جستجوی مقالات مرتبط با کلیدواژه « عملکرد دانه » در نشریات گروه « زراعت »

With the increase in population and improvement in diet diversity, there is a growing need for the quantitative and qualitative development of oil seeds. Camelina (Camelina sativa), an oil seed plant from the Brassicaceae family, is an ideal candidate as it contains 50 to 60% unsaturated fatty acids and omega-3 fatty acids, and has the ability to thrive in adverse environmental conditions. By introducing this new oil plant into cultivation programs, it can significantly contribute to the production of high-quality edible or non-edible oil in the developing countries such as Iran. However, achieving maximum grain yield and appropriate fatty acid composition in camelina oil relies heavily on selecting the appropriate planting date. Additionally, providing necessary nutrients, particularly nitrogen, to the plants is a key aspect of agricultural management to achieve desired quality and quantity of crop products. This research aims to investigate the impact of planting date and different levels of chemical and biological nitrogen fertilizers on the growth characteristics, yield, and oil content of camelina plants in the Eghlid, south of Iran.

This research was conducted in the cropping year of 2021-2022 at the Eghlid Agricultural Research Station in Fars province, south of Iran (Long. 52 42, Lat. 30 55, and Alt. 2375 m above sea level). The experiment was performed as a split-plot design based on a randomized complete block design with three replications. The main plots included different nitrogen fertilizers at four levels: 100% chemical nitrogen (250 kg/ha urea), 75% chemical nitrogen (187 kg/ha urea) + nitrogen biofertilizer, 50% chemical nitrogen (125 kg/ha urea) + nitrogen biofertilizer, and non-use of nitrogen fertilizer (control). The sub-plots included four planting dates: September 11, 2021, September 26, 2021, April 9, 2022, and April 24, 2022. The experimental plots (sub-plots) were determined to be 5 x 2 meters. Each plot consisted of 4 stacks with a distance of 50 cm between them. The distance between sub-plots was 50 cm, the distance between main plots was 150 cm, and the distance between replications (blocks) was 300 cm. On both sides of each stack, seeds were planted in two rows with a distance of 25 cm to achieve a density of 120 plants/m2. One-thirds of the urea nitrogen fertilizer was added to the plots of each treatment before planting, one-thirds at the 6-8 leaf stage, and the remaining third at the stemming stage of camelina. In the biofertilizer treatment, the camelina seeds were inoculated with biofertilizer containing Azotobacter sp. and Azospirillum sp. before being sown. The cumulative growth degree days of seedling emergence, flowering, and ripening, as well as plant height, chlorophyll index, grain yield, yield components and seed oil percentage were evaluated.

With delaying planting from September 11, 2021, to April 24, 2022, the GDD (Growing Degree Days) for camelina emergence decreased, additionally, a delay in planting led to a shorter growth period until full flowering of the camelina plants. Planting in September 26, 2021, led to the longest growth period until full maturity of the camelina plants, while spring planting resulted in a decreased length of the growth period until maturity. The highest plant height (43 cm) was achieved in the presence of 75% chemical fertilizer + biofertilizer nitrogen and the lowest (41 cm) was in the absence of nitrogen fertilizer application. The planting date of September 11, 2021 and April 24, 2022 showed the highest (43 cm) and lowest (37 cm) plant height of camelina. The decrease in plant height during the late planting date was primarily due to the decrease in internode elongation as a result of changes in day length and a shorter vegetative growth period. The highest chlorophyll index (66) was achieved by using 100% nitrogen chemical fertilizer, while the lowest chlorophyll index (52) was observed in the control, lack of fertilizer application. This trait decreased when the planting was delayed. The delay in planting led to a decrease in leaf area, resulting in a decrease in the chlorophyll index during the late planting date. No application of nitrogen fertilizer had the highest seed oil percentage (29.4%), while the application of 75% chemical fertilizer + biofertilizer nitrogen resulted in the lowest oil percentage (18.5%). The delay in planting from early autumn to late spring led to a decrease in the seed oil percentage. This decrease can be attributed to increase in nitrogen content, which promotes the formation of nitrogenous protein precursors. Consequently, more photoassimilates are allocated to protein formation, reducing the available photoassimilates for fatty acid synthesis and, ultimately, limiting oil production capacity. The decrease in oil percentage observed in the most delayed planting dates is likely due to the increase in temperature during the seed filling stage and the reduction in net photosynthesis.
Mean comparison of the interaction between nitrogen fertilizer and planting date on camelina grain yield showed that applying 75% chemical fertilizer + biofertilizer nitrogen, compared to no nitrogen fertilizer, on planting dates of September 11, 2021, September 26, 2021, April 9, 2022, and April 24, 2022, increased grain yield of camelina by 80, 100, 150, and 190 percent, respectively.

The Findings show that in the Eghlid region, autumn-sown camellia out-yields spring-sown one. Additionally, by using a combination of 75% chemical fertilizer and nitrogen biofertilizer, a higher grain yield is achieved compared to using 100% nitrogen chemical fertilizer alone. Considering the importance of production of oilseed plants, like camellia, in Iran and the need for sustainable plant production programs, it appears that growth-promoting bacteria can play a significant role in reducing the need for nitrogen fertilizers.

 Sesame is one of the most important oil plants in the world, especially in arid and semi-arid regions and is known as the queen of oil seeds. The high percentage of oil with the combination of suitable fatty acids, medicinal properties and very low water requirement are the characteristics of this oil plant. The main challenge for the lack of development of sesame cultivation all over the world is seed shattering at the time of ripening. Many efforts have been made to obtain non-shattering sesame cultivars with the characteristics of indehiscent capsule at the ripening stage and resistance to seed loss. In this article, we introduce and evaluate the agronomic characteristics of new indehiscent sesame cultivars named Barkat, Mohajer, Chamran and Dezful.

 Indehiscent sesame cultivars with the proposed names of Barkat, Mohajer, Chamran and Dezful have been improved during a breeding program at Shahid Chamran University of Ahvaz in collaboration with Shahid Rajaei Agriculture Company. For registration and commercialization, these cultivars were subjected to Distinctness, Uniformity and Stability (DUS) tests and agricultural Value of Cultivation and Use (VCU) experiments under the supervision of the Seed & Plant Certification and Registration Research Institute during the two cropping years 2022-2023. In these experiments, new indehiscent sesame cultivars along with commercial cultivars of dehiscent sesame named Oltan, Sardar and Shevin as control cultivars were evaluated in four regions with different climatic conditions of Iran, including Dezful, Darab, Mughan and Gorgan in the frame of complete blocks design with four replications. In addition, the mechanized cultivation of four promising indehiscent sesame cultivars was performed separately in 100-hectare fields in the Dezful region, and harvesting was done with a combine harvester.

The highest plant height was obtained in Barkat with an average of 144 cm and the lowest in Chamran with 140 cm. The highest number of capsules per plant, with an average of 89.8 and the highest number of seeds per capsule, with an average of 72.3, was observed in the Mohajer. The thousand-seed weight was reported between 2.41 and 3.72 g in Dezful and Mohajer respectively. A significant difference (P≤0.01) was observed in the group comparison between indehiscent and dehiscent (control) sesame cultivars, whilst dehiscent cultivars with an average of 1.05 tons per hectare were completely superior to the control cultivars with 0.80 tons per hectare. The highest average seed yield of cultivars in different regions during two years of experiment was obtained with 1.08 tons per hectare in Barkat and Mohajer cultivars. In the mechanized harvesting of indehiscent sesame cultivars with a combine harvester, the amount of seed loss was estimated to be less than 2.8%. The evaluation of morphological traits showed that indehiscent sesame cultivars had indeterminate growth habits and could produce 1-6 sub-branches per plant depending on the genotype and plant density. The superiority of seed yield for all indehiscent sesame cultivars was observed in compare with the control cultivars. The indehiscent sesame cultivars had appropriate agronomic features and could increasing about 24% seed yield in compare to control cultivars. This issue promises a significant increase in sesame production in Iran.

Finally, Barkat, Mohajer, Chamran and Dezful sesame cultivars were introduced as the first cultivars with resistance to seed shattering during ripening in the country. In addition to the higher seed yield in compare to the control cultivars. These cultivars are able to be harvested using a combine harvester in the mechanized systems at the time of full ripening. Ultimately, the widespread use of these cultivars in the agricultural cultivation pattern of the country promises food security in oil production and water consumption reduction in the stressful season of summer.

Aram is a new oilseed rape cultivar, extracted from the R308 (earlness line) and RGS003 (high-yield cultivar) cross population through pedigree method in three years. To reach high-yielding and compatible lines and cultivars, preliminary and advanced investigations were carried out in Gorgan and Sari (2014-2015) and Zabol, Gorgan, Sari and Borazjan (2016-2017). The line SRL-93-12 (Aram cultivar) with a yield of 2955 kgha-1 and 2774 kgha-1 was the first in the above-mentioned tests, respectively, and the SRL-93-12 line was also recognized as the most stable genotype based on the lowest Lins and Binns superiority index and highest seed yield. Extension research project results on farmers' farms in Behbahan, Moghan, and Gorgan regions showed that the new line with 594 kgha-1 higher yield than the check cultivar was in the first rank. According to the results as well as desirable agronomic traits such as good tolerance to dormancy and uniformity in maturity, this line was released with the name Aram.

Maize cultivar Chavoosh or single cross 380 (SC380) as a new early-maturing hybrid is produced from the crossing between KE76009/312 and K1263/1 maize inbred lines. In the preliminary yield trial, the new hybrid with 11.92 tha-1 grain yield in Karaj region in 2006 was included in the group of superior hybrids and was selected for studying in the next step in the semi-final yield trial in 2007. At this stage, the grain yield mean of the new hybrid in four regions (Karaj, Mashhad, Shiraz, and Kermanshah) was 12.18 tons per hectare that showed 910 kg per hectare increase in grain yield compared to the control cultivar Dehghan. The average grain yield of new hybrids in eight regions during 2014 and 2015 was 11.54 tons per hectare in the final stage experiment and showed the superiority of 750 kg compared to the control cultivar Dehghan. This superiority became more apparent because the new hybrid had 100 days growth period and was nine days earlier than the control hybrid Dehghan. The promising new hybrid also showed higher grain yield stability using GGE-biplot stability methods and Lin and Binns index. This new hybrid with an average grain yield of 12.28 tons per hectare showed a yield superiority of 1.15 tons per hectare compared to the control cultivar Dehghan in the yield trial in five regions (Karaj, Mashhad, Isfahan, Shiraz, and Kermanshah) in 2016. In the research-extension experiments in the Kermanshah region in 2016, the new cultivar (Chavoosh) and control cultivar Fajr produced similar grain yield (7 tons per hectare) that was lower than the control cultivar single cross 704, but for early-maturing hybrid Chaavosh less irrigation (in average, 2 to 3 times) was done. Therefore, it is estimated that using Chaavosh hybrid under pressurized irrigation systems can save about 800 to 1200 cubic meters, and under traditional irrigation systems can save about 1600 to 2400 cubic meters of water per hectare. In general, Chaavosh hybrid is recommended for spring planting in temperate and cold temperate regions due to its shorter growing period, lower water consumption and also its good grain yield. It is also recommended for summer planting in temperate regions.

Low diversity and poor genetic basis of germplasm in temperate regions is a significant challenge in maize breeding. Maize germplasms from tropical and subtropical regions often contain a broader genetic base and show larger diversity than germplasms from temperate regions. Therefore, it seems that foreign germplasms, especially germplasms from tropical and subtropical regions, can be used as a potential solution to strengthen the genetic base of germplasm in temperate regions. However, the efficiency of screening methods to identify superior and suitable sources of foreign germplasm remains a major challenge. The objective of this study was to determine the optimum number of testers and select suitable testers for screening maize lines derived from tropical and subtropical CIMMYT germplasm.

In this experiment, three testers of temperate regions (MO17, B73, K1264/5-1) were crossed with 25 lines originated from the CIMMYT maize germplasm based on line × tester mating system. A total of 75 crosses along with the control hybrid (SC704) were evaluated in alpha-lattice experimental design in two replications each with four incomplete blocks in two regions (Moghan and Jiroft). Analysis of variance was done based on line × tester method, as well as separation of the effect of crosses into its components using the method suggested by Kemptorn (1957). GGE-biplot graphical analysis based on the methodology proposed by Fan et al. (2010) was also used to estimate the effects of general combining ability (GCA) and specific combining ability (SCA).

The results showed that out of the 75 crosses, 32 crosses had higher and significant grain yield compared to the control hybrid SC704. The superiority of the superior cross compared to the control hybrid ranged from 1.46 to 3.77 tons per hectare. These findings highlighted the potential of utilizing tropical and subtropical CIMMYT germplasm to enhance maize yield in temperate regions of Iran. Based on the results, the lines No. 22, 9, 19, 12, 20, 5, 17, 21, 24, 14, 15, 23, and 11 had the highest positive GCA for grain yield, respectively. In general, in terms of grain yield, GCA, and SCA, it is possible to directly use lines No. 4, 5, 9, 11, 12, 19, 22, and 24 extracted from tropical and subtropical CIMMYT germplasm to improve grain yield in temperate regions. Evaluating the efficiency of the temperate maize testers also showed that two testers B73 and MO17 were highly efficient in selecting superior line derived from tropical and subtropical CIMMYT germplasm.

The results of the current study showed that it is possible to use maize germplasms from tropical and subtropical regions of CYMMIT to improve grain yield in temperate regions. Also, one temperate maize tester has the ability to distinguish superior sources (not all of them), although the use of two testers greatly reduces the risk of not choosing (deleion) a superior source.

The water deficit is one of the most important problems in rice cultivation, particularly when the decrease in rainfall and dry season affects its vegetative growth and grain yield. Drought stress is known as one of the most effective factors of yield reduction in crops. Identifying and introducing tolerant genotypes is a good way to cope incompatible environmental conditions. For easier evaluation of genotypes under drought conditions and identification of drought tolerant genotypes, various indices have been suggested as criteria for selection of genotypes based on their yield under stress and non-stress conditions. The present study was conducted to evaluate some rice genotypes under drought stress conditions as well as to introduce drought tolerant genotypes using important tolerance and sensitivity stress indices.

This experiment was conducted in split plots based on randomized complete block design with three replications in Azadshahr, Golestan province, Iran. The main factor included two irrigation levels (drought stress and flooding as control) and the sub-factor included eight rice varieties. The experimental plots were three m2 with a distance of one m from each other. After randomly assigning the treatments to the experimental units, transplanting was done as four plants per pile. Each genotype was cultivated in six two-meter rows with a distance of 25 × 25 cm. Irrigation of the experimental field under both stress and non-stress conditions until the tillering stage of the genotypes was conducted as flooding. Then, under stressful conditions, irrigation was carried out from 40 days after transplanting (maximum tillering stage) until the end of the cropping season at an interval of 25 days, which according to the climatic conditions of the studied region, irrigation was done only once in stressful conditions. From the six rows planted in each plot, one row from around each plot was removed as border and the second to fourth rows were selected for sampling. After measuring traits and calculating different indices, the data were analyzed by SAS software. Two-dimensional biplot diagram was also drawn by STATGRAPHIC software.    
Research

The results of analysis of variance showed a significant difference between the genotypes for all studied traits under both drought stress and flooded (control) conditions. Comparison of means showed that the highest average grain yield under both control and stress conditions belonged to Fajr, IRAT216, Sang-Jo, and Sang-Tarom Gerdeh genotypes, and the lowest grain yield belonged to the Sepidrood variety. The results of the correlation coefficients showed that grain yield in control conditions had a positive and significant correlation with mean productivity (MP), geometric mean productivity (GMP), harmonic mean (HARM), and drought tolerance (TOL) indices, respectively, and the highest correlation was observed between grain yield and MP index (r = 0.918). Also, under drought stress conditions, grain yield showed a high correlation with the harmonic mean (HARM), geometric mean productivity (GMP) and mean productivity (MP) indices, the highest of which was related to harmonic mean index (r = 0.933). The results of principal component analysis showed that 94.31% of the total variation between data was justified by the first and second principal components. Cluster analysis based on drought stress indices separated rice genotypes into three groups, and the genotypes in the first cluster had the highest drought tolerance.

The results of biplot analysis and correlation between stress indices indicated that GMP, MP, and HM indices were the best indices for selecting high-yielding genotypes under both stress and non-stress conditions in this experiment. Based on these indices and biplot diagram, Fajr, Sang-Tarom Gerdeh, Sang-Jo, and IRAT216 genotypes were identified as high-yielding and drought-tolerant genotypes, and Sepidrood and Gharib Siah Reyhani varieties as low yielding and drought sensitive genotypes.

Quinoa (Chenopodium quinoa L.) is a dicotyledonous, allotetraploid, three-carbon, annual, optional salt-loving plant and is native to South America and the Andean highlands. The growth period of the plant varies between 70 and 240 days depending on the cultivated area. The main product of this plant is the seed, which has a high nutritional value in terms of protein, amino acid balance, unsaturated fat, vitamins, and minerals. Like other plants, quinoa faces various environmental stresses during its growth period, and its growth and yield are a function of environmental factors and their mutual effects. The occurrence of high temperatures during the sensitive stages of plant growth, such as flowering and seed formation, may cause a significant decrease in quinoa yield, and high temperature has been cited as one of the most important challenges for the cultivation and expansion of quinoa in the world. Salicylic acid acts as a signal molecule and plays an important role in regulating growth and development processes in plants under environmental stress. Salicylic acid increases the content of relative humidity, accumulation of dry matter, and the amount of chlorophyll.

The objective of this research is to assess the physiological responses of quinoa cultivars to varying planting dates and the impact of foliar application of salicylic acid in mitigating the adverse effects of end-of-season heat stress during the 2021-2022 crop year. The study was conducted at the research farm of the Faculty of Agriculture, Shahid Chamran University of Ahvaz, using a split-split plot design within a randomized complete block framework, with three replications. In this experiment, three factors a) planting date including October 12, November 11, and December 11, and b) foliar application of salicylic acid in the two stages of budding and the beginning of flowering including non-application, 1.5 mM and 3 mM and c) Quinoa cultivars including Titicaca, Giza, Q12 and Redcarin were investigated.

The effect of investigated factors such as planting date, salicylic acid, and variety on different traits had statistically significant differences. The results showed that the maximum amount of stomatal conductance and the relative content of leaf water belonged to the date of October 12. The highest biological yield and seed yield were observed under conditions of application of 1.5 and 3 mM salicylic acid, respectively. Probably, salicylic acid has increased the growth and accumulation of dry matter by improving carbon fixation, synthesis of metabolites, and maintaining the water status of plant tissues. Based on the results of the comparison of the mean of the three-way interaction, the maximum amount of biological yield and seed as the most important goals of quinoa plant cultivation, respectively, in the treatment of not using salicylic acid in the Redcarin cultivar on the planting date of December 11 and the application of 3 mM salicylic acid was obtained in the variety Redcarin on the planting date of October 12. The highest rate of net assimilation and the growth rate of the product belonged to the treatments of no application of salicylic acid in the Redcarin cultivar on December 11 and no application of salicylic acid in the Giza cultivar on October 12, respectively. The treatment of not using salicylic acid in the Redcarin variety on the planting date of October 12 was also able to achieve a high harvest index.

 According to the obtained results, it seems that to achieve a high seed yield of quinoa, it is possible to benefit from the treatment of 3 mM salicylic acid in the Redcarin variety on the planting date of October 12.

Environmental disorders that significantly disturb the growth and yield of plants are considered as stress conditions and cause disturbances in biological. Drought stress is one of these environmental conditions which has been increased as a result of climate change and has been a negative effect on the yield of crops in the world. Every year about 12 million hectares of productive land has become dry and barren due to human activities and climate. More than 6000 varieties of quinoa are cultivated by farmers in the worlds. Quinoa is a plant responds to drought stress through escape, tolerance and avoidance of drought and has an extraordinary capacity for cultivation in dry and low-water soils because of its capabilities such as low inherent need for water, the maintenance of leaf surface and the ability to resume the speed of photosynthesis after drought stress. Titicaca, Redcarina and Giza-1 are three quinoa cultivars. Titicaca and Redcarina, were registered on December 14, 2009 and January 31, 2005, respectively, and are native to Denmark and Netherlands, respectively, and Giza1 is native to Egypt. Increasing yield in water deficit conditions requires the identification of genotypes resistant to drought stress. Different quantitative indicators have been provided to evaluate the reaction of genotypes in environmental conditions and also to determine their tolerance and sensitivity.

In order to evaluate the indicators of drought stress tolerance of quinoa cultivars, a factorial experiment with four stress levels (100, 75, 50 and 25% of water requirement) and three varieties of quinoa (Titicaca, Giza-1 and Redcarina) were conducted with three replications in two locations (Birjand and Sarbisheh region) and two planting dates, spring (March) and summer (July) in 2018 and 2019. Evaluation of cultivars in terms of drought tolerance was done using stress sensitivity indices, such as tolerance (TOL), mean productivity (MP), stress tolerance index (STI), geometric mean productivity (GMP) and harmonic mean (HM). Decomposition into main components on yield under stress and non-stress conditions and drought stress tolerance indices were displayed in the form of a biplot diagram using STATISTICA software.

The results showed that in both regions the highest amount of STI, MP, GMP and HM indices, were recorded for Redcarina variety in all three levels of drought stress at spring cultivation, but they were belonged to Giza-1 at summer cultivation. Due to the dispersion of the results, SSI and TOL indices had less diagnostic power to evaluate the drought tolerance of quinoa cultivars. Principal components analysis showed that Redcarina cultivar was collinear with yield vector in stress condition and MP, GMP, STI and HM indicators and was located in yield potential and tension tolerant area in bi-plot diagram in two regions (Birjand and Sarbisheh) at spring cultivation. In summer cultivation, Giza-1 variety was located at sensitive to stress area and yield potential in bi-plot diagram and was collinear with grain yield vectors in non-stress conditions and MP, GMP, STI and HM indices in two regions. This showed the more yield of this variety in non-stress condition. In most of the planting dates and places were studied, Titicaca cultivar had collinearity with SSI vector or located at the closest position to this vector, which indicated that this cultivar was sensitive to stress.

In general, in July, Giza-1 variety and in March Redcarina variety were the most tolerance varieties and Titicaca was most sensitive cultivar to drought stress.
Keywords

Beans are one of the cheap and important sources of high-quality vegetable protein, which is present in the diet of many people in developing countries and completes the cereal protein. Bean seeds have almost as much energy per unit weight as cereal seeds, and their protein content varies from 20-25% (about twice that of cereal). With 8-14% protein content, bean straw is very suitable fodder for livestock. The production of vegetable protein of grains has several advantages over animal protein in terms of cost and consumer health. Among other features of this plant, we can point to the ability to coexist with air nitrogen-fixing bacteria and their role in productivity, as well as strengthening and improving the physical properties of the soil. Through the ability of nitrogen fixation in these plants, placing them in rotation helps the stability of agricultural systems. At present, the largest area of bean cultivation is in the form of traditional cultivation and bean irrigation is also in the form of flooding. In this production method, more than 15,000 cubic meters of water is consumed. This amount of water consumption, along with the lack of proper productivity of other factors in production, has caused beans to be one of the least efficient products in terms of water consumption efficiency.
 

In order to investigate the effect of four irrigation methods on the damage of weeds, two-spotted spider mite (Tetranychus urticae Koch) and bacterial blight disease in chitti bean (Phaseolus vulgaris L.), a research study was conducted in 2022 and 2023 at the Bean Research and Education Center in Khomein, Iran. Despite employing a field with uniform conditions, the study was designed as a multi-location (regional) experiment using a randomized complete block design with three replications. The irrigation methods were categorized into four treatment levels: classical sprinkler irrigation, New-fit sprinkler irrigation, rain flat irrigation, and drip tape irrigation. Different types of chitti bean cultivars with three growth habits were randomly sown in these locations.
 

The experimental results showed that the irrigation method had a significant effect on seed germination percentage and bean plant height. The highest and lowest seed germination percentage and plant height were associated with drip tape irrigation and classical sprinkler irrigation, respectively. Also, the type of irrigation significantly impacted weed density, total biomass of weeds, the intensity of two spotted spider mite infestation, and bacterial blight disease. The highest weed density and biomass were observed in the New-fit and classical sprinkler irrigation methods, and the classical sprinkler irrigation exhibited the highest incidence of bacterial blight disease, too. Conversely, the lowest values for these parameters were obtained with the drip tape irrigation method. However, the highest damage caused by two spotted spider mite was observed in the drip tape irrigation method, while the lowest damage by two spotted spider mite was present in the classical sprinkler irrigation method. Furthermore, both irrigation method and bean cultivar significantly affected bean grain yield. The highest grain yield (293.6 g.m-2) was associated with drip tape irrigation, while the lowest yield (225.4 g.m-2) was observed in the classical sprinkler irrigation treatment. Among the different bean cultivars, the highest grain yield (274.1 g.m-2) was obtained from the Kousha cultivar. One of the important solutions in achieving the goals of reducing water consumption and increasing the efficiency of water consumption in bean cultivation is the implementation of pressurized irrigation instead of conventional cultivation. Pressure irrigation methods in planting beans reduce water consumption to a great extent and increase the efficiency of water consumption. The two main methods of irrigation under pressure in the country are the drip tape method and the fixed classical sprinkler with a movable sprinkler, each of which has its own advantages and disadvantages. In addition to the positive aspects of increasing yield, drip tape irrigation method in bean planting will help to further reduce water consumption.
 

In general, the experiment results demonstrated that drip tape irrigation not only increased seed germination percentage and plant height in different bean cultivars, but also led to higher grain yield compared to other irrigation methods. Additionally, the presence of weeds and bacterial blight disease were reduced in the drip tape irrigation method.

Maize is an important crop that is cultivated in many parts of the world. The evaluation of genotypes in breeding programs often faces two important challenges, the genotype × environment interaction effect for the target trait and unfavorable relationships between the target traits. Even though many methods have been offered for stability analysis, especially graphical tools and their relatively good efficiency in interpreting the results, it seems that the best linear unbiased predictions (BLUP) method estimates the means with high accuracy, especially in mixed models, in multi-environmental trails (MET). Therefore, the stability index of weighted average absolute scores (WAASB), which is estimated from the integration of the two stability methods of additive main effect and multiplicative interaction (AMMI) and best linear unbiased predictions, can be used in METs to estimate more accurately the stability of genotypes. Maize breeding programs prioritize high grain yields and earliness as important traits. The multi-trait stability index (MTSI) is a valuable tool for the simultaneous selection of multiple traits. It is estimated based on the average performance and simultaneous stability of genotypes in different traits and environments. Therefore, the current research aimed to identify stable and high grain yield maize hybrids along with the optimal level of grain moisture percentage at harvest time and days to physiological maturity using the integration of AMMI and BLUP methods with WAASB, WAASBY, and MTSI indices.

This study involved the evaluation of seven promising maize hybrids along with four commercial check varieties, including SC647, TWC647, SC704, and SC715, in maize METs based on a randomized complete block design with four replications across 10 regions (Karaj, Moghan, Shiraz, Kermanshah, Kerman, Mashhad, Dezful, Miyandoab, Jiroft, and Mazandaran) during two cropping seasons of 2019-2020. The recorded traits were grain yield adjusted at 14% moisture content, grain moisture percentage at harvest time, and days to physiological maturity. The WAASB was used to estimate genotypic stability for each genotype. It was computed from the singular value decomposition (SVD) of the matrix of best linear unbiased predictions of genotype vs. environment interaction effects generated by a linear mixed-effect model. The WAASBY index for simultaneous selection based on grain yield (Y) and stability (WAASB) was  estimated by assigning different weights to grain yield and stability. The simultaneous selection for grain yield and stability based on several traits was conducted using the scores obtained from an exploratory factor analysis (MTSI).

Based on the grain yield across 10 environments over two years, promising hybrid NO. 3 had the highest grain yield with 12.80 tons per hectare. According to the likelihood ratio test (LRT), the genotype-by-environment interaction was significant for the traits of grain yield, grain moisture percent at harvest time, and the days to physiological maturity. Therefore, BLUP analysis can be performed on these data due to the significant genotype by environment interaction. The BLUPs performed for hybrids were followed by stability analysis using the AMMI method on these BLUPs. The results indicated that the first and second components justified 27.7% and 24.6% of the hybrid by environment interaction variances, respectively. The highest predicted grain yield by the BLUP method belonged to hybrids No. 3, 2, 4, and 1, with higher than average predicted grain yields. Based on the biplot for the first principal component of the environments against the nominal grain yield, hybrids 2, 6, 3, and 1, having the lowest scores of the first principal component (coefficient b or line slope), had a negligible contribution to the hybrid by environment interaction and were distinguished stable. To enable simultaneous selection based on both grain yield and stability, the WAASBY index was estimated by integrating grain yield (Y) and the WAASB stability index. Considering the 50% contribution of each of the two grain yield and yield stability components, five hybrids (1, 2, 3, 6, and 4) showed above-average WAASBY. Among these, hybrids 1, 2, and 3 had significantly higher WAASBY than the other hybrids. All four control cultivars SC647, TWC647, SC704, and SC715 had lower-than-average WAASBY. Based on the MTSI, hybrid 3 was selected as the best hybrid. In addition, the estimated variance components by restricted maximum likelihood (REML) for grain yield indicated that 75.72% and 7.57% of the phenotypic variance were explained by the environment and GEI variances, respectively, whereas the contribution of residual variance to the phenotypic variance was 16.77%.

Based on the results, hybrid 3 (K47/2-2-1-4-2-1-1-1× MO17) was identified as a high-yielding hybrid, which can be introduced to farmers as a new superior maize hybrid. It seems that the use of the ratio of the WAASB stability index to grain yield (WAASB/Y) and the selection of superior genotypes based on the MTSI could identify hybrids with high grain yields, stability, and desirable levels of important agronomic traits.

As one of the most important cereals, bread wheat is an essential part of food security in the world, which supplies one-fifth of the total calories of the world population. Nowadays, the yield of wheat has been affected by climate change-driven drought as one of the most important abiotic stresses that has become an important threat to food security in the world. Root and stomatal traits are especially important in breeding plants to withstand drought stress. Stomata play a key role in controlling carbon dioxide uptake and water loss through transpiration. Therefore, stomatal characteristics are used as indicators of water status and plant growth, especially in drought stress conditions. Having a wide range of physiological and morphological characteristics, roots play an essential role in absorbing water and nutrients. They are also the first organ that sends signals to control the stomata in response to dryness. Therefore, the difference in the structure of the root system can cause the difference between the performance in different cultivars. This study was conducted to investigate stomatal characteristics and their relationship with the root system and plant performance in 24 bread wheat lines and cultivars.

To investigate the relationship between stomatal dimensions and density with the root system, an experiment was conducted on 24 bread wheat genotypes in the form of a randomized complete block design with three replications in the rainfed conditions of the research farm at Zanjan University Faculty of Agriculture in the crop year 2018-2019. In this experiment, PVC pipes were used to study the root system. Twelve seeds were planted in each tube, which were thinned to seven after germination. In each experimental unit, there were two tubes for each genotype, one of which was used to evaluate traits and final yield, and the second tube was used for root studies. Stomatal traits, including the length and width of stomata and number of stomata per unit area, root traits including root length, root diameter, root volume, root surface, and root biomass, and seed yield were measured in the end. The resulting data from the measured traits were analyzed in the form of a randomized complete block design, and the averages were compared using the LSD method. The data were analyzed using multivariate statistical analyses, including regression analysis, path analysis, and factor analysis, and cluster analysis was used to group genotypes. Statistical calculations were done using SAS 9.0 and SPSS 21 software.

The results of analysis of variance and mean comparison showed high variability among genotypes for all measured traits. The results of the mean comparison of genotypes showed that genotypes 2, 5, 8, and 16 had the highest yield, and genotype 23 had the lowest yield among the examined genotypes. The highest number of stomata on the upper and lower leaf surfaces belonged to genotypes 5 and 2. In terms of root traits, the highest diameter, volume, length, root surface, and root dry weight at a depth of 0-25 cm were recorded for genotypes 2, 3, 18, and 5, respectively. There was a high and significant correlation between the yield and the number of stomata on the upper and lower leaf surfaces, the length and width of  the stomata on the upper leaf surface, diameter, volume, dry weight, and root surface at a depth of 0-25 cm in the soil. Based on the results of stepwise regression analysis, two variables, the number of stomata on the lower leaf surface and root dry weight at a depth of more than 25 cm explained 91.4% of the changes in grain yield. According to the results of the causality analysis of the number of stomata on the lower leaf surface, the most direct effect had a positive effect on seed yield. The results of factor analysis grouped the studied traits into three factors with 82.48% variability justification. The shares of the first, second, and third factors to explaining data changes were 48.86%, 24.62%, and 8.99%, respectively. Based on the plot obtained from factor analysis, genotypes 2, 5, 8, and 16 had high values for the first and second factors. According to the coefficients of the factors, it can be claimed that the genotypes located in this area have high performance, a high number of stomata, and strong root traits, which were found at the soil depth of 0-25 cm. For this reason, these are the genotypes that could produce high yields by absorbing water from the surface layers of the soil by having a large number of stomata and carrying out more photosynthesis. Moreover, the investigated genotypes were divided into three groups from cluster analysis by the ward method and Euclidean distance. Genotypes 2, 5, 8, and 16 were placed in the first group and had the highest mean values for grain yield traits, number and width of stomata on the upper and lower leaf surfaces, and root traits including diameter, volume, and dry weight at a soil depth of 0-25 cm, and root diameter at a depth greater than 25 cm. The lowest values for stomatal length were observed in both leaf surfaces. These were the best genotypes for cultivation in dry conditions.

A strong superficial root system can provide the plant with water from scattered rains that occur with low frequency at the end of the growth period. On the other hand, the increase in the number of stomata along with their smaller size reduces leaf pores and enables a faster response of the stomata, and the rapid response of the stomata maximizes water use efficiency. Therefore, having a strong superficial root system along with high stomatal density can increase seed yield in dry conditions.

Intercropping is one of the most important crop management methods to achieve sustainable agriculture goals. Therefore this study was conducted to evaluate safflower with lentil intercropping under dryland conditions.

The experiment was conducted as a randomized complete block design with three replications and five treatments during 2018-2019 at the research farm of the Razi University. The experimental treatments included Safflower monoculture, Safflower and Lentil intercropping with 25:75 ratio, Safflower and Lentil intercropping with 50:50 ratio, Safflower and Lentil intercropping with 75:25 ratio, and Lentil monoculture. Safflower was considered as the main plant and Lentil as the alternative plant. The evaluated traits were leaf area index, radiation absorption, crop growth rate, relative growth rate, total dry matter, radiation use efficiency, and grain yield.

 The results showed that the leaf area index and consequently, radiation absorption in intercropping compared to monoculture increased by 6.2% and 48%, respectively. Trend of changes in safflower’s crop growth rate in intercropping canopy compared to monoculture did not change, but the relative growth rate showed a 7.7%increase. The amount of total dry matter and radiation use efficiency in intercropping canopy did not change much compared to monoculture. Grain yield of Safflower was higher in monoculture (2472 kg.ha-1), which did not significantly differ from the treatments with 75:25 (2294 kg.ha-1) and 50:50 (2107 kg.ha-1) ratio of Safflower and Lentil.

Generally, the results showed that the intercropping of safflower with lentils was not economically beneficial, however, alternative intercropping patterns with ratios of 25:75 and 50:50 of safflower and lentil were more efficient in terms of the investigated traits.

Among the most common problems and stress in the conditions of Khuzestan province, heat stress at the end of the season and the deficiency of nutrients, which occurs in different periods of rapeseed growth, depending on their severity, causes physiological and metabolic disorders and ultimately reduces the yield of rapeseed plants with different intensity depending on the type of plant genotype, they affect

With the aim of evaluating the growth and yield response of rapeseed cultivars (Brassica napus) to boron element levels in late season heat stress conditions caused by late sowings dates, this study was carried out in a split-split plot arrangement in the form of a randomized complete block design with three replications. The expeiment was carried out in the crop year of 2021-2022 in the research farm of Agricultural Sciences and Natural Resources University of Khuzestan. Sowings dates (November 21, December 11, and December 31) in the main plots, four levels of boron (zero, 4, 8, and 12 kg/ha) in the subplots and rapeseed cultivars (RGS, Zafar, and Saffar) in the sub-sub-plots were investigated.

The results of the research showed that sowing date and end of season heat stress in Khuzestan conditions had a significant effect on most of the studied physiological traits, seed yield and biological yield. In addition, the effect of boron on traits such as leaf area index, leaf area ratio, and relative moisture content of leaf water, leakage of electrolytes, grain yield and biological performance was significant. The triple interaction effect of planting date, boron and variety was also significant on traits such as relative moisture content of leaf water, leakage of electrolytes, grain yield, and biological performance. So that with the delay in planting and the consequent increase in temperature and heat stress at the end of the season in the period of growth of the rapeseed plant, it causes a decrease in traits such as leaf area index, relative moisture content of leaf water, leaf area ratio, leaf specific area, seed yield and biological yield. And conversely, due to the heat stress at the end of the season, the leakage of electrolytes and the canopy temperature increased significantly. In general, the highest seed yield was obtained in Safar variety on the sowing date of December 11 and the boron level was 4 kg/ha with an average of 4590 kg/ha. Also, the highest average leaf area index was observed on the first sowing date and Safar variety with an average of 5.43 and the lowest value was observed on the third sowing date and Safar variety with an average of 2.11. It was also observed that the application of boron caused a significant decrease in the leaf area index in all three studied cultivars. This issue can indicate the lower need of boron consumption of the studied cultivars in this experiment.

In general, the heat stress at the end of the season, which occurs in different periods of rapeseed growth, especially the seed filling period, depending on its intensity, causes physiological disorders in the plant and finally affects the grain yield with different intensity and depending on the genotype of the plant. The analyzed rapeseed genotypes also showed tolerance to different levels of boron element in the heat stress conditions of the end of the season and showed different reactions with different amounts of boron consumption per hectare.

Considering the speed of environmental changes and the extent of the data obtained from breeding evaluations, there is a need to employ fast and reliable data analysis methods. Biplot graphical methods greatly contribute to the advancement of breeding programs by offering the possibility of quick, comprehensive, and accurate analysis of information, along with easy interpretation of the results. A number of 100 oilseed sunflower genotypes were evaluated in terms of plant height, number of leaves, leaf length, leaf width, petiole length, stem diameter, chlorophyll content, days to flowering, days to maturity, head diameter, relative water content, seed oil percentage, and seed yield in the form of simple 10 x 10 lattice design under normal and limited irrigation conditions during 2012 and 2013. To identify the superior genotypes in each irrigation conditions, the genotype-trait biplot analysis method was used. Under both irrigation conditions, a high correlation was observed between the traits including leaf length, leaf width, stem diameter, head diameter, seed oil percentage, and petiole length with seed yield. In terms of all studied traits under both irrigation conditions, genotype with code number of 8 was the best and genotypes with code numbers of 59, 42, and 72 and genotypes with code numbers of 19, 59, and 17 were the worst genotypes under normal and drought stress conditions, respectively. Based on the results, the traits including stem diameter and head diameter can be used as indirect selection criteria for seed yield improvement under normal and drought stress conditions, respectively.

Pearl Millet (Pennisetum glaucum L.) is one of the most important crops in arid and semi-arid regions that are cultivated for grain and forage. Due to cross pollination and high heterosis, the development of hybrid varieties is the most important breeding method of pearl millet. In order to study the preliminary yield comparison of hybrid cultivars and investigate the possibility of replacing open-pollinated cultivars with hybrid cultivars, 11 promising pearl millet hybrid cultivars with a check variety (Mehran cultivar) were planted in the randomized complete block design with three replications in Karaj, Isfahan and Zabul. The days to 50% flowering, plant height, stem diameter, leaves number, panicle length, panicle thickness, tiller number, fresh fodder yield, dry matter yield, 1000 seed weight, and seed yield were evaluated. The results of combined variance analysis and mean comparisons showed that there is considerable genetic diversity for the studied traits. The results showed that the cultivars H294, H444, H504, H604, H824, and H794 had the highest grain yield compared to the total mean of the experiment. In addition, five cultivars H543, H333, H353, H563, and H604 were above of total average in terms of fodder production and had good potential to be used in the field as commercial cultivars with the aim of fodder and seed production.

The production of oilseeds plays a significant role in saving currency, accelerating the process of economic development, security and food independence of the country. Camellia (Camelina sativa L. Crantz) from Brassicaceae family, is able to grow in different weather and soil conditions and requires less water, fertilizer and pesticides than other oilseeds. Therefore, the current research was conducted with the aim of introducing this plant and evaluating its yield potential and cultivation compatibility in Mazandaran.

This experiment was carried out as factorial based on randomized complete block design in four replications at Bayekola Agricultural Research Station (Mazandaran Agricultural and Natural Resources Research and Training Center). Six sowing dates (November 5, November 21, December 5, December 21, January 4 and January 19) and five planting distances (15, 20, 25, 30, and 35 cm) were selected as the study factors.

The results of analysis of variance showed that the treatments of planting distance and planting date had a significant effect on different traits of camellia plant. Plant height, number of sub-branches and biological yield were influenced by the interaction effect of the studied factors. The highest plant height values were observed on the planting date of November 15 and at 20 and 30 cm intervals (125.5 and 124.75 cm, respectively). Also, the characteristics of seed yield, days to flowering, days to maturity, the number of seeds in a pod and 1000 grain weight were affected by sowing date factor, and the traits of days to flowering, days to maturity and 1000 grain weight were affected by planting distance factor.

In the field of seed production and obtaining more seed yield, although the planting dates of November 5 to December 5 did not have significant differences with each other; but the planting date of November 21 is the best possible planting date due to the highest seed yield and the higher number of seeds in the pod. Also, the treatment combination of planting distance of 25 cm and planting date of December 5 with high biological yield can be a suitable treatment combination.

After soybean and oil palm, rapeseed has the third place in supplying vegetable oil in the world, so that it accounts for 14.7% of the total production of vegetable oil. The current research was carried out using modeling approach in order to simulate the replacement of wheat cultivation with rapeseed cultivation in terms of water and economic productivity in four locations (Aleshtar, Khorramabad, Pol-e Dokhtar, and Kuhdasht) in Lorestan province. APSIM model was used to simulate the growth and yield of wheat and rapeseed crops. The model validation results showed that it accurately simulates wheat and rapeseed grain yield with nRMSE of 8.6%. The results showed that wheat cultivation (3524.4 kg) had a higher grain yield than rapeseed cultivation (2750.2 kg). In addition, wheat cultivation system (1.45 kg m-3) compared with rapeseed cultivation (1.15 kg m-3) had higher water productivity. However, the difference between these two cultivation systems in terms of irrigation productivity was not considerable (0.11 kg m3). Also, economic productivity and net income of rapeseed cultivation system were 0.220 million tomans per cubic meter and 59.9 million tomans per hectare, respectively, while they were 0.014 million tomans per cubic meter and 41.1 million tomans per hectare, respectively, for wheat cultivation system. In general, the results approved that moving from wheat cultivation to rapeseed cultivation can be environmentally and economically sustainable in the agro-ecosystems of Lorestan province, especially in Khorramabad county.

In order to effect of potassium nano chelate on physiological and yield characteristics of barley in irrigation cut-off conditions, this research was done as split plot in randomized complete blocks design with three replications. Main treatment consisted: full irrigation, no irrigation at the beginning of stem elongation, and no irrigation at the pollination stage and sub treatment consisted: no foliar application (control), 35 mg.L-1 and 65 mg.L-1 potassium nano chelate. results showed that the effect of deficit irrigation cut-off and potassium nano-chelate on number of spikes, number of seeds per spike, weight of 1000 seeds, grain yield, stomatal conductance, canopy temperature and relative water content leaf were statistically significant at 1% level of probability. Interaction irrigation cut-off and potassium nano-chelate number of spikes, weight of 1000 seeds, in canopy temperature and relative water content leaf were significant at 1% probability and stomatal conductance at 5% probability level. The highest grain yield was in full irrigation (control) (5308 kg.ha-1) and 65 mg.L-1 potassium nano-chelate (4854.9 kg.ha-1) and the lowest was in irrigation at anthesis (3169.4 kg.ha-1) and no foliar application (control) (3588 kg.ha-1). the maximum relative water content of leaf was in complete irrigation (control) and foliar application of 65 mg.L-1 potassium nano-fertilizer (73.13%) and the minimum was in non-irrigation at anthesis and non-foliar application of potassium nano-fertilizer (35.99%). maximum stomatal coductance was in complete irrigation (control) and foliar application of 65 mg.L-1 potassium nano-fertilizer (185.87 mlmol.m-2s-1) and the minimum was in non-irrigation at anthesis and non-foliar application of potassium nano-fertilizer (47.99 mlmol.m-2s-1). as a result, foliar application of 65 mg.L-1 potassium nano-fertilizer at different irrigation cut-off periods cause improves grain yield and leaf water in comparison to control (no foliar application) and is recommended.

Heavy metals especially cadmium (Cd), with potential toxicity and injurious effects for plants and humans, are one of the most important abiotic stresses for crop plants such as maize which lead to a considerable reduction in the crops production in developing countries including Iran. Therefore, assessing genetic diversity for Cd stress tolerance, as one of the basic principles of plant adaptation to abiotic stresses, is very important. In this regard, the present study was carried out to evaluate the genetic diversity of maize pure lines and hybrids based on important agronomic traits associated with grain yield under non-stress and Cd stress environmental conditions. The results of this research can be useful for maize breeders in identifying suitable parental genotypes for maize breeding programs to develop high-yielding and Cd stress-tolerant genotypes in regions contaminated to this heavy metal.

In this study, 95 maize genotypes comprising pure lines and hybrids, were evaluated in a randomized complete block design with three replications under two non-stress and Cd stress conditions. The experiment was performed in a pot experiment in an open area of the Agricultural and Natural Resources Research Station of Jiroft, Kerman province, Iran, in two cropping seasons, 2020-21 and 2021-22. Under Cd stress conditions, cadmium chloride solution (CdCl2.2H2O) with a concentration of 30 mg.L−1 was applied at two important stages of maize plant growth, including six-leaf stage (Code 16 in Zadoks scale) and the appearance of first male flowers (Code 50 in Zadoks scale). The measured traits included 24 different phenological, morphological, and agronomic traits. Grouping of maize genotypes in term of the studied traits was performed using cluster analysis based on Ward’s minimum variance method, and discriminant function analysis was used to confirm and validate the results of cluster analysis.

The results of this study indicated that there was an extensive genetic diversity among the studied maize genotypes for most of the studied traits, especially for grain yield and its components under non-stress and Cd stress conditions. Cluster analysis grouped the maize genotypes into four separate clusters with accuracy probabilities of 91.6% and 97.9% under non-stress and Cd stress conditions, respectively. Comparison of means between these four groups showed that under non-stress conditions, 41 and 24 genotypes in the third and fourth groups were the high yielding genotypes of this experiment, respectively. Under Cd stress conditions, 49 genotypes with the higher grain yield and yield components in the second and third groups (such as Ma002, Ma003, Ma004, Ma005, and Ma007) were identified as Cd-tolerant genotypes. These genotypes mainly showed short to medium phenological periods. Also, 11 genotypes (Ma001, Ma008, Ma030, Ma033, Ma036, Ma039, Ma042, Ma045, Ma072, and Ma089), indicated the lowest means for important agronomic traits including yield and its components under both non-stress and Cd-stress conditions. These genotypes were unable to tolerate Cd stress under the conditions of this experiment and were identified as sensitive genotypes.

The present study led to the identification of 40 tolerant maize genotypes to Cd stress (such as Ma003, Ma005, Ma007, Ma013, Ma014, and Ma015). These genotypes in addition to exhibiting desirable yield and yield components under non-stress environment, also showed suitable yield under Cd stress conditions. Therefore, by carefully selecting the parents among Cd-tolerant genotypes and carrying out targeted crosses between them, it is possible to obtain suitable hybrids for cultivation in Cd-stressed environments by exploiting genetic phenomena such as transgressive segregation and heterosis.

Investigating the role of agronomic factors is very important in improving the quantitative and qualitative characteristics of oilseeds. In order to determine the composition of fatty acids and grain yield in camelina (Camelina sativa L.), a two-year experiment (2017-19) was conducted in Karaj, Iran. The experiment was carried out as a split plot-factorial in a randomized complete block design with three replications, where the planting date (7th Oct., 22nd Oct., and 6th Nov.) in main plots and planting density (40, 50 and 60 plants m-2) and humic acid (including non-application and application of 0.003 HUMAX 95-WSG) in two stages of 4-leaves and stem elongation were considered in sub-plots. The highest grain yield with an average of 2485 kg ha-1 was obtained on 7th Oct., at 40 plants m-2 and application of humic acid. In addition, application of humic acid in delayed planting date (6th Nov.) and 40 plants m-2 showed the highest positive effect on 1000-grain weight and grain yield (wit increases of 17.8 and 32.7%, respectively) compared to non-application. Also, application of humic acid in delayed planting date (6th Nov.) and 40 plants m-2 showed the highest percentage increase of oleic acid (0.9%) compared to non-application. Furthermore, application of humic acid in all normal (7th Oct.), relatively late (22nd Oct.) and late (6th Nov.) planting dates, caused a significant decrease of erucic acid and glucosinolate concentrations compared to non-application. Therefore, application of humic acid is beneficial to camelina growth and grain yield, particularly when sown in a delayed date.