مجله تولید و فرآوری محصولات زراعی و باغی
سال سیزدهم شماره 2 (پیاپی 98، تابستان 1402)

In order to evaluate the quantitative and qualitative performance of spring bread wheat cultivars under different planting dates, an experiment was conducted in Gonbad Agricultural Research Station, Gonbad, Golestan province, Iran, during two cropping seasons (2020-2022) as split plot based on randomized complete block design (RCBD) with four replications. Seven planting dates (1 November, 11 November, 21 November, 1 December, 11 December, 21 December and 31 December) were placed in main plots and four bread wheat genotypes (Araz, Arman, Taktaz and N-93-9) were placed in subplots. The delayed planting led to a significant decrease in the length of the phenological stages and the grain filling period. The highest grain yield was obtained from the planting at 11 November (5813 kg ha-1), which was not significantly different from grain yield in 21 November (5788 kg ha-1) and 31 November (5641 kg ha-1) planting dates. In most of the agronomic traits, the delayed planting dates (21 December and 31 December) had significantly lower values than planting in 11 November, 21 November and 1 December. Mean comparison for interaction effect of planting date×cultivar showed that planting Arman cultivar in 11 November, Araz cultivar in 11 November, 21 November and 1 December, Arman cultivar in the 21 November and Taktaz cultivar in the 21 November led to the highest grain yield. In the three delayed planting dates (11 December, 21 December and 31 December), the grain yield of Taktaz and Araz cultivars was higher than other genotypes. Mean comparisons on the traits related to bread-making quality showed that the two delayed planting dates (21 December and 31 December) had higher values in terms of protein and wet gluten content, compared to the two early planting dates (1 November and 11 November). Taktaz cultivar had the highest bread-making quality, particularly because it indicated the highest protein and wet gluten content.

Heat stress during grain filling period can lead to the reduction of grain yield of wheat. Therefore, in order to evaluate the probable mitigative effect of nitrogen and zinc application of heat stress on physiological properties, grain yield and protein content of wheat (Chamran cultivar), a split-split plot experiment based on RCBD in four replications was carried out in an experimental field of Khuzestan Agriculture and Natural Resources University, Ahvaz, Iran during autumn of 2018-19 growing season. Experimental factors were three planting date (22 November, 11 December and 31 December) as main plot, four nitrogen levels (0 as a control, 75, 150 and 225 kg ha-1 N from urea 46%) as subplot and zinc levels (0 as a control, 10 and 20 kg ha-1 from zinc sulfate) in subplots. The results showed that the delay in planting significantly (P≤0.01) reduced grain protein, leaf chlorophyll index, cell membrane stability index, grain yield, biological yield, and harvest index. Nitrogen application reduced the effects of heat stress on wheat grain yield so that by consuming 75, 150 and 225 kg N ha-1 in cultivation, wheat grain yield was improved by 43%, 59% and 64% for 11 December cultivation date and 50%, 70% and 55% for 31 December cultivation date, respectively, compared to control fertilizer. Zinc application also reduced the effects of heat stress on wheat grain yield, where at late and very late cultivation dates, with the application of 10 and 20 kg ha-1 zinc, wheat grain yield was improved by 5%, 6%, 35% and 40%, respectively. Consumption of zinc also reduced the effects of heat stress on wheat grain yield by increasing grain weight and caused a 24% increase in grain weight. Wheat harvest index decreased by about 18% due to heat stress. Meanwhile, application of nitrogen and zinc at 150 and 10 kg ha-1, respectively, showed the greatest effect in reducing the adverse effects of terminal heat stress on the agronomical and physiological properties of wheat. In general, in case of delayed cultivation, the use of zinc (at least 10 kg ha-1) and nitrogen (at least 150 kg ha-1) can reduce the harmful effects of terminal heat stress in Ahvaz climate and improve physiological (chlorophyll content and cell membrane stability), agronomic and protein content of bread wheat.

Drought is one of the most important abiotic stresses limiting plant survival, growth, and production in many regions of the world. Approximately one-thirds of the world's agricultural lands are in arid and semi-arid regions, including Iran. Therefore, there is a need to improve plant cultivars with high adaptability and low water requirement. This study was conducted to evaluate the drought tolerance of Bromus inermis and Dactylis glomerata genotypes and investigate the relationship between seed yield and forage yield to select better genotypes in terms of these traits, simultaneously. In this study, 36 genotypes selected from polycross populations of both species were clonally propagated and evaluated under normal and drought-stressed conditions during 2014 and 2015 at the Research Farm of Isfahan University of Technology, Isfahan, Iran. In both species, high genetic variation was observed among genotypes for seed yield and its components indicating high potential for improving these traits through targeted selection in breeding programs. Drought stress negatively affected seed yield and its components and reduced the genetic diversity of most traits. Most of the studied traits had relatively high heritability; therefore, improvement of these traits is possible through recurrent selection in breeding programs. The significant association between seed and forage yield indicated that it is possible to select superior genotypes based on seed and forage yield in both normal and water stress conditions, simultaneously. However, the intensity of this association was higher in Dactylis glomerata than Bromus inermis. In both species and under both normal and drought stress conditions, better genotypes were identified in terms of seed and forage yield. These genotypes can be used in developing genetic populations for simultaneous improvement of seed and forage yield in future studies and also for the development of synthetic varieties in both species.

Tomato (Solanum lycopersicum L.) is one of the most popular and widely consumed vegetable fruits all over the world. Given the vast area (about 2200 hectares) under cultivation of this crop in Golestan province (north of Iran) and the importance of replacing old open-pollinated cultivars with new high-yielding hybrid cultivars, a field study was carried out by evaluating the new determinate tomato hybrid genotypes suitable for outdoor cultivation named A-Z15 and A-Z16 along with Mahdis (control) hybrid cultivar. A-Z16 consisted of two treatments of without and with treating seeds with Probio 96 bacteria named A-Z16a and A-Z16-b, respectively. This study was carried out during 2022 in two agricultural research stations of Golestan, Gorgan and Gonbad Experiments carried out as complete block designs with three replications. Characteristics such as fruit yield/hectare, average weight of fruit, number of fruit carpel, percentage of fruit size (small, medium, large), diameter and length of fruit, number of fruit cavity, fruits/plant, pH of fruit juice, amount of total soluble solids, proportion of fruits with white layer and shelf life of fruit after harvest were recorded and measured. The results of analysis of variances showed significant differences in most of the examined traits in two experimental locations. Based on mean comparisons, cultivar Mahdis (control) was superior in fruit yield and fruits/plant, but this cultivar in qualitative characteristics such as shelf life of fruit, the lower proportion of fruits with white layer and total soluble solids was ranked last. The highest average weight of fruit and shelf life of fruit belonged to A-Z16-b. After Mahdis, A-Z16-b produced highest fruit yield. In conclusion, Mahdis (control) and in a lesser extent A-Z16-b (A-Z16-a treated with Probio 96 bacteria) showed better fruit yield attributes compared to others.

A field experiment was carried out at the research field of Payame Noor university of Shadegan, Khuzestan province during 2021-2022 growing season to evaluate the grain and oil production of sesame under deficit irrigation in response to vermicompost application. The experiment was conducted as split-plot in three replications, where irrigation treatments (I1: full root zone irrigation and I2: partial root zone irrigation) were allocated to main plots and vermicompost (0.0, 5.0, 10.0, 15.0 and 20.0 t ha-1) were assigned as sub plots. Results indicated that oil percentage, grain and oil yield of sesame were reduced 3.0%, 17.7% and 23.9% under partial root zone irrigation, respectively. Significant reduction (P≤0.01) of grain number and grain weight under partial root zone irrigation (30% and 11.2%, respectively) showed that grain yield of sesame was affected by both components of grain yield. However, grain number was more sensitive to water shortage compared with grain weight. Water consumption in the limited irrigation treatment was reduced by 49.2%, and this caused the water productivity for seed and oil production to increase by 61.7% and 49%, respectively, compared to the full irrigation of the root system. The use of vermicompost fertilizer led to the improvement of sesame grain and oil yield and their related traits, so that with the consumption of 20 t ha-1 of fertilizer, the grain and oil yield increased from 791 to 1248 kg ha-1 (57.8% increase) and 374 to 657 kg ha-1 (75.7% increase), respectively. Therefore, the use of vermicompost fertilizer can help to improve the yield of sesame seeds and oil under limited irrigation conditions.

In order to investigate the possibility of improvement of yield, yield components and the concentration of some nutrients in rice leaves (Tarom variety) by using rice straw and its biochar, a factorial experiment was conducted in the form of a randomized complete block design in nine treatments and three replications in the farm of Sari Agricultural Sciences and Natural Resources University, Sari, north of Iran, in 2021. The first factor was rice straw (S) at three levels of zero, 2 and 4 tons/ha and the second factor was rice straw biochar (B) at three levels of zero, 1 and 2 tons/ha. The maximum concentration of potassium (1.22%), nitrogen (4.73%) and iron (208 mg/kg) in the flag leaf was observed when rice was grown in the high levels of rice straw and particularly its biochar. Also, the concentration of silicon, manganese and zinc in the flag leaf increased with the increase in the levels of rice straw and its biochar. By increasing the use of rice straw and its biochar, the number of tillers, plant height, panicle length, weight of 1000 seeds and the number of filled seeds increased significantly. The combined use of rice straw and its biochar increased the rice grain yield, indicating a 1.78 times increase in the treatment of 2 tons/ha of rice straw biochar + 4 tons/ha of rice straw (S2B2) compared to the control. Therefore, it can be concluded that the application of 2 tons/ha of biochar and 4 tons/ha of rice straw can lead to the maximum grain yield by increasing the concentration of nutrients in the flag leaf and improving the growth and yield components of rice.

The effect of heat stress on yield, yield component and some agronomic traits of barley, was evaluated during the growing season of 2022-2023 using a randomized complete block design with three replications under normal and heat stress conditions. Eight barley cultivars including Nik, Mehr, Khatam, Reyhan, Nosrat, Fajr 30, Yoosef and Afzal were grown in Abarkouh, Yazd, central Iran. The results of combined analysis of variance revealed that cultivar effect was significant in all traits except 1000 grain weight and peduncle length. Heat stress × cultivar interaction was significant for spikes/m2, grains/spike, and grain yield. Heat stress led to a significant decrease in days from sowing to physiological maturity, plant height, peduncle and spike length, spikes/m2, grains/spike, and grain yield and a significant increase in days from sowing to tillering. Grain yield under both conditions had significant negative correlation with days from sowing to tillering. Grain yield had significant positive correlation with spikes/m2 under normal condition and with spikes/m2, and grains/spike under heat stress condition. Stepwise regression results showed that grains/spike and plant height could be used as criteria for increaseing grain yield under heat stress condition. Mean comparison of data for studied cultivars showed that Reyhan and Nosrat genotypes could be suggested for cultivation under both conditions.