotypes took 135-147 and 100-116 days after sowing (DAS) to reach maturity in winter and summer, respectively. This means, winter grown safflower took long days to reach physiological maturity compared to summer grown crops across all genotypes resulting with genotypes Gila and Sina as early and late maturing respectively, across seasons.