Effects of safflower (Carthamus tinctorius L.) genotypes on growth, development, yield and yield components, and oil content and yield

Abstract

Safflower (CarthamustinctoriusL.) 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 May to October 2015 and January to April 2016 in a completely randomized block design 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 significantly (P < 0.05) differed 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% in winter, respectively, depending on genotype. In summer the seed yield ranged from 1421 to 2140 kg/ha. The safflower genotype PI537598-SINA-USA out performed all the other safflower genotypes including the local genotype Kiama Composite. This research showed that safflower has a big potential as an oilseed crop in semiarid Botswana.