Some Growth Parameters and Yield of Four Sesame Varieties as Affected by Melatonin

Abstract

A field experiment was carried out at Albu Aytha Research Station of College of Agriculture - University of Anbar during the summer season of (2021) in order to study the effect of spraying four concentrations of melatonin (0,10,20 and30) mg L-1 on some growth characteristics and yield of four varieties of sesame crop, (Rafidain, Sumer, Wadaa, Had). The experiment was applied on the basis of randomized complete block design (RCBD) according to the arrangement of the split plots and with three replications, the main plots included melatonin concentrations, while the sub plots included sesame varieties. The results of the statistical analysis showed that there were significant differences in all the studied traits as a result of being affected by the study factors. 1- Wadaa variety was superior in most of the studied traits, including leaf area duration, dry matter duration, crop growth rate, total chlorophyll content, dry weight, number of capsules per plant, number of seeds per capsule, seed yield and biological yield with averages of (34902 cm2 day-1, 2840.3 g month-1, 0.597 mg cm-2 day-1, 4.444 mg g-1 fresh weight, 165.60 g, 171.50 capsule plant-1, 71.67 seed capsule-1, 2.352 ton h-1 and 12.524 ton h-1) respectively, while Had variety was superior in characteristics of specific leaf weight, number of branches, leaf area, with an average of (3.67 mg cm-2, 3.69 branch plant -1 and 16377.7 cm 2 plant-1) respectively, Rafidain variety was superior in plant height with an average of 151.06 cm, Sumer was superior in 1000-seed weight trait with an average of 3.596 seeds. 2- Spraying with a concentration of 30 mg L-1 of melatonin led to a significant increase in leaf area duration and net assimilation rate (33829 cm2 day-1 and 2.988 mg cm-2 day-1) and the plants sprayed with the same concentration excelled with the highest the average number of capsules per plant, number of seeds per capsule, and weight of 1000 seeds, seed yield and biological yield ( 189.83 capsule plant-1, 72.75 seed capsule-1 and 3.779 g) respectively, which was reflected in seed yield (2.795 ton h-1 ). 3- The interaction between the two factors of the study was significantly affected in all the studied traits except for the number of days from planting until the beginning of flowering and the number of seeds per capsule.