جستجوی مقالات مرتبط با کلیدواژه « cereal » در نشریات گروه « کشاورزی »

One of the non-biological stresses for crop plants is drought and lack of water, which is the most important factor limiting the growth of crop plants in arid and semi-arid areas, including Iran. Drought impairs normal growth, disturbs water relations, and reduces water use efficiency in plants. Plants, however, have a variety of physiological and biochemical responses at cellular and whole organism levels, making it a more complex phenomenon. The rate of photosynthesis is reduced mainly by stomatal closure, membrane damage, and disturbed activity of various enzymes, especially those involved in ATP synthesis. Plants display a range of mechanisms to withstand drought, such as reduced water loss by increased diffusive resistance, increased water uptake with prolific and deep root systems, and smaller and succulent leaves to reduce transpirational loss. Therefore, the effects of drought stress and seed nutritional priming on plants can play an important role in managing different irrigation regimes to deal with adverse environmental conditions and improve crop yield management.

Quinoa is one of the crops that has received special attention in recent years due to its high nutritional value and resistance to dehydration. For this purpose, an experiment was conducted in the form of a factorial split plot, with three rounds of irrigation of 7, 10 and 14 days as the main factor and seed priming at two levels without prime as a control and Iron sulfate + zinc sulfate combination as the second factor was applied on three genotypes (Q12, Q29 and Giza1) of quinoa as secondary factors, in the crop year of 2021-2022 in the regions of Neishabour and Kashmar.

Moisture stress decreased the relative water content and percentage of membrane stability. In Kashmir region, the highest relative water content was observed in cultivars Q12 and Giza under the treatment of irrigation once every 14 days. While in the Neishabur region, the highest value of the mentioned variable was obtained in the treatment of irrigation once every 7 days and cultivar Q29. Slicing analysis of the interaction effect of cultivar and irrigation treatments and the interaction effect of irrigation and priming in Kashmir region showed that the 7 and 10 day irrigation treatment was significant on cell membrane stability. Comparison of the average interaction effect of the three tested factors in Neishabur area showed that the variety Q12 (regardless of seed priming) along with applying 14 days of irrigation caused a significant increase in membrane stability in Neishabur. Although the lowest level of membrane stability was obtained in the priming treatment of Q12 and Giza cultivars with the application of 7 days of irrigation once. It was observed that the priming treatment of Q29 and Giza cultivars with irrigation every 10 and 7 days, respectively, showed the highest amount of total chlorophyll in the Kashmir region, while in the Neishabur region, the highest amount of total chlorophyll was obtained in non-priming of Giza cultivar with the application of 10 Irrigation once a day. The results of the experiment showed that seed priming of Q12 and Q29 cultivars under irrigation once every 7 days caused a significant increase in seed yield in Kashmir region. In Neishabur region, the highest amount of seed yield was obtained in the non-priming cultivar Giza under irrigation once in 10 days.

In general, seed priming with zinc sulfate and iron sulfate can improve the physiological characteristics of quinoa under water stress. Although in regarding the relative water content, the Q29 variety had a dominant effect on the priming treatment in Neishabour region. According to the results of the Q29 variety in the Kashmar region and the Giza variety In the Neishabour region, it will help plant growth by maintaining the chlorophyll content of the leaves under low irrigation conditions.

The use of synthetic contact insecticides is one of the common strategies to prevent the damage of storage pests. Considering the economic importance of storage insect pests and their resistance to common chemical insecticides, it is necessary to find a safe, suitable, economical and durable method. In this research, the insecticidal activity of 400 mg/kg concentration of a commercial formulation, Silicosec®, an Iranian formulation Dryasil, Dryasil + 0.05% Mentha longifolia extract, talcum powder alone, talcum powder + 0.05% of M. longifolia extract was evaluated on Tribolium confusum adults in different grains including wheat, barley, rice, paddy rice and corn. Untreated grains were considered as negative controls and grains treated with talcum powder were considered as positive controls. The mortality of adult insects were counted 1, 5, 7, 10 and 14 days after treatment. In most cases, the Dryasil formulation followed by Silicosec® significantly controlled the tested insect population in the grain mass. The mean mortality percentage of T. confusum 14 days after treatment in wheat, barley, rice, paddy and corn treated with Dryasil formulation was reported 54.44, 80.0, 54.44, 45.55, and 45.55 %, respectively. In the same time period, Silicosec® was able to control 56.66, 65.55, 34.44, 50.0, and 43.33% of T. confusum adults in wheat, barley, rice, paddy rice and corn, respectively. The results showed that the insecticidal efficacy of diatomaceous earth increased over time. Moreover, Dryasil can be recommended as a suitable grain protectant to control storage insect pests.

Todays, efforts to increase crop yields have led to the indiscriminate use of chemical fertilizers, especially nitrogen (N) and phosphorus (P) fertilizers. It has caused soil and groundwater pollution and the destruction of soil microbial communities. Therefore, researchers should look for ways to replace N fertilizers and reduce their side effects. Intercropping of cereals and legumes due to differences in the distribution and depth of roots in the soil profile can reduce competition for water and the survival of these plants in water shortage conditions. Among the methods that may reduce the use of N and P fertilizers and thus reduce sensitivity to water stress is the intercropping of cereals and legumes. Using growth-promoting N-fixing bacteria such as Azospirillum brasilense and phosphorus solvents such as Pseudomonas fluorescens as biofertilizers can be another way to reduce the use of N and P fertilizers and the adverse effects of water stress. Therefore, the aim of this study was to investigate the effects of different fertilizer systems [chemical, integrated, and biological] on yield and competitive indices in triticale (× Triticosecale Wittmack) - chickpea (Cicer arietinum L.) intercropping under water stress conditions in Southern Iran (Fars province).

This experiment was performed as a split factorial on a randomized complete block design with three replications in the research farm of the Darab Faculty of Agriculture and Natural Resources-Shiraz University in the 2019-2020 growing season. Experimental treatments included two levels of irrigation (Ir) [Normal: irrigation based on plant water requirement (IRN) and water stress: irrigation based on plant water requirement up to the milking stage (WS)] as the main factors. The Sub-factors included three sources of fertilizer (F) [Chemical: 50 kg P.ha-1 +150 kg N.ha-1, Bio-organic: 40 tons of manure sheep ha-1 + inoculation with Pseudomonas fluorescens and Azospirillum brasillens, Integrated: 25 kg P ha-1 + 75 kg N.ha-1 + 20 tons of manure sheep ha-1 + inoculation with Pseudomonas fluorescens and Azospirillum brasilens] and three types of cropping systems (Cp) [Monoculture of triticale, monoculture of chickpea, and intercropping of triticale-chickpea (1:1)]. The crops Grain yield were measured, of the crops was measured and competitive indices including land equivalent ratio (LER), aggressivity (A), competitive ratio (CR), and system productivity index (SPI) were computed. The SAS 9.1 software was used to analyze the data, and the means were separated using the least significant difference (LSD) test at a 5% probability level.

 The results showed that the cessation of irrigation after the milking stage put severe stress on the triticale and chickpea during the grain filling period and reduced grain yield of both plants. The Ir × F interaction for triticale and chickpea grain yield showed that the lowest reduction of their grain yield (31% and 27%, respectively) were obtained in Bio treatment due to water stress as compared to IRN. Furthermore, The Ir × Cp interaction for triticale and chickpea grain yield showed that the water stress reduced their grain yield. However, the reductions were lower in intercropping system of triticale (38%) and chickpea (24%) as compared with their sole cropping. Late season water stress increased triticale, chickpea and total LER as compared with IRN conditions by 40, 65 and 51%, respectively. Furthermore, the Ir × F interaction showed that the highest and the lowest reductions (55% and 17%, respectively) of SPI were achieved in chemical and Bio treatments as a consequence of water stress conditions. 

 Based on the results obtained from this study, it can be concluded that the intercropping system of triticale and chickpea is superior to their monocropping under late season water stress conditions. Also, the lowest reduction of chickpea and triticale grain yields as a consequence of water stress was obtained by the application of Bio and integrated fertilizers. Therefore, the use of Azospirillum brasiliens and Pseudomonas fluorescens with sheep manure fertilizer not only mitigates the negative effects of water stress, but also reduces the excessive use of N-P chemical fertilizers and their harmful environmental effects and it can be an effective step for sustainability of agricultural systems.

Knowledge of genetic diversity and understanding the genetic architecture of complex traits in crop species can play a key role in exploiting genetic diversity and lead to crop cultivation's adaptation, development and expansion in different geographical environments. In this regard, identifying and utilizing informative markers related to quantitative traits is a prerequisite for application in breeding programs and marker-assisted selection (MAS). One of the major uses of these markers is the construction of genome-wide molecular maps and genetic analysis. In genome-wide association study (GWAS) and genomic selection (GS), determining of extent and level of linkage disequilibrium (LD) is critical in sample size and marker density. Moreover, selection for increasing frequency in new mutations advantageous only in a subset of populations leaves some signatures in the genome. Locations of selection signatures are often correlated with genes and QTLs affecting economically important traits. Access to next-generation sequencing technologies, high phenotypic data and a variety of sophisticated statistical tools have enabled LD-based association mapping studies in plants to identify gene loci controlling quantitative traits successfully. Alternatively, the LD-based association mapping (AM) approach can enhance the genetic map resolution to a greater extent due to the representation of a more comprehensive gene pool and more recombination events in history. Association mapping has emerged as a tool to resolve complex trait variation down to the sequence level by exploiting evolutionary recombination events at the population level. Genetic diversity, LD extent in genome and intra-population relationship, determine quality of mapping, marker diversity, statistical methods and power of mapping. LD in population is the foundation of GWAS, whereas it is always affected by genetic drift, population stratification and natural selection. Of the above threats, population stratification is recognized as a major one to the validity of GWAS results. Therefore, knowledge concerning the pattern of LD is essential for performing GWAS and GS. As one of the most important measures in population genetics, LD is the basis of effective population size estimation, genomic selection, GWAS study and QTL mapping. Due to the importance of LD method in mapping studies of the quantitative traits, in this review, we will present LD, its application in population, current status, limitations, and its use in plant breeding, especially in cereals. Finally, this study provides some information about commonly used statistical software and packages in the calculation of LD, and the challenges and perspectives of this approach have been discussed in this study as well.

Agriculture is one of the most important economic activities highly dependent on climatic conditions more than any other factors. Climate change significantly affects crop production. Due to the limitation in production factors, inputs, climatic and geographic properties of different provinces, identification of the comparative advantage of crops is essential. Lack of knowledge about comparative advantage would lead to improper and non-optimal use of resources. Therefore, knowledge about comparative advantage in different regions is useful to plan and exploit the resources. The present study was conducted to identify the comparative advantage of some important rainfed winter crops.

In the agronomic section of this study, the yield of rainfed crops including wheat, barley, chickpea and lentil in Ardabil, Fars and Khorasan Razavi provinces were simulated using the SSM-iCrop2 model. Long-term meteorological data were used to decrease climatic fluctuations and more precise estimation. Economic evaluations were performed using policy analysis matrix (PAM), domestic resource cost (DRC) and social cost-benefit index (SCB) methods. Also, nominal protection coefficient (NPC), effective protection of crops (EPC) and nominal protection input (NPI) were measured. In the agronomic section of this study, the yield of each region was simulated according to the climatic conditions and using the SSM-iCrop2 model (to determine the production potential of each region). For this purpose, long-term weather data were used and simulation was done for a 30-year period from 1986 to 2015. Under the moderate production conditions (moderate agronomic management or unsuitable climatic conditions), 50 percent of the yield potential, and under the optimum production conditions (optimum agronomic management or good climatic conditions), 70 percent of the potential yield is attainable. Therefore, 50 and 70 percent of yield potential were simulated using the SSM-iCrop2 model and their effect on comparative advantage and social profit were investigated.

The results indicate that according to the DRC index, Ardabil in wheat, chickpea and lentil production, Khorasan Razavi in chickpea and lentil and Fars in chickpea production have a comparative advantage. Based on the SCB index, the production of wheat in Ardabil, chickpea in all three provinces and lentil in Ardabil and Khorasan Razavi provinces have social profit. According to the results, increase yield leads to improved comparative advantage and social profit so that all three provinces will have social profit in crop production (rainfed, wheat, barley, chickpea and lentil) provided that the farmers attain at least 50 percent of the yield potential (exploitable yield). According to the results of the simulation, Fars and Ardabil had the highest exploitable yield in wheat production, and regarding barley, chickpea and lentil, the highest exploitable yield was related to Ardabil province. Based on the actual yields, only Ardabil province had high yields and was superior to other provinces in terms of the economic indices.

Wheat, barley, chickpea and lentil crops had higher yield in Ardabil province due to the suitable climatic conditions of this region. One of the reasons for the advantage of crop production in Ardabil is its higher yield which has increased the income of growers compared with the other two provinces, and production of rainfed crops in this province has led to benefits.

In order to investigate the possibility of reducing the negative effects of heat stress at the end of the wheat season by using Silicon nanoparticles and mycorrhiza, this experiment was carried out in a split form in the form of a Randomized Complete Block Design in three replications in the crop year 2018-2019 in the research farm of the Faculty of Agriculture of Lorestan University. The main factor is the interruption of irrigation at the end of the season in the three control levels (normal irrigation), the interruption of irrigation from the flowering stage and the interruption of irrigation from the milking stage to the end of growth and the first secondary factor, silicon nanoparticles in the three levels of not using silicon nanoparticles, silicon nanoparticles 40 mg/liter and silicon nanoparticles 80 mg/liter and the second factor was mycorrhiza biofertilizer in two levels of not using mycorrhiza and using mycorrhiza. The interaction effect of three treatments showed that in the treatment of normal irrigation + Silicon nanoparticles 40 mg/liter + mycorrhiza, the highest seed yield (5279 kg/ha), 1000 seed weight (36.87 grams), number of seeds per spike (46.3 units), the number of spikes per square meter (699 units), raw protein yield and biological yield (774 and 15150 kg/ha) were obtained, on the other hand, in the treatment of stopping irrigation in the flowering stage and not using silicon nanoparticles and mycorrhiza, the most The percentage of crude seed protein (17.33%) was obtained. it is worth mentioning that the highest harvest index (37.70%) belonged to the treatment of stopping irrigation at the milking stage + 80 mg/liter of silicon nanoparticles + mycorrhizal inoculation. In this experiment, differences of 60.45, 40.22 and 55.91 were observed between the highest and lowest seed yield, protein yield and biological yield. The results showed that the use of mycorrhiza biofertilizer and Silicon nanoparticles were useful for increasing the quantity and quality of wheat, especially at the end of the growing season. Considering that the sources of Silicon and mycorrhizal fungi are obtained at the lowest cost, therefore, it is suggested that farmers use the above inputs in wheat cultivation in order to produce more.

At present, cereal bran is offered in our country without any processing to remove anti-nutritional compounds which can have adverse effects on consumers health. In this study, the effects of different conditions (power and time) of microwave treatment on the moisture content, anti-nutritional compounds (phytic acid and oxalic acid) and shelf life of barley, oat, and rice bran were evaluated. The samples were treated with microwave power of 2, 4, 6, 8 and 10 kW for 15, 30, 60, 90 and 120 s. The most optimum treatment to reduce moisture for barley, oat, and Iranian rice bran was 8 kW for 120 s. During the treatment at 8 and 10 kW microwave power for 120 s, around 50% loss in phytate and oxalate content was observed. There was no statistically significant difference between the results obtained for 8 and 10 kW radiation power. Therefore, treatment at 8 kW for 120 s to reduce phytate and oxalate in brans was identified as the optimal treatment. During the 28-day storage period under accelerated conditions, no statistically significant difference was observed between the moisture content and the percentage of free fatty acids in the treated samples with power of 8 and 10 kW. The results of the present study showed that treatment with 8 kW microwave power for 120 s for barley and rice brans and 10 kW for oat bran significantly reduced the amount of moisture, anti-nutritional factors of phytic acid and oxalic acid in all three bran samples and also reduced the amount of moisture, reduced lipase activity and production of free fatty acid during the 28-day accelerated storage period.

Crop rotation is an annual succession of crops grown on the same land. Good crop rotation is a systematic succession of the different classes of farm crops. Crop rotation should be done in such a way to give large yields and provide the farm at the least expense of labor and fertilizes the soil. Pulses in crop rotations can improve the productivity of subsequent crops due to increased soil available N and other agronomic benefits. However, the magnitude of this effect can vary with environmental conditions, agricultural management practices and legume genotypes. Also, Legume plants can promote C storage by enhancing the formation and stabilization of soil aggregates that protect soil organic C from mineralization. In order to Evaluation of Nitrogen Use efficiency and Wheat Growth and Yield under Fertilizer Management and Pre-Cropping with crops an experiment was conducted.

A factorial experiment was designed based on randomized complete blocks with three replications and implemented on a sandy clay soil during 2012-13 and 2013-14 growing seasons, at the Agricultural Research Station, Faculty of Agriculture, University of Bu-Ali Sina, Hamedan, Iran. The first factor consisted of chickpea and corn (forage) and the second factor was urea fertilizer levels of 0, 40, 80, 120, 160 and 200 kg/ha. Harvest operation was done on July, 2013 and 2014. SAS procedures and programs were used for analysis of variance (ANOVA) calculations.

The results showed that about all of the evaluated properties of wheat affected by pre-cropping and nitrogen fertilizer treatments. But, none of the wheat traits do not affect by pre-cropping × nitrogen fertilizer. The highest biological yield (1486 g m-2), grain yield (675 g m-2) and protein percentage (13.70%) were observed in chickpea pre-cropping treatment. Chickpea pre-cropping treatment increased wheat biological yield and grain yield and protein percentage about 17, 21 and 18 percent in comparison to corn pre-cropping treatment. Pay attention to the improved physicochemical conditions of the soil after cropping legumes such as chickpea, it is normal to improve the growth and yield characteristics of the next crop (in this study, wheat). Among the nitrogen fertilizer levels the lowest wheat biological yield and grain yield and protein percentage (about 1102 and 417 g m-2 and 11.06%, respectively) was achieved at 0 kg ha-1 N fertilizer consumption. Also, the highest wheat biological yield and grain yield and protein percentage (about 1544 and 775 g m-2 and 13.24%, respectively) was observed at 200 kg ha-1 N fertilizer consumption, but it had not significant difference with 160 kg/ha treatment. One of the most well-known effects of nitrogen fertilizers is to increase the crops properties of growth and yield. The highest nitrogen use efficiency was observed at chickpea pre-cropping and lowest level of fertilizer application. In this study, wheat growth and yield characteristics such as plant height, chlorophyll index, grain yield components, biological and grain yield, harvest index, and percentage of grain protein increased due to urea application.

It seems that in the wheat farming, legumes pre-cropping such as chickpea pre-cropping is a good solution to reduce the use of nitrogen fertilizers and to contribute to environmental health. Also, attention to optimum fertilizer levels and non-overuse of fertilizers will contribute to agricultural sustainability.