مجله به زراعی کشاورزی
سال بیست و چهارم شماره 1 (بهار 1401)

To evaluate the effect of living mulches on weed control and yield of Black cumin (Nigella sativa L.)  weeds by living mulch, a factorial split experiment has been conducted in the form of a randomized complete block design with four replications in the research farm of Aburaihan Campus, the University of Tehran in the 2017-2018 crop year. Factors of seedbed planting (stale seedbed and simple), type of living mulch (berseem clover (Trifolium alexandrinum L.), fenugreek (Trigonella foenum-graecum L.), and alfalfa (Medicago sativa L.), as well as planting time of living mulch (two weeks before and at the same time of black seed cultivation). The first factor is in the main plots and the combination of the second and third factors, in the subplots. Results show that fenugreek and alfalfa have been more successful in terms of weed control than clover with a 40% reduction in weed density and biomass, compared to the control without either live mulch or weeding. Also, in order to achieve the highest percentage of black cumin yield traits (83.02, 93.44, and 50.50), the number of capsules per plant, number of seeds per capsule, and 1000-seed weight are compared to the control. It is recommended to cultivate fenugreek at the same time as black cumin. In case of alfalfa, pre-sowing is also recommended. Stale seedbed planting system does not play a positive and significant role in weed control and increase in black seed yield traits. It is also better to grow fenugreek at the same time as black seed to get more seed yield in black cumin, but in case of alfalfa, it is better to plant earlier than black seed in the absence of any significant difference among planting times. It seems that alfalfa and fenugreek control weeds by accelerating canopy closure, increasing weed competition with black seed, not interfering negatively with black seed growth, and providing nitrogen to black seed have increased its yield.

Due to its antioxidant properties, selenium has an effective role in increasing plant tolerance to adverse environmental effects.To determine the optimum concentration and priming time of quinoa seed by selenium, a factorial experiment based on a completely randomized design with three replications was carried out in the Shahed University Tehran/Iran in 2019. Experimental treatments included was different concentrations of Selenium in six levels (0, 0.5, 1.5,3,4.5,6 mg/l) and the second factor was priming time in four levels (0, 8, 12 and 24hours). The results showed Simple and interaction effect of experimental treatments on traits on germination percentage, was significant (p<0.01) on germination percentage, germination rate, mean germination time, mean daily germination, daily germination rate, germination rate coefficient, seedling length, seedling dry weight, index Longitudinal vascular length and seedling vigor weight index. Across all with the concentration of selenium increased From 0 to 3 mg / L, a significant increase was observed in most of the mean traits and with increasing selenium concentration above 3 mg / L, there was a decreasing trend in the mean traits. The highest percentage of germination (96.33) at a concentration of 3 mg / l selenium for 8 hours showed an increase of 23.5% compared to the control treatment. Also, the highest mean germination time was 6 mg of selenium and 24 hours of priming had an increase of 41.3% compared to the control treatment. Therefore, in order to improve the germination of quinoa, better results can be obtained by priming the seeds using selenium.

In this study, the genetic diversity of 122 safflower genotypes from the institute of plant genetics and crop plant research (IPK) and International Maize and Wheat Improvement Center (CIMMYT) were evaluated and their agronomic characteristics were compared with five Iranian Safflower cultivars. This experiment was conducted at research field of Seed and Plant Improvement Research Institute using a Augmented with randomized complete block design in Karaj during 2017-2018 year. The results indicated high genetic variation in the germplasm. Among safflower genotypes, 36 genotypes without thistle, 81 genotypes with thorns and 10 genotypes with few thistle were observed. Principal component analysis led to the identification of three main components that accounted for 56.5% of the total varition. The first and second components accounted for 29.5% and 15.9% of the total variation, respectively. The first and second components were named as a yield components and phenology and plant architecture, respectively. Safflower genotypes divided into four groups by principal components analysis (PCA). Genotypes in the first groups had the higher grain yield than others. Genotype No. 70 with the highest grain yield (5667 kg.ha-1) was placed in this group. Numerical values of yield components such as 1000-seed weight, number of heads and number of seeds per plant in the third group were higher than other groups. Generally, german genotype No. 70 with high yield and genotype No. 45 with early flowering can be used in safflower breeding programs.

Biotic and abiotic stresses lead to the production of reactive oxygen species (ROS) in plants, damage to the host plant, reduction of its strength, and sometimes plant death. Cut flower rose is one of the most popular ornamental plants, suffering from crown gall caused by Agrobacterium tumefaciens. In order to investigate the activity of some antioxidant enzymes and physiological characteristics in two cultivars of cut roses, A. tumefaciens inoculation was performed as a factorial design in a completely randomized design with three replications at the time of grafting by stenting method in Shahrekord university research greenhouse in September 2020. Treatments include contamination (Agrobacterium suspension inoculation and water inoculation) as the first factor and cultivar treatment (Angelina and Pearl) as the second factor. Three months after grafting, results show that the effect of cultivar/infection interaction has significant effect on ion leakage, proline, and guaiacol peroxidase at the level of one percent probability. The highest levels of soluble sugars, MDA and protein are observed in infected samples, 298.6 (μg/g Fw), 488.6 (µmolg-1 Fw) and 36.7 (mg/g Fw), respectively and the highest RWC and leaf area in healthy samples are 68.5% and 21.5 (cm2). In this study, inoculation of the crown gall lead to active oxygen species and oxidative stress, causing some changes in lipids, soluble sugars, and total protein.

The purpose of this study is to use meta-analysis to combine the results of experiments conducted in Iran on the effect of drought stress due to irrigation cessation at different stages of development, on yield and yield components of canola. The studied traits include grain yield, oil and dry matter, number of pods per plant, number of seeds per pod, 1000-seed weight, and grain oil content. Results show that all traits under the influence of stress at different stages of development are significantly affected by drought stress. Irrigation interruption in different stages on average cuts grain yield by 34.5%, oil yield by 36%, oil content by 4.7%, dry matter by 25.8%, number of pods by 35.4%, seeds per pod ratio by 18.5%, and 1000-seed weight by 17.5%, while raising the proline content by 49.9%. The highest reduction rate in grain and oil yield belongs to the irrigation cut-off treatment, in turn leading to a reduction of 41% and 46% of these two traits, respectively. Also, regarding the yield components, the highest reduction in the number of pods per plant, number of seeds per pod, and 1000-seed weight is observed in the cut-off treatments of stem, flowering, and podding, respectively.

In order to investigate the effect of different mycorrhizal fungai species and drought stress levels on physiological characteristics of chickpea cultivars, a factorial experiment was conducted in a completely randomized design in the greenhouse of Kurdistan Agricultural and Natural Resources Research Center in 2020. Its factors include irrigation at three levels (optimal irrigation at field capacity, moderate stress, and severe stress), application of mycorrhizal fungus at four levels (mosseae, Simiglomus hoi, Rhizophagus irregularis, and no inoculation (control)) and chickpea cultivar at two levels (ILC-482 and Pirooz). Results show that irrigation level has had a significant effect on the evaluated traits. Thus, by decreasing the amount of available plant water, both dry weight and chlorophyll content drops. Catalase activity increases under severe stress, compared to moderate stress and lack of drought stress up to 37% and 71.9% in Pirooz cultivar and up to 69.4% and 82.6% in ILC-482 cultivar, respectively. In case of the latter, the highest peroxidase activity is observed in severe stress conditions, which almost doubled compared to non-stress treatment. The activity of peroxidase enzyme is affected by the use of mycorrhizal fungi so that plants inoculated with G. mosseae has had the highest and non-inoculation with mycorrhiza the lowest peroxidase activity. In severe stress, the lowest amount of malondialdehyde has been obtained using G. mosseae. Inoculation of chickpeas with mycorrhizal fungi can be considered as a way to improve growth in non-stress conditions and increase tolerance to drought stress conditions.