Evaluation of safflower genotypes under the semi-arid conditions in Botswana

Safflower (Carthamus tinctorius L.) is a multipurpose oil seed crop that is drought, heat, cold and saline tolerant, but minor and neglected despite its many uses. However, recently there is renewed interest in safflower due to its drought tolerance and the suitability of its oil for nutritional or industrial purposes. Under semi-arid conditions of Botswana, farmers have difficulty in increasing crop productivity and diversity in crop rotations due to unfavourable conditions imposed by high and cold temperatures, inadequate rainfall and very high evapotranspiration rate and saline soils in some parts of the country. In such conditions, safflower appears a promising alternative crop. Therefore, the objective of this study was to evaluate the adaptability of safflower genotypes to the semi-arid conditions of Botswana. Nine safflower genotypes were evaluated during the rainy seasons of September to December 2014 and January to April 2015 in a randomized complete block design (RCBD) with three replications in the Botswana University of Agriculture and Natural Resources, Notwane Farm under sandy loam soils. The results of the study showed that safflower genotypes differed significantly (p < 0.05) in agro-morphological traits, growth habit, maturity date, seed yield and yield components, oil content and oil yield. The seed yield, oil yield and oil content significantly (p< 0.05) varied between 888-3113 kg/ha, 226-1313 kg/ha and 26-42%, respectively, depending on genotype. The safflower genotype PI537598-SINA-USA out performed all the other safflower genotypes including the local cultivar Kiama Composite. This research showed that safflower has a big potential as an oilseed crop in semi-arid Botswana.