saeed seifzadeh

This experiment was conducted to study yield increase of forage sorghum by its intercropping with forage legumes and weed control. This study was carried out in a factorial experiment based on a randomized complete block design with 3 replications at the Research Station of University of Zanjan in 2015. In this experiment, a different proportatios of sorghum with forage legumes including pure culture of sorghum plants, lathyrus and hairy vetch, increased percent of sorghum by 33%, 66% and 100% of hairy vetch and lathyrus, and different weed control management, including full weed control during season, single weed control and no weeds control, were examined. The results showed that the highest and lowest fresh and dry yields of sorghum were obtained in intercropping of sorghum with 33% vetch and 100% lathyrus, respectively. The highest chlorophyll content and leaf area belonged to sole cropping of sorghum and full weed control. The highest height of sorghum and cover crops was observed in 100% sorghum+ 100% lathyrus and weed-infested. On the other hand, in the sole culture of vetch and lathyrus and full weed control treat, the cover crops had the highest dry weights. The results of this experiment also showed that the highest dry weights and density of weeds were obtained under sole culture and weed-infested condition. As a result, it can be said that by selecting the appropriate intercropping ratios and forage legumes, we can control weed population to a large extent also improve the quantitative yield of sorghum forage.

To study the effect of winter planting and zinc spraying on yield and yield components of canola (Brassica napus) cultivars, a factorial split plot experiment based on randomized complete block design with three replications was conducted for two years (2014-2015 and 2015-2016 cropping seasons) at the experimental farm of Seed and Plant Improvement Institute of Agricultural Research, Education and Extension Organization of Karaj, Iran.. In this experiment, winter plantings with three levels (24th February, 6th, and 16th March) and Zinc factors with two levels, including application of zinc sulfate spray and spray with pure water assigned to main plots and spring cultivars, including RGS003, Zafar, Julius, Jerry, Zabol 10, Hyola 4815 to subplots. The results of combined analyses of data showed that the effect of year, planting date, zinc spray, cultivar and planting date × cultivar interaction effects on qualitative traits (grain glycosinolate content and fatty acid percentages) in different planting dates and cultivars were significant at 1% level of probabilities. According to the results, the highest (66.89%) and lowest (66.02%) oleic acid percentages belonged to zafar and zabol10 cultivars, respectively. Planting dates × cultivar interaction effect on the glucosinolate content indicated that the lowest glucosinolate content produced by Zafar (8.313 mg.g-1) and hyola4815 (8.567 mg.g-1), when they were sown on March 16th. The results of this experiment showed that delayed planting, decreased percentages of palmitic, linoleic and oleic acids of seed oil, while increased percentages of linolenic and erousic acids and glycosinolate contents.

Relationship, between seed yield and it morphological characteristics and their relative importance in 25 bread wheat genotypes under both rain-fed and supplementary irrigation conditions studied using a randomized complete block design with three replications were evaluated during growing seasons of 2014 and 2016 at the Kermanshah’s Sararud Rainfed Agricultural Research Station. Analysis of variance showed that all traits under study, except spike length, exhibited significant differences in rainfed and supplementary irrigation condition. In supplementary irrigation conditions, these traits showed higher values as compared to those of rainfed condition. The application of supplementary irrigation resulted in reduced leaf and canopy temperatures. The coefficients of simple correlation between the traits, for both of the rain-fed and supplementary irrigation systems, indicated that cell membrane stability, flag leaf length, straw yield, relative water content, 1000 seed weight, chlorophyll content, leaf and canopy temperatures were maximally correlated with the seed yield. Traits like straw yield and flag leaf length were inserted into the regression model of rainfed irrigation condition and traits such as the straw yield, flag leaf length, relative water content and spike yield were also inserted into the regression model of supplementary irrigation condition the results demonstrated that the former traits accounted for 0.741 of the seed yield variations and the latter traits explained 0.899 of the seed yield variation. Path coefficient analysis showed highest positive direct effect on seed yield in rain-fed condition, and straw yield and flag leaf length, relative water content, flag leaf length and spike yield in supplementary irrigation condition. Based on the results of this study, straw yield was found to be the most important indicator to select for higher yielding varieties of wheat under both rainfed and supplementar irrigation conditions.