جستجوی مقالات مرتبط با کلیدواژه "سرعت رشد محصول" در نشریات گروه "زیست شناسی"

In order to efficiency of different herbicides on weed control, forage yield, crop growth rate (CGR) of alfalfa (Medicago sativa L), an experiment with nine treatments based on randomized complete block design (RCBD) with three replications at the research field of Iranian Research Institute of Plant Protection located in Meshkindasht, Karaj, during 2014-2016 was conducted. The treatments consisted of Eradicane 4.1 g ai/ha (EPTC), Metribuzin 525 g ai/ha, 2,4-DB 1269 g ai/ha, 2,4-DB 1480 g ai/ha, Bentazon 144 g ai/ha, Imazethapyr 50 g ai/ha (with 200 ml Sitogit), Imazethapyr 100 g ai/ha (with 200 ml Sitogit), non-herbicide control (weedy) and whole-season weeding control (weed free). Among different herbicides, application of Imazethapyr (1L/ha) led to control of Flixweed (Descurania Sophia) and wild mustard (Sinapis arvensis) (control percentage more than 95%). The lowest percentage of dry weight reduction in both weeds (flixweed and wild mustard) was related to Eradicane herbicide, which was 42 and 41% in the first cutting and 40 and 35% in second cutting. The highest and lowest fresh and dry weight of alfalfa (qualitative forage yield in 5 cutting were observed weed free and application of Metribuzin herbicide treatments. Also, index of crop growth rate (CGR) was more in weed free and application of Imazethapyr herbicide (1L/ha) treatments. Therefore, weed control in alfalfa established, application of Imazethapyr herbicide (1L/ha) as post emergence (3-4 leaves of weeds) is recommended.

In order to evaluate the effect of deficit irrigation treatment and foliar application of ascorbic acid and jasmonic acid on morphophysiological traits of safflower genotypes (Carthamus tinctorius L.), the experiment was set out in a split plot factorial in a randomized complete block design with three replications at Shahrekord University Agricultural Research Station during the two years, i.e. 2016-2017. The main factor consisted of three levels of irrigation of 100%, 75% and 50% of the plant's water requirement of safflower and sub-factor including safflower genotypes including Sinai, Isfahan local, Faraman and foliar application with three levels including (0 concentration, foliar application of jasmonic acid with 0.5 mM concentration and foliar application of ascorbic acid with 20 mM concentration(. The results showed that the highest cholliorophyll a, cholliorophyll b, relative water content, leaf area index, crop growth rate, oil percentage, grain yield and oil yield related to Sina genotype and 100% of the plant's water requirement and The least of these traits were from Isfahan local genotype and 50% of the plant's water requirement. The results of this study showed that the interaction effects of genotype× deficit irrigtion and genotype× foliar application were significant only on cholliorophyll a and oil yield. Also foliar application of Jasmic acid and ascorbic acid increased all traits compared to non foliar application treatment. The results of this study showed that the differences between the genotypes and also effect of foliar application of jasmonic acid and ascorbic acid to increase of these traits were important components that could be used to select genotypes and suitable compounds to reduce undesirable effects of water stress in order to achieve increased economic performance.

This research was done in order to study the effects of irrigation (I) and nitrogen (N) levels on occurrence time of phenological stages and growth indices of seed corn, SC704 cultivar. The experiment was conducted at Campus of Agriculture and Natural Resources, Razi University, Kermanshah, Iran, during 2014 and 2015 growing seasons as split-plot based on randomized complete block design with three replications. Main-factor was four I levels including supply 120, 100, 80 and 60% of water requirement. Sub-factor was four levels 140, 100, 70 and 40% of recommended N based on soil analysis. Results showed that tasseling, anthesis and silking stages delayed by reducing of water supply. Increasing of N supply has not significant effect on date of tasseling and anthesis, but silking accelerated. Deficiency of I and N supply led to increasing of anthesis until silking interval. In 120, 100 and 80% of I supply, physiological maturity occurred later by increasing of N. Increasing of N supply, in each I treatment, increased leaf area index and crop growth rate, but the positive effect of N was decreased due to I deficit treatments. Under optimum I conditions, increasing of N supply increased amount and rate of dry matter accumulation, and delayed end of dry matter accumulation.

To investigate the effects of sowing date on yield and some physiological index of six forage maize cultivars in Rasht region, a field study was conducted in 2010. The experimental design was randomized complete blocks with factorial arrangement with three replications. Treatment consisted of four levels of sowing date (22 May, 3, 15 and 25 June), and six maize cultivars (SC 260, DC 370, SC 500, SC 647, SC 700 and SC 704). Results showed that sowing date and cultivar had significant effects on forage yield (dry and fresh) traits. The sowing date 3 June and cultivar SC 700 from a point forage yield (dry 28220.6 kg ha-1 and fresh weight 87017 kg ha-1) were better than other cultivars and sowing dates. The maximum LAI and CGR obtain from sowing date 3 June and cultivar SC 700. Based on the results obtained from this study sowing date 3 June and cultivar SC 700 with more suitable growth indexes is the reasons of increasing in leaf area development, plant photosynthesis activity, dry matter yield and finally more yield, was suggested in Rasht reign conditions.