نشریه پژوهش های به زراعی
سال چهاردهم شماره 1 (بهار 1401)

In order to study the effect of priming and foliar application of salicylic acid on germination, yield and some morphological characteristics of different wheat cultivars, an experiment was conducted as factorial based on randomized complete block design with three replications in agricultural research station of Sarab plain in Khorramabad in 2015-16. The application factor of the salicylic acid solution was in four levels (control, foliar application of distilled water, priming and foliar application of salicylic acid with concentration of 1 mm, foliar application of salicylic acid with a concentration of 1.5 mm and foliar application of salicylic acid with a concentration of 2 mm) and the factor of rainfed wheat in three levels (Qaboos, Kareem and Kuhdasht) was the test agents. The simple effect of cultivar and salicylic acid solution on performance and most of the attributes were significant. According to the results, the rate of Qaboos with 3974.6 kg / ha had the highest seed performance among the studied figures. According to the obtained results, the best treatment for priming the seeds was the use of 1.5 mm salicylic acid, which caused significant effect on germination percentage and rate of germination .Priming and leaf foliar application with a concentration of 1.5 mm salicylic acid caused the seed performance to significantly increase in comparison to control treatment, so that seed yield was increased (10.3%) compared to control treatment by priming and leaf foliar application with a concentration of 1.5 mm salicylic acid. The results of priming and foliar application of two mm salicylic acid showed has compensated the reduction caused by priming on germination percentage and germination rate of seeds and increased the performance and performance components compared to the control treatment. Due to the positive effect of Qaboos and priming and foliar application of 1.5 mm salicylic acid in improving wheat grain performance, we can use priming and foliar application of 1.5 mm salicylic acid for rainfed Qaboos wheat in Khorramabad climate.

In order to identify drought tolerant genetic sources in wheat and investigate the changes of traits related to this characteristic, a number of 512 accessions from the wheat collection of the National Plant Gene Bank of Iran along with the drought tolerant cultivars Kavir, Roshan and Mahooti were investigated in the field of Yazd Agriculture and Natural Resources Research Center in the form of two separate augmented statistical design (normal irrigation and drought stress). Drought stress was applied by limiting times of irrigation, i.e. once after planting and the other during seed filling stage. In total, 66 accessions were survived and the evaluation of agronomic traits was carried out according to the international descriptor. The results showed a decrease in the values ​​of all evaluated traits under drought stress condition, and the greatest decrease was in the traits of five-spike seed weight (57.34 %) and number of fertile tillers (48.59 %). A large number of accessions with superior traits compared to the check cultivars were identified under normal and drought stress conditions. Based on the results of principal component analysis under drought stress, the first five components contained 73.84% of the total changes in data. The superior accessions were distinguished based on the characteristics of each component. The studied accessions were separated into four groups with different characteristics using cluster analysis. The results of the present research showed a wide diversity in the evaluated germplasm and the superior accessions identified can be used in future wheat breeding programs to improve tolerance to drought stress.

In order to investigate the agronomic characteristics of Potato under water deficit stress conditions using line-source sprinkler irrigation method and potassium fertilizer amounts an experiment was done in Khorasan Razavi Agricultural and Natural Resource Research Center during 2015-2016 as split plot design based on completely randomized blocks design. Water deficit levels at 0.75m from line-source (control), at 3.75m from line source (very light), at 6.75m from line-source (light), at 9.75m from line-source (severe deficit), at 12.75m from line source (very severe deficit) were considered as main factor and potassium levels included 0, 90, 180, and 270 kg.ha-1 K2O were as subfactor. Studied traits were included, tuber yield, percent of small, medium and big tuber yield, number of tuber per plant, average of tuber weight, plant height and stem number per plant. The results showed that water deficit stress levels had significant effects on total traits and potassium nutrition levels had same effects except percent of small and medium tuber yield and stem number per plant. Higher water deficit levels significantly decreased the tuber yield, tuber number per plant and average of tuber weight that in very severe deficit these traits reduced 92.29, 84.32, and 53.81 percent respectively. The highest tuber yield (17.92 ton.ha-1), tuber number per plant (7.94) and average of tuber weight (38.73 g) resulted in 270 kg.ha-1 K2O. The highest and lowest tuber yields were in control with 270 kg.ha-1 K2O and very severe deficit with 0 kg.ha-1 K2O.

In order to evaluation of some related to seed germination and seedling vigor traits of six mono germ sugar beet cultivars by accelerated ageing test, a research was conducted as factorial 4×6 (6 cultivars and 4 seed size) by 4 replications based on completely randomized design in seed quality analysis laboratory of Seed and Plant Certification and Registration Institute (SPCRI) at Karaj during 2019. Experiment treatments were including, Toucan, Dorotea, Rasta, Sharif (006), Pars (005) and Torbat (004) cultivars and seed width sizes, including 2, 3, 3.25 and 3.5 mm. By standard germination test conducting, after seeds accelerated ageing, final germination and normal seedlings percent, germination rate, germination meantime, coefficient of germination uniformity, seedling dry weight and length and seedling weight and length vigour indices determined. Results revealed that cultivar× seed size interaction effect was significant for all measured traits. The most final germination and normal seedlings percent and belonged to Sharifcultivar3.5 mm size seeds. AlsoTorbatcultivar3.5 mm size seeds had the most germination rate and the lowest mean germination time. Sharif cultivar 2 and 3 mm size seeds had highest coefficient of germination uniformity. The highest seedling dry weight belonged to Rasta and Doreata cultivars 3.5 size seeds. Rasta cultivar 3.5 mm size also had the most seedling length. Pars, Rasta and Toucan cultivars 3.5 mm size seeds had the most seedling weight vigour index and the most seedling length vigour index investigated in 3.5 and 3.2 mm size seeds of Torbat cultivar 3.5 mm size seeds. Generally, Sharif cultivar and 3.5 mm size seeds had more germinability and strong vigour.

For compare the efficiency of different herbicides in controlling narrow-leaved weeds of rice drying fields of Tisa cultivar with the focus on the use of pre-growth herbicides, this study was conducted as a randomized complete block design (RCBD) with 4 replications. Experimental treatments was Stomp herbicide application (3 liters per hectare), Rifit (3.25 liters per hectare), Oxadiargyl (3250 ml), council (150 g), Clomazone (1000 cc), Thiobencarb (6 liters), Ronstar (3 liters), Penoxsulam (250 cc), Pendimethalin (Prowl) (3 liters) and hand weeding (titanium consumed).Effect of herbicide application on number of grainclusters, grain yield, direct harvest yield, total weight of harvested rice plants, fresh weight of paddy, dry weight of paddy, dry weight of straw, straw yield, number of weeds and dry and fresh weigths of Echinochloa crus-galli,Cyperus rotundus, Portulaca, Cucumis melo, Fallopia convolvulus and Physalis alkekengiwere significantat the probability level of 1% but on thousand grain weight the probability level of 1% were significant. The results showed that the lowest number of Echinochloa crus-galli (1.62), the lowest fresh weight of Echinochloa crus-galli (147.43 g) and the lowest dry weight of Echinochloa crus-galli (33.8 g) were related to Penoxsulam treatment and the highest number of Echinochloa crus-galli (12.47), the highest fresh weight of Echinochloa crus-galli (477.27 g) and the highest dry weight of Echinochloa crus-galli (110.5 g) were related to Rifit herbicide treatment. In general, the results showed that in order to better control the common weeds in the rice field, the use of herbicides was better than weeding.

The experiment was conducted to investigate the response of rice crop plant to nitrogen management in in different geographical regions in northern Iran as factorial based on a Randomized Complete Block Design (RCBD) with three replications in Mazandaran province (Band pay Babol and Babol Plain) and Guilan province (Lahijan region) during 2019 and 2020. Three levels of nitrogen fertilizer including 50, 90 and 130 kg N ha-1 from urea sources were used as main plots and three levels of nitrogen splitting in basal applied, initial heading stage and full heading stage were used as sub plots. The findings revealed that grain yield in Lahijan region (6044 kg ha-1) was 6.57% and 5.53% lower than Band pay region and Babul Plain. With increase of 90 and 130 kg N ha-1 compared to 50 kg N ha-1, panicle length, number of panicle per hill, number of spikelet per panicle, filled spikelet percentage, grain nitrogen uptake, protein yield and nitrogen harvest index (0.77% and 2.44%, respectively) were significantly enhanced which resulted in enhance of grain yield (24.87% and 12.71%, respectively). GY with application of 50, 90 and 130 kg N ha-1 was 5602, 6314 and 6995 kg ha-1, respectively. In contrast, nitrogen utilization efficiency (108.21% and 30.37%, respectively) and nitrogen uptake efficiency (26.02% and 16.53%, respectively) were significantly decreased. Therefore, nitrogen management in the paddy field could be an effective approach to enhance performance of rice and nitrogen utilization efficiency is a major objective of future.