حمید مدنی

In order to investigate the effect of biochar fertilizer and humic acid foliar application on quantitative and qualitative characteristics of Roselle (Hibiscus sabdariffa) a split plots experiment in a randomized complete block design was performed with three replications in the Research Field of Islamic Azad University, Arak Branch during 2017-2018 and 2018-2019. Experimental factors included 3 levels of biochar (non-consumption or control, 4 tons ha-1, and 8 tons ha-1) and the second factor of foliar spraying of humic acid 82% at 4 levels (non-consumption or control, 100 mg/l, 200 mg/l, and 300 mg/l. Interaction of biochar and humic significantly affected fruit yield. In the treatment with 8 t/ha biochar and 200 mg/l humic acid, the fresh weight of shoots was 465.1 g plant, showing an increase by 32% compared to the minimum value obtained from fertilizer control. At different levels of humic acid, consumption of 8 tons per hectare biochar always increased fruit yield compared to non-biochar treatment and consumption of 4 tons per hectare biochar. The interaction of biochar and humic acid on color intensity was significant. In the combined treatment of 8 tons per hectare of biochar and 100/l of humic acid, a red index of 14.67 was obtained. At different levels of humic acid, consumption of 8 tons per hectare biochar increased the red color index. Considering the fact that the intensity of red color in Roselle indicates the quality of the product, the consumption of 300 mg per liter humic acid and 8 tons per hectare biochar increased this trait, improving its functional traits.

The use of potassium solublizing bacteria (KSB) in soils containing an accumulation of insoluble and non-absorbable potassium by plants can help further solubility of these potassium mineral sources in the soil and thus the uptake of this element by the plant. Also, the application of KSB on the yield and yield components of wheat can prevent the overuse of potassium chemical fertilizers and instead predispose soil conditions for the development of plant nutrition. Therefore, the aim of this study was to determine the effect of application of KSB in comparison with the application of common potassium chemical fertilizers in the country's farms on quantitative and qualitative traits of wheat grain. To study the effect of application of KSB on the yield of wheat cultivars in southern Kerman, Iran, this experiments were performed over two years in the form of split plots in a randomized complete block with three replications in the research farm of Islamic Azad University of Jiroft in loamy sand soil. Various wheat cultivars including Chamran 2, Barat and Khalil were located in the main plot and sources and amounts of calcium were at four levels: 1. Control (without fertilizers) 2. Application of chemical sulfate potassium (at the rate of 200 kg / ha based on soil test results 3. Half of the recommended chemical fertilizer at the rate of 100 kg/ha + consumption of KSB from the source of Potabarvar biofertilizer at the rate of 100 g/ha 4. KSB (at the rate of 100 g/ha as the seed treatment), were placed in sub-plots. The results showed that wheat cultivars showed different reactions to different levels and sources of fertilizer during the two years of the study. The highest grain yield in Chamran 2 cultivar was obtained by applying KSB at the rate of 8 t/ha. Application of KSB alone in Khalil cultivar and application of potassium solfate along with KSB in Barat cultivar produced 7.49 and 7.6 tons of grain per hectare, respectively, Whithout significant different by 8 tons per hectare. Application of KSB could significantly improve grain yield, spike length, number of grains per spike, grain nitrogen percentage and grain protein percentage. The results showed that the applied KSB improved the quantitative and qualitative traits in wheat grain. Although the application of potassium sulfate based on soil test results also had an effective role to increase wheat traits, but it is suggested that in agriculture based on sustainability in agriculture, potassium biofertilizer should be used with half of the recommanded potassium sulfate fertilizer. In addition to reducing the consumption of chemical fertilizers, this can be effective in reducing wheat production costs and farm health.

To investigate sensitivity indicators of five new sunflower cultivars under water stress conditions in terms of drought tolerance (DT) and water use efficiency (WUE), a split plot experiment based on the randomized complete block design (RCBD) with three replications was conducted in 2020 in the Braun Area of Isfahan Province, Iran. The surface irrigation treatments included three levels based on evaporation from class A evaporation pan: 90 (no-stress), 120 (mild stress), and 150 mm (severe stress), as the main factor, and sunflower hybrids Chiara, Oscar, Fantasia, Hysun33, and Shams, as the secondary factors. Indicators such as economic yield (EY), biological yield (BY), WUE, harvest index (HI) and DT were analyzed. The highest rates of HI (43%), WPe (4854 kg.ha-1), and BY (13457 kg.ha-1) were obtained from no-stress treatment, followed by 120 mm treatment. Among the cultivars, Fantasia variety with BY equal to 12268 kg.ha-1, economic yield (4081kg.ha-1), and HI of 43% had the highest values. The highest WUE was obtained in the conditions of mild stress and severe stress  equal to 0.85 and 0.72 kg.m-3, respectively. Among sunflower cultivars, the highest WUE belonged to Hysun 33 with 1.04 kg.m-3. Fantasia with 0.96 kg.m-3and Shams with 0.84 kg.m-3 ranked next. Also, the lowest values of WUE were related to Oscar and Chiara cultivars with values of 0.81 and 0.75 kg.m-3, respectively. In total, deficit irrigation in the 120 mm treatment had the least negative effect on yield and harvest index, and it was suitable in terms of WUE. Finally, Fantasia showed the highest BY, DT, and HI with suitable WUE.

This research was carried in cropping years 2017-18 and 2018-19 to study the effect of plant density on morphological traits, flowering pattern, boll production and seed cotton yield of new cotton cultivars in Varamin region of Iran. In this research, five cotton cultivars including Varamin, Shirpan603, Cocker100, NO200 and SP731 in three plant densities were evaluated using a factorial experiment in a randomized complete block design with three replications. In this study, the number of flowers and flowering date in cultivars for 11 weeks (1 July to 15 September) were counted. The results of analysis of variance showed that the differences between cultivars were significant for plant height, number of nodes, number of flowers, number of bolls and fiber and seed cotton yield at 1% level. The results also showed that there is a significant difference between the years of project implementation for plant height, number of bolls and fiber and seed cotton yield at the level of 1%. The mean of plant height for the first and second years were 93.2 and 119.9 cm and the average number of bolls per plant were 15.9 and 11.41 and the seed cotton yield were 5242 and 4050 kg/ha, respectively. In this study cultivars did not differ significantly in terms of number of days from planting to flowering, number of days from flowering to harvest and early ripening. Investigation of flowering process in 11 weeks showed that the peak of flowering for both years of research was the eleventh week after planting with an average of 41.8 and 44.6 flowers per plant. Most of the bolls were produced from the flowers of the eleventh week for first year and from the flowers of the tenth week for second year. The cumulative growing degree days during the vegetative and reproductive growth period for two years of experiment was significantly different.  So that at the end of the seventeenth week after planting (last week of flowering) the cumulative growing degree days in the first and second years was 1734.9 and 1245.5, respectively, Which can be one of the important reasons in reducing the number of bolls and fiber and seed cotton yield in the second year.

This study was conducted to investigate the effect of potassium and phosphorus biofertilizers on growth characteristics and yield of alfalfa (cv. ‘Nikshahri’) at different ages.

This combined experiment was conducted as factorial based on a randomized complete block design with three replications during two consecutive years under the climatic conditions of Jiroft, Kerman, Iran. The studied factors included alfalfa age (one, three and five-years old) and bio-fertilizers (Control, Pota-Barvar, Phosphate Barvar II, Pota-Barvar + Phosphate Barvar II). The biofertilizers were used along with irrigation water.

The results of the combined variance analysis showed that there was a significant difference between different ages of alfalfa in terms of some growth characteristics and yield. The highest yield and growth characteristics were related to three-year-old plants and the yield significantly decreased by increasing the age to 5-years old. Based on the results, the highest growth characteristics (except internode length) and yield were related to Pota-Barvar + Phosphate Barvar II treatment, which was not significantly different with Pota-Barvar treatment in term of leaf area index and leaf: stem weight ratio. The interaction effect of age and biofertilizer showed that the combined application of biofertilizers improved the growth characteristics and yield of the older alfalfa plants and the highest yield was found in 3-years old plants treated by combination of both biofertilizers.

The combined application of both biofertilizers (PotaBarvar + Phosphate Barvar II) can be an effective way to prevent alfalfa yield decline in old farms.

In order to evaluate different irrigation regimes and planting date on yield, water use efficiency, and harvest index of Roselle (Hibiscus sabdarjffa L.), an experiment was conducted in form of split plot in randomized complete blocks with three replications in Karaj in 2017. Experimental treatments included irrigation round (Irrigation intervals of 8, 10, and 12 days) as a main plot, andplanting date treatments at three levels of 4th June, 18th June, and 2th July as a sub-plot. Results showed that the main effect of irrigation treatments was significant on all traits except harvest index. Planting date had a significant effect only on plant height, stem diameter, biological yield, flower water use efficiency, and sepal water use efficiency. The interaction of irrigation treatment levels and planting date only made a significant difference in biomass water use efficiency. Also, the flower harvest index was not affected by any of the applied treatments.The greatest plant height (181.2 cm), stem diameter (2.91 cm) and biological yield (14.6 t.ha-1) were obtained in the irrigation interval of 8 days. The highest sepal water use efficiency of (0.18 g.L-1), flower water use efficiency (0.034 g.L-1) and sepal harvest index (11.12 %) were observed in the irrigation interval of 12 days. The irrigation interval of 10 days had the highest sepal yield (1.59 t.ha-1) and flower yield (307.7 kg.ha-1).Delay in planting caused a decrease of 12, 16, and 7% in plant height, stem diameter, and biological yield, respectively and increase in the sepal water use efficiency and biological yield water use efficiency by 22 and 20%, respectively compared to optimum planting time. The highest biological yield water use efficiency (2.41 g.L-1) was obtained in irrigation interval of 12 days and one month delay in planting. Based on the obtained results, irrigation interval of 10 days is recommended to achieve maximum flower yield and sepal yield, increase the flower water use efficiency and sepal harvest index. Also, in order to shorten the cultivation period and save water consumption, the date of 18th June is recommended for plant cultivation in Karaj.

The use of fertilizers that consider increasing yield while preserving production resources and increasing the productivity of production inputs is necessary and inevitable. One of the most important issues affecting environmental health and food production sustainability is the use of organic fertilizers instead of chemical fertilizers. This experiment was carried out in the form of split split plots in a randomized complete block design with three replications in Sari, Iran, region in the in the two years(2017 and 2018). Experimental factors include the combination of humic acid and fulovic acid with equal proportions as the main factor in four levels of zero (control), 3, 6 and 9 g/l, the combination of phosphoric acid solution and mono ammonium phosphate as a secondary factor in four levels (Control), 5, 10 and 15 g/l and planting date as a sub-factor in three levels were 25 April, 4 and 14 May. The results showed that the combination of humic acid and fulovic acid increased grain yield per plant, feeding seedlings with different amounts of phosphorus compounds increased the grain yield. The highest grain yield was obtained from the consumption of 3 g/l humic acid and folic acid, which showed an increase of 28.09% compared to the control. The highest grain yield was obtained by treatment of 5 g/l of seedling feed with different amounts of phosphorus compounds, which indicated a 28.98% increase in grain yield. The highest grain yield was obtained by treatment of 5 g/l of seedling feed with different amounts of phosphorus compounds, which indicated a 28.98% increase in grain yield. Grain yield  in sowing date of 4 and 14 May was better than 25 April. Grain yield had positive significant correlation with all off measured traits at %1 level. Based on the results, the use of humic acid and folvic acid along with feeding the seedlings with different amounts of phosphorus compounds in different planting dates improved grain yield. The suitable sowing date could be more effective by making better use of environmental factors and improving vegetative properties and allocating more photosynthetic material to the seed.

To investigate the agronomic response of cotton cultivars and hybrids at different densities this study was conducted in 2017 and 2018 on the farm of the National Cotton Research Institute, Varamin, Iran. 10 cultivars and hybrids including Varamin, Bakhtegan, Sajedi, Sahel, T2, T14 and hybrids (Sahel × Sajedi), (Bakhtegan ×T2), (Varamin ×T14), and (Sajedi ×T14) under 5.5, 6.4 and 12.8 plants per square meter were evaluated. The field experiment was performed as a split-plot in a randomized complete block design with 4 replications. During the growing season and after the physiological maturity stage, plant yield, boll weight, number of bolls per plant, plant fiber weight, seed weight per plant, and plant height were carefully measured. During the growing season and after the physiological maturity stage, plant yield, boll weight, number of bolls per plant, plant fiber weight, seed weight per plant, and plant height were carefully measured. The results of comparing the mean interaction of cultivar and plant density on plant yield showed that ور hybrid cultivar Varamin× T14 at a density of 5.5 plants per square meter in the crop years 2017 and 2018, respectively, had the highest plant yield, a number of bolls per plant, fiber weight, grain weight per plant To other cultivars and hybrids studied. Also, the results of this study showed that the density of 5.5 plants per square meter is very suitable and recommended for cotton and especially for the new hybrid of Varmin×T14, which had better quantitative and qualitative characteristics than other cultivars.

The purpose of this research was to investigate the effects of the planting date from spring to winter on the phenological stages and the performance of three types of tropical legumes (local beans, cowpeas and mung beans). This study was performed as a factorial in a complete randomised block design with 3 replications for two years (2018-2019) in Agricultural Research Center in Jiroft, Kerman, Iran Experimental treatments included three planting dates of 30th Jan, 9th Feb and 19th Feb and three tropical legumes. The results indicated that legumes requirement 1200 degree-days of temperature growth during their developmental stages, considering the base temperature of 15˚C. The highest degree-days of growth from planting to germination, greening and from one to five leaves stage belonged to mung bean. the results showed that the cumulative temperature gradually decreased during the stages of flowering initiation, full flowering, pod initiation and grain filling in Mung beans and two types of beans. Mung bean seed yield stability on all three planting days averaged 0.7 t.ha-1, demonstrating the ability of this crop to adapt to temperature. The seed yield in local beans and cowpeas was the highest content averaged 2.3 and 4.6 t/ h in last cultivation on 19th Feb. Cultivation of legumes in early winter is therefore recommended as it has the opportunity to provide a cumulative temperature and growing day. It can reduce the negative effects on plant growth caused by intense heat and evaporation. High transpiration should be superior to spring patterns cultivation.

To evaluate different irrigation regimes and planting dates on plant height, stem diameter, yield, and yield components of okra (Abelmoschus esculentus L.) a split plot experiment based on randomized complete blocks with three replications was conducted in Karaj during 2017 growing season. Experimental treatments were irrigation intervals (8, 10 and 12 days) as a main plot, and planting dates with three levels (4th, 18th of June and 2th July) as a sub-plot. The results of analysis of variance showed that the main effect of irrigation interval was significant on all traits under study. Planting date treatment had a significant effect only on plant height, stem diameter, number of plant branches, number of plant leaves, number of fruits, fresh fruit yield and dry fruit yield. The interaction of irrigation interval treatment and planting date had no significant effect on the trails under study. The highest chlorophyll concentration (3.68 mg.g-1 FW), plant height (100.4 cm), number of branches (3.1), number of leaves per plant (24.8), number of fruits per plant (10.5) and fresh fruit yield (4023 kg.ha-1) were belonged to the irrigation interval of 8 days. Irrigation interval of 12 days decreased by 30.4, 21.7, 21.3 and 28.4 % in stem diameter, fruit length, fruit diameter and dry fruit yield, compared to irrigation interval of 8 days interval, respectively. The highest plant height (99.2 cm), number of branches (2.5), number of leaves per plant (23.3) and number of fruits (9.77) were observed of June 4th planting date. The highest fruit yield was obtained in June 18th planting. Based on the results obtained it can be concluded that irrigation interval of 8 days is recommended to achieve maximum fruit yield and to shorten the length of growing period, saving in water consumption and maximum yield performance in the Karaj region, the date of 18th June is recommended.

Damask rose is a perennial and drought- resistant plant. In order to envestigate effect of potassium silicate on quantitative traits and essential oil of damask rose (Rosa damascena Miller) under water- deficit stress, an experiment was carried out as a split-plot based on a randomized complete block design with three replications at the Karimeh Zaer Farm, Qom province, Iran, in 2018. The main plot was water deficit stress at four levels (100 (without stress), 75, 50 and 25% of the plant water requirement) and the sub plot was spraying with potassium silicate at seven levels (without spraying, spraying with a concentration of 0.2 and 0.4% in the spring or summer alone or combination). The results showed that water deficit stress increased the essential oil percentage. Irrigation equivalent to 25, 50 and 75% the plant water requirement increased water use efficiency by 1.3, 1.9 and 3.3 times in comparison with the control, respectively. Foliar application with different rates of potassium silicate increased leaf silica rate under optimum and water deficit stress. The maximum of essential oil yield was recorded from foliar application of 0.2% of potassium silicate in the spraying along with summer under 25% f the plant water requirement and treatment of the foliar application of 0.4% of potassium silicate in the spraying along with summer under 50% the plant water requirement, respectively. Results showed that with foliar application of potassium silicate under water deficit stress equal to 50 and 25% the plant water requirement could increase quality and quantity damask rose.

In order to investigate the effect of different methods of seed priming on germination indices, biochemical characteristics and yield component of three safflower cultivars under drought stress conditions, two experiment was carried out in the form of filed (as split factorial in randomized complete blocks design) and laboratory (as factorial based on completely randomized design) with three replications. The experimental factors included drought stress in two levels of complete irrigation during the growing season and drought stress at the stem elongation as the main factor and seed priming with osmopriming, hydropriming, hormopriming and control (without priming) and safflower cultivars included Isfahan, Sofeh and Goldasht as subplot factor. Simultaneous application of hydropriming and drought stress in Isfahan cultivar resulted in the highest root length (4.8 cm). Hydropriming and hormopriming increased the coefficient of velocity of germination in Isfahan cultivar 52.34% compared to control. Hydropriming increased the germination percentage by 11.33% compared to the control. The highest seed yield (100.72 g / m2) were obtained in Sofeh cultivar during complete irrigation and hydropriming application. The highest soluble carbohydrate amount (15.14mg/g FW) was related to the interaction between stress and no priming. Goldasht cultivar had the highest oil yield (24.93 g / m2) at the time of complete irrigation and hydropriming application. Usage of hydropriming during stress in Goldasht cultivar caused the highest amount of proline (10.08 mg/g FW). The interaction of hormopriming with drought stress causes the most activity of superoxide dismutase enzyme (56.1 mg protein/min).

Using of potassium soloblizing bacteria in mineral potassium-rich soils can increase the solubility of soil potassium and its absorbtion by plants. Therefore, the aim of this study was to determine the effect of potassium biofertilizer in comparison with common potassium chemical fertilizers in the region on yield and yield components of bread wheat.

In this study, the effect of K bio-fertilizer application on wheat cultivars in Kerman., Iran was evaluated. For this purpose, these experiments were conducted in Split-Plot in a randomized complete block design with three replications in Islamic Azad University farm, Jiroft, Iran. Different cultivars of wheat at three levels including Chamran 2, Barat and Khalil were as main plot and sources and amounts of K fertilizer were at four levels were in sub plots. K fertilizer levels were included 1. Control (without using any K fertilizers)2. Potassium sulfate fertilizer application (based on soil test results) 3. Half recommended fertilizer based on soil test results plus fertilizer application and 4. Potassium bio fertilizer Alone (From the source of Potabarvar).

Results showed that bread wheat cultivars had different response to different levels of K fertilizer treatment during two years of study. However, application of K biofertilizer alone and in combination with 50% reduction in recommended fertilizer could improve grain yield in Chamran wheat cultivars (8 t.ha-1) and Khalil (7.49 t.ha-1) and Barat cultivar (7.6 t.ha-1), respectively.What was evident in the results was that potassium bio fertilizer improved biological yield and grain yield, harvest index, thousand seed weight and plant height.

The application of potassium biological fertilizer combined with 50% of recommended K chemical fertilizer significantly reduce the amount of mineral K fertilizers and production costs and improve product health.

Planting pattern and plant density are efficient management tools for maximizing crop yield by reducing soil surface evaporation and optimizing resource utilization such as light, nutrients, and water. A two-year (2017-18) field trial was conducted to determine the effects of plant density and planting pattern on some agro-physiological and biochemical traits of Tepary bean (Phaseolus acutifolius L.) at the Research Station of Islamic Azad University, Arak Branch, Iran. The experiment was performed as a split-plot arranged in a randomized complete block design with three replications. The treatments were two planting patterns (one-row and two-row plantations) and three plant densities (30, 40, and 50 plants per m2). The results showed that that one-row planting pattern and 40 plants per m2 improved seed yield by 75% and 65% compared to 30 and 50 plants per m2 in one-row planting pattern in the second year, respectively. The plant chlorophyll content increased by 20% with two-row plantation and medium plant density compared to high and low plant density in the first year. The highest accumulation of seed carbohydrates (38.26 mg. g-1 FW) was obtained with two-row cultivation and medium plant density in the second year. The relative seed water content significantly decreased with one-row plantation and low plant density compared to a two-row plantation and medium plant density. The least malondialdehyde and proline aggregation (3.2 and 225 µ mol. g-1 FW, respectively) was achieved with two-row plantation and medium plant density. Finally, a two-row planting pattern with medium-density cultivation is recommended to obtain optimal Tepary bean seed yield in the region.

Plants adjust physiochemical attributes to maintain sustainable growth under different agricultural practices such as the management of sowing date and planting pattern.The present experiment aims to investigate the important role of sowing date (SD) and planting pattern (row arrangement) on physiochemical attributes of tepary bean (Phaseolusacutifolius L.) as a split-split plot designs with three replications during 2017 and 2018 .The main plots were two planting patterns (PP1: one-row and PP2: two-row plantation) and sub plots were three sowing dates (early, medium and late planting respectively June 15:SD1, June 30:SD2, and July15:SD3). The results showed increased chlorophyll (Chl) and carotenoid content was observed under two-row plantation and medium sowing date . Although Chl content improved at PP2, carotenoid had no response to planting pattern .The greater relative water content (RWC) was observed in plants under SD2, but the increased proline accumulation was reported at SD3. The least catalase and superoxide dismutase aggregation with 19 and 9.3(Umg-1protein) was obtained in plants under two-row plantation and medium sowing date respectively. Photosynthesis pigments represented the significant and positive correlation with RWC, but they negatively correlated with proline, CAT and SOD. Sowing date and planting pattern influence the microclimate of tepary bean, which affect the physiochemical properties. Therefore, physiochemical attributes are recommended to observe the optimal situation of tepary bean under the management of sowing date and planting pattern in arid and semiarid areas.

Use of organic fertilizers is one of the important ways to improve agricultural productions reduce the risk of environmental pollution and to achieve sustainable goals. To compare the effect of different levels of planting date, organic and chemical fertilizers on yield and yield components of maize, a split plot experiment with eight treatments and three replications was conducted at The Research Farm of Islamic Azad University, Research and Sciences Branch, at Varamin, in 2019. Treatments were two levels of planting time (timely planting and late planting) and four fertilizers levels (control, 450 kg.ha-1 urea, 25 ton.ha-1 of compost manure and 15 ton.ha-1 of vermicompost fertilizer). The results showed that all of the traits under except 1000-grain weight were affected by different treatments. Delayed sowing significantly decreased yield and yield components. In most of the traits studied, significant differences between urea, compost and vermicompost treatments were not observed. However, stem diameter, seed content of nitrogen, number of kernel per ear and 1000-seed weight were not affected by the applied fertilizer treatments. Urea and vermicompost increased leaf soluble carbohydrates by (32.9 µg.g-1 FW and 31.9 µg.g-1 FW, respectively) and biological yield by (29.7 ton.ha-1 and 28.8 ton.ha-1, respectively). Also, grain yield increased by the use of compost (6.9 ton.ha-1) and urea (7.3 ton.ha-1) treatments. According to the results of this study, compost and vermicompost fertilizer can be a good alternative to urea in production of corn in Varamin region.

This research was carried out to study the flowering process and production of boll in different cultivation densities of cotton cultivars in 2017 in Varamin, Iran. In this research, five cotton cultivars including Varamin, Shirpan603, Cocker100, NO200, and SP731 in three planting densities of 5.5, 6.4, and 12.8 plants per square meter was evaluated using a factorial experiment in the form of a randomized complete block design in three replications. The number of flowers of the cultivars was counted during the period time from 1 July to 15 September (11 weeks). The results of the analysis of variance showed that the effects of plant density on flower number, number of bolls, and cottonseed were significant at 1% level and on fiber weight at 5% level. Also, with an increasing number of plants per unit area, the number of flowers, the number of bolls, boll weight, and fiber weight decreased. So, with increasing density from 5.5 to 6.4 and 12.8 plants per square meter, the average number of flowers decreased from 40.97 to 38.83 and 28.25 flowers per plant, and the average number of bolls decreased from 18.64 to 17.16 and 11.94 boll/plant. In this study, the percentage of boll retention had no significant difference in plant densities. The findings of this study showed that the peak flowering stage and boll formation occurred 11 weeks after planting by receiving about 1148 GDD. Moreover, 91% of the bolls that were made from flowers had appeared until the end of the 13th week.

Grasspea (Lathyrus sativus L.) is a forgotten plant and its cultivation is important in the scope of sustainable crop production. In a field experiment, using split factorial arrangements in randomized complete block design with three replications, the effects of irrigation regimes; 50, 75 and 100% of evaporation of class A evaporation pan, and different rates of phosphorous fertilizer (triple superphosphate); 0, 60 and 120 kg ha-1 on growth characteristics, seed yield and forage yield of two grasspea ecotypes; Lalehzar and Sharekord, in Lalehzar region in Kerman province, Iran, in 2018 and 2019 growing seasons was studied. The results showed that drought stress significantly reduced pod no. m-2, plant height, seed yield and biological yield. Application of phosphorous fertilizer increased grasspea growth and yield. Overall, Shahrekord ecotype showed higher seed yield (2401 kg ha-1) and biological yield (5612 kg ha-1). The highest phosphorus productivity (39.98 kg seed kg P-1) achieved in 75% of evaporation irrigation regime plus 60 kg ha-1 triple superphosphate fertilizer. Therefore, growing Shahrekord grasspea ecotype in Lalehzar region would be reasonable in terms of saving water and managing the application of phosphorous fertilizer.

One of the main problems in crop production in Iran is the difference between actual yield and attainable yield which is called yield gap. Thus, identifying yield constraints and yield gap are important. Therefore, a study was conducted in 60 farms in Parsabad Moghan, during 2013-14 and 2014-15 crop years using Comparative Performance Analysis (CPA). In this study, several attributes related to management operations and crop characteristics were recorded and measured. Then, the relationship between different variables and grain yield were considered, using stepwise regression. The results showed that there is a 2317.42 kg/ha difference (gap) between actual yield (average farmerschr('39') yield) and attainable yield (maximum farmerschr('39') yield). It was identified that planting time, spike density, the number of vents of split application of urea, the number of land preparation operations, farming experience and repeated use of fungicides with contributions of about 18, 29.7, 20, 4.6, 14.3 , and 13.4 percent, respectively, were responsible for this yield gap. Further analysis of the data revealed that most of the variables listed above can be controlled by the agronomic management. It was concluded that with proper farm management and considering the listed yield gap factors, it would be possible to obtain higher grain yields of about 2316 kg/ha in the irrigated wheat farms, compared to the current average farmers’ yield.

To investigate the effect of delayed sowing on seed and oil yields of rapeseed (Brassica napus L.) genotypes, a field experiment was carried out at the research field station of Seed and Plant Improvement Institute, Karaj, Iran in 2015-2016 and 2016-2017 cropping seasons. The experimental design was split plot arrangements in randomized complete block design with three replications. Optimal sowing dates (02 October) and delayed sowing date (01 November) were assigned to the main plots, and 17 rapeseed genotypes [French (eight), Iranian (five), Hungarian (two) and German (two)] were randomized in sub-plots. Combined analysis of variance showed that all main and interactions effects were significant on all studied traits (except the main effect of year on seed oil content). Plant developmental stages experienced different environmental conditions due to delayed sowing and led to decreases in seed yield and yield components, seed oil yield and biological yield. The highest seed yield in optimal sowing date belonged to Garou (in the first year) and HL2012 (in the second year) genotypes with an average of 5240 and 5805 kg ha-1, respectively. However, Okapi (in the first year) and Garou (in the second year) had the lowest seed yield in delayed sowing date with an average of 3624 and 2702 kg ha-1, respectively. Lauren (in the first year) and Darko genotypes (in the second year) had the lowest grain yield reduction (%) in delayed sowing date which accounted for 21.5% and 35.9%, respectively.

In order to evaluation of value for cultivation and use of seven new spring rapeseed cultivars (Foruzan, Mahtab, Zaman, Moj, Dalgan, Z10B, SAN14) and seven commercial cultivars of Rapeseed (Sari Gol, RGS003, Hayola 420, Hayola 308, Hayola 401, Hayola 50, and Zafar) as a Reference collection were carried out in a randomized complete block design with three replications at the Seed and Plant Certification and Registration Institute-Karaj in 2015-2016. The measured agronomic traits were including, 1000-seed weight, number of silique per plant, number of seeds per silique, oil percent, Maturity date and grain yield were determined according to the UPOV instruction. The results show that, hybrid cultivars such as Hyola 50 and Hyola 401 have the highest yield. Considering the superiority of Mahtab, Zaman and Dalgan cultivars in terms of yield and having crop value compared to other cultivars, these varieties can be introduced as new cultivars for registration and commercialization. Keywords: Rapeseed, Reference collection, Spring varieties

In order to investigate the effect of plant density and phosphorus resources on yield and yield components of black cumin (Nigella sativa L.), medicinal plant, at dryland conditions, a split-plot experiment based on randomized complete block design with three replications was conducted at Soil and Water Conservation Research Center, University of Tehran, located in kouhin dryland farms in Qazvin Province, Iran in 2016-2017. Phosphorus resources were chemical Phosphorus (150 kg/ha di-ammonium phosphate or control) (p1), 50% chemical Phosphorus + 50% biological Phosphorus (p2), biological Phosphorus Barvar II® alone (p3) and plant density levels were (d1)20, (d2) 30 and (d3)40 plants/m2. Results showed that interaction effect between plant density and phosphorus resource were significant on number of capsule per plant, number of grain per capsule, number of grain per plant, grain yield, biological yield and harvest index. Also number of grain per carpels was affected by phosphorus treatment, but the number of carpels per capsule and 1000 grain weight were not significant. The highest grain yield (206.25 kg/ha) was obtained from biological Phosphorus fertilizer application (P3) with 40 plants/m2 plant density and the lowest grain yield (42.34 kg/ha) was recorded for control (P1) treatment with 40 plants/m2 plant density. So, application of biological phosphorus and high plant density (40 plant/m2) had the highest grain yield however, chemical phosphorus (control) in high plant density produced the lowest grain yield.