Oil and seed yields affected by sowing dates and irrigation regimes applied in growth phenological stages of safflower

Abstract

Research establishing optimal sowing dates and irrigation can help to alleviate the adverse effects of drought on safflower (Carthamus tinctorius L.). The main objective of this study was to assess the effects of sowing date and irrigation quantity on safflower traits. Irrigation treatments were applied based on crop evapotranspiration (ET c ) at the vegetative, flowering, and capitulum development stages. Evapotranspiration increased as the number of irrigations increased. Morphological, yield and oil traits, and water use efficiency (WUE) were significantly higher in the early than in late sowing. Grain yield varied from 440 to 1,460 kg ha −1 in early and from 340 to 1,240 kg ha −1 in late sowing dates. Oil yield of early sown safflower varied between 188.56 and 338.84 kg ha −1 and between 24.4 and 308.82 kg ha −1 in late sowing.The oil yield of one supplemental irrigation in the vegetative stage (I1V treatment) was significantly lower than in treatments with two (I2VF, vegetative and flowering stages) and three supplemental irrigations (I3VFG, vegetative, flowering, and capitulum development stages) in early sowing. In late sowing, the oil yield of I2VF was higher than other irrigation treatments. The range of saving irrigation water in I1 treatments was from 57.0 to 83.0% in early sowing but with a corresponding 30.0 to 66.0% reduction in grain yield compared with full irrigation treatment. For most of the tested traits, irrigation in the vegetative and especially flowering stages improved safflower yield and WUE, and thus can be an alternative irrigation strategy for water conservation in dry regions.

Physiological Indices for the Selection of Drought-Tolerant Safflower Genotypes for Cultivation in Marginal Areas

“…As a result, the lower carbon uptake led to a lower seed yield in oilseed rape genotypes. The results of a study on safflower under water deficit stress at different growth stages showed that water supply at the flowering and capitulum development stages improved the water use efficiency and seed yield of safflower [35]. Pradawet et al [36] studied maize crops under normal and dry stress conditions and found a significant correlation between the plant water stress index and stomatal conductance (R 2 = 0.90).…”

Effect of Water Deficit on Safflower Cultivation at Different Phenological Stages

“…The number of capitula showed significant differences among the analyzed treatments, with the treatment that received irrigation only during its reproductive stage having the highest mean (5.00) compared to the others (Table 5). Baseri et al (2022), in their work on safflower with different sowing times and irrigation regimes applied during phenological growth stages, also demonstrated better results for the number of capitula in treatments with supplementary irrigation during the reproductive stage.…”

Effect of Sowing Dates on Seed Yield, Yield Traits and Oil Content of Safflower in Northwest Turkey

“…Kumar Barla et al (2020) reported that there was no significant difference between combination of sowing dates and safflower cultivar for number of seeds per head. Gholami Baseri et al (2022) emphasized that late sowing can reduce the number of seeds per head in safflower.…”