مجله تولید و فرآوری محصولات زراعی و باغی
سال سیزدهم شماره 1 (پیاپی 97، بهار 1402)

In order to investigate the effect of nitrogen fertilizer and plant density on the agronomic characteristics of rice cv. Tarom Hashemi, a field experiment was carried out as a randomized complete blocks design with three replications during 2018 and 2019 in a farm located in Sari, north of Iran. The present study consisted of 10 levels of plant density (hills m-2) and N fertilizer, named T1 (20 hills + [50 percent after transplanting + 50 percent at the beginning of tillering]), T2 (20 hills + [33.3 percent after transplanting + 33.3 percent at the beginning of tillering + 33.3 percent at panicle formation]), T3 (20 hills + [40 percent after transplanting + 40 percent at the beginning of tillering + 20 percent at the end of panicle emergence]), T4 (20 hills + [33.3 percent after transplanting + 33.3 percent at panicle formation + 33.33 percent at the end of panicle emergence]) as a control, T5 (30 hills + [33.3 percent after transplanting + 33.3 percent at the beginning of tillering + 33.3 percent at panicle formation]), T6 (30 hills + [40 percent after transplanting + 40 percent at the beginning of tillering + 20 percent at the end of panicle emergence]), T7 (30 hills + [33.3 percent after transplanting + 33.3 percent at panicle formation + 33.3 percent at the end of panicle emergence]), T8 (30 hills + [25 percent after transplanting + 25 percent at the beginning of tillering + 25 percent at panicle formation + 25 percent at the end of panicle emergence]), T9 (40 hills + [33.3 percent after transplanting + 33.3 percent at panicle formation + 33.3 percent at the end of panicle emergence]), and T10 (40 hills + [40 percent after transplanting + 40 percent at panicle formation + 20 percent at the end of panicle emergence])..The results showed that the effect of year was not significant on grain yield. But the grain nitrogen concentration was lower in the second year (with a difference of 0.185 percent). The maximum total number of tillers per hill (18.61 tillers), panicle length (25.0 cm) and harvest index (40.9 percent) were obtained under T1, T2 and T3 treatments, respectively. Grain yield was not affected by the experimental treatment, however, its maximum (6865 kg ha-1) was obtained under T9 treatment due to an increase in the number of panicles per square meter (510 panicles), indicating an increase of 19.0 percent compared to the control treatment (T4). A density of 40 hills per square meter with nitrogen splitting of 33.3 percent after transplanting + 33.3 percent at panicle formation + 33.3 percent at the end of panicle emergence (T9) is recommended to achieve maximum grain yield of rice under the conditions of this experiment in northern Iran.

In order to investigate the effect of pre-emergence and post-emergence herbicides on nutrient depletion, weed population and nutrient uptake by wheat in sesame-wheat cropping system in Khuzestan a field experiment was conducted in randomized complete block design with three replications in the research farm of Shahid Chamran University of Ahvaz in 2019-2020. Treatments included no weeding, hand weeding, Pendimethalin+Atlantis, Pendimethalin+Metribosin, Trifluralin+Atlantis, Trifluralin+Metribozin, Pendimethalin+2,4-D, Trifluralin+2,4-D, green mungbean+2,4-D and 2,4-D in plots seeded by wheat cv. ‘Mehregan’. Weed population varied notably among the experimental treatments. At 60 days after sowing, while the mean number of weeds was 5.6 plants per m-2, it was significantly different among the weed control treatments. Moreover in this growth stage, Pendimethalin+Atlantis and Pendimethalin+Metribuzin treatments significantly reduced the weed population compared to the control no weeding condition. Generally, hand weeding and Pendimethalin+Atlantis treatments improved the growth and yield of wheat compared to Trifluralin+Atlantis, Trifluralin+Metribosin, and Trifluralin+2,4-D treatments, due apparently to reducing weed interference and increasing the uptake of nitrogen, phosphorus and potassium of the wheat plants. We concluded that the pre-emergence application of Pendimethalin herbicide along with post-emergence application of Metribozin and Atlantis herbicides at the seedling stage of wheat may increase the absorption of nutrients and grain yield.

In this research, 50 quinoa genotypes were investigated using 40 pairs of microsatellite markers (SSR) to identify the superior genotypes in terms of grain yield, the components affecting it, and the features linked to the studied traits were also introduced using Association Analysis. The study of grain yield traits and the factors affecting it showed that the traits of day to physiological maturity, panicle length, number of panicle per plant, and 1000 -grain weight were the most important traits affecting grain yield, and finally genotypes 1, 32 and 49 were the essential traits in terms of these traits. They were introduced as superior genotypes. Studying the population structure using Structure software showed two possible subgroups (K=2) in the studied population and the results of the bar plot confirmed it. The results of the correlation analysis using the general linear model (GLM) and the mixed linear model (MLM) numbers 49, 53 (GLM) and number 48, 52 (MLM) showed a significant indicator-adjective relationship, respectively, for the first year (2018) and the second (2019). Among the significant marker-trait relationships identified for different traits, the highest number of meaningful relationships were identified for grain yield and 1000-grain weight traits with 6 and 5 relationships, respectively. In conclusion, based on the results of the correlation analysis, 12 continuous markers were identified with a significant relationship with the evaluated traits during both years. Therefore, these markers can be used as fixed and stable markers in different quinoa breeding programs.

To identify genotypes tolerant to drought stress in rice germplasm, a factorial pot experiment was carried out in the form of a completely randomized design with three replications and 70 rice genotypes originating from Central and West Asian countries in non-stress and drought-stress conditions at the Rice Research Institute of Iran, Rasht, north of Iran, in 2019. Based on the results of this year (i.e. 2019), 19 genotypes selected and cultivated in the form of randomized complete block design with three replications in two environments (normal and drought stress) in 2020. Based on tolerance and sensitivity indices and the results of cluster analysis, rice genotypes were divided into two groups, and based on the comparison of means and deviations from the total mean, genotypes of the second group (Shirodi and Neda (Iran), Sela-Zodras and Shisham-Bagh-2014 (Afghanistan) and Dijla (Iraq) recognized as stress-tolerant genotypes. Also, six genotypes (Nada and Shiroudi (Iran), D3 (Iraq), Sela-Zodras, Jalal-Abad Indica-2014, and Shisham Bagh-2014 (Afghanistan)) were identified by biplot analysis and the ranking method of seven genotypes (Shirodi, Neda and Gilaneh (Iran) Sela-Zodras, Jalal Abad Indica-2014 and Shisham Bagh-2014 (Afghanistan) and D3 (Iraq) were recognized as drought stress tolerant genotypes. Altogether, based on the methods of cluster analysis, biplot, and ranking, the genotypes of Shiroudi and Neda (Iran), Sela-Zodras, and Shisham Bagh-2014 (Afghanistan) were recognized as drought tolerant genotypes. The mentioned selected genotypes can be used in advancing breeding programs for developing new rice genotypes with higher tolerance to drought stress.

In order to evaluate and compare 15 different hybrid genotypes of greenhouse tomato (Solanum lycopersicum L) in Gorgan, Golestan, north of Iran, an experiment was carried out in randomized complete block design with 3 replications at two Golestan province greenhouses (greenhouse of Gorgan Agricultural and Natural Resources Research and Education Center and a private greenhouse in Gorgan).  Investigated traits were fruit yield per plant, number of fruits per plant, number of fruits per cluster, average fruit weight, fruit diameter, fruit height, stem length, total soluble solids, pH, pericarp thickness, total phenolics content and flavonoids content. Statistical analyses were suggestive of significant difference in all of the studied traits between different genotypes in both greenhouse experiments. In both of the greenhouse experiments, the highest fruit yield per plant was observed in 4129, Omagna, and then Izmono, 10161, Hirad and Sakhia genotypes. Dafnis and Hiva cultivars were intermediate in terms of fruit yield compared to other genotypes. In traits such as fruit number, fruit weight, fruit size, plant height, pericarp thickness, total soluble solids, pH, phenolics content and flavonoids great differences were observed between the studied genotypes. Positive correlations of fruit yield with number of fruits per plant, mean fruit weight and fruit diameter traits were observed in both greenhouse experiments. Therefore, selecting based on the latter three attributes may improve fruit yield of tomato in seed and variety breeding programs.

This study aimed to investigate the genetic parameters of ten Cucurbita pepo L. hybrid cultivars, including seven foreign hybrid cultivars (F1 Shiraz, F1 Khaleej, F1 Samar, F1 Roham, F1 Daphne, F1 Asma and F1 Oto) and three domestic hybrid cultivars (F1 Peronesh, F1 BL and F1 CL) in the form of a randomized complete block design with 3 replications at the Pest Investigation Research Station and the Shahid Fozveh Research Station of Isfahan, central Iran, in 2019. The bed preparation operation was done and the seeds were sown in the mid-June. The results showed that the highest fruits/plant was observed in CL and Shiraz genotypes and the highest yield/plant in four harvests was observed in Peronesh genotype. Roham and Otto genotypes showed the lowest total yield/plant. BL genotype showed the highest mean fruit diameter in four harvests and the highest fruit weight of the seed sample. The highest seed weight was obtained in Shiraz and Asma genotypes and the highest seed-to-fruit weight ratio was obtained in Samar genotype. BL, Asma and Shiraz genotypes showed the highest seed dry weight. The highest seed length and the highest dry weight of 100 seeds were observed in Peronesh and BL genotypes. A positive and significant correlation was also observed between some traits. Among the investigated genotypes, Peronesh and BL genotypes outranked the other genotypes in most of the traits. Also, Shiraz genotype had a significant advantage in some seed traits compared to other genotypes. According to the presented results, different genotypes of the pumpkin plant were significantly different from each other in terms of various traits, indicating that the ground is prepared to employ these resources for improving the yield of this plant species.

An imbalanced nutrients status in the nutrient solution, i.e. poor nutrition of the plant, is often responsible for the low quantity and quality of strawberry fruit. The present study was conducted to investigate the effect of different ratios of potassium to magnesium (K/Mg) (T1, 2:1, T2, 4:1, T3, 6:1 and T4, 8:1) on fruit yield and quality of strawberry cv. Albion under hydroponic conditions. Different K/Mg treatments did not have a significant effect on fruit yield and quality attributes such as ascorbic acid and total soluble solids. The highest fruit yield was obtained when plants were exposed to a 4:1 ratio (i.e. T2). Fruit quality attributes such as total anthocyanin, total antioxidant, total phenolic, total flavonoids, total chlorophyll, calcium, Mg, and K concentrations in the leaves and antioxidant enzymes activities were significantly affected by the K/Mg treatments. The highest total phenolic (925 mg/100g FW) and total flavonoids (163 mg/100g FW) were observed when plants grown in the presence of a 4:1 ratio (i.e. T2). Whereas, the highest antioxidant activity (89.2%) was detected in plants exposed to the 8:1 ratio (T4). The highest activity of guaiacol peroxidase (2.88 and 2.78 unit/g FW), ascorbate peroxidase (2.11 unit/g FW), and catalase (2.23 unit/g FW) were observed in T3 and T4, T4, and T4 treatments, respectively. It can be concluded that among the tested treatments, the 4:1 ratio of potassium:magnesium is optimal for the strawberry production.