شهرام نظری

The social responsibility of the executive trustees of municipal sports organizations plays an important role in the growth and development of the society. In order to promote sports culture, they should have plans to involve the local community in sports activities and promote a healthy lifestyle and educational and research activities. The purpose of this study was to investigate the analysis of the dimensions of social responsibility of executive Officials of sports organizations based on ISO 26000.

The research method was descriptive survey, the statistical population was all managers and experts of sports organizations in Tehran municipality. Based on Cochran's limited population size formula, 221 people were selected as a sample using random cluster sampling. The research tools were the demographic characteristics form and the ISO 26000 questionnaire by Niknam Shiri (2010). Descriptive statistics and structural equation modeling were used to analyze the data.

The results showed that the general situation of social responsibility is at an unfavorable level. Also, organizational social responsibility in terms of environment, human rights, organizational governance, work style, fair practice, consumer and community participation, and development are at an undesirable level.

Since the status of all the social responsibility components of Tehran Municipal Sports Organization is at an unfavorable level, it is suggested to address the components (organizational governance, human rights, working methods, environment, fair methods, consumer issues and community development), a unit should be established in each municipal sports organization and follow up on matters related to the organization's social responsibility.

Knowledge of educational content is important to help students to implement motor skills and instructors to help students. The purpose of this study was to examine the effect of educational content knowledge on the performance of fourth graders in table tennis forehand and selective attention. 

For this study, 40 students with an average age of 10.73 and a standard deviation of 1.12 were randomly selected and divided into two groups of experimental and control groups (N=20). The experimental group received instruction on table tennis forehand skills from a teacher for 6 sessions lasting 90 minutes each. The teacher then participated in a six-hour workshop and taught the same skills to the control group. The test included accuracy in table tennis forehand performance and the Stroop test.

The results indicated that the effect of the test and test*group was significant for both variables. While there was no initial difference between the groups in the pre-test, the post-test and retention results showed that the experimental group outperformed in both variables compared to the control group.

These findings suggest that content knowledge workshops can enhance the performance of learners. Therefore, implementing such workshops in sports and physical education can be beneficial.

Competitive advantage is the distinguishing factor that positions an organization or company ahead of its competitors. It encompasses superior product or service features, cost-effectiveness, organizational culture, and innovative technologies. Companies must prioritize continuous improvement and innovation to sustain and enhance their competitive edge. This study scrutinizes the indicators of the Islamic Republic of Iran Skating Federation's competitive advantage, employing the Importance-Performance Analysis framework. It also explores its implications for business, employment, and entrepreneurship within the skating industry.

This research adopts an applied purpose and a descriptive method. The statistical population includes experts in the field of skating. Given the expert-centric approach used to analyze importance and performance, 73 individuals within the skating sports community were selected as samples. Criteria such as extensive experience in skating sports and appropriate education were considered in the selection process.

According to the findings, four variables were placed in the first quarter. After prioritization and weighting, the priority is attracting sponsors, the second priority is the development of facilities and infrastructure, the third priority is customer orientation, and the fourth priority is the development of international relations in the country they were determined.

Originality: 

This research pioneers an exploration of the skating federation's competitive advantage, offering valuable insights into its current state and implications for the broader business landscape, employment opportunities, and entrepreneurial endeavors within the skating industry. The findings can inform strategic planning and international goal-setting initiatives, providing a novel perspective on the skating federation's competitive positioning and multifaceted impact.

The present study was carried out to investigate the attitudes towards virtual learning and its relationship with job motivation and self-efficacy among physical education teachers in Ahvaz during the COVID-19 pandemic. The research method was correlational, and the statistical population consisted of all physical education teachers in districts one to four of Ahvaz during the 2020-2021 academic year. From this population, a sample of 244 teachers was selected using convenient sampling. They were assessed using the Virtual Learning Attitude Questionnaire (Vatanparast et al., 2016), Teachers' Sense of Efficacy Scale (Tschannen-Moran & Woolfolk Hoy, 2001), and the Job Motivation Questionnaire (Lodahl & Kejner, 1965). The data were analyzed using Pearson correlation coefficient and path analysis with SPSS version 22 and AMOS version 20. The results showed that the mean scores for attitudes towards virtual learning, job motivation, and self-efficacy among physical education teachers in Ahvaz were at the expected level. There was a positive and significant relationship between attitudes towards virtual learning and the components of job motivation and self-efficacy. However, there was no significant relationship between attitudes towards virtual learning and the self-confidence component of physical education teachers in Ahvaz. Path analysis results also indicated that the research model had a good fit. The findings of the study demonstrated that positive attitudes towards virtual learning increase job motivation and self-efficacy among physical education teachers in Ahvaz.

To develop a model for the expansion of schools’ sport programs, the views of a group of 17 experts on the subject were sought through extensive and semi-structured interviews. The analyses of these data lead to the identification of three main themes: factors affecting schools’ sport programs, strategies for the expansion of such programs, and the consequences of such expansions. In the light of the discovered themes, a questionnaire with an adequate validity and reliability, was constructed and then given to a group of 387 experts and physical education teachers in Tehran. The data collected through the questionnaire were used to construct a structural model wherein all the components were of adequate goodness of fit. It can be concluded that the expansion of sport programs in schools requires a multilateral and systemic look in order to utilize the appropriate strategies for the expansion of sports programs, given the expected outcomes.

: Foodborne pathogens (including bacteria, viruses, and parasites) are a major public health concern worldwide. One of the substances that has a high antimicrobial effect is egg white.

The aim of the present study is to the examine antibacterial effects of egg whites of some birds on gram-negative and gram-positive bacteria in vitro.

In this study, by using the micro-broth dilution and zone of inhibition method were tested the antibacterial effects of egg white of some birds on gram-negative and gram-positive bacteria. Minimum inhibitory concentration (MIC) minimum bactericidal concentration (MBC) and zone of inhibition against gram-negative and gram-positive bacteria were examined according to clinical and laboratory standards Institute (CLSI).

The MIC of natural and turkey egg whites were in the dilutions of %50 - 6.25 and artificial eggs and goose were in the dilutions of %50 - 25 for the studied bacteria. Also, the MBC of the white of natural, artificial, turkey, and goose egg whites was obtained in the dilution of %50 for some of the studied bacteria. The zone of inhibition was found in the range of 18 - 8 mm for the studied bacteria.

: The results of the present study show that goose, turkey, natural, and artificial chicken egg whites are effective in the removal of gram-negative and positive bacteria. Meanwhile, natural egg whites had a greater antibacterial effect than other whites on the studied bacteria.

One of the most important public health concerns worldwide is foodborne pathogens (bacteria, viruses, parasites). Egg white is one of the substances with high antimicrobial properties. The purpose of the present research is to determine the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of egg whites of quail, duck, natural broiler chicken, and country chicken on a number of gram-negative and gram-positive bacteria in vitro

In this study, using the micro-broth dilution and disc diffusion method were tested the antibacterial effects of egg whites of quail, duck, natural broiler chicken, and country chicken  on a number of Gram-negative and Gram positive bacteria. In this experiment, Shigella dysentery, Bacillus subtilis, Klebsiella oxytoca, Staphylococcus aureus, Salmonella typhimurium, Escherichia coli, and Pseudomonas aeruginosa were exposed to different concentrations of egg white, and MIC, MBC, and the zone of growth inhibition  were determined according to the instructions of the Clinical and Laboratory Standards Institute (CLSI).

The MIC of country chicken and quail egg whites were in the range of 6.25-50% and broiled chicken and duck egg whites were in the range of 25-50% for the studied bacteria. Moreover, the MBC the egg white of broiled and country chicken, quail, and duck was in the range of 50% for some of the studied bacteria. The zone of inhibition was found to be in a range of 9-14 mm for the studied bacteria.

The results of the present research show that egg whites of quail, duck, broiled chicken, and country chicken are effective in eradicating Gram-negative and Gram-positive bacteria.

Yarrow is a member of the Asteraceae family, utilized extensively in the field of medical sciences. Among the medicinal plants, one may encounter few specimens like the aforementioned plant, which enjoys widespread distribution across various regions of the globe and boasts a diverse array of uses that contribute to its renown. The aim of the present study was the synthesis of Yarrow extract evaluation of its antibacterial effects on a group of intestinal bacteria and comparing its antibacterial properties with phenol.

In this experimental study, Yarrow plant extract was extracted with the hydroalcoholic method. The aerial parts of Achillea ageratum plant with herbarium number 1753 were prepared from the slopes of Ardabil mountains and after determining the identity, the extract of this plant was extracted by hydroalcoholic method. In this method, after preparing the plant and drying the aerial parts of the plant, 10 g of it was crushed in a sterile mortar, then it was poured into an Erlenmeyer flask, and 50 mL of 100% ethanol was added to it. After 24 hours of mixing in a magnetic stirrer using a Buchner funnel with Whatman filter paper and a vacuum pump, the remaining components of the plant were separated. Then, a certain amount of distilled water (20 ml) was added to the desired solution and placed again in the magnetic stirrer whose temperature was set at 80 degrees Celsius, so that the alcohol was completely removed from the reactor. The Antibacterial effect of yarrow extract was performed by disc diffusion method and micro broth dilution on standard species of Enterobacteriaceae families including the standard bacterial strains of Klebsiella pneumoniae (ATCC:10031), Escherichia coli (ATCC:23591), Shigella dysentery (ATCC:25922) and Enterobacter aerogenes (ATCC:13048). All experiments were performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines.

In the present study, the growth rate of bacteria decreased by increasing the concentration of yarrow extract. The MIC of Yarrow plant extract for Klebsiella pneumonia and Enterobacter aerogenes was obtained in %6.25 and for Shigella dysentery and Escherichia coli was obtained in %12.5 and %25, respectively. Also, the MBC of extract for Shigella dysentery, Klebsiella pneumonia, and Enterobacter aerogenes bacteria was obtained in 25%, and for Escherichia coli it was obtained in 50%. The results of MIC and MBC show that the most sensitive bacteria to yarrow extract among the studied bacteria is Enterobacter aerogenes and the most resistant is Escherichia coli. The diameter of the inhibition zone for Shigella dysentery, Escherichia coli, Klebsiella pneumoniae, and Enterobacter aerogenes bacteria was obtained at 19, 18, 20, and 23 mm, respectively. In this experiment, Enterobacter aerogenes bacteria were the most sensitive and Escherichia coli was the most resistant among the investigated bacteria. Comparative investigation of the antibacterial properties of yarrow extract with phenol, showed that yarrow extract had a lower killing effect than phenol at 5, 10, and 15-minute contact time. In this test, the most resistant bacteria are Shigella dysentery and the most sensitive bacteria are Escherichia coli and Enterobacter aerogenes. The reason that the type of resistant and sensitive bacteria was slightly different in the method of comparing the antibacterial effect of yarrow extract with phenol with the results of MIC, MBC, and non-growth halo diameter is related to the reduction of contact time of the extract with bacteria.

The results of the present research show that the hydroalcoholic extract of the yarrow plant is very effective in the removal of gram-negative intestinal bacteria. Also, the hydroalcoholic extract of the yarrow plant is more effective in removing gram-negative bacteria than phenol

The aim of this study is to identify the key factors contributing to the excellence of the National Table Tennis Federation at an international level and to provide practical implementation solutions. The research design employed a mixed-methods approach (qualitative and quantitative) utilizing a mixed-exploratory strategy. The qualitative phase involved the participation of 15 sports management professionals, professors, knowledgeable managers, and experts, while the quantitative phase involved 12 participants from the previous phase, selected using purposeful and criteria-based sampling methods. The qualitative data were analyzed using the thematic analysis method, while the analytical hierarchical process (AHP) was used to analyze the quantitative data. The study identified five main concepts that influence the excellence of the federation, namely relations and organizational support, human resource factors, contextual factors, organizational factors, and sports factors. In addition, the study identified three main strategies that were effective in promoting excellence: organizational strategies, structural strategies, and sports-technical strategies. Based on the findings, the key factors contributing to the success of the National Table Tennis Federation were identified as sports factors, organizational relations and support, organizational structure, human resource factors, and contextual factors. To achieve excellence at the international level, it is recommended that the table tennis federation implement organizational, structural, and technical strategies in a continuous and integrated manner.

The increase in the resistance of fungal species and the high side effects of antifungal drugs have led researchers to study and find new treatment methods against fungi. This study evaluated the anti-candidacy effects of local and artificial egg whites and compared them with amphotericin B.

This study was conducted experimentally in May 2023 in the Microbiology Laboratory of Khalkhal Faculty of Medical Sciences. This research tested the antifungal effects of local and machine chicken egg whites and amphotericin B using the micro broth dilution and zone of inhibition method. In this experiment, Candida albicans species were placed in the vicinity of different concentrations of substances, and the minimum inhibitory concentration (MIC) and minimum fungicide concentration (MFC) of these substances on C. albicans were determined according to the guidelines of the Clinical and Laboratory Standards Institute.This study has been registered with the ethical code IR. IR.KHALUMS.REC.1401.019 in the Ethics Committee of Khalkhal Faculty of Medical Sciences.

Based on the results of the tests, the MIC of local and machine chicken egg whites on C. albicans was 25%, and their MFC was 50%.  However, in these concentrations, no growth was observed in the presence of amphotericin B. Moreover, the MIC and MFC values of 25 µl of amphotericin B with 75 µl of local and machine egg whites were 3.125% and 6.25%, respectively. The zone of inhibition for C. albicans in the vicinity of local and machine chicken egg white and amphotericin B was 12, 11, and 16 mm, respectively.

Local and machine chicken egg whites have antifungal properties against C. albicans.

The purpose of this study was to investigate the relationship between perceived autonomy support, sport motivation and the level of physical activity among male junior high school students in Tehran with the mediating role of autonomy motivation and fear of failure. This descriptive-correlational study is in the category of applied research. The statistical population of the study was comprised of all male seventh graders in Tehran (N=142554). The sample included 384 students which was selected based on random cluster sampling method. The research instruments comprised Autonomy Motivation Questionnaire (Hagger et al., 2007), Black and Deci Autonomy Support Perception Questionnaire (2000), Sport Motivation Scale (Pelletier et al., 2013), Conroy et al.'s Inventory of Fear of Failure (2002), and Measurement of Habitual Physical Activity Questionnaire (Baecke et al., 1982). Structural equation modeling was utilized to analyze the data. Results revealed that teachers’ autonomy support had a direct, positive effect on sport motivation and students’ amount of physical activity. Autonomy motivation and fear of failure play a mediating role in the link between teachers’ autonomy support, sport motivation, and the amount of physical activity. Therefore, physical education teachers can use autonomous supportive behaviors to motivate students to make decisions and thus reduce students' fear of failure and increase students' sport motivation to engage in physical activities.

Today, sports organizations have recognized the significance of their brand concerning their products and services. This study investigated the association between integrated marketing communications and brand prestige in the national olympic committee of Iran.

 The research utilized a descriptive-correlational approach, employing structural equation modeling as the research method. The participants comprised all the 140 managers and specialists affiliated with the national olympic committee. Questionnaires on integrated marketing communication from Lee and Park (2007) and brand prestige questionnaires from Beak et al. (2010) were employed to collect data. SPSS26 and AMOS24 software were used to analyze data.

 The findings showed a significant positive relationship between integrated marketing communications and its influence on brand prestige. The path analysis results indicated that the effectiveness of individual communication in delivering a consistent message and creating a favorable impression, as well as strengthening communication with recent customers, had a considerable positive impact on the brand prestige of the national olympic committee. The coefficient of dimensions showed 33.6% of the total variance in brand prestige changes. The structural equation model results further indicated that integrated marketing communications had a significant positive effect on the brand prestige of the national olympic committee.

Sports organizations must employ diverse and innovative communication methods to nurture customer relationships in today's evolving landscape. A well-designed marketing communication program should assist organizations in achieving this objective by reinforcing customer engagement through practical communication activities.

The aim of this study was to investigate the effect of personality traits on organizational apathy with the mediating role of organizational silence (Case study: physical education teachers). The population included all physical education teachers in 19 districts of Tehran (1600 people). Due to the limited research community, based on the Cochran's formula, 351 teachers were randomly selected as a sample. In this study, questionnaires of personality (Gosling et al., 2003), organizational silence (Vacola and Borados, 2005) and organizational apathy (Danaee Fard et al., 2010) were used. In order to analyze the data, descriptive and inferential statistical methods were used. Based on the results, personality traits have a significant negative effect on organizational apathy (Sig = 0.001, t = 8-520); Personality traits have a significant negative effect on organizational silence (Sig = 0.001, t = -2.679); Organizational silence has a significant positive effect on organizational apathy (Sig = 0.001, t = 2.507). It was also found that personality traits through the mediating variable of organizational silence have a significant effect on organizational apathy of physical education teachers. As it turned out, the personality factor determines the degree of organizational apathy and organizational silence of physical education teachers, so it is recommended to use personality tests when hiring teachers to maximize the fit of personality and jobs.

Pomegranate is a plant with an ancient history that has been widely used in medical sciences and its components have many properties. The aim of the present research is to synthesize pomegranate peel extract and investigate its antibacterial effects on a group of bacteria of intestinal bacteria and compare its antibacterial properties with phenol.

In this experimental study, pomegranate peel extract was extracted with the hydro alcoholic method. The Antibacterial effect of pomegranate peel extract was performed via disc diffusion and micro broth dilution methods on standard species of intestinal bacteria. All experiments were performed according to the guidelines of Clinical and Laboratory Standards Institute (CLSI). This study has been registered with the ethical code IR.KHALUMS.REC.1402.006 in the Ethics Committee of Khalkhal Faculty of Medical Sciences.

The MIC of pomegranate peel extract for Shigella dysentery, Escherichia coli, Klebsiella pneumoniae and Enterobacter aerogenes bacteria were 12.5%, 12.5%, 25% and 6.25%, respectively. Also, the MBC of pomegranate peel extract for Shigella dysentery, Escherichia coli, Klebsiella pneumonia and Enterobacter aerogenes bacteria were obtained 25%. The zone of inhibition for Shigella dysentery, Escherichia coli, Klebsiella pneumoniae and Enterobacter aerogenes bacteria was 18, 19, 16 and 22, respectively.

The results of this study has been showed that the hydroalcoholic extract of the pomegranate peel is very effective in the removal of intestinal bacteria in vitro. Also extract than phenol in lower contact time cause killing these bacteria.

This study aimed to evaluate the carcinogenic and non-carcinogenic health risks of heavy metals in seven types of tobacco widely consumed in the east of the country through inhalation exposure.

This descriptive-analytical study was conducted from April 2022 to October 2022 in the city of Bojnord, Iran on sook of seven popular tobacco brands. Metal concentrations in sook of tobacco were determined using inductively coupled plasma-optical emission spectroscopy. In order to analyze the data and ensure the accuracy of the results, the amount of metals in the samples was repeated three times, and their average was analyzed. Monte Carlo software was used to assess possible risks.

The results of this study showed heavy metal concentrations in sook tobaccos were, respectively, Fe>Zn>Mn>Ba>Pb>Ni>Cu>Mo>Cr>As>Cd. The concentration of heavy metals such as arsenic, cadmium and molybdenum in Alrah brand tobacco was higher than other types of tobacco. So that the amounts of heavy metals including arsenic, cadmium and molybdenum for this brand were 14.2±0.05, 10.4±0.06 and 11.6±0.04 micrograms per gram, respectively. The hazard index (HI) values for different types of tobacco, including Al-Rah, Amordadsub, Al-Fakher, Al-Rubi, Mazaya, traditional flavorless, and Nakhle, were 2.64, 2.41, 2.05, 1.7, 1.49, 1.46, and 1.44, respectively. The lifetime cancer risk (ILCR) for Amordadsub, Al-Rah, Nakhla, Mazaya, Al-Rubi, Al-Fakher, and traditional flavorless tobaccos was 2.8×10-3, 2.43×10-3, 1.72×10-3, 1.58×10-3, 1.43×10-3, 9.58×10-4, and 8.08×10-4, respectively. Lead in Alrah tobacco sook had the highest non-carcinogenic risk value with a value of 1.59.

According to the obtained results, Alrah tobacco sook has a higher cancer and non-cancer risk than regular tobacco and can cause non-carcinogenic and carcinogenic risks for consumers. Thus, it is necessary to regularly monitor the quality of prevalent tobacco to reduce delete human health risks.

To determine the extent to which learning agility mediates the effect of psychological empowerment on personal development, a sample of 325 physical education teachers from among 1500 in Tehran was randomly selected and given three questionnaires to measure their learning agility (Gravett & Caldwell, 2016), personal development (Dachner, 2013), and psychological empowerment (Hatami & Dastar, 2012). Data analysis revealed that psychological empowerment affects teachers’ personal development, both directly (0.36), and indirectly through learning agility (0.21). Teachers with high empowerment and agility scores showed greater inclination towards learning new subjects that help them with their personal growth. Such individuals are curious and constantly in pursuit of personal development and improvement. It is recommended that responsible authorities pay attention to these findings and provide the necessary conditions for improving the learning agility of physical education teachers.

The purpose of this research was to investigate the relationship between decision-making styles and social power of consumers of table tennis sports brands (comparison of domestic and foreign brands). The research method was applied from the point of view of purpose and correlational in terms of data collection, which was carried out in the field. In order to collect data, consumer decision-making styles questionnaires from Sproles and Kendall questionnaire (1986) and consumer social power questionnaire from Brill (1992) were used. The statistical population was all male and female buyers of table tennis sports products. The research sample was 382 customers. which were selected by available sampling method. In order to analyze the data, descriptive and inferential statistics (SPSS software version 25 and AMOS version 24) were used. The results showed that fashionable, hedonistic and loyal decision-making styles had a significant negative effect on the social power of consumers and based on the coefficient of determination, 43.9 percent of the variance The total amount of changes in consumers' social power is related to hedonistic, loyal, and fashion-oriented styles. Also, the results of the ANOVA test showed that brand-oriented, hedonistic, price-oriented, careless, and confused decision-making styles are different in men and women. There was a significant difference between the social power of male and female sports consumers. Therefore, it is suggested that domestic sports brand managers should increase quality, appropriate pricing, recognize the needs of sports consumers, interact and coordinate more with their sellers, expand online sales, and produce their sports products in line with global standards of sports products and with extensive advertising. and inclusive of creating awareness about your brand in the mind of the consumer can create more sales and reduce the regret of the purchase.

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.

 Rice (Oryza sativa L.) is one of the world’s most important food crops. Currently, more than one third of the human population relies on rice for their daily sustenance. Rice is predominantly grown by transplanting seedlings into puddled (conventional wet-tillage) soil and kept flooded for most part of the growing season. The puddled soil ensures good crop establishment, weed control with standing water, and reduces deep-percolation losses. However, the conventional method of rice crop establishment requires a large amount of water, labour, and energy, which are gradually becoming scarce and more expensive. Thus, reducing the profitability and sustainability of puddled transplanted rice. Dry direct seeded rice has shown promise under several ecologies and production systems to overcome these challenges, and is considered as potential alternative to puddled transplanted rice. Weed infestation in direct-seeded rice fields remains the single largest constraint limiting their productivity. An effective early weed management tactic is imperative for any direct-seeded rice production technology aiming at achieving higher productivity and profitability.

 In order to investigate the effect of different weed managements on yield and yield components of rice in the direct crop system, an experiment was conducted in 2020 on farms located in Babolsar (Behnamir). The experiment was performed as a factorial based on randomized complete block design with three replications. Experimental factors include rice cultivars (Shiroudi, Khazar and Hashemi) as well as other treatments including weed control by increasing the competitiveness of rice seeds by coating and weed management at five levels including coating the seeds with CaCl2 and KCl, weeding, chemical control (Council active) and control  (no weeding).

 Weed management by coating rice seeds with calcium chloride, potassium chloride, chemical control and weeding was reduced 26, 26, 23 and 63% dry weight of broadleaf weeds and 14, 27, 9 and 36% dry weight of narrow leaf weeds, respectively, compared to control treatment. The maximum emergence percentage in Shiroudi cultivar with 99, 97 and 95% was obtained under weeding, coating the seeds with CaCl2 and KCl treatment, respectively. Also, the highest emergence rate was observed under the management of weeding and coating of potassium and calcium chloride seeds. Seed coating with CaCl2 and KCl substantially improved the stand establishment under drought and well-watered conditions owing to early completion of pre-germination metabolic activities during priming. In general, the results of mean comparison showed that weed management improved rice height compared to the control treatment. The results of this study attributed the increase in height to the effect of pretreatment on increasing the rate of emergence and better establishment of seedlings due to better plant use of related resources. The results showed that the maximum number of seeds per panicles with 137 were obtained in Khazar cultivar. The highest number of seeds per panicles with 127, 124 and 122 seeds was under weeding management and coating with CaCl2 and KCl, respectively. The results of cultivar effect showed that the maximum 1000-seed weight with 23.83 g was observed in Shiroudi cultivar. Also, 1000-seed weight in Khazar and Hashemi cultivars were 22.1 and 21.09 g, respectively. The reason for the increase in the number of 1000-seed weight in Shiroudi cultivar can be attributed to the genetic potential and physiological quality of this cultivar. Also, the results of weed management effect showed that coating rice seeds with calcium chloride and potassium chloride, chemical control and weeding increased 14, 26, 4 and 33% of grain yield and 4, 14, 2 and 18% of biological yield compared to control treatment, respectively. Improved yield by seed coating in direct seeded rice might be the result of enhanced dry matter partitioning toward the panicles that resulted in improved kernel yield.

 According to the results of this study, seed coating treatments with CaCl2 and KCl in rice cultivars can increase rice yield by improving seedling characteristics. Therefore, farmers can be advised to use a simple and inexpensive crop management method to pretreated seeds with CaCl2 and KCl.