hasan alizade

Swallow-wort (Cynanchum acutum L.) is a perennial and invasive weed that infested many sugarcane fields in Khuzestan. Field experiment was conducted to find out an efficient method for C. acutum control in sugarcane during 2018 and 2019. The experiment was split-split plots in a randomized complete block design with three replications. Main plots were pre-emergence application of metribuzin, metazachlor + qinmerac, pendimethalin, indaziflam and acetochlor; Sub plots were one time hand hoeing (four weeks after pre-emergence application), two-times hand hoeing (four and eight weeks after pre-emergence application), and without hand hoeing and sub-sub plots were post emergence application of 2,4-D+MCPA, mixture of 2,4-D+MCPA and metribuzin, and bromoxynil + MCPA herbicides. Results showed that individual application of Pendimethalin, and indaziflam herbicides, two-times if hand hoeing, and then post emergence application of 2,4-D+MCPA and metribuzin as a had the highest efficiency with an average of 96% in reducing mass dry weight. The application of mentioned treatments increased cane yield 104.7 and 102.9 t/ha respectively compared to the control (without weeding, with 110 t. ha-1). However, the experimental treatments did not show a significant effect on quality traits of sugarcane.

In the process of globalization, organizations need to be prepared to cope with rapid environmental change, and every organization must adapt to diverse environmental demands and needs, and there is a sense of learner leadership that seeks to improve leadership learning. The purpose of the present study is to study the effect of learner leadership on the willingness to change the attitude of law enforcement personnel considering the mediating role of organizational trust.
The purpose of this study is applied and descriptive - survey in nature and method. The statistical population of the study consisted of 725 law enforcement personnel of Tabriz city. Based on Cochran's relation, 251 persons were selected by random sampling. Content and face validity were used to determine the validity of the data collection tool, and internal consistency (Cronbach's alpha) for reliability, and structural equation modeling was used to analyze the data.
The results of the data analysis showed that the learning leadership variable indirectly and through organizational trust mediator (4.8%) had an impact on the desire variable and z-coefficient (283.3) of the effect of learner leadership on the tendency to change in positive employees, using the significant coefficient z (59/16) and standardized path coefficient (0/669) indicating the impact of learner leadership on organizational trust and with the use of the coefficient of significance z (0/460) and standardized coefficient (0/57) indicates the positive effect of organizational trust on desire for change in employees.
According to the results, the dimensions of learner leadership on the willingness to change the attitude of law enforcement personnel considering the mediating role of organizational trust were positively influenced and finally practical suggestions were made.

To determine the optimum weed management method and plant population density on chickpea yield، a split plot experiment based on RCBD with four replications was carried out at the University of Tehran Research Farm (located in Karaj) during 2010-2011. The Main factor consisted of nine treatments including: 1. Trifluralin pre-plant، 2. Pendimethalin pre-plant، 3. Complete weeding، 4. Imazethapyr post-emergence، 5. Mechanical weeding، 6. Imazethapyr pre-emergence، 7. Pyridate along with mechanical weeding، 8. Pyridate post-emergence، 9. Control (no weeding) and sub factor included of three crop densities of 35، 45 and 55 plants/m2. The predominant weeds were Chenopodium album L.، Amaranthus retroflexus L. and Amaranthus blitoides L. Results revealed that weed management had a significant effect on weed population and dry mass reduction. At the end of the growth period after hand weeding treatment، Pyridate + mechanical control، pre-emergence Imazethapyr and pendimethalin were the most effective treatments based on weed dry mass reduction، but due to weed population decline at this time، after hand weeding treatment، pendimethalin was the most effective and produced the highest chickpea grain yield. Chickpea population densities of 55 and 45 plants/m2 produced the highest grain yield and simultaneously reduced the weed population and dry mass as compared with 35 plants per m2، significantly. Therefore، application of both pendimethalin and use of 45 chickpea plants per m2 were the effective weed control method and produce a higher grain yield at a similar condition to this experiment.

Barnyardgrass has always been considered as the most important weed of rice all over the world. Meanwhile, establishment of new species of this genus which is more adaptable to paddy ecosystem will increase the importance of this genus as a new threat to rice. In order to evaluate the competition of two species of barnyardgrass with rice, an experiment was conducted at Rice Research Institute of Iran (Rasht) in 2007. The experimental design was a randomized complete block with three replications arranged in a partial additive series. The treatments included two barnyardgrass species (E. crus-galli and E. oryzoides), and species density at four levels (0, 10, 20 and 40 plant.m-2), transplanted with Hashemi land races cultivar rice in local normal density (20 bunches.m-2) and each bunch included three seedlings. Destructive samples were taken two weeks after transplanting up to harvesting, that is, 5 times by 10 days interval in 0.25 m-2. Rice total dry matter accumulation (TDM), Leaf area index (LAI), crop growth rate (CGR), relative growth rate (RGR), yield and yield components were measured. Results showed that yield, yield components and growth indices were affected by both weed species significantly and no interaction between species occurred. Fitting the hyperbolic yield loss model to rice grain yield in barnyardgrass density showed that two weed species were not significantly different. Morphological similarity and ecological adaptability of new barnyardgrass species including resistance to flooding and also high similarity to crop plant that makes its hand weeding less efficient, implies E. oryzoides as a new threat for rice cultivation in northern paddy field of Iran. More investigation on biology of this species is suggested in order to present an applied integrated method for E. oryzoides management.

In order to investigate the absorption and translocation of glyphosate and 2,4-D during various stages of growth in swallow-worts weed populations, this study was carried out in 2010 at the Iranian Agricultural, Medical and Industerial Research Institute of Atomic Energy Organization. Treatments used in this study included three different stages of growth, four weed ecotypes of swallow-worts, and two types of herbicides labelled with carbon 14 (glyphosate and 2,4-D), respectively. Extraction and counting of labelled herbicide showed that herbicide absorption and translocation in different growth stages of different ecotypes of swallow-worts considering the absorption and transfer to different parts of the plant were significantly different. Labeled glyphosate herbicide detected in swallow-worts rhizome showed that the development of recycling and transport to the site of inoculation and shoot to root at the highest levels were different. The least amount of herbicide uptake and transport of herbicides to the leaves above the inoculation site and the plant was in Ahwaz ecotype and other ecotypes and growth stages were not significantly different from each other. But in the case of herbicide transport to the inoculation site and transporte to the roots, Ahvaz ecotype had the highest transmission and the rest showed no significant differences. Different ecotypes also showed significant differences in absorption and transfer steps. Detection of labelled glyphosate herbicide in swallow-worts showed that there was no significant difference in the percentage of transport to a higher place of the inoculation site and transport to the root between ecotypes. However, the transfer of herbicide to the lower site of inoculation and the target leaves were significantly different. This study also showed that the uptake and transport of herbicide 2,4-D in all stages and in different ecotypes with different levels were significantly different. By detection of this herbicide in the plant, it was shown that, except to the amount of absorption by the target leave, the remaining steps of capturing, transporting and recycling of herbicides were significantly different.