فصلنامه زراعت و اصلاح نباتات
سال شانزدهم شماره 1 (بهار 1399)

In order to investigate the effect of iron, manganese and zinc foliar spray on the yield and grain protein in barley, an experiment was carried out in a randomized completely block design with 3 replications in Darab, during 2012-2013. The total of 8 treatments were used that consisted of T1- Control test without spraying, T2- Spraying with a concentration of 0.2% iron, T3- 0.2% zinc, T4- 0.2% Mn, T5- T2+T3, T6- T2+T4, T7- T3+T4 and T8- T2+T3+T4. The results showed that application of micronutrient fertilizers increased the yield and yield components of barley. So that the simultaneous application of iron, zinc and manganese could significantly increase the grain yield, number of grains per ear, 1000 seed weight, biological yield, harvest index, stem soluble carbohydrates and grain protein. The highest concentrations of iron, zinc and manganese in grain and leaf were observed when each one of the elements was individually sprayed on plant aerial parts. The lowest concentrations of iron, zinc and manganese in grain were obtained in the combination of zinc+ manganese, iron+ manganese and iron + zinc, respectively. Among the applied, iron had the best effect on the increase of grain yield than the other elements. By increasing the number of elements used in the spraying solutions, their efficiency in supplying the plant requirement was reduced. Based on the results of this study, it can be concluded that in addition to grain enrichment, the micronutrient fertilizers have been able to increase the yield and yield components of the barley

In order to evaluate the salinity tolerance of spring rapeseed varieties, 15 hybrids obtained from the intersection of 5 lines and 3 testers with their parents (total of 23 genotypes) in two conditions of normal and salinity irrigation in two randomized complete block designs with 3 replications were studied in 2009-2010 at Kerman Agricultural and natural Resources Research Center. Significance of the effect of treatment on all studied traits (a total of eight traits) under two irrigation conditions showed that there was sufficient genetic diversity between crosses, which justified line × tester analysis. Decomposition of hybrids into their components based on line-tester analysis showed that the effects of lines, testers, and the effect of line-tester in terms of the studied traits were significant, and the lines had different reactions in combination with different testers. Estimates of more than one for the ratio of the mean squares of general combining ability to squares of specific combining ability showed that the additive action of genes has greater role in their genetic control. High values and low amplitude changes of broad sense heritability showed that genetic variance was greater than environmental variance. The lowest amount of specific heritability for the trait of 1000-kernel weight (58.74%), and the highest amount was related to grain yield (89.89%) under normal irrigation conditions. Crosses SPN179 × Dalgon and RGS003 × SPN179 are the best hybrids in terms of grain yield under normal and salinity conditions, respectively, with the highest values of specific combining and are recommended

Drought stress is one of the most important limiting factors in the expansion and regeneration of plants in the agricultural systems and natural environment, which the best way to deal with it is to introduce cultivars resistant to stress. For this purpose, by experimenting in the 2015 -2016 cropping year, the response of 5 cultivars of chickpea including 3 Kabuli cultivars (Arman, Azad and ILC482) and 2 Desi cultivars (Pirooz and Kaka) to drought stress resistance under 5 levels of water potential (0, -3, -6, -9 and -12 times), using 6000 polyethylene glycol in the laboratory in a factorial design in a completely randomized design with 3 replications. Cultivars were evaluated in field conditions in the form of a randomized complete block design with 4 replications at the research site of the Kurdistan Agricultural Research Center. The results showed that there are significant relationships between the characteristics measured in laboratory and field conditions. Among the studied cultivars, only Desi cultivars showed good germination potentials in (-9) and (-12) times. Therefore, in terms of drought stress tolerance at the germination stage, they had a significant advantage over Kabuli cultivars. In reducing the potential from zero to (-6) times, the greatest difference was seen in all traits. The highest number of days to flowering, day to maturity and the number of seeds per plant belonged to Kaka cultivar and the highest grain yield belonged to Arman cultivar. Cluster analysis revealed the similarity of Kabuli cultivars and their genetic distance from Desi cultivars.

This experiment was performed to investigate the effect of different rice residue management on growth parameters of canola. This experiment was performed as a split plot experiment in the form of a randomized complete block design with three replications in the agricultural lands of Izeh city. The studied treatments include rice residue management at four levels (including 1- conventional cultivation (stubble burning), 2- cultivation in plowed land with rice residues, 3- cultivation in rice residues with a height of 20 cm, 4 - cultivation in rice residues with a height of 40 cm) and the second factor was three canola cultivars (including 401, 4815 and okapi). The results showed that the effect of rice residue management on leaf area index, total dry matter, crop growth rate, relative growth rate and net assimilation rate were significant. The effect of cultivars were significant in all measurement traits. There was no significant difference interaction between rice residue management and cultivar type on all studied traits. The maximum and minimum values in the studied traits were observed in cultivation management in cultivation in plowed land with rice residues and conventional cultivation, respectively and among different canola cultivars, the maximum and minimum values in the traits were observed in cultivar 4815 . In general, the results of the experiment showed that the cultivation in plowed land with rice residues is superior to conventional cultivation and other managements and leads to the improvement of growth parameters. Also, 4815 cultivar is superior to 401 and okapi cultivars.

In order to study the effect of priming sunflower seeds by potassium nitrate on germination seeds was conducted experiments in salinity and drought conditions. Location of experiments was Physiology Laboratory, Faculty of Agriculture, Bu Ali Sina University, Hamedan. Salinity experiment was conducted as factorial based on randomized complete block design (RCBD) with two factor of seed priming and salinity and three replications. Priming levels included control and seed treatment by potassium nitrate and salinity levels included 0, -2, -4, -6, and -8 bar. Also, drought experiment was conducted as factorial based on randomized complete block design (RCBD) with two factor of seed priming and drought levels in three replications. Drought experiment treatment included control (non-priming) and priming by potassium nitrate and drought stress treatment were five levels (0, -2, -4, -6, and -8 bar). The results of two experiments showed that increasing in salinity and drought stress, decreased germination components including germination, germination rate and dry weight of seedlings. However, this reduction was lower for seeds that were treated by potassium nitrate. In terms of the studied traits, at all of the levels of salinity and drought treatment seeds were better than control seeds. In general, it can be concluded that the priming of sunflower seeds by potassium nitrate improved the germination components under salinity and drought stress and can increase sunflower plant resistant against these stresses in the germination stage.

Water extracts from allelopathic plants like sorghum, sunflower and brassica especially when it is used in combination with reduced dose of herbicides. A field experiment was carried out to examine the feasibility of using sorghum water extract as a natural weedicide in rabi season crop (wheat) during 2015-2016 at Agronomy Research Form, Sorgaab sprays with three different concentration (1:3, 1:4,1:5) in combination with Weedicide (affinity) in three different levels (1/3,1/2 and 2/3 of the recommended dose), with three application timing (emergence, tillering, 50% at emergence and 50 % at tillering), were tested and compared with hand weeding, unweeded and with weedicide sole. Results of the study showed that the herbicide sole followed by hand weeded plots were more effective among all the treatments for controlling weed dry weight increased grain yield. Sorghum extract sprayed at 1:5 resulted in decreased dry weight (127.2 g m-2), more leaf area tiller-1 (101 cm2), more leaf area index (3.0) and higher grain yield (3727 kg ha-1). Herbicide (affinity) at the rate of 1317g ha-1 and increased leaf area tiller-1 (100 cm2), leaf area index (2.9) and higher grain yield (3665 kg ha-1). Sorghum extract concentration with combination sprayed at tillering stage gave reduced dry weight (132), increased leaf area tiller-1 (99 cm2), more leaf area index (2.9) and grain yield (3727 kg ha-1). It is concluded that sorghum extract concentration 1:5 with 1317g ha-1 of herbicide affinity applied at tillering stage is recommended for higher yield and yield components of wheat crop.