Title: The effect of priming and seed coating on improving morphological characteristics, yield, and yield components of two rice cultivars
Author: shahram Nazari
In order to investigate the effect of seed priming (Pretreatment) and coating on seedling characteristics, root morphology, and phenological stages of rice, a two-year experiment was conducted at the Rice Research Institute of Iran (Rasht) in two years 2020 and 2021. The experiment was performed as a factorial in a randomized complete block design with three replications. Experimental factors included two rice cultivars (Hashemi and Gohar) and the seed pretreatment of rice cultivars in seven levels including 1- Priming with calcium chloride (-1.25 MPa in 24 hours), 2- Priming with potassium chloride (1.25 MPa in 24 hours), 3- Priming with zinc sulfate (concentration of 0.5 mM in 12 hours), 4- Hydropriming (48 hours) + Coating the seeds with calcium chloride, 5- Hydro-priming (48 hours) + Coating With potassium chloride, 6- hydropriming (48 hours) + coating with zinc sulfate and 7- hydropriming (48 hours as control). The results showed that the highest percentage and germination rate was observed with 99.5% and 0.23 seeds per day under seed priming with potassium chloride in the Gohar cultivar, respectively. The least time required of days to achieve 90% emergence was obtained from Hasehmi and Gohar cultivars studied by priming with potassium chloride and calcium chloride. The highest root length of 24.6 cm was observed in priming with potassium chloride in the Gohar cultivar. The highest root dry weight in Hashemi and the Gohar cultivars was 2.14 and 4.9 g plants, respectively, in priming with potassium chloride. The results also showed that the maximum root volume and area were obtained with 43 cm3 and 155.28 cm2 in priming with potassium chloride in the Gohar cultivar, respectively. The least time required to achieve maximum tillering, 50% flowering, and physiological maturation was observed in priming treatment with calcium chloride and potassium chloride. Seed priming with potassium chloride and coating with calcium chloride increased grain yield by 22 and 13%, respectively, compared to the control treatment (3684 kg. ha-1). The highest biological yield was observed in calcium chloride and potassium chloride coating treatments as well as potassium chloride priming with 11738, 11597, and 11504 kg. ha-1 in the Gohar cultivar, respectively, which were statistically treated with potassium chloride and sulfate priming. In general, rice seed priming with calcium chloride and potassium chloride promoted plant yield by improving seedling characteristics, root system, and phenological stages.
Keywords: Calcium chloride, emergence percentage, flowering, potassium chloride, root volume