نشریه پژوهش های کاربردی زراعی
پیاپی 123 (تابستان 1398)

Introduction Potato is amongst the most important crops in the world, which is the third most consumed crop worldwide after rice and wheat and is followed by corn in this regard (Kazemi et al., 2016). Abiotic stresses like drought may cause adverse effects on growth and tuber yield of potato plants as they are very sensitive to soil moisture reduction (Deblond et al., 1999). Potassium is used as a cofactor of enzymes, osmotic activities and plant electrolyte regulation, and is an essential element for osmotic control that can reduce osmotic potential and improve plant acclimatization under drought conditions (Taiz & Zeiger, 1991). Given the importance of potato production and its high demand for water and because of scant research being conducted on the planting patterns of this crop, the present study aimed to investigate the effects of various planting patterns and different potassium levels on potato growth indices under water-limited conditions in Khorasan Razavi province. Materials and Methods This experiment was conducted in Jolge Rokh- agricultural research station over spring and summer of 2016 and 2017 cropping seasons. The experiment was set up as split split plot arrangement based on a randomized complete block design with three replications. The trial factors consisted of three planting patterns including common planting, common dense planting and zigzag planting designated as the main plots, and irrigation with three levels [control (without stress), irrigation based on 80% of the crop water requirement (as deficit irrigation treatment), and irrigation based on 60% of the crop water requirement (as stress treatment)] designated as the sub -plots, and three levels of potassium fertilizer (0 (control), 75 and 150 kg potassium sulfate per hectare) designated as sub-subplots The water needed for the plant was determined based on water requirement of the potato, which was determined using the software (OPTIWAT) and FAO Penman- Monteith method. The leaf area and leaf dry weight were measured during the growing period at two-week intervals. Results and Discussion The results showed that the greatest leaf area index (LAI), crop growth rate (CGR) and total dry matter (TDM) were observed with zigzag planting pattern at either year of the study. The maximum TDM under common, common dense and zigzag planting in the first year were 634.3, 671.9 and 870 g.m-2, respectively, while the corresponding values for the second year were 808.5, 919.2 and 1065 g.m-2, respectively. Irrigation treatments based on 80 % and 60% of the crop water requirement reduced the growth indices and yield of the tubers. The greatest tuber yield was observed with full irrigation treatment (100% of the crop water requirement (32 and 35.2 ton. ha-1 in the first and second year, respectively), while the lowest tuber yield was obtained with 60% of the crop water requirement (20.2 and 20.4 ton. ha-1 in the first and second year, respectively). The results showed that potassium sulfate increased TDM, LAI, CGR, NAR and tuber yield. The application of 150 kg of potassium sulfate produced the greatest TDM (850.2 and 1118.9 g.m-2 in the first and second year, respectively), whereas no fertilizer usage gave the lowest TDM (584.2 and 743 g.m-2 in the first and second year, respectively). In potato plants, sufficient quantities of potassium increase the number of tubers and dry matter production through strengthening potato stems, and at the same time, the plant can acclimatize to environmental stresses. Conclusion The results showed that the greatest LAI, TDM, CGR, NAR and tuber yield were observed with the zigzag planting. On the other hand, irrigation based on 60% the crop water requirement reduced the growth indices and tuber yield. It is worth noting that applying 80% of the crop water requirement also decreased the investigated the growth traits of the potato plants. Therefore, it is recommended that the exposure of potato plants to deficit irrigation conditions be avoided and the efforts should be made to provide them with adequate water. But the remarkable point was that the usage of potassium sulfate fertilizer could enhance and improve growth rates under low irrigation and water stress conditions.

Evaluation of quantitative and qualitative traits and resistance populations to powdery mildew in sainfoin plant Onobrychis vicifolia) Extended Abstract 1 – Inroduction: Powdery mildew is an important disease in the major areas of crop sowing in Iran, which is mainly caused by the Leveillula taurica mushroom with the form of Oidiopsis taurica .This Fungi is capable of contamination of 700 species belonging to 59 plant families including pepper, tomato, alfalfa and cotton (Correll et al., 1987). Symptoms of this disease including: necrotic spots with white mucous membrane covering on leaves, plant growth retardation, infestation of leaves, fine grains and wrinkling of seeds and, consequently, reduction of crop(Sharifnabi and Banihashemi, 1990). The highest damage caused by L.taurica is the major cause of Powdery mildew of sainfion in the rangelands of Lorestan province, with the second and third cuttings (Sepahvand et al.2000). This disease has been observed in different areas of sainfion cultivation in Zanjan province. In this research, theseeds 17 populations of Sainfoin were sown and evaluated using Randomize Block Design with thee replications in field of Khirabad station of Agricultural and natural resource of research and education center Zanjan from 2014 to 2016. The quantity traits including: Fresh and dry forage weight, medium infection percentage and disease severity index of the populations were evaluated for three cuttings during three years. The quality traits including:protein content (CP), Dry material digestibility(DMD), water soluble carbohydrate (WSC), insoluble fiber in acid detergents (ADF), insoluble fiber in neutral detergents (NDF), ash content (ASH) and crude fiber (CF) were measured. Two population 15364, 1601 with fresh forage yield (9240, 8608)kg/ha) and dry forage yield (3048 and 3057)kg/ha were higher than other populations.The crude fiber, insoluble fiber in neutral detergents of two populations of 8799, 4083 (36.48, 36.9) were lower than other populations, therefore for this reason they have high quality of forage. Three populations of 3001, 15353 and Oshnavieh were tolerant to powdery mildew disease due to low disease severity index and also they have high quality forage due to high dry material digestibility. This result confirmed by Alizadeh et al. (2012) because with an experiment , they concluded that three populations of 3001, 15353 and Oshnavieh were tolerant to powdery mildew disease due to low disease severity index. The dendrogram of cluster analysis and the main component of (byplot) have defined that three populations of 3001, 15353 and Oshnavieh were grouped in a group and were superior than other populatios for their tolerance to powdery mildew disease. Three populations of 3001, 15353 and Oshnavieh were tolerant to powdery mildew disease due to low disease severity index and also they have high quality forage due to high dry material digestibility. Key word: Sainfion, powdery mildew, Leveillula taurica, tolerance, yield and forage quality References Alizadeh, M.A., and Jafari,A.A., 2013. Evaluation of sainfion (Onobrychis viciaefolia) with response of powdery mildew (Leveillula taurica)in field condition. J. Res.Genet and Plant Breed. Forest and Rangeland, 28(1): 48-58. ijrfpbgr.rifr-ac.org. Correll, J.C., Gordon, T.R., and Elliott, V.J., 1987. Host range, specification and biometrical measurements of Leveillula taurica in California. Plant Disease 71:284-251. Sepahvand, K., Moridi, M., and Nazari, S., (2000): Evaluation and identification of powder mildew of range land plant in Lorestan province, Research project Final report , 2000, Pp: 58-71

Extended Abstract: Effect of different densities of wild mustard (Sinapis arvensis) on the growth indices of wheat (Triticum aestivumL.)cultivars in Gorgan Introduction There are many species of weeds that damage wheat farms in Golestan province, however, Sinapis arvensis is one of the most common weed species in the wheat farms, which results in lower yields and increased production costs (Pawar, 2009). Growing cultivars with high competitive potential is one of the strategies for combating weeds in the integrated weed management system. Agronomic competition is one of the least expensive and the most commonly used methodsby farmers to control weeds, which is consistent with the goals and new criteria of sustainable agriculture practices(Kristense et al., 2008). Among the factors contributing to weed competition with crops, cultivars and planting intensity are of great importance. In this regard, plant growth analysis canbe indicative of the competitive ability of crops against weeds. The aim of this study was to investigate the effect of different densities of Sinapis arvensis on some growth indices and yield loss in four wheat cultivarsunder climatic condition of Gorgan. In order to investigate the effect of wild mustard (Sinapis arvensis) competition on the growth indices of wheat cultivars, an experiment was conducted at agricultural research station of Gorgan in two cropping years (2009-2011). The experiment was conducted as factorial in a randomized complete block design with four replications. The experimental factors consisted of four wheat cultivars: Arta, Tajan, Moghan and Morvarid and five wild mustarddensities of 0, 4, 8, 16 and 32 plants/m2. Wheat density was maintained at a constant 350 plants/m2 during the two years of the experiment. The evaluated traits included leaf area index(LAR), crop growth rate(CGR), relative growth rate(RGR), dry matter accumulation (DMA)and wheat grain yield. The leaf area index was measured using the Delta-T model leaflet. These data were used to determine growth indices. Statistical analysis of data was performed using SAS software. Charts were drawn using Excel 2007 and Sigma plot software. The combined analysis results showed that the effect of year on the all traits was not significant at 1% probability level. But the effects of cultivar, density and interaction of cultivar and wild mustard (Sinapis arvensis) density were significant. The results of the mean comparison showed that by increasing the density of Sinapis arvensis from 4 to 32plants/m2, the trend of changes for the growth indices of the wheat cultivars was decreasing. However, the trend of yield reduction among the wheat cultivars due to competition with Sinapis arvensiswas not similar. The significant interaction between cultivars and density levels onwheat grain yield indicates that the economic performance of different wheat cultivars did not decline in the same rateunder thedifferent densities ofwild mustard. In this study, Morvarid cultivar was found to be highly resistant to Sinapis arvensis because it was able to produce higher DM yields, LAI, CGR and RGR in competition with wild mustard than the other cultivars. One of the important factors for dry matter production and crop yield formation is the increase in leaf area index. The higher LAI and greater light consumption efficiency can facilitate the optimized light absorption, leading to increased yield production. In other words, if a plant can efficiently convert the absorbed light to higher biomass yied, it will be more successful in biomass production and yield formation (Blackshaw et al., 2008).In general, the resultsshowed that the grain yield performance of wheat cultivars while competing with wild mustard weed was influenced by the growth indices and Morvarid cultivar was more successful than the three other cultivars. The results of this study showed that the competition ability of the wheat plants was strongly influenced by wild mustard (Sinapis arvensis) density. Wild mustard has a high potential competitivenessagainst wheat due to its unlimited growth pattern and greater height, LAI and DMA, facilitating the capture of resources needed for growth. Therefore, in the wheat producing areas wherewild mustardis problematic, in addition to implementing other management practices, it is necessary to grow suitable cultivars such as Morvarid.

In addition to economic production of crops in various different country's countries, the ability to create vegetation, prevent soil erosion and wind, increase soil organic matter, prevent direct evaporation of soil moisture during the growing season, increase water use efficiency by the plant (Pirkhezri, 2009; Mahdikhani et al., 2015). Due to the characteristics of the crop and its medicinal properties, the diversity of indigenous and local populations and the genetic resources of this plant in different habitats, it is necessary to enter the agricultural system and be domesticated and corrected. Taking and selecting and selecting from indigenous populations is helpful in correcting the plant. So necessarily, in order to achieve these goals in the domestication process, we must first consider the simplest way of reforming the selection of the population (Taiz and Zaiger, 2000). Due to the fact that hawthorn is one of the most important medicinal plants, this study is to study and select among native peoples of Khorasan Razavi province for quantitative traits. In this study, 10 populations of Husqvarna including Davarzan, Almagagh, Bashrooye, Sarband Kalat, Golmakan, Fariman, Kashmar, Rabat Sang, Ghale Zou and Bakhzar were used. To analyze the variance and analyze the data obtained using SPSS 19 and SAS software Became Optimum Duncan test was used to compare the means. Excel software was used to draw shapes and charts. Histogram and dentogram were used in this study. In the 6th generation of Flixweed cultivars, the highest 1000-seed weight was observed in the flowering population of 1.17 grams. The minimum weight of 1000 seeds was also obtained in the robotic population of 1.12 grams. There was a significant difference between the Golmakan treatments with the second largest population, namely, the population of Almagagh. The results of cluster analysis of functional traits (germination percentage, germination rate, seed germination index, mean germination time) are shown in the form of dentograms in the first and last generation. According to the results, in the first generation, the most similarity was observed in the low and poor levels of functional traits in the wildlife species, Rabat Stone and Fariman, which are above the graph. Also, in the first generation, the highest similarity was observed in terms of high values of functional traits in Golmakan, Sarband Kalat and Qala Zou populations, which are below the graph. According to the results obtained in the 6th generation, the most similarity was observed in the low and low levels of functional traits in the populations of Bashrooye, Davarzan and the rock interface, which are above the graph. Also in the 6th generation, the most similarities were observed in the germination traits in Golmakan, Sarband Kalat, Qala Zou populations, which are below the graph. This suggests that the populations mentioned include Golmakan, Sarband Kalat, Qala Zhu have a high potential for reforming processes and increasing functional traits, which is the most important part for plant breeding.

Abstract Introduction World food security in the future depends on the generation of enough food for the world's population, which predicts that the world's population will reach more than nine billion by 2050. Achieving food security in the current environment depends on realizing the potential yield achieving in the agricultural land (Hochman et al., 2016; Guilpar et al., 2017). Hence, improving the crop yield is necessary in view of the increasing pressure and global demands for food. On the other hand, loss of high quality land, annual decline in crop yield, increased use of chemical fertilizers and the adverse environmental impact of chemical inputs indicate that the development of new strategies to increase yield with minimum environmental impact is necessary (Chapagain & Good, 2015). Moreover, ensuring environmental sustainability leads to research into changing agricultural management practices (Gaydon et al., 2017). As noted, many factors prevent farmers from achieving the crop attainable yield. It seems that, by determining the effect of each managing factors that affected on the amount of yield gap and, consequently, the knowledge of the farmers, it is possible to minimize the yield gap between the actual yield and the achievable yield. Therefore, this research was conducted with the aim of determining and ranking the factors causing the canola yield gap in the climate of eastern province of Mazandaran in Iran. Material and Methods Research was done in 100 canola fields in Neka, Mazandaran, Iran from 2015-16 and 2016-17. All managerial operations from seedbed preparation to harvest were recorded through field studies. Field identifications were done in a way that includes all main production procedure in specific region with variation in management view point. For defining yield model (production model), relationship between all measured variables and final model was designed by controlled trial and error method. The final model was obtained through the controlled trial and error method, which can quantify the effect of yield limitations. The average paddy yield was calculated by the model by placing the observed average variables (Xs) in the fields under study in the yield model. Thereafter, by putting the best observed value of the variables in the yield model, the maximum obtainable yield was calculated. The difference between these two has been considered as yield gap. Different procedures of the software SAS version 9.1 were used for analysis. With approximately 150 variables under study, the final model with seven independent variables including soybean pre-sowing, rice pre-sowing, top dressing, K2O usage, nitrogen usage in vegetative stage, herbicide frequency usage and weed problem were considered as independent variables was chosen against depended variable of paddy yield. The yield gap caused by top dressing and K2O usage variables were equal to 462 and 294 kg.ha-1 equals 27 and 17% of the total yield gap. The yield gap related to the effect of soybean pre-sowing and herbicide frequency was 170 and 411 kg.ha-1, respectively, and equal to 10 and 24% of the total yield variation. In yield model by CPA method, the actual yield and calculated potential yield were equal to 2394 and 4119 kg.ha-1, respectively. The amount of yield gap equals 1725 kg.ha-1. Among the five variables entered in the model, the effects of potassium consumption, soybean pre-sowing, top dressing and herbicide frequency usage were remarkable, which can compensate for a significant part of the yield gap in the farmers’ fields by managing potassium consumption and using integrative pest control. Based on the finding, it is expressed that the model precision (production equation) is appropriate and can be applied for both estimation of the quantity of yield gap and determining the portion of each restricting yield variables.

Evaluation the effect of heat stress on winter and summer planting systems on quantitative and qualitative yield of potato cultivars in field conditions Abstract Potato is one of the most important crops in the world which currently is cultivated in many climates of the different parts of the world. In order to evaluate the response of different potato varieties to the planting date in Boshrooyeh area, two independent experiments were carried out using split plot desing in randomized complete block dising in February 2015. The first experiment was conducted using three sowing date, including: February 9, February 24, and March 11, 2016, as main plot and three potato vareties, including: Fontane, Picasso and Sante, as subplot. In the second experiment (summer crop), the same cultivars were cultivated at the sowing dates of August 11, August 27, and September 11, 2016. The results showed that, in both winter and summer planting dates, delaying in planting caused to decrease in tuber yield. In the winter crop, the highest yield was obtained from Sante in sowing date of February 9, and in summer crop, the highest yield was obtained from Fontane and Picasso in sowing date of August 11. The dry matter percentage of the tubers also decreased with delay in planting date, both in winter and summer planting dates. Potato is one of the most important crops in the world which currently is cultivated in many climates of the different parts of the world. In order to evaluate the response of different potato varieties to the planting date in Boshrooyeh area, two independent experiments were carried out using split plot desing in randomized complete block dising in February 2015. The first experiment was conducted using three sowing date, including: February 9, February 24, and March 11, 2016, as main plot and three potato vareties, including: Fontane, Picasso and Sante, as subplot. In the second experiment (summer crop), the same cultivars were cultivated at the sowing dates of August 11, August 27, and September 11, 2016. The results showed that, in both winter and summer planting dates, delaying in planting caused to decrease in tuber yield. In the winter crop, the highest yield was obtained from Sante in sowing date of February 9, and in summer crop, the highest yield was obtained from Fontane and Picasso in sowing date of August 11. The dry matter percentage of the tubers also decreased with delay in planting date, both in winter and summer planting dates.

Introduction Wheat breeders have been constantly working to develop new varieties with improved productivity and yield and resistance to pests and diseases. These varieties are being released frequently and are replaced existing ones over and released on basis of their performance under open conditions. Intercropping has been widely applied to reduce soil erosion and water loss, restoring ecological balance, improving radiation and nutrient use efficiency, raising land equivalent rate and increasing economic benefits. The objective of the present work was to determine the effect of row intercropping of old and newwheat cultivars and canola as additive series on the yield, yield components, radiation use efficiency and land equivalent ratio under climatic conditions of Mashhad. Materials and Methods This experiment was conducted as factorial layout based on a randomized complete block design with three replications at the Agricultural Research Ftation of Ferdowsi University of Mashhad, Iran during two growing season of 2014-2015 and 2015-2016. The first and the second factors were wheat varieties (the old: Roshan and Tabasi and the new: Parsi and Sirvan) and intercropping ratios of wheat and canola in additive series (0:100, 25:100, 50:100, 75:100, 100:100 and 100:0), respectively. Investigated traits were seed, biological and straw yield of wheat and number of pods per plant, number of seeds per plant, 1000-seed weight, seed, biological and straw yield of canola, radiation use efficiency based on seed yield and total dry matter land equivalent ratio. For analysis of variance SAS 9.1 was used. All the means were compared according to least significant test (p≤0.05) Results and discussion Results showed that the highest wheat yield and yield components, except for 1000-seed weight, were obtained for under monoculture and by increasing the proportion of canola to 75%, significant decrease was observed in seed yield and biological yield of wheat. There was a significant increase in seed yield of new wheat varieties compared to Tabasi as an old variety while the biological yield was not affected by the variety. As compared to other wheat variety, in the presence of the new variety Sirvan, seed and biological yield and radiation use efficiency of canola were significantly increased. However, between different wheat varieties there was no significant difference in radiation use efficiency. The maximum land equivalent ratio (1.41) was calculated with 25% canola+100% wheat. Conclusion Results revealed that yield of wheat and canola were significantly affected by intercropping ratio and wheat varieties in which yield of both crops due to competition was reduced. However due to different criteria of these species associated with better use of water, radiation and nutrient resources when they are intercropped, land use efficiency was increased. New varieties of wheat seems to preform better when intercropped with canola. However, there was no significant differences in radiation use efficiency and land equivalent ratio between the old and the new wheat varieties. Acknowledgement This research (32693) was funded by Vice Chancellor for Research of Ferdowsi University of Mashhad, which is hereby acknowledged.