Document Type : Research Paper


1 MSc student of Weed Science, Sari Agricultural Sciences and Natural Resources University.

2 Department of Agronomy, Sari Agricultural Science and Natural University

3 Research Assistant Professor, Department of Seed Improvement, Rice Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran.

4 Research Assistant Professor, Department of Agronomy, Faculty of Crop Sciences, Sari Agricultural Sciences and Natural Resources University, Sari, Iran.


In order to investigate the effect of different weed control managements on emergence characteristics and morphological growth of rice seedlings in seedling stage in direct seeding system, an experiment was conducted in 2020 growing season. The experiment was performed as a factorial in a randomized complete block design with three replications. Factors included Shiroudi, Khazar and Hashemi cultivars as well as various weed control managements. Coating the seeds with calcium chloride, potassium chloride and weeding were able to reduce the dry weight of grasses, respectively 54.60, 68.02 and 84.68% in Shiroudi cultivar, 78.53, 62.94 and 53.53% in Khazar cultivar and also 29.67, 57.86% and 34.71% in Hashemi cultivar compared to the control. The highest percentage of germination with 99.33, 97.67 and 94.67% was obtained under the seed coatings with potassium chloride, calcium chloride and weeding in Shiroudi cultivar, respectively. The highest germination rate was observed in potassium and calcium chloride seed coating treatments and weeding. The lowest density of broadleaf weeds with 0.91 plants m-2 was obtained in Shiroudi cultivar and by managing the seeds coating of this cultivar with calcium chloride. The highest seedling length and weight vigor indices were obtained with 3559 and 1362.62 in Shiroudi cultivar under weeding management, respectively. The results showed that seed coating improves the seed yield of rice cultivars.