Effect of cultivars and harvest dates on rice seeds vigore

A laboratory experiment was carried out according to a completely randomized design with four repetitions on the seeds resulting from a field experiment applied for the two seasons, 2020 and 2021, to find out the effect of the cultivars (Ambar 33, Yasamin, Dijlah, Ambar Al-Baraka and Furat 1) and the harvest dates (at physiological maturity and after 7 and 14, 21 and 28 days of physiological maturity) on the vigour of rice seeds. The results showed the superiority of the seeds of the cultivar Anbar Al-Baraka at first and final counting, dry weight of the seedling, seedling vigor index and electrical conductivity, and the superiority of the seeds of Dijla cultivar at accelerated aging test and cold test without significant difference with the Anbar Al-Baraka cultivar in both seasons. The harvest date exceeded 14 days after physiological maturity at all studied traits in both seasons. Anbar Al-Baraka at the harvest 14 days after physiological maturity was superior at most studied traits. It can be concluded that the seeds of the cultivar Amber Al-Baraka showed the best performance at seed vigor, primarily harvested after 14 days of physiological maturity. Keywords: accelerating aging, cold test, Oryza sativa, first count, seedling vigour, physiological maturity