Macronutrient accumulation and cytological and morphological response of safflower affected by the foliar application and harvest date

Abstract

The present experiment was conducted to investigate the effect of the foliar application of growth stimulators and harvest date on plant growth and quality attributes of safflower at the Agricultural Research station of Urmia (Iran) during the 2015–2016 and 2016–2017 growing seasons.The experiment was carried out in a factorial randomized complete block design with 10 treatments and four replications. The first factor was the foliar application of (i) nano-Fe 2 mg L−1, (ii) humic acid 2.5 mL L−1, (iii) magnetic water at 2 L m−2, (iv) ascorbic acid 30 mg L−1, and (v) control (distilled water), and the second factor was two harvest dates including of 121 and 136 days after sowing. The highest total unsaturated fatty acid content was obtained from the foliar application of nano-Fe. This treatment also resulted in a 12% increase in the total unsaturated fatty acid. The foliar application of humic acid and nano-Fe significantly promoted the growth of the safflowers via improving photosynthetic characteristics, such as chlorophyll index. The highest total N (3.65 ppm), available P (0.362 ppm), and K (1.32 ppm) contents of the seeds were obtained from the second harvest date. As well, the total unsaturated and saturated fatty acid percentage and harvest index were significantly affected by the second harvest date. Percent of chromosome abnormality was also decreased on the second harvest date.