Shahram Nazari; maryam hossieni; Mehrzad Allahgholipour
Abstract
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 has been conducted in the Rice Research Institute of Iran (Rasht) between 2020 and 2021. The experiment is performed as a factorial ...
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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 has been conducted in the Rice Research Institute of Iran (Rasht) between 2020 and 2021. The experiment is performed as a factorial in a randomized complete block design with three replications. Experimental factors include 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) hydro-priming (48 hours) + coating the seeds with calcium chloride, (5) hydro-priming (48 hours) + coating with potassium chloride, (6) hydro-priming (48 hours) + coating with zinc sulfate, and (7) hydro-priming (48 hours as control). The results show that the highest percentage and germination rate has been observed with 99.5% and 0.23 seeds per day under seed priming with potassium chloride in the Gohar cultivar, respectively. The lowest time required to achieve 90% emergence has belonged to Hasehmi and Gohar cultivars through priming with potassium chloride and calcium chloride. The highest root length (with 24.6 cm) has been observed in priming with potassium chloride in the Gohar cultivar. The highest root dry weight in Hashemi and the Gohar cultivars has been 2.14 and 4.9 g, respectively, in priming with potassium chloride. The results also show that the maximum root volume and area are obtained with 43 cm3 and 155.28 cm2 in priming with potassium chloride in Gohar cultivar, respectively. The least time required to achieve maximum tillering, 50% flowering, and physiological maturation takes place in priming treatment with calcium chloride and potassium chloride. Seed priming with potassium chloride and coating with calcium chloride have increased grain yield by 22% and 13%, respectively, compared to the control. The highest biological yield is observed in potassium chloride priming and coating with calcium chloride treatments with 5552 and 5414 kg. ha-1 in Gohar cultivar, respectively. In general, rice seed priming with calcium chloride and potassium chloride promoted plant yield by improving seedling characteristics, root system, and phenological stages.
Shahram Nazari; maryam hossieni; Sajjad Rahimi-Moghaddam; Mohammad Mohammadi
Abstract
In order to determine the phenological differences of some improved rice cultivars in Iran for applying in crop simulation models, an experiment has been conducted in the research farm of the Rice Research Institute of Iran (Rasht) in 2020 as a randomized complete block with three replications. The experimental ...
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In order to determine the phenological differences of some improved rice cultivars in Iran for applying in crop simulation models, an experiment has been conducted in the research farm of the Rice Research Institute of Iran (Rasht) in 2020 as a randomized complete block with three replications. The experimental treatment consist of six rice cultivars (Rash, Anam, Gohar, SA1, SA6 and M7). Results show that the highest development rate can be observed in development rate in juvenile phase and grain filling phase in Anam cultivar. The minimum and maximum time required to start emergence with 3 and 6 days are in Anam and Gohar cultivars, respectively. The maximum time required to achieve maximum flowering and physiological maturity is obtained with 71 and 103 days in Gohar cultivar. The highest flowering period with 19 and 20 days is obtained in late maturing Rash and Gohar cultivars, respectively. The highest growth degree days (GDD) in beginning of grain filling to maturity stage is observed with 401 GDD for M7 cultivar. The highest growth-day for pre-flowering with 1208 GDD belongs to Gohar cultivar. The highest harvest index is obtained with 50.91% in Gohar cultivar. The results also show that the single grain weight under ideal growing conditions with 0.030 g is observed in Gohar and M7 cultivars. The highest plant height belongs to cultivar M7 with 150 cm and the highest total nitrogen uptake is observed in the plant at maturity of Anam cultivar. Overall, the estimated genetic coefficients in different models differ between cultivars and the coefficients vary in the range defined in the model for different groups of maturity. To accurately calculate the genetic coefficients, it is suggested that this experiment should be repeated over several years and in different ecosystems under rice cultivation.
Mehdi Esmaeiltabar; Faezeh Zaefarian; Shahram Nazari; Rahmat Abbasi
Abstract
In order to investigate the effect of different weed control managements on emergence characteristics and morphological growth of rice seedlings in the seedling stage in a direct seeding system, a field experiment has been conducted in the 2020 growing season, Babolsar, Bahnemir, Iran. Being a factorial ...
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In order to investigate the effect of different weed control managements on emergence characteristics and morphological growth of rice seedlings in the seedling stage in a direct seeding system, a field experiment has been conducted in the 2020 growing season, Babolsar, Bahnemir, Iran. Being a factorial in a randomized complete block design with three replications, the experiment employs the following treatments: Shiroudi, Khazar, and Hashemi cultivars as well as various weed control management in five levels of seed coating with calcium chloride, seed coating with potassium chloride, weeding, chemical control, and control. The interaction effect of weed management and cultivar shows that coating the seeds with calcium chloride, potassium chloride, and weeding cuts the dry weight of grasses by 55%, 68%, and 85% in Shiroudi cultivar, by 79%, 63%, and 54% in Khazar cultivar, and 30%, 58%, and 35% in Hashemi cultivar, respectively, compared to the control. The maximum percentage of germination with 99%, 97%, and 95% belong to seed coating with potassium chloride, calcium chloride, and weeding in Shiroudi cultivar, respectively. The highest germination rate could be observed in potassium and calcium chloride seed coating treatments and weeding. The lowest density of broadleaf weeds with 0.91 plants m-2 is obtained in Shiroudi cultivar and by managing the seeds coating of this cultivar with calcium chloride. The highest seedling length and weight vigor indices are obtained with 3559 and 137 in Shiroudi cultivar under weeding management, respectively. Results show that seed coating improves the seed yield of rice cultivars.
Mohammad Khademi; Faezeh Zaefarian; Shahram Nazari; Mohammad Ali Esmaeili
Abstract
To investigate the effect of seed priming on emergence characteristics, root morphological growth, and phenological trends of rice in direct seeding, an experiment has been conducted in Sari Agricultural Sciences and Natural Resources University within 2019. The study is conducted as factorial in a randomized ...
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To investigate the effect of seed priming on emergence characteristics, root morphological growth, and phenological trends of rice in direct seeding, an experiment has been conducted in Sari Agricultural Sciences and Natural Resources University within 2019. The study is conducted as factorial in a randomized complete block design with three replications. The factors include Tarom Hashemi and Shiroudi cultivars and priming at five levels, namely hydropriming (for 48 hours), calcium chloride, and potassium chloride priming (Ψs -1.25 MPa), ascorbate acid (10 mg l-1), and control (no priming). The effect of priming on emergence percentage shows that the highest amount of this trait belongs to 90% in priming with calcium chloride, which is not significantly different from priming with potassium chloride and water. The rate of emergence of priming with calcium chloride, potassium chloride, and water has increased by 50%, 36%, and 29%, respectively. Results show that priming with calcium chloride, potassium chloride, ascorbate acid, and water has increased by 55%, 50%, 33%, and 38% of the plant height and by 48%, 29%, 12%, and 25% of plant dry weight, respectively. In Shiroudi and Tarom Hashemi cultivars, the time required for the onset of tillering has been 27.40 and 24.53 days; panicle appearance, 90.4 and 53.87 days; flowering, 100.53 and 70.87 days; and maturity 132.26 and 94.61 days, respectively. The least time required for panicle appearance and flowering is observed in priming with calcium chloride, although this has not been significantly different from other priming, and decreased by 11.17 and 7.5 days to the control, respectively.