احمد علی شوشی دزفولی

Decreasing the effect of weeds on the characteristics of the main product increases the production and quality of the seeds and finally stabilizes the agricultural ecosystems. This research was conducted in order to investigate the effect of Dwarf Mallow weed on yield, yield components, competition index, Greenness and photosynthesis rate in wheat fields in North Khuzestan. 

The experiment was carried out as a factorial experiment based on randomized complete block design with three replications during the two crop years of 2018-2019 and 2019-2020 in the agricultural research and studies center of Safi-abad, Dezful. Treatments included of three varieties of wheat; (Mehregan, Chamran 2 and Barat) and five Density of Malva (control (zero), 8, 16, 24 and 32 plants/m2). 

The results showed that the length of the plant increased by 2.38, 7.42, 15.44 and 20.47%, respectively, compared to the control treatment, with the increase in the density of the weed and the spike length decreased by 7.42, 8.47, 16.47 and 29.71% compared to the control treatment with increasing the density of Malva weed. The number of seeds in the spike of Chamran 2 and Mehrgan cultivars decreased by 1.45% and 11.72% respectively compared to Barat cultivar. The number of seeds in the spike decreased by 13.22, 20.65, 28.84 and 44.60%, respectively, compared to the control treatment with the increase in the density of the Malva weed. Seed yeild with increasing density of Dwarf Mallow weed in Mehrgan variety 19.41, 29.44, 36.24 and 48.22%, in Chamran 2 variety 6.27, 15.84, 21.78 and 43.89% and in Brat variety 28.51, 39.06, 40.23, and 50.78% showed a decrease compared to the control treatment, respectively. The biological yield decreased by 13.08, 15.86, 20.40, and 32.44%, respectively, compared to the control treatment, with the increase in the density of the weed. The photosynthesis ratio with increasing the density of Malva weed in Mehrgan variety 14.25, 24.49, 60.86 and 80.66%, in Chamran 2 variety 23.81, 31.48, 52.92 and 74.28% and of 25.02, 43.70, 49.42 and 74.00% in Brat variety respectively, showed a decrease compared to the control treatment. The tolerance index of Chamran 2 and Mehregan cultivars decreased by 1.08 and 1.85%, respectively, compared to Barat variety, and with the increase in the density of Dwarf Mallow weed, it decreased by 3.68, 7.45 and 11.32%, respectively, compared to the density of 8 Dwarf Mallow weed plants. 

The results of the experiment showed a decrease in the values of developmental and physiological characteristics and a decrease in seed and biological yield, photosynthesis rate and tolerance index due to the increase in the density of Malva weed. In general, the control of Dwarf Mallow weed density can be recommended to improve quantitative yield, morpho-physiological indicators of bread wheat in order to achieve sustainable agricultural goals and increase grain and biological yield per unit area in the agricultural areas of North Khuzestan.

To select the high yielding and adapted pecan genotypes for Dezful climatic conditions in Iran, 50 seedling trees were evaluated in 2019-2021 in Dezful in southwest of Iran. The results showed that P200-7 and P200-8 genotypes had the largest and smallest nuts with 14.3 and 4.2 grams, respectively. P220-2-1 genotype had the highest and P200-9, and P220-2-5 genotypes had the lowest percentage of blank nuts. Kernel removal was easy in P200-1 and P200-10 genotypes, while it was very difficult in P200-3 and P200-31 genotypes. Fruit ripening time was the earliest in P200-1 and P220-2-5 genotypes and the latest in P200-23. P200-23, P220-1-1 and P200-9 genotypes had the highest yield index with 65, 49 and 39 g cm-2 of tree trunk, respectively. The results of evaluation for heat stress tolerance in pecan genotypes showed that 40 to 70% of the branches of all genotypes were damaged by hot temperatures in the summer of 2021 with 430 hours of temperatures above 45 oC, while the branches of P200- 23 genotype were not damaged. In addition, the results indicated that heat stress damage had significant correlation with yield index (r = 0.311*) and kernel color (r = 0.323*). There was highly significant (r = -0.597**) correlation between shell thickness and kernel removal. The relationship between mean fruit weight and nut length (r = 0.386**) and nut width (r = 0.440**) were also highly significant. Factor analysis showed that nut length, shell thickness, blank nuts percentage, nut weight, yield index and heat stress damage accounted for 67% of the total variance. Finally, P200-23 genotype with high yield index, golden bright kernel color and very high heat stress tolerance, and P220-1-1 genotype with high yield and low percentage of blank nuts were identified as promising genotypes for future supplemental research.

Water resources limitation and plant stress due to water shortage is one of the important and common environmental stresses in agricultural production, including forage production in hot and dry areas. Therefore, the selection and development of drought-tolerant cultivars are very important. In irrigated lands of Iran, the average of irrigation efficiency is 37% and water productivity is 0.8 kg per cubic meters, which is lower than the world average. For increasing water efficiency, maintaining the production capacity and creating sustainable agriculture, it is necessary to identify the effective factors on the reduction of irrigation water productivity and provide an appropriate solution. In arid regions such as Khuzestan province, by using both a proper irrigation program and irrigation levels below the water requirement, obtaining the acceptable yield of alfalfa could be expected. In order to achieve these objectives, determination of the irrigation water productivity of tropical alfalfa cultivars and their drought tolerance under different irrigation regimes were the main aims of this study.

For evaluating tropical alfalfa genotypes under different drought stresses, an experiment was carried out based on split plots design with three replications in Safiabad Agricultural Research Center, Dezful, Iran, in 2019-2020. The main factor was four levels of irrigation (25, 50, 75 and 100% of water requirement) and the second factor was five alfalfa cultivars (Baghdadi, Nikshahri, Yazdi, Mesasirsa, and Omid). In this experiments, plant characteristics including dry and wet forage yield, percentage of dry forage, leaf to stem weight ratio, chlorophyll index (SPAD), electrolyte leakage from the leaf cell membrane (EL), relative leaf water content (RWC), and Maximum quantum yield in the dark-adapted conditions (ΦPSɪɪ) were determined.

The results showed that by applying drought stress, wet and dry forage yields, RWC, and ΦPSɪɪ were decreased but the percentage of dry forage, leaf to stem weight ratio, EL, and SPAD were increased. Among the studied genotypes, the Baghdadi genotype had the highest dry forage yield in all situations; non-stress conditions (16.9 t/ha), mild drought stress (15.094 t/ha), moderate drought stress (9.58 t/ha) and severe drought stress (4.664 t/ha). The Yazdi genotype had the lowest dry forage yield; 9.9, 9.7, 5.7 and 3.6 t/ha for non-stress, mild, moderate, and severe drought stresses conditions, respectively.

In our experiment, the Baghdadi genotype showed a high-stress tolerance index (STI) and we highly recommend planting it in the north of Khuzestan province, but the Yazdi alfalfa genotype despite low dry forage yield under both non-stress and drought stress conditions is not recommended due to low production. We suggest using Yazdi genotype in eugenic plans due to high yield stability index (YSI) under drought stress conditions and having some favorable physiological and photosynthetic parameters associated with drought stress tolerance.

One of the important activities to achieve drought tolerant cultivars is screening and selection of cultivars, based on yield and biochemical characteristics. A split-plot experiment arranged in a randomized complete blocks design with three replications has been carried out in Safiabad Agricultural Research Center during two growing seasons (2017-19). The main plots are consisted of different irrigation regimes based on crop’s water requirement (25%, 50%, 75%, and 100%) and sub plots include five levels of alfalfa cultivars (Baghdadi, Nikshahri, Yazdi, Omid, and american Mesa-Sirsa). Results show that drought stress due to irrigation regimes have resulted in a significant reduction of forage dry matter yield and considerable changes of soluble sugar, glutation peroxidase, and catalase in alfalfa leaves. However, it has not greatly affected total protein. For forage dry matter yield, the highest statistical class belongs to Baghdadi cultivar under 100% water requirement supply treatment (2.824 t.ha-1). The lowest statistical class for forage dry matter yield has been observed in Yazdi and Mesa-Sirsa cultivars under 25% water requirement supply treatment (0.598 and 0.546 t.ha-1), respectively. Among the cultivars, examined in this experiment, Yazdi has been identified as a drought tolerant cultivar due to the stability of dry forage yield as well as high leaf antioxidants content.

To investigate the effect of drought stress and foliar application of ascorbic acid, salicylic acid and methanol, and post-harvest seed deterioration, two separate experiments were carried out as split plot based on randomized complete block design with three replications on maternal plants in field conditions and a factorial based on completely randomized design considering by using seed under storage conditions. The main plots were consisted of three irrigation levels, irrigation after 60 mm evaporation from basin, considered as control treatment (optimum irrigation), cessation of irrigation at flowering and silique stages, and sub plots consisted of 10 levels of foliar application, (100, 200, 300 mg.lit-1 ascorbic acid, 100, 200, 300 μmol salicylic acid, 10, 20, 30 vol% methanol and the foliar application with distilled water as control treatment). Seeds obtained of maternal plant were evaluated under no-storage (control) and storage at 40°C for one month. The results showed that foliar application of ascorbic acid (300 mg.lit-1) increased seed yield by 29% under optimum irrigation as compared with non foliar application under the same irrigation condition. Cutting off irrigation of maternal plant decreased radical and plumule weights under both no-storage and one-month storage conditions. The maximum germination percentage belonged to foliar application of ascorbic acid (300 mg.lit-1) under optimum irrigation condition at both no-storage one-month stored seed. The minimum germination percentage belonged to no use of growth regulators application and cessation irrigation at flowering stage. Maternal plants which sprayed with ascorbic acid contained the highest seed weight vigor index at all irrigation treatments.

Introduction Water stress is the most important cause of reduced wheat yield in semi-arid areas. In most regions under wheat cultivation, especially in regions with Mediterranean climates, wheat plants are exposed to various stresses during the seed filling. Seed filling often occurs when temperature rises and less water is available. Irrigated wheat in Khuzestan Province mainly faces end-season drought caused by limited water supply on the one hand and the reduced precipitation and competition by other crops for water on the other hand. Therefore, introducing wheat genotypes tolerant to end-season drought is of great importance for this Province. Materials and methodsThis research was conducted at the Agricultural and Natural Resources Research Center of Safiabad- Dezful in the crop years 2014-2015 and 2015-2016. Eight promising durum wheat lines in warm regions in Iran together with the Behrang cultivar were studied. The following two separate experiments were conducted using the randomized complete block design with two replications: (1) full irrigation until maturity and (2) application of end-season water deficit stress through irrigation cessation from the spike emergence stage to physiological maturity.Results and discussion Results indicated that the effect of year was significant under drought conditions but not significant in the absence of drought conditions. Moreover, the mutual effect of genotype and year were significant in the absence of drought but not significant under drought conditions. The mean two-year yield under conditions without water deficit stress was 4844 kg/ha, with the highest average seed yield (5101 kg/ha) belonging to line 1 and the lowest (4669 kg/la) to line 2. Although yield of line 3 under conditions without water deficit stress (5039 kg/ha) was a little lower than that of line 1, it enjoyed higher yield stability compared to the other lines because it had the average ranking of 2.5 and the standard deviation of 0.5. Furthermore, the mean two-year seed yield under end-season drought conditions was 3991 kg/ha, with the highest mean seed yield of 4332.5 kg/ha belonging to line 4 and the lowest (3710 kg/ha) to line 9. Under end-season drought conditions, line 4 had the largest seed yield and the highest yield stability in the two years of experiments with the average ranking of 2.5 and the standard deviation of 0.5.Principal component analysis (PCA) and the shape of the by plot were employed for the simultaneous study of the relationships between the genotypes and the quantitative drought tolerance indices. Results of the PCA showed that most of the variance in the data could be explained by the two components of PCA1 (the first component) and PCA2 (the second component) with 63% and 30%, respectively. In addition, among all of the calculated components, only PCA1 and PCA2 had eigenvalues higher than 1 (5.67 and 2.66, respectively). ConclusionThe strong positive correlation between seed yield in the two environments with and without water stress and the STI, MP, and GMP indices indicated that these indices had a high efficiency in selecting drought tolerant genotypes. Based on the results of PCA, genotypes 1 and 3 were selected as water deficit stress tolerant genotypes because of their high PCA1 and suitable PCA2 values and also due to their closeness to the important drought tolerance indices MP, GMP, K1STI, K2STI, and STI; whereas lines 6, 9, and 10 were introduced as water deficit stress sensitive genotypes because of their low PCA1 and PCA2 values and also due to their closeness to the SSI vector. Line 7 was between important drought tolerance indices and drought sensitivity indices and enjoyed relatively desirable drought tolerance, but the high estimated values of SSI and TOL for this cultivar indicated that it lacks suitable yield stability. Moreover, this cultivar is close to the Yp vector, which shows that drought tolerance in this genotype is due to its high yield in stress free environments.

To evaluate the effects of drought stress by withholding of irrigation during reproductive stages and foliar application of micronutrients (Zn, Mn and B) on seed yiled and oil quality, an experiment was carried out as split plot arrangements in randomized complete block design with three replications at Safiabad Agricultural and Natural Resources Research and Education Center, Dezful, Iran, in two growing seasons (2013-2015). Main plots consisted of three irrigation levels: full irrigation (control), withholding of irrigation from flowering stage, and withholding of irrigation from silique stage, and sub plots included 10 levels of foliar application of micronutrients (2, 4, 6‰ zinc, 2, 4, 6‰ manganese, 2, 4, 6‰ boron, and the foliar application of distilled water as control). Foliar applications were made during both budding and initiation of flowering stages. Results showed that withholding of irrigation significantly decreased seed yield and yield components. Withholding of irrigation from flowering and silique stages reduced the silique no. plant-1 by 40% and 8%, respectively. Mean comparison of withholding of irrigation and foliar application showed that the highest seed yield (4301 kg.ha-1) belonged to full irrigation and foliar application of boron (4‰) in both growing seasons. The lowest seed yield (1863 kg.ha-1) obtained in withholding of irrigation from flowering stage and no micronutrient. Withholding of irrigation from flowering stage led to decrease oleic and linoleic acids content. The highest oil content (45.6%) measured in full irrigation and application of zinc (6‰) and boron (6‰). The lowest oil content (40.3%) observed in severe moisture stress conditions and no micronutrients. The results of this experiment showed that withholding of irrigation from flowering stage imposed severe stress on crop and should be avoided. The highest seed yield belonged to application of manganese and boron (4‰) and zinc (6‰) under withholding of irrigation from silique stage. To obtain reasonable seed yield, full irrigation and foliar application of zinc (4‰) and boron (4‰) is possible.

Khouzestan province with about 1000 hectares of seed clover is the most important region for seed production of berseem clover (Trifolium alexandrinum) in Iran. Extending the cultivation area of berseem clover (BC) is important due to the favorable effects of BC on soil fertility and the necessity of this region to a desirable crop rotation. The harvest date of summer crops such as corn leads to delay in optimum sowing date of BC. Several investigators in other areas have demonstrated that early sowing dates improved yield of BC. On the other hand, the most important factor in crop yields is water irrigation; it plays an important role in sustainable agriculture. Based on the existing literature, early sowing date reduces the number of irrigation events and increases water irrigation use efficiency (IWUE). Therefore, this experiment was conducted to evaluate the response of spring BC sowing date and last irrigation cutoff time on seed yield and IWUE. This study was carried out in Safiabad Agricultural Research Center in two years (2014-15). Soil texture of the experimental field was silty clay loam, well drained without salinity (ECe=1.2ds m-1), with 0.75 percent organic carbon. The statistical design of the experiment was split plot based on a randomized complete block design with four replications. The main plots were allocated to sowing date including 10th Feb, 20th Feb, 2st Mar and 12th Mar, and the sub plots were assigned to irrigation cutoff dates including 5th Jun, 15th Jun and 25th Jun. Daily evaporation from class A evaporation pan of the Safiabad weather station (nearby the experimental field) was measured to calculate water irrigation depth, and BC evapotranspiration was calculated by applying a pan coefficient of 0.8. Irrigation interval was managed based on 80 mm accumulated evaporation from the pan evaporation. The measured traits included seed yield, IWUE, number of seeds per inflorescence (NSI), number of inflorescences per square meter (NI), days to flowering, straw production, total dry matter (TDM), harvest index (HI) and weighed a thousand seeds. There was a significant difference between the irrigation cutoff date for all traits except the number of days to flowering and HI. The results of the mean comparison showed that the, sowing date of 20th Feb and irrigation cutoff in 15th Jun, with seed yield (631 kg.ha-1) and IWUE (0.72 kg.m-3) was better than the other treatments. In this treatment, the plant growth period in the first sowing date (88.6 days), and the NI (623 numbers), and the NSI (37.1 numbers) was higher than the other treatments. The correlation between seed yield and other traits was positive and the stepwise regression analysis showed a positive and high effect of NI on seed yield in BC. The results of this trial confirm previous findings that BC early sowing dates, will had higher seed yield. Also, the results showed that delaying in irrigation cutoff is effective in decreasing IWUE, so that irrigation until 25 th  June in comparison with 15 th June, In spite of significant increasing in yield, decreased IWUE significantly.

Salinity is one the major problems for production and increasing the area under cultivation around the world and Iran. Understanding of defense mechanisms and genes involved could improve tolerance to different stresses in crops by using some methods such as genetic manipulation. Regulation in the gene transcription phase is one the most methods to control stress in plants. Transcription factors thought binding with transcription elements in DNA promoters regulate genes expression which plays a key role in tolerance to salinity stress in plants. An experiment was conducted to evaluate four genes expression of transcription factors of MYB (MYB14 and MYB112) and WRKY (WRKY53 and WRKY70) in leaf and root tissue of Yazdi genotype (tolerant genotype to salinity) and Diabloverde (sensitive genotype to salinity) under salinity stress. The selection of these genes was based on the statistical analysis of the microarray data that was related to a study on the effect of salinity stress on Medicago truncatula. Short-term salinity stress caused a significant variation in the expression of these genes in leaf and root tissues of Yazdi and Diabloverde genotypes. Real-Time PCR analysis revealed that higher expression of transcription factors (MYB112 and MYB14) associated with more tolerance to salinity stress. This finding could be assisted plant breeders to apply these transcriptional factors to choose tolerant genotypes to salinity in alfalfa.

The recurrent selection was used in this study. For this purpose, 49 alfalfa ecotype seeds collected from all over the country and planted in Khuzestan Agricultural and Natural Resources Research and Education Center in 1990. Based on forage yield comparison, 20 ecotype were selected in 1993, provided at least 100 compatible stem cuttings, rooted and planted in separated plots and produced 20 seed sample. Based on 20 ecotype performance in 1995, eight ecotypes were removed and seeds of 12 ecotypes were harvested separately and cultivated in isolated region in 1996. The final comparison resultsed in the removal of 6 other ecotypes. After open pollinating between six remaining ecotypes, modified population was obtain in 1998 and planted in the isolated farms for until 2005. This population was compared with the best ecotypes of sub tropical regions including Baghdadi, Nikeshahri, Bami, Yazdi and Mesasersia in a research project during the years 2006 to 2010. The results showed that the improved alfalfa population with 19.3 t/ha total dry matter produced the highest forage yield and was superior to the others that thay have 17.8, 17.6, 16.8, 15.6, and 14.9 t/ha dry forage yield respectively. According to the survey, this improved population was not sensitive to common diseases like as Uromyces striatus, Stemphyllium botryosom, Pseudopeziza medicaginis (Lib.)Sacc. and Green florescence. Due to the superiority of yield and the lack of susceptibility to diseases, this population was named "Omid" alfalfa and was recommended for cultivation in sub tropical regions.

In order to investigate the effect of drought tension after flowering on dry matter remobilization in 56 wheat genotype, the present experiment was conducted as rectangular lattice 8x7 with two replications during 2010-11 cropping year at research farm of the Campus of Agriculture and Natural Resources of Kermanshah Razi University. Results showed that there was a significant difference at one percent level among genotypes in terms of grain yield and about 27.2 percent reduction in grain yield was observed in response to drought tension after flowering. Mean comparison of yield in different wheat genotypes showed that under humidity control conditions, Darab 2, Navid and UN-11 genotypes (760, 690 and 662 gram per meter square, respectively) had the highest and Rasad cultivar (419 gram per meter square) had the lowest grain yield and also under drought tension conditions after flowering, 330 and Moghan1 genotypes by 542 and 510 gram per meter square, respectively, had the highest and Shiroudi cultivar by 187 gram per meter square had the lowest grain yield. In terms of dry matter remobilization and remobilization efficiency, lower stem internodes compared to peduncle and penultimate internode, showed superiority. Under studied genotypes had a significant difference in remobilization and dry matter remobilization efficacy. According to the obtained results, it appears that remobilization efficiency has been affected under genetic and environment and probably higher production of dry matter at flowering stage would be resulted to higher dry matter remobilization to the grain.

To study yield and its relationships with yield components in 10 varieties of foxtail millet (KFM1 to KFM10), an experiment was carried out in Safiabad Agricultural Research Center in RCBD design with three replications for a period of three years (2003 to 2005). Vegetative and reproductive characteristics of each cultivar were recordered during the growing seasons. Three year results showed significant differences among cultivars for all the traits. KFM10 was found out as the most adaptable among the studied cultivars in Safiabad region due to its high seed and forage yield and less lodging because of its stem thicknes. Path analysis was employed to study the correlations among seed yield, dry forage yield as well as other traits. Results of path analysis for seed yield indicated that the number of tillers, stem diameter and days to 50% flowering positively and direct affected seed yield (respectively 0.564, 0.516, 0.472) while effected negatively (-0.323) spike length. Results of path analysis for dry forage yield indicated that the number of seeds per spike, number of leaves, number of tillers as well as days to 50% flowering had positive direct effect on the yield (respectively 0.247, 0.221, 0.3, 0.628). To improve seed yield in foxtail millet, it is finally recommended to select late maturity cultivars with high number of tillers, thicker stems and shorter spike lenght. In order to increase dry forage yield, the first priority should be firstly given to a selection of late maturity plants and then to plants with a higher number of leaves & tillers as well as higher number of seeds per spike. High residual effect for seed yield (0.67) and for dry forage yield (0.667) was indicative of the fact that lots of traits that affected seed yield and dry forge yield had not been dealt with in this research.

In order to evaluate the effects of irrigation regime and row spacing on seed yield of alfalfa cultivar Baghdadi, this experiment was conducted at Safiabad Agricultural Research Center Farm 2002 to 2004. The soil of the experiment site was silty clay loam.The experiment was arranged in a split plot based on a RCBD. Main plot was allocated to irrigation regimes based on evaporation from pan evaporation(including irrigation after 100,150,200 and 250mm evaporation from pan) and sub plot was allocated to row spacing( including 50,60 and 75 cm). The results showed that there were significant differences for yield and water use efficiency among irrigation regimes. Irrigation after 250 mm evaporation from pan had higher seed yield and WUE. The row spacing of 75cm with higher seed yield (178.7 Kgha-1) and higher seed germination (80.5%) was superior to other row spacings. The significance of years effect for most of the traits indicated the difference in changes of these traits in different years after alfalfa establishment.

This experiment was conducted in Safiabad Agricultural Research Center for two years starting from 7th October 2001 in order to evaluate and selection of the best cultural, chemical and integrated control methods of Protapion trifolii (L.) (Col.: Apionidae) in Berseem clover. The effects of control methods were investigated using 9 experimental treatments (including chemical and cultural controls, and the integration of these two methods) in the form of a 2-factor split plot design with 3 replications. Vertical factors were two insecticides, Ecamet and Durseban, and an "untreated" treatment, and horizontal factors were the dates of second mowing (for seed) in 1st, 16th & 31st March 2002. In order to evaluate the amount of damage and the effects of different control methods on yield components, the percentage of inflorescence infestation to larvae before and after spraying, the amount of seed yield, the number of seeds per inflorescence, the number of inflorescences per m2, 1000 seeds weight, the amount of fresh forage, dry forage and the amount of produced protein were recorded. The results of two years combined analysis showed no significant difference among spraying treatments for all the mentioned characteristics, except the percent of larvae infested inflorescences after spraying. Contrary to spraying treatments, there were significant differences among mowing treatments for the percent of larvae infested inflorescences before spraying, the amount of seed yield, the number of inflorescences per m2, the amount of fresh forage, dry forage and the amount of produced protein. Considering the main objective of this experiment (obtaining the highest seed yield) and the high economic value of the clover seeds, the results showed that the mowing date of 16th March 2002 could be suggested as the best date. Also, the chemical control of P. trifolii had no significant effect on seed yield despite its effect on the population of the pest itself, so probably the chemical control of this pest in seed farms of Berseem clover has no economic justification in addition to its harmful environmental effects.