نشریه پژوهش های به زراعی
سال دوازدهم شماره 1 (بهار 1399)

The objective of this study was to evaluate genotypes (G), environments (E) and to analyze genotype by environment (GE) interactions on the seed yield of 20 barley promising lines by the additive main effects and multiplicative interaction(AMMI) model. The trials were conducted at two research stations (Neyshabur and Torogh Mashhad) for two successive years (2015-2017). The result’ s of AMMI analysis for seed yield indicated that the Genotype main effects, environment, and GE interactions as well as two first interaction principal components (IPCA1-2) were significant. AMMI biplot was able to distinguish stable genotypes and environments with high and low genotype discrimination ability. The genotypes 1 and 10 with higher mean yield than total mean were to be most stable genotypes, while the genotype 19 and 2 with the highest contribution to GE interaction, were to be the most instable. The result of recommended genotypes based on AMMI analysis showed that the genotypes 18, 9 and 1 were highly adapted to Mashhad and genotype 20 was adapted to Neishabour environments during this study.

To investigate the effect of sowing date on vegetative characteristics, yield and yield components of faba, 5 faba bean genotypes along with Barekat cultivar (control), a split plot experiment based on completely randomized design with 4 replications was conducted at Agricultural Research Station of Gorgan in 2014-2015. Three sowing dates of 6th of December, 21st of December and 5th of January and Barekat cultivar and 5 large seeded genotypes of G-faba-8, G-faba-10, G-faba-621, G-faba-9 and G-faba 620 were assigned to main-plots and sub-plots, respectively. The results of variance analysis showed that interaction of sowing date ×cultivar was significant for all studied traits except for plant height and tillers per plant. Due to significance of the interaction, it was sliced. The results of mean comparison showed that delay in sowing led to significant reduction in plant height, 100 grain weight, green pods and grain yield. Mean genotype yield for sowing dates of 6th of December, 21st of December and 5th of January was 403.17, 346.04 and 337.15 g.m-2, respectively. At 5th of January, G-faba-621 ،G-faba-620 and G-faba-10 genotype had a higher yield compared to other genotypes. According to the findings, higher yields may be obtained in delayed cropping using genotypes.

In order to investigate the effect of seaweed extract application on the reduction of toxicity due to heavy metal chromium (Cr) stress in cowpea (cv. Kamran), a pot experiment was conducted in Shahre rey region in summer 2019. The research was a factorial experiment at the basis of completely randomized design with 8 treatments and 3 replications. In this experiment, the first factor was Cr stress at two levels including concentrations of 0 and 50 mg/kg of Cr from potassium dichromate source (K2Cr2O7) and the second factor was the application of seaweed extract (Ascophyllum nodosum) at four levels including no application, pre-treatment for 12 hours, two and three stages foliar application at the concentration of 7 mL/L. According to the results of this study, Cr stress (50 mg/kg) reduced number of pods per plant, number of seeds per pod, 100 seed weight, grain yield, biomass and harvest index. On the other hand, application of seaweed extract improved the above traits under Cr stress. In this study, the highest seed yield per plant (38.58 g) was obtained from control treatment with three-stage foliar application of seaweed extract and the lowest grain yield per plant (7.64 g) was recorded in Cr stress conditions with no application of seaweed extract. In other words, three-stage foliar application of seaweed extract increased grain yield by 90 and 94% in both non-stress and Cr stress conditions, respectively. Therefore, based on these findings, three-stage foliar application of seaweed extract can be used to improve growth and yield of cowpea under non-stress and Cr stress conditions.

In salt stress conditions, the use of moderating substances such as potassium-containing fertilizers can reduce the negative effects of saline on yield and yield components of crops. The objective of this study was to determine the effect of potassium amount on yield and yield components of Common Purslane (Portulaca oleracea L.) grown under salt stress. The study was conducted in pot experiments under greenhouse conditions in Sabzevar branch, Islamic Azad university in 2016. A factorial experiment was carried based on completely randomized design with three replication. Factors were: amount of potassium (0. 150 and 300 kg k2O ha-1) as Solopotash form and salinity levels (0, 6, 9 and 12 dS.m-1). The results showed that increasing potassium amount in salt stress conditions increased the yield and yield components of Common purslane and the highest plant height, number of lateral branches, number of capsule per plant, number of seeds per capsule, dry weight of plant, grain yield, potassium content and lowest amount of sodium was obtained by consuming 300 kg. ha-1. Salinity at 12 dS.m-1 level, 57.75% reduced plant height, 55.75% number of lateral branches, 37.27% capsules per plant, 68.56% seeds per capsule, 67.57% 1000 seed weight, 71% plant dry weight, 47.21% grain yield and 41.91% plant potassium content and increased 27.65% sodium content compared to control. In total, the results showed that till 9 dS.m-1 grain yield was not statistically significant and consumption of 300 kg.ha-1 was more suitable for reducing the effects of salinity stress.

In order to study the effect of Plant Growth Promoting Rhizobacteria (PGPR) on yield and yield components of Black cumin (Nigella sativa L.) under drought stress conditions in Shahr-e-Rey region, an experiment was done as split plot based on completely randomized block design with three replications in research farm of Islamic Azad University Yadegare-Imam Khomeini (RAH) Shahre-rey Branch during 2015. In this experiment, irrigation as a major factor in three levels (55, 95, 135 mm evaporation from class A evaporation pan ) and methods of PGPRs application as a sub in four levels (seed inoculation, using in irrigation water, seed inoculation + using in irrigation water) were considered. The results showed that drought stress had significant effect on all traits at %1 level of probability, so that the highest plant height (99/18 cm), number of branches per plant (4.5), capsules number per plant (6), number of seeds per capsule (2.19), 1000 grain weight (18.2 g), grain yield (234.79 kg/ha), biological yield (626.58 kg/ha), harvest index (%42.37) were conducted in irrigation at 55 mm evaporation from class A evaporation pan. The use of PGPRs on plant height, number of branches per plant, number of capsules per plant, grain yield, biological yield and harvest index were significant at 1% level of probability. The highest amounts of traits were observed in seed inoculation + using in irrigation water. So it can be stated that the PGPRs application can reduce destructive effects of drought in black cumin. The seed inoculation + using in irrigation water were the best recommended treatment in water deficit stress conditions.

The present study was carried out to investigate the effect of drought stress, nitrogen resources and plant density on some agro-physiological traits of Sunflower (Haysan variety) in the north of Golestan province. This experiment was done as split plot factorial based on completely randomized design with 3 replication for two consecutive years and 27 treatments in 2017 and 2017. Irrigation factor in 3 levels: S1: rainfed, S2: one planting irrigation stage, S3: three irrigation (planting, flowering and seed filling) as main factor and nitrogen fertilizer resources in 3 levels: N1: 100% urea, N2: 50% urea and 50% nitroxin, N3: 100% nitroxin and plant density in 3 levels: D1: 50000 plants per hectare, D2: 75000 plants per hectare, D3: 100000 plants per hectare were considered as sub factor. The results showed that the highest mean of CGR was obtained in the S3N2 and N3D3 treatments with an average of 26.041 and 22.0300 g/m2, respectively. The highest plant height with values of 155.75 cm and 1252.89 cm was related to S3N2 and S3D3 treatments, respectively. The highest number of seeds per inflorescence belonged to S3N2 (285.68) the maximum 1000 seed weight with 29.27 g and 26.69 g were gained in S3D3 and N1D1 treatments. According to findings, the highest economic yield (192.88 kg/ha ) was conducted in irrigation at 3 stages, 50% urea fertilizer consumption + 50% nitroxin and 100,000 plant density per hectare.