نشریه پژوهشهای زراعی ایران
سال بیستم شماره 3 (پیاپی 67، پاییز 1401)

Mung bean (Vigna radiata L.) is native to India and its seeds are rich in phosphorus and protein. Drought is one of the most important limiting agents of plant production. Carbohydrate metabolism and the process of dry matter distribution is disrupted by limitation of carbon stabilization due to stomata closure and reduction of photosynthesis under drought stress. Potassium is an essential nutrient and the most abundant cation that it has a major role in plant growth and almost all related activities. The presence of potassium enhanced the synthesis of hydrocarbons and proteins, which results in amplification of plant tolerance to drought stress.

Experiment was performed at Agricultural Research Institute, in 2017-2018 to study the yield and nutritive value of mung bean. This research was conducted as split plot based on a randomized complete block design with three replications. Main plot was drought stress consist of 60, 90 and 120 mm evaporation from the A class pan and sub plot was including 0, 85, 170 and 255 kg.ha-1 potassium sulfate fertilizer. The characteristics plant height, biological yield, seed yield, insoluble fiber in neutral detergent, insoluble fiber in acid detergent, water soluble carbohydrate, crude protein and dry matter digestibility were measured. The samples nitrogen content was estimated by Kjeldahl set and it was multiplied by the protein coefficient 6.25 and the crude protein percentage was calculated. Van Soest method was used for measuring of insoluble fiber in neutral detergent and insoluble fiber in acid detergent. Ethanol was utilized to measure soluble sugars by sulfuric acid method. The percentage of digestible dry matter was estimated according to Equation (1).DMD= 88.9 - (0.779×ADF%) (1) Variance analysis of data was carried out by MSTAT-C software and the comparison of the means was done with Duncan's multiple range test at the 5% probability level.

The results showed that drought stress treatment on all mung bean plant characteristics was significance at 1% level. The effect of sulfate potassium fertilizer on plant height, biological yield, seed yield, insoluble fiber in acid detergent, water soluble carbohydrate, crude protein and dry matter digestibility at 1% significance level and on insoluble fiber in neutral detergent were significant at 5% level. The interaction effect of drought stress and potassium sulfate fertilizer on Plant height, biological yield, insoluble fiber in neutral detergent, insoluble fiber in acid detergent, water soluble carbohydrate, crude protein and dry matter digestibility at 1% significance level and on seed yield were significant at 5% level. The results showed that in the control irrigation + application of potassium sulfate fertilizer (170 kg.ha-1) compared to the control potassium treatment, plant height and biological yield increased by 37.9% and 89.6%, respectively. In the control irrigation + application of potassium sulfate fertilizer (170 kg.ha-1) compared to the control potassium treatment, dry matter digestibility increased by 30.12% and insoluble fiber in neutral detergent and insoluble fiber in acid detergent decreased by 44.3% and 43.8%, respectively. The most amount of water soluble carbohydrate (18.3%) in 120 mm evaporation from A class pan and the highest value of crude protein (22.8%) in 90 mm evaporation from A class pan and in both characteristic application were effective 170 kg.ha-1 of potassium sulfate.

The result showed that interaction of drought stress and potassium sulfate fertilizer on quantitative and qualitative of mung bean traits was significant. Plant height and biological yield increased 37.9% and 89.6% by addition of sulfate potassium consumption from 0 to 170 kg.ha-1, respectively. Seed yield enhanced compared to control treatment (33.8%) by using of 255 kg.ha-1 potassium sulfate. Drought stress decreased dry matter digestibility and it increased crude protein, water soluble carbohydrate, insoluble fiber in neutral detergent and insoluble fiber in acid detergent. Potassium sulfate fertilizer amount 170 and 255 kg.ha-1 recommend for maintaining of yield and qualitative of mung bean in Sistan region in non-stress and drought stress conditions.

Due to climate change, increasing and maintaining the current level of production in low rainfall conditions in semi-arid regions is an important challenge. On the other hand, agriculture in these areas is often of low productivity due to low water use efficiency. Considering the fact that Iran is one of the challenging arid and semi-arid regions of the world, so it faces the problem of water shortage and precipitation. Therefore, in such circumstances, finding eco-friendly solutions to increase water use efficiency to achieve sustainable agricultural goals seems necessary. In recent years, many efforts have been made in this field, in this regard, limited irrigation and the use of superabsorbent into the soil as two practical strategies for water conservation and optimal use have been considered.Optimizing the effective factors in production and management of water use in the farm could saves limited water resources and protects the soil, moreover, can increase yields. Extensive research has been done on the effect of different levels of irrigation, superabsorbent and fertilizer on different crops, but in the field of simultaneous optimization of these factors using statistical techniques, there is little or no information, so this study aims to optimize consumption of irrigation water, superabsorbent and cattle manure were designed and conducted in low-input sesame cultivation using surface-response methodology and Box-Behnken design.

The experiment was conducted as a Box-Behnken design. Experimental factors including a combination of different levels of irrigation water, superabsorbent and cattle manure. The total number of treatments required for this experiment was 15 treatments including 12 factorial combinations and 3 replications of the central point. The Box-Behnken design is essentially applicable and analyzed with one replication, but to fit the level of response equations, it is necessary to repeat the central points that represent the average level of high and low levels of each of the experimental factors. Using the Box-Behnken design, it is possible that most information from the minimum executive operation would be obtained through the distribution of trial points in the treatments. The values of these factors were determined by using software due to low and high levels of irrigation water (1500 and 3000 m3 ha-1), superabsorbent (0 and 160 kg ha-1) and cattle manure (0 and 30 ton ha-1) using software.In the Box-Behnken method, the response variable (y) is estimated by Equation 1.Where y is a dependent variable and according to sesame seed yield, biological yield, leaf area index, leaf dry weight, number of pods per plant, number of seeds per pods, 1000-seeds weight, relative water content and seed oil percentage were calculated separately; Xi is the independent variable, XiXj i the interaction of the independent variable i and the independent variable j, Xi2 the second power of the independent variable i and βi to βii are the coefficients of the equation. After obtaining the simulation results, using calculations and statistical methods, a quadratic polynomial is obtained which expresses the response rate (yield) as a function of input variables. Finally, after optimizing the obtained relationship and eliminating ineffective sentences, using statistical tests and criteria such as F test value, Lack of Fit test, Pvalue and R2 (coefficient of determination), the final relationship for predicting yield and other response variables is calculated for the present study (Equation 2).The obtained relationship is valid only within the limits defined for the input parameters and has no predictive power outside this range. In this equation, y: is a dependent variable already defined for Eq. 4. X1 is the independent variable of irrigation water, X2 is the superabsorbent, and X3 is the independent variable of manure, a1 to a9 are the equation coefficients. Optimal amounts of irrigation water, superabsorbent and manure were determined according to the possibility of maximum seed yield. Finally, the estimated values were compared with the observed data and the validity of the regression models was evaluated using the root mean square error (RMSE).

In general, considering the significant effect of linear component of manure from regression model and biological yield as well as linear effect of irrigation and manure on the number of seed per pod, it can be concluded that the use of manure ultimately increased seed yield. Regarding the quality yield of sesame (seed oil percentage), the significance of the linear component of the superabsorbent effect can guarantee the quality yield of sesame. The high significant (p≤0.01) effect of the second order (full quadratic model) component of manure on 1000-seeds weight also indicates the effectiveness of manure on yield components and finally seed yield. Optimization was performed with three scenarios. First, considering all three factors, irrigation, superabsorbent and manure were done. Optimization was done to produce the highest seed yield, in which case the highest seed yield (4541 kg ha-1) was obtained with 3,000 m3 ha-1 of irrigation water, without superabsorbent and with 30 t ha-1 of manure. In the next step, to investigate the role of superabsorbent in water saving, optimization was performed with half irrigation water, 100 kg ha-1 of superabsorbent and with no application of manure, which resulted in the production of 3380 kg ha-1 of seed. In the third case, the results of optimization for irrigation water in the range of 1500 to 2250 m3 ha-1 (limited irrigation), with no use of superabsorbent and the amount of manure from zero to 30 t ha-1, showed that applying 2250 m3 ha-1 of water and 30 t ha-1 of manure could be resulted in a seed yield of 4186 kg ha-1. The highest amount of irrigation water productivity, equal to 2.2 kg seed per m3 of water, was obtained from 2250 m3 of irrigation water. Third scenario compared with the first scenario shows a reduction of 750 m3 in the volume of irrigation water that resulted in only an 8% reduction in seed yield (4186 vs. 4541 kg of seed), therefore, the third scenario potentially could be chosen by the farmers. Depends on the level of availability of water resources, the balance of economic value of water against seed yield, and other environmental and management options, if the application of 30 t ha-1 of manure to achieve the stable seed yield is not economical for the farmer compared with the application of 100 kg ha-1 of superabsorbent, we can recommend the second scenario (1500 m3 of water plus 100 kg of superabsorbent, with no manure) that will result in the seed yield by 3380 kg ha-1. The difference in seed yield in this scenario compared with the third scenario is 806 kg of seed, so the farmer must take into account all economic and managerial conditions to select the appropriate scenario. In general, the results of this study showed that using eco-friendly inputs, it is possible to produce stable sesame in an arid and semi-arid region and achieve a yield beyond of the conventional high-input systems.

Direct seeding of rice is one of the most common farming methods in the world. Economic efficiency, faster and easier cultivation, reduction of growth period and earlier maturity (7-10 days), needing to less labour, higher water efficiency, more mechanization and reduction of rice vulnerability due to end-of-season drought are some benefit of direct rice cultivation; while, the most important problem in this planting system is weed control, and if weeds are controlled properly; the yield of rice in direct seeding will be almost equal to that of transplanting system. So, this study was conducted to evaluate the effect of weed management methods on different cultivars of rice in direct seeding system.

This research was performed as a factorial in randomized complete block design in three replications at Rice Research Institute, Amol in 2018. Treatments include three different rice cultivars of Tarom Hashemi, Shiroodi and Neda under six weed management methods (no weeding, twice weeding (40 days after emergence and in the earing stage), using rice husk mulch (0.5 kg m-2 after sowing), application of triafamone+ethoxysulfuron herbicide (30 g ai ha-1 in 5 days after emergence in two-leaf stage), application of triafamone+ethoxysulfuron herbicide (30 g ai ha-1 in 5 days after emergence in two-leaf stage) + weeding (40 days after emergence) and complete weeding (all weeds are removed during the growing season) were considered. The studied traits included: plant height, tiller number, panicle length, 1000-grain weight, filled grain number, empty grain number, panicle number per square meter, grain yield, biological yield and total weed density and dry weight.

The results showed the highest plant height (137.7 cm) and number of tillers (24.7) was obtained in Tarom Hashemi and Shiroodi cultivars under complete weeding, respectively. The results of mean comparison of the main effects of the experimental treatments indicate that the filled grain number in Tarom Hashemi, Neda and Shiroodi cultivars were 67.6, 69.3 and 90.1 per ear and 1000-seed weight in these cultivars, was 19.9, 18.6 and 21.1 g, respectively. When Shiroodi cultivar had more seeds per ear and 1000 seeds weight. Also, the maximum filled grain number (94.9) and the highest 1000-seed weight with 22.7 g was observed in the complete weed control treatment. The highest panicle number per square meter (316.7) was related to Shiroodi cultivar and complete weed control, which had no significant different with herbicide + weeding and twice weeding in the same cultivar, as well as complete weeding in Neda cultivar. The highest grain yield (8192.5 kg ha-1) was observed in Shiroodi cultivar + complete weeding, which had no significant different with Neda + complete weeding and Shiroodi + herbicide + weeding. Lack of weed control in Tarom Hashemi, Neda and Shiroodi cultivars reduced 38.2, 63.3 and 61.7% of grain yield compared to complete weed control, respectively. The results showed that at all three stages of sampling, the lowest weed density and dry weight in all three sampling stages was related to herbicide + weeding treatment in Shiroodi cultivar which had good control over weed and was able to reduce weed density and its dry weight.

In general, it can be concluded that although the yield of rice in the direct planting system was the highest in the absence of weed contamination; however, since the application of triafamone+ethoxysulfuron herbicide along with weeding caused reduction the density and dry weight of weeds, and also, improved the yield and yield components of all three rice cultivars, so this management method can be used to control weeds more effectively and achieve proper yield in this system.

Wheat is one of the most important cereals in the human diet and widely used in many processed nutrition products. Water deficit stress is a main limiting factor of wheat growth and productivity in the world. Major objective of plant breeding is improving grain yield under drought stress condition. In the breeding programs, selection based on multi-traits is an important approach to improve grain yield. This research was conducted out to evaluate the effect of phenological and agronomic traits of 10 bread wheat near isogenic lines (in three genetic backgrounds) and cultivars on grain yield under cyclic drought stress condition and detection a function to use all effective secondary traits simultaneously.

Six Near-Isogenic Lines (NILs) as well as their parents were evaluated at the research field of Shahid-Bahonar University of Kerman, during growing seasons of 2018-2019 and 2019-2020 under cyclic drought stress condition based on randomized complete block design (RCBD) with four replications. The field was irrigated every 28 days in autumn and winter and every other week in the spring. In the present research grain yield, phenological and agronomic traits were measured. Analysis of variance was performed using SAS v9.1. Broad sense heritability (h2bs) was calculated following the method of Fehr (1987) as follows:h2bs=  σ2g / σ2g + σ2e  (1) Phenotypic coefficient of variability (PCV) and genotypic coefficient of variability (GCV) were calculated as the following formula proposed by Singh and Chaudhary (1985):PCV= (σp/ µ) × 100 (2) GCV= (σg/ µ) × 100  (3) Where µ, σp and σg are mean, phenotypic standard deviation and genotypic standard deviation, respectively. Expected response (R) toselection in breeding programs was calculated following the methods of Falconer and Mackay (1996) as follows:R= ih2bσp  (4) Where i is selection intensity, which is equal to1.694 if 10% of genotypes are selected (p = 10%) in breeding program.
The studied genotypes were designated as group one and two based on grain yield under drought stress condition. Those traits that could significantly separate two groups based on t-test entered the discriminant analysis. These traits were standardized before discriminant analysis, as follows:Zij = (Xij - µ) / Si (5)where Zij is standard score for jth genotype in ith traits, Xij is raw data of for jth genotype in ith traits and Si is standard deviation of ith traits. Discriminant analysis was performed using MINITAB.

Among several secondary traits only awn length, flag leaf length and grain number per spike (grains/spike) could significantly distinguish high and low yield genotypes under water stress condition. These results showed the importance of the mentioned traits in the breeding programs for drought prone environments. Discriminant function of these traits was used as a comprehensive index for selection of high yield genotypes (Eq. (6)).DS= -1.32 + 2.07 FLL + 1.63 AL – 0.04 GNS  (6)  Where DS, FLL, AL, and GNS are discriminant score, flag leaf length, awn length and grains number per spike, respectively. This index could explain 72% of grain yield variation and had significant positive correlation with grain yield in water stress condition (r = 0.85**). Also it could well separate genotypes with the accurate classification rate of 90%. Discriminant function revealed that flag leaf and awn length were the most important effective traits on grain yield under drought stress condition, respectively. This index can be used as criteria for simultaneous selection of the mentioned traits in the future breeding programs.

Awn length, flag leaf length and grain number per spike that entered to the discriminant function had high correlation with grain yield, high heritability and easy evaluation. Therefore, selection based on these traits is a good approach to improve grain yield in drought prone environments. Discriminant function obtained in this study could be an appropriate technique to selecting high yield genotypes under drought stress condition.

Aging seed can be defined as loss of seed quality, viability and vigor. This process is irreversible over time and its intensity increases with increasing temperature and humidity. Aging seed is one of the major factors reducing quality and quantity in the agricultural sector, especially oilseeds. The use of antioxidants can reduce the damaging effects of aging. Ellagic acid is a natural plant antioxidant that can play a role in reducing the effects of stress on plants. This substance is a phenolic compound and among different antioxidants, due to its polyphenolic properties, it is one of the best scavengers for oxygen free radicals.

To investigate the effect of ellagic acid on improving the quality of plants obtained from normal and aged soybean seeds, an experiment was conducted in the research farm of Shahroud University of Technology during the two cropping years 2019 and 2020. In this study two sets of seeds including control seeds (un-aged) and aged seed were used and ellagic acid (50 mg. l-1) was applied for control, seed pretreatment, foliar spray and seed pretreatment+foliar spray. Farm research was conducted a factorial experiment based on a randomized complete block design (RCBD) in three replications. Soybean seeds var. DPX were collected from Mazandaran agricultural research center. The water content of seeds was 12%. The seeds were those that harvested in the same year and kept in a controlled storage room at the temperature between 14 to 17 °C and relative humidity of 30 to 40% at the Agricultural Research and Training Center and Natural Resources of Mazandaran Province. To prepare aged seeds in the laboratory, the seeds were incubated at 41°C and 95% relative humidity for 72 hours. Seed pretreatment with a concentration of 50 mg.L-1 ellagic acid was performed under ventilation condition for 6 hours. The seeds were then dried in the shade and used to continue testing and measuring traits compared to normal seeds. Foliar application was done early in the morning at the beginning of flowering (R1) and in favorable environmental conditions.

The results showed that aging reduced the mean daily seedling field emergence by 61.39% compared to normal seeds. The ratio of chlorophyll a to b, total chlorophyll, stomatal conductance and membrane stability index in the leaves of plants from aged seeds decreased by 9.9, 6.3, 7.0 and 28.9%, respectively, compared to the control. The amount of free amino acids and soluble sugars in the leaves of plants from aged seeds increased compared to normal seeds. Pretreatment of normal and aged seeds with ellagic acid increased the mean daily seedling field emergence by 23.1% and 19. 7%, respectively. The content of insoluble sugars were increased with application of both pretreatment and foliar spray of ellagic acid 32.0% respectively. The highest oil yield in both conditions was observed with application of both pretreatment and foliar spray of ellagic aicd. The yield seed increased with ellagic acid compared to the control 23.6%. Grain yield was higher than 23.2% in the plants that had received ellagic acid in a form foliar spray. In the end, the pretreatment+foliar spray of ellagic acid had the highest grain yield, which increased to control 55.5%.

However, in this study, the application of ellagic acid as a seed pretreatment and foliar spray had a positive effect under normal and aging conditions, but in the scope of the research, the combined application of ellagic acid as seed pretreatment and foliar spraying can be recommended to increase seed yield and seed oil yield in soybean. In general, ellagic acid can be introduced as a powerful antioxidant in aging conditions to reduce some of the destructive effects of the reactions involved in aging.

Saffron (Crocus sativus L.) is a perennial plant of the Iridaceae family and is cultivated in Iran, Morocco, India, Greece, Italy, and Spain. Iran is considered the main producer of saffron, with the most optimum climate for saffron. Today, the dramatic increase in food production in the world requires high amounts of chemical fertilizers. However, some of the adverse effects of chemical fertilizer overuse in conventional farming practices have been well reported. In this regard, manure can be a good alternative, which can guarantee both agricultural production and nature protection. Potassium is one of the most important nutrients for plant growth after nitrogen. In spice plants, potassium indirectly improves nitrogen utilization and protein formation, flower size, flower yield, oil content, color, etc. in spice plants. This study investigated the effect of different animal manures in combination with different levels of potassium sulfate on saffron flower criteria.

The factorial experiment was carried out based on a randomized complete block design with three replications at the agricultural lands of Jovein County, during the three cropping years of 2015-16, 2016-17, and 2017-18. The first factor includes three types of organic manure: laying poultry manure (5 and 10 ton.ha-1), broiler poultry manure (5 and 10 t.ha-1) and cow manure (20 and 40 ton.ha-1) and control (without the use of organic manure) and the second factor includes different amounts of potassium sulfate fertilizer (0, 100 and 150 kg.ha-1). The basis for determining the consumption of each organic fertilizer was applied based on the recommended nitrogen and soil test. Saffron was cultivated in September 2015 in the length of 3 m and width of 1 m plots. Flower yield was determined randomly from 40 × 50 cm-2 quadrates. Data analysis and figure drawing were performed using SAS 9.1 and MS-Excel software.

The results of analysis of variance in two years showed that the effect of animal manure and potassium sulfate and their interaction were significant on the number of flowers, total flower weight, stigma dry weight, and style dry weight. Also, potassium sulfate and manure's main effects and interaction were significant on the dry weight of flowers without stigma and style in the second year. However, the main effects of potassium sulfate and manure significantly affected on the dry weight of flowers without stigma and style, but their interaction was not significant in the third year. The highest number of flowers was obtained in the treatment of 150 kg.ha-1 potassium sulfate and 40 ton.ha-1 cow manure in the second year, and it was obtained in the treatment of 150 kg.ha-1 potassium sulfate ten ton.ha-1 laying poultry manure in the third year. The highest total flower weight belonged to the treatment of 150 kg.ha-1 potassium sulfate and 10 ton.ha-1 was laying poultry manure in second and three years. The highest stigmas dry weight was observed in 100 kg.ha-1 potassium sulfate and 40 ton.ha-1 cow manure treatment in the second year, and the highest amount of this trait was related to the treatment of 100 kg.ha-1 potassium sulfate and ten ton.ha-1 broiler poultry manure in the third year. The results of this experiment indicate that the application of animal manures and potassium sulfate combination has positive effects on improving the yield of saffron flowers and eco-friendliness. It seems that the combination of animal manures and chemical fertilizers can reduce the use of chemical fertilizers.

The results of this study showed that the best treatment for most traits was 150 kg.ha-1 potassium sulfate and 40 ton.ha-1 cow manure interaction treatment in the second and third years, and then the 150 kg.ha-1 potassium sulfate and ten ton.ha-1 laying poultry manure treatment could be mentioned as the superior treatment. In general, according to the findings of this study, it seems that the simultaneous application of optimal amounts of ecological inputs and chemical fertilizers of potassium sulfate can reduce the destructive effects caused by excessive use of chemical fertilizers on this valuable medicinal plant while improving the properties of saffron flowers.

Most areas under spring sugar beet cultivation face severe water restrictions and increasing the area under cultivation of this crop in most of these areas is contrary to the principle of conservation of water and soil resources. The use of new areas for winter sugar beet cultivation should be the area under cultivation of this crop in hot and dry areas. Therefore, winter sowing (pending) of sugar beet with emphasis on the limitations of the country's water resources has been proposed as a solution.

In this study, the quantitative and qualitative yield of 16 sugar beet genotypes in winter planting were studied as a randomized complete block design with four replications in the Torbat-e-Jam region in the two cropping years (2020-2021 and 2021-2022). The studied genotypes included F-20739, F-20837, F-21083, SBSI-5, SBSI-15, SVZA 2019-JD389, SVZA 2019-JD0402, SVZA 2019-JD0400, SVZA 2019-JD0401, FDIR 19 B 3021, FDIR 19 B 4028, F-20591, SBSI-6, SBSI-16, SBSI-7 and SBSI-17 are the breeding populations obtained from the gene bank of the Sugar Beet Seed Breeding Research Institute. In this research, traits such as root yield, sugar content, sugar yield, white sugar yield, Na, K, N, alkalinity, molasses sugar, white sugar content, and extraction coefficient of sugar were measured. Data were analyzed using SAS 9.1 software. The analysis of variance on test data and comparison to the middle of the Duncan test was performed at the 5% level. Factor analysis was calculated to identify the main factors using MINITAB software. Cluster analysis of the studied genotypes was obtained after standardizing the data by the Ward method and using Euclidean distance criterion with the help of SPSS software.

The results of the combined analysis of variance showed that there was a significant difference between different genotypes of sugar beet at the level of 1% probability for all studied traits except for nitrogen content. The mean comparison showed that the SBSI-15 genotype had the highest root yield (60.66 ton.ha). It should be noted that this genotype in terms of yield index traits did not show significantly different from genotypes F-20739, SBSI-15, SVZA 2019-JD389, SVZA 2019-JD0402, SVZA 2019-JD0400, SVZA 2019-JD0401, and FDIR 19 B 4028. Also, the F-20739 genotype had the highest amounts of sugar content (19.5%), white sugar content (16.3%) and extraction coefficient of sugar (83.2%) and the lowest amount of potassium (4.24 meq .100 g-1 of root weight) and Molasses sugar (2.7%). In addition, the highest sugar yield (10.69 t/ha) and white sugar yield (8.68 t/ha) were in FDIR 19 B 3021 genotype. Investigating the correlation of traits showed the highest positive and significant correlation was between sugar yield and white sugar yield (0.99**) and the highest negative and significant correlation was between extraction coefficient of sugar and molasses sugar (-0.95**). Principal factor analysis based on the mean of the traits identified three factors that accounted for a total of 91% of the variability between the data. SBSI-15, SVZA 2019-JD0398, SVZA 2019-JD0402, SVZA 2019-JD0400, SVZA 2019-JD0401, FDIR 19 B 3021, and FDIR 19 B 4028 genotypes are distinguished different from other genotypes and they were as superior genotypes in terms of yield index traits. The dendrogram generated from the cluster analysis for white sugar yield classified genotypes into three main groups.

In general, SVZA 2019-JD0401, FDIR 19 B 3021, and FDIR 19 B 4028 genotypes were introduced as superior genotypes with the highest white sugar yield and suitable for winter sowing in Torbat-e Jam region.

Among the various nutrients, nitrogen (N) is the limiting element for crop yield, which application of the optimum doses of this fertilizer in addition to increasing the yield components and grain yield in paddy fields, enhances the profits of rice cultivation in the region. One of the sustainable soil management techniques in paddy fields is the application of rice husk biochar. Biochar improves rice yield by improving soil chemical properties, increasing nutrient storage capacity, and also reducing soil acidity. Zinc deficiency can be the most important limiting factor of rice yield after N, P, and K. Therefore, the application of zinc fertilizer in the form of nanoparticles can be an effective technique to increase the quantitative and qualitative characteristics of rice. Therefore, the present study was conducted to investigate the effects of nitrogen doses along with the application of biochar and also zinc fertilizer in the form of nanoparticles on the quantitative and qualitative characteristics of rice.

The field experiment was carried out as a split-plot based on a randomized complete block design with three replications at the farmer's field located in Amol (North of Iran) in cropping season of 2019-2020. In this study, the doses of nitrogen applied at four levels of 0, 25, 50, and 75 kg.ha-1 as the main factor and application of fertilizers at four levels of control or no application of biochar and zinc nanoparticles, application of biochar, foliar application of zinc nanoparticles and combined application of biochar and zinc nanoparticles as the sub-factor were considered. The fertilizers of biochar and zinc nanoparticles at 40 ton.ha-1 and 50 mg.l-1 were used in this experiment, respectively. At harvest time, the yield components, yield, and N and Zn concentrations in grain were measured. Analysis of variance was performed using SAS software (ver. 9.2) and mean comparisons based on the least significant difference (LSD) test at the level of 5% probability.

The results showed that the simple effects of experimental treatments were significant on all morphological traits, yield components, and grain yield except the number of filled grains per panicle. The grain N concentration was not affected by biochar and zinc, while grain Zn concentration was significant under this treatment. Also, the impact of N application was significant on N and Zn concentrations in grain. The interaction between experimental treatments was not significant on the studied traits except for the number of fertile tillers per hill. The maximum fertile tillers number per hill (17.66 tillers) was obtained by using a combination of biochar + zinc nanoparticles + 50 kg N ha-1, which indicates the positive impacts of simultaneous application of these fertilizers. The application of N fertilizer at the amounts of 50 and 75 kg.ha-1, respectively, resulted in maximum grain yield (4340 kg.ha-1) and production of the highest grain N concentration (1.30%). Although the use of each of the biochar and zinc oxide nanoparticles improved the yield components, yield, and nutrient concentrations in rice grain, the combined application of biochar and zinc nanoparticles significantly increased the quantitative and qualitative characteristics of rice, so that the highest grain yield (4062 kg.ha-1) and greatest Zn concentration in grain (28.5 mg.kg-1) was observed under the simultaneous application of biochar + nanoparticles.

According to the results of the present study, N application at the rate of 50 kg.ha-1 and simultaneous application of rice husk biochar + zinc nanoparticles are introduced as the optimal dose of N and the ideal fertilizer option to increase crop yield and enrich rice grains.