leaf area index

Henna (Lawsonia inermis L.) is a perennial, dicotyledonous plant native to North Africa and Southeast Asia. This plant is cultivated in tropical regions as an ornamental species and for its dye production (Singh, Luqman, & Mathur, 2015). Drought stress directly affects a range of physiobiochemical and phytochemical processes, as well as molecular responses (Farooq, Wahid, Kobayashi, Fujita, & Basra, 2009; Rady, Belal, Gadallah, & Semida, 2020). Salicylic acid is a phenol-based phytohormone that regulates vital physiological activities within the plant, including water uptake, ion transport, transpiration, and photosynthesis (Klessig, Choi, & Dempsey, 2018). Sodium nitroprusside is a nitric oxide-releasing compound (Farouk & Al-Huqail, 2020). Nitric oxide inhibits free radicals by inducing gene expression and enhancing the activity of antioxidant enzymes, thereby protecting cells from damage caused by abiotic stresses (Ahmad et al., 2016).

This experiment was conducted in 2021 on a farm located in Qaleganj City, Kerman Province. The climate of Qaleganj is classified as semi-desert according to the dry amber method. The characteristics of the soil at the test site are detailed in Table 1. The experiment was carried out in the form of split plots based on a randomized complete block design with four replications. The main factor included three levels of irrigation (50%, 75%, and 95% of crop capacity), while the secondary factor involved foliar spraying with growth regulators (control, salicylic acid, sodium nitroprusside, and a combination of salicylic acid and sodium nitroprusside). The seeds of the henna plant (Lawsonia inermis L.) were obtained from the Faculty of Agriculture at Bahonar University, Kerman, Iran. The planting date for the henna plant was April 1, and the harvesting date was November 5.

The results showed that drought stress caused a decrease in traits such as plant height, leaf area index, and yield. Additionally, drought stress increased traits such as malondialdehyde concentration, ascorbate peroxidase enzyme activity, catalase enzyme activity, and phenylalanine ammonialyase enzyme activity. The application of the combination of salicylic acid and sodium nitroprusside enhanced the leaf surface index, ascorbate peroxidase enzyme activity, catalase enzyme activity, and phenylalanine ammonialyase enzyme activity. The highest seed yield from the treatment with the combination of salicylic acid and sodium nitroprusside was 3546.66 kg.ha-1 under irrigation conditions of 95% of crop capacity, while the lowest seed yield, from the treatment without growth regulator application, was 2243.33 kg ha-1 under 50% crop capacity conditions.

When faced with drought stress, the henna plant employs osmotic regulation mechanisms by increasing the accumulation of proline, thereby tolerating water deficit conditions to some extent. Spraying the combination of salicylic acid and sodium nitroprusside resulted in an increase in antioxidant enzymes, leaf surface index, and leaf density per hectare, helping to mitigate the destructive effects of stress. Based on the results of this research, it is recommended to use a salicylic acid and sodium nitroprusside solution under drought stress conditions to maintain performance in henna plants.

In order to investigate the effects of organic and chemical fertilizers on the growth traits, yield and yield components of two varieties of rice in an intensive cultivation management system, an experiment was conducted as a split plot experiment in a randomized complete block design with three replications in the field of Haraz Technology Promotion and Development Center in Mahmoudabad, Mazandaran province in the years 2020 and 2021. The main factor included chemical fertilizer and organic fertilizer (100% chemical fertilizer, 50% chemical fertilizer + 50% chicken manure, 100% chicken manure, 100% cow manure, 50% cow manure + 50% chemical fertilizer), and the secondary factor included rice varieties was Fajr (modified) and Hashemi (local). In both cultivars, the maximum leaf area index was observed in the treatment of chemical fertilizer + chicken manure, respectively, 4.56 and 3.95, and the highest ratio of leaf area in Fajar and Hashemi cultivars, respectively, in the treatment of chemical fertilizer (0.980 and 0.781 g/m2) and the combination of chemical fertilizer + chicken manure. (0.892 and 0.751 g/m2) were observed. The height of the plant in the treatment of chicken manure + chemical fertilizer was reduced by 26.4%, compared to the treatment of only chemical fertilizer, in the Fajr variety, and the number of claws and the number of clusters per square meter were the same, but in the Hashemi variety, the height of the plant and the number of clusters were 2.99 and 6.99, respectively. The percentage of reduction and the number of claws and the weight of 1000 seeds increased by 5.76 and 3.36%, respectively. The largest increase in grain yield was due to the treatment of chicken manure + chemical in Fajar cultivar, which increased by 4.2%, compared to the treatment of only chemical fertilizer; while Hashemi cultivar had the highest seed yield in chemical fertilizer treatment. In Fajr and Hashemi cultivars, the highest plant dry weight was observed with the application of chicken + chemical fertilizer, which increased by 3.56% and 4.48%, respectively, compared to the chemical fertilizer treatment. It seems that in the intensive cultivation system, combining chemical fertilizer and chicken manure is a suitable solution for the sustainability of rice production and reducing the consumption of chemical fertilizer. Regarding the grain yield, the use of organic fertilizers in Fajr variety compared to Hashemi variety was more effective than the use of organic fertilizers.

This study was conducted to examine the interaction between cultivars and the nitrogen fertilizer applied to spring safflower growth and yield. It was performed as a factorial experiment within a randomized complete block design with three repetitions at the experimental field of the Faculty of Agriculture at Tarbiat Modares University during the 2021 crop season. The treatments included two safflower cultivars, Parnian and Goldasht, and six levels of pure nitrogen (0, 45, 90, 135, 180, and 225 kg/ha). The cultivar influenced the leaf area index and the number of capitula per unit area, while nitrogen fertilizer affected all traits significantly. The leaf area index was approximately 25% higher in the Parnian than the Goldasht cultivar. However, there was no significant difference in dry matter production between the cultivars. The highest leaf area index and dry matter were observed under 135 and 180 kilograms of nitrogen per hectare, respectively, and higher nitrogen did not result in significant increases. The highest number of capitula and seeds per capitula were obtained with 180 and 135 kg/ha, respectively, and further nitrogen did not significantly increase these traits. The increasing nitrogen enhanced seed and oil yield in safflower, with the highest significant yields obtained at the 180 kilograms per hectare of nitrogen. The number of capitula and seeds per capitula had a higher correlation with seed yield. Based on the results of this study, an increase in safflower yield can be expected with an increase in nitrogen fertilizer up to 180 kilograms per hectare.

Roselle (Hibiscus sabdariffa L.) is used as food, hot and cold drinks, flavoring, and medicine. During the critical stages of development when plants require optimum moisture and temperature during planting, germination, flowering, and fruit formaion, choosing the suitable sowing date can affect growth and yield of medicinal plants (Mir et al., 2011). The purpose of this study was to evaluate the effect of sowing date and plant density on some growth characteristics and yield components of roselle (sour tea) under the climatic conditions of Ahvaz, Iran.

In order to evaluate the effect of sowing date and plant density on the growth and yield of roselle (sour tea), an experiment was carried out as split plot arrangements in randomized complete blocks design with three replications in the research farm of the Agricultural and Natural Resources Research and Education Center of Khuzestan province in Ahvaz, Iran, in 2022. Sowing dates at five levels (April 11, April 21, April 31, May 10, and May 22) were assigned to the main plots, and plant densities at three levels (4, 8, and 12 plant m-2) were randomized in sub-polts. After emergence, seedlings were thinned to reach the defined plant density (4, 8, and 12 plant.m-2) at three to four leaf stages. The growth characteristics were measured during five growth stages from 30 days after sowing dates and at intervals of 30 days. Roselle plants were harvested at the stage of boll ripening. After harvesting roselle plants, some characteristics related to yield components include plant dry weight, boll dry weight, number of boll.plant-1, number of seed.boll-1, 1000 seed weight, sepal weight.plant-1, biological yield, dry sepal yield and seed yield were measured and recorded.

Analysis of variance showed that the interaction of sowing date and plant density was significant on plant height, number of boll.plant-1, number of seed.boll-1, seed weight, sepal weight.boll-1, biological yield, sepal dry weight, seed yield and seed harvest index. Also, the effect of sowing date was significant on leaf area index, plant dry weight, boll dry weight, sepal anthocyanin content and sepal harvest index. Mean comparison showed that the highest plant height was measured in Aprill 21 with 12, 4, and 8 plant.m-2 (198.2, 197.9, and 194.6 cm, respectively). The highest number of seed.boll-1 was recorded in April 30 with 4 and 8 plant.m-2 (24 and 22.7, respectively). The heaviest single seed weight obtained in April 21 and April 30 with 8 plant.m-2 (19 g). The highest of sepal weight.plant-1 was obtained in April 31 with 12 plant.m-2 (43.9 g.plant-1). The highest biological yield was harvested in April 21 with 8 plant m-2 (44707.2 kg.ha-1). Also, the highest leaf area index (9), boll dry weight (0.893 g), number of boll.plant-1 (209.9) and sepal anthocyanin content (0.329 µmol g-1) were measured in sowing date of April 30.

The results of this experiment showed that most of the growth characteristics and yield components of roselle (sour tea) plants sown on April 30 with 8 plant.m-2 were higher compared to other treatments. Delay in sowing date caused decreases in the growth characteristics and yield components, which is probably due to the increase in temperature and its effect on the growth and production of roselle plants. Considering the results of this experiment, the planting date of April 30 with plant density of 8 plant.m-2 was identified suitable packge for the growing of roselle under the environmental conditions of Ahvaz in Iran.

Radiation use efficiency is important ecophysiological characteristics for realization of crops growth, development and radiation absorption. With the same aim, in order to study In order to study of radiation use efficiency in rice cultivars, This two-years experiment was conducted in a split-split-plot arrangement based on randomized complete block design with three replications during 2019-2020 and 2020-2021growing seasons. The main plot was cultivar at three levels included Champa, Anbouri and Danial, the sub plot was planting arrangement at three levels included 15 cm× 15 cm, 15 cm× 20 cm and 15 cm× 30 cm and the sub sub plot was seedling age at three levels included 30, 40 and 50-day old seedlings. results showed that the highest LAI (5.8) was related to the 30-days seedlings of Champa variety in the planting arrangement of 15x15 cm. The highest CGR plant was obtained in the 15x15 cm treatment in the Daniel cultivar (33.3 g/m2 day). The rate of net photosynthesis in 50-day seedlings of Daniel variety at the end of the growing season found an upward trend due to the vertical arrangement of the leaves. At the beginning of the growing season, the 40-day transplant of Anbouri cultivar, in the planting arrangement of 15 x 30 cm showed the highest relative growth rate 0.18 g.m2.d. Increasing the number of hills per unit area in the planting arrangement of 15x15 cm caused the faster maximum LAI, which led to an increase in the radiation use efficiency in this planting arrangement and changing the planting arrangement from 15x15 cm to 30x15 cm. reduced the radiation use efficiency from 2.16 to 1.60 g.MJ-1. The results results of showed that the highest yield of rice in all three cultivars of Champa, Anbori and Daniyal in 30 days of transplanting in 15 x 15 cm planting arrangement was 6563, 6100 and 9466 kg/ha, respectively. Generalll, the 30-day seedlings of the studied rice cultivars in the planting arrangement of 15x15 cm were more suitable for improving the yield of rice in the area where the experiment was done due to having a higher LAI, higher CGR and radiation use efficiency, and Daniyal cultivar according to the Due to the difference in the performance of paddy compared to other varieties (30%) and more compressibility, it is a solution to achieve the stability of the performance in the conditions of Khuzestan.

Studying the effects of Azospirillum and nanoparticles (silicon and zinc) on grain yield and some traits of Triticale under salinity stress was conducted as a factorial experiment with randomized complete block design and three replications at the research greenhouse of the University of Mohaghegh Ardabili in 2022.

The experimental factors included salinity levels (no salinity as control, salinity of 60 and 120 mM by NaCl), application of Azospirillum (no inoculation as control and seed inoculation with Azospirillum), nanoparticles foliar application (foliar application with water as control, foliar spraying 0.8 g.L-1 nano zinc oxide, 50 mg.L-1 nano silicon, combined foliar application of nano zinc oxide as 0.4 g.L-1 and nano silicon as 25 g.L-1).

The application of Azospirillum and nanoparticles in 120mM salinity increased proline content (37.46 percent), hydrogen peroxide (41.66 percent), malondialdehyde (37.57 percent) and the activity of peroxidase and polyphenol oxidase enzymes (53.86 and 47 percent, respectively) compared with non-saline conditions and lack of Azospirillum and nanoparticles application. Application of Azospirillum and nanoparticles increased the content of soluble sugar (18.68 percent) and catalase enzyme activity (28 percent) as compared with treatments that did not receive Azospirillum application and foliar spraying. Not applying Azospirillum and nanoparticles under 120 mM salinity increased dry matter remobilization from aerial organs (54.25 percent) and the contribution of dry matter remobilization from aerial organs (126.14 percent) compared with the application of Azospirillum and nanoparticles under non-saline conditions.

It seems that applying Azospirillum and nanoparticle foliar application can increase grain yield of triticale under salinity stress due to improved biochemical traits.

Rapeseed is the third most important oilseed product after soybean and oil palm in the world. Evaluating the growth and drought indices of different cultivars can help introduce the optimal cultivar for a given region to achieve optimal production. The current research was conducted in four counties of Lorestan province including Aleshtar, Khorramabad, Kuhdasht, and Pol-e Dokhtar for simulating the growth and drought indices of three rapeseed cultivars (Hyola308, Hyola401, and RGS003) using modeling technique. APSIM model was used to simulate the growth and yield of rapeseed. On average across all counties, Hyola401 had the maximum LAI (4.7), CGR (21.1 g m-2 day-1), RGR (0.8 g g-1), and TDW (1507.4 g m-2 day-1). Grain yield varied from 21.1 tons ha-1 in Aleshtar to 4.8 tons ha-1 in Pol-e Dokhtar. Also, on average across various counties, the average grain yield for Hyola308, Hyola401, and RGS003 cultivars was 3.9, 4.5, and 4 tons ha-1, respectively. For the water stress factor (WSF), water stress was not observed in Aleshtar, but in other counties, water stress started after the flowering stage and lasted until the maturity stage. The drought pattern indicated that in most counties, except Aleshtar, suitable irrigation management at the end of the rapeseed growth period can help to improve grain yield in the studied counties.

This research was conducted in order to investigate the effect of foliar application of micronutrients on the yield and some physiological traits of new corn hybrids during 2016and 2017 in Safiabad Dezful research farm. This experiment was performed as a split plot based on a randomized complete block design in four replications. The main treatment includes foliar application of micronutrients in the eight-leaf stages and the time of full emergence of plant organs in the control levels, Fe, Mn, Zn, Fe+Mn, Fe+Zn, Mn+Zn, Mn+Zn+Fe and hybrid levels (single cross) including 637 (45/1-2z25), hybrid 637 (45/1-2z2), hybrid 670 (mol7), hybrid 701(mx11z18/1), hybrid 677 (1/64/018z35), hybrid702 (2/12/15/3-1) and hybridimbin (mx11z18/2) were considered as secondary treatment. The results of variance analysis showed the simple effect of micronutrient elements and hybrid on leaf area index, number of seeds per cob, 100 grain weight, grain yield, biological yield, harvest index and seed nitrogen percentage at the probability level of one percent and the interaction effect of micronutrient elements in hybrid on the grain yield was significant at the 1% probability level. The highest index of leaf area and biological yield in the second year was obtained from the combined foliar application of iron, manganese and zinc. The highest seed yield (14.61 ton/ha) was obtained in the second year with the combined application of iron, manganese and zinc in hybrid 670, which increased by 45% compared to the control treatment in hybrid 702. According to the above results, it is recommended to spray the three micronutrient elements iron, manganese and zinc in two times of eight leaves and the time of full appearance of the plant organs to increase the yield and improve the physiological characteristics of hybrid corn 670 in the conditions of the region.

Growth analysis has a significant perspective on the function of agricultural plants. In the early stages of plant growth, the growth indicators, including the leaf area index, the growth rate of the product decreases, and then due to suitable vegetation, the absorption of light radiation is better, and the accumulation of plant dry matter also increases, and after that Due to aging and yellowing, the leaves are reduced. The amount of light radiation absorbed by the plant varies during the growth period, which depends on the leaf surface index and the arrangement of the leaves of the plant.

The experiment was conducted in the research farm of Khuzestan University of Agricultural Sciences and Natural Resources in 2021-2022. In this research, the effect of three factors of irrigation interruption, cultivars and density was investigated in the form of factorial split with the base design of randomized complete blocks in three replications. The factor (no interruption of irrigation (control), interruption of irrigation at the beginning of flowering until the formation of 50% of the pod and interruption irrigation at the stage of pod formation until harvest the main factor, rapeseed cultivars Hayola 4815 and Aram and plant density per meter square (80, 110 and 140 plants per square meter) were considered as secondary factors.

Irrigation interruption caused a decrease in growth indicators, including the amount of plant dry matter accumulation, leaf surface index, and leaf surface durability. The changes in harvest index and durability of leaf surface and accumulation of dry matter at the beginning of the development of leaves had a slow trend until a little before the appearance of inflorescences, but after that the slope of the mentioned parameters increased. During the experiment, changes in growth parameters including LAI, LAD, RGR, CGR and TDW were evaluated. At the beginning of the plant growth season, the growth rate of the product was low due to the lack of complete vegetation cover and proper light consumption efficiency. In all treatments, with the passage of time, the growth rate of the crop was gradually increasing and it reached the maximum value in the reproductive stages and then went through a decreasing process. The effects of stopping irrigation on dry weight were evident and the accumulation of dry matter was observed during the increasing time. which can be due to the increase in dry weight of stems, leaves and reproductive organs over time. Also The relative growth rate also showed an increasing trend with the increase of the leaf area index at first and then a decreasing trend.

It seems that the second-stage irrigation interruption treatment at a density of 80 plants per square meter and Haiola 4815 variety, by maintaining more green area through more leaf surface durability and lower light consumption in the condition of irrigation interruption at the end of the growing season, was able to achieve a higher RUE100 compared to other treatments. to dedicate The highest seed yield (1572.61 kg per hectare) was obtained from the density of 110 plants per square meter and Hayola variety 4815.

Crop simulation models provide the possibility to study the effect of agronomic management practices on agricultural production activities in a given location. The models are mechanistic and process-oriented that are able to simulate different agricultural systems (including arid and semi-arid areas such as Iran) through different sub-models (biological, environmental, managerial, and economic sub-models) connected with the main engine of the models. The APSIM-Barley model can be used to evaluate the management practices on barley crop. The current research was carried out to evaluate the APSIM-Barley model in relation to simulating the growth, development, and yield of three barley cultivars (Azaran, Jolgeh, and Bahman) under different conditions of nitrogen and irrigation supplies.

 In order to evaluate the APSIM-Barley model regarding simulating and quantifying the phenological stages, biomass, and grain yield of different barley cultivars, some independent experiment datasets were used. For crop model calibration, an experiment was conducted in a factorial split plot design at the Agricultural Research Center of Hamedan in 2019. The main factor consisted of three irrigation levels (30-40, 60-70, and 90-100% of the field capacity) and sub-factors included cultivar levels (Azran, Jolgeh, and Bahman as early, mid, and late cultivars, respectively) and three nitrogen levels (zero, medium, and optimum). For model validation, another series of independent datasets in different years consisting of published articles and research projects were used. For assessing the efficiency of the crop model and comparing the simulated and measured values, R2, nRMSE, d-index, and MBE indices were used and OriginPro software was considerd for all statistical analysis and drawing of figures.

 The simulation results of APSIM-Barley model in the calibration step showed that nRMSE for days to flowering and maturity was 2.43 and 2.4%, respectively.  Also, under full water and nitrogen conditions, nRMSE for the leaf area index of Azaran, Jolgeh and Bahman cultivars was 13.5, 14.1, and 10.7%, respectively, and under severe water and nitrogen stresses, it was 16.5, 18.6, and 26.5% respectively. At this step, and nRMSE and d-index for biomass and grain yield were 24.9% and 0.98 and 15.2% and 0.96, respectively.  In model validation step, nRMSE, d-index, R2, MBE were 15.02%, 0.96, 0.82 and 0.34 t ha-1, respectively, for grain yield.

In general, the results showed that the APSIM-Barley model was able to simulate the growth, development, and grain yield of different barley cultivars with acceptable accuracy under different water and nitrogen management conditions in different years and regions. Therefore, the APSIM-Barley model can be used as a reliable tool in future studies such as climate change assessment, yield gap analysis, agricultural zoning, and etc. by other researchers.

The highest concentration of protein is found in plant-based sources, whereas animal protein production tends to be more challenging and costly compared to plant-derived proteins. Within plant sources, legumes emerge as a primary reservoir of protein. A notable proportion of protein compounds within legumes boast relatively high nutritional value. The amount of protein in most plants of the legume family, including beans, is reported between 18 and 32%. guar or cluster bean (Cyampsis tetragonoloba (L.) Taub.) is an annual plant from the legume family, which is cultivated in dry plains as an alternative crop due to its high tolerance to drought and salt conditions. This plant, like most legumes, is important in the balance of soil mineral elements in agricultural systems due to its ability to symbiosis with nitrogen-fixing bacteria. Planting date and optimal plant density are two effective factors to achieve the potential performance of plants. Considering the importance of guar as an edible, industrial, fodder and medicinal product, it seems necessary to conduct research on the growth response of this plant to management factors, especially the date and density of plant planting. The present study was conducted with the aim of investigating the effect of planting date and row spacing on guar plant as an alternative plant for the climatic conditions of southern Kerman and other similar climates, in order to achieve the highest yield and grain quality.
 

The experiment was carried out as split plots based on the completely randomized blocks design with three replications in the research farm of South Kerman Agricultural and Natural Resources Research and Education Center (Jiroft) in two years 2018-2019. Jiroft region has a latitude of 57 degrees and 32 minutes north and a longitude of 28 minutes and 32 degrees east and is located at an altitude of 628 meters above sea level. The experimental treatments include planting date as the main factor in six levels (10 and 25 May, 9 and 24 June, 9 and 24 July) and seed planting intervals as secondary factors in four levels (20, 30, 40 and 50 cm).
 

The results showed that the maximum dry weight of leaves and stems, the number of leaves in the secondary stem, the height of the plant and the length of the pod were observed on the date of 24 June and the row spacing was 50 cm, and in all planting dates, increasing the row spacing led to an increase in the mentioned traits. The comparative analysis of average planting dates reveals that the highest metrics were achieved on June 9th. This includes a 43% increase in the number of pods per plant, a 23% increase in the number of grains per pod, a 66% increase in biological yield, a 45% increase in grain yield, and an 18% increase in harvest index. The highest leaf surface index (15%) and number of leaves in the main stem (91%) was observed on the 24 June. In general, with the delay in planting after early June (9 June) to late June (24 June), the yield and yield components of guar gradually decreased and reached the lowest value. The results comparing the mean effect of row spacing showed the highest number of pod per plant and seeds per pod at 50 cm row spacing, but the highest grain yield was obtained at 30 and 40 cm row spacing.
 

In general, among the planting dates, guar planting in June to early July in Jiroft region is the best planting date. While, early planting (May) and late planting (late July) were not favorable for guar and led to a decrease in plant yield. Therefore, in order to obtain the best yield and agronomic characteristics of guar plant in the south of Kerman province and similar conditions, it is recommended to cultivate this plant from early June to early July and at a row distance of 30 to 40 cm, because in the mentioned dates and row spacing, the plant makes the best use of environmental factors and with the reduction of competition between the plants, its performance and components increase Because.

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.

The availability of organic matter in deficit irrigation conditions can be a practical solution to compensate the negative effects of drought stress. In order to investigate the effect of deficit irrigation and chemical fertilizers on yield and some physiological traits of quinoa an experiment was conducted in 2019 as split plot based on a randomized complete block design in two locations (Mashhad and Neishabour). Irrigation levels included, I0: full irrigation, I1: irrigation at emergence stage, I2: irrigation at stem elongation stage, I3: irrigation at flowering stage, I4: irrigation at seed setting stage. Fertilizer treatments included control (no fertilizer application); chemical fertilizer application according to local practices; manure application of 10 tons; and manure application of 20 tons per hectare. Seed yield and yield components, leaf area index, crop growth rate and relative growth rate were measured. The highest 1000-seed weight was obtained in 20 tons of manure and I2 treatment in Neishabour. The lowest 1000-seed weight was obtained in 10 and 20 tons of manure and I1 in Neishabour. The lowest grain yield in I1 treatment was observed in Neishabour and the highest grain yield in I0 treatment with 20 t.ha-1 manure was observed in Mashhad. Fertilizer treatments increased crop growth rate in both experimental sites, but the effect of manure on increasing crop growth rate was greater than the effect of chemical fertilizer. However, due to the high fat content of quinoa, the use of 20 tons of manure per hectare is recommended if it is purely economic. In general, I2 treatment along with the application of manure in both places had high grain yield and dry matter production.

The production of oilseeds, edible leaves, and secondary metabolites of dragon's head makes it an important food, forage, and medicinal plant. Choosing a proper planting date and plant nutrition can make a significant effecton crop plantsgrowth, quality and yield.The effects of planting date (16 March, 14 April, and 13 May 2019) and foliar application of zinc sulfate (zero as control, 2 and 4 g.L-1) on growth indices and seed yield of dragon's head was evaluated under a field experiment.Delayed planting date reduced the days to flowering, days to seed ripening, plant height, leaf area index (LAI), crop growth rate (CGR), relative growth rate (RGR) and grain yield, and yield components.In contrast, the use of zinc sulfate increased plant height, LAI, CGR and RGR. There was a correlation between plant height and number of branches and consequently there were more capsules per plant.The highest effect of zinc sulfate application on seed yield and yield components was observed in the first planting date and with delay in planting, the efficiency of zinc sulfate fertilizer application decreased. On the third planting date, zinc sulfate application had no significant effect on grain yield. As a result of late planting, fewer branches, fewer capsules per plant, and smaller seeds contributed to the yield reduction.It was found that early cultivation and application of zinc sulfate increased plant height, number of branches, number of capsules per plant, 1000-seed weight, and thus seed yield, by increasing the days to flowering, days to ripening, LAI, CGR, and RGR.

To evaluate the effect of planting date on the morphological traits, growth indices and seed corn yield of three varieties, an experiment was carried out in the research farm of University of Tehran in Karaj city in 2019.

The experiment was conducted as a split-plot design based on randomized complete blocks with four replications. In this experiment, planting date in 3 levels (May 24, June 21, and July 18) was considered as main plots and variety (early KSC400, medium-early KSC647, and late KSC704) as sub plots.

The results showed the highest yield is related to the second planting date (11.98 ton/Kg-1), and the longest period until the appearance of the the tassel was belonged to the first planting date (63.7 days).
The third (129/7 days), the second (122/3 days) and first planting date (113/3 days) had the longest period of physiological maturity, respectively. Also, KSC704 had the highest plant height and stem diameter, and KSC647 had the highest number of leaves. Also, the maximum leaf area, the growth rate of crop in the flowering stage was related to the cultivar KSC704 on the second and third planting date, respectively, and the maximum relative growth rate and the net absorption rate in the first vegetative stages were related to the cultivar KSC704 on the third planting date and the second planting date.

Overall, the second planting date and KSC704 variety are suggested as the suitable date and variety for Karaj city.