نشریه فیزیولوژی گیاهان زراعی
پیاپی 56 (زمستان 1401)

To evaluate the quantitative and qualitative forage yield of clover cultivars under water deficit, a split plots experiment was conducted in randomized complete block design with three replications at the Seed and Plant Improvement Institute, Karaj, Iran, for two cropping years (2017-18 and 2018-19). Three irrigation regimes included full irrigation (supplying 100% of clover water requirement), moderate stress (supplying 75% of clover water supply) and severe stress (supplying 50% of clover water supply) as the main factor, and five clover cultivars (Karaj, Elite, Ekinaton, Win and Alex) were evaluated as the sub-factor. The results showed that the maximum yield of fresh forage and dry matter in all three irrigation levels were obtained from Win and Karaj cultivars and the minimum from Ekinaton cultivar. The highest water use efficiency for the production of lactation energy at the irrigation levels of 100%, 75%, and 50% was obtained from Win, Alex and Elite cultivars, respectively. In water deficit stress, dry matter yield, metabolizable protein yield, content and yield of net lactation energy decreased, whereas metabolizable protein content increased. In addition, water deficit stress increased water use efficiency for the production of dry matter, metabolizable protein, and net lactation energy. Overall, due to the both quantitative and qualitative traits, Elite and Karaj cultivars are recommended as the best genotypes for cultivation under water deficit stress conditions.

In order to effect of application time of polyphosphate slow release fertilizer (PSRF) and humic acid on some agronomic characteristics of corn (Hybrid AS 71), an experiment was carried out with factorial based on randomized complete block design (RCBD), with three replications in Gotvand, during 2017-2018. The first factor included polyphosphate slow release fertilizers application time in four levels (leafy 4, leafy8, before the emergence of tassels, milky grain) and the second factor was humic acid application time at four levels (leafy 4, leafy8, before the emergence of tassels, milky grain). The results of experiment showed significant differences in main effect and interaction of experimental factors on all the studied characteristics. The highest amount of characteristics were used PSRF + humic acid in stages leafy 4 and leafy 8, and the least amount in most characteristics was observed with the application of PSRF + humic acid in the milk grain stage. The results of experiment showed , simultaneous application of PSRF + humic acid, especially, in the early stages of growth, due to suitable providing of elemental nutrients at the beginning of plant growth can lead to increased yield and components yield of Corn.

Dehydration has become the most important factor in reducing the growth and yield of crops in recent decades, while a number of simple and inexpensive operations can reduce the impact of dehydration on plants and increase plant growth and yield. The aim of this study was to investigate the effect of different levels of irrigation (irrigation after 70,100,130 and 160mm evaporation from pan class A) and application of mycorrhizal treatments (no Application of mycorrhizal fungus, application of Glomus mossae, Glomus Hoei, Glomus intraradise and application of all three species of mycorrhizal fungi on the growth and yield of St. John's wort and its physiological characteristics were performed. This study was carried out in two cropping years in the fields of Tabriz Azad University as a split plot based on a randomized complete block design. Based on the results of this study, the highest essential oil yield with 13.45 g was obtained in the treatment of application of all three species of mycorrhizal fungi + irrigation after 100 mm evaporation from pan class A. The treatment of application of all three species of mycorrhizal fungi had the greatest effect on dry weight and percentage of essential oil of St. John's wort. Due to the results and the importance of essential oil yield, reducing irrigation water to irrigation 100 mm in the class A pan and applying a mixture of mycorrhizal treatments, can increase the essential oil yield in the climatic conditions of the study area.

In order to study the effect of hormone cytokinin on morphological and yield traits of sunflower cultivars under terminal heat stress, a field experiment carried out in a split plot factoril in randomized complete block design with three replications at the research farm of Shahid Chamran University of Ahvaz in 2021. The main plots consisted of three sowing dates; 3 Feb, 18 Feb and 5 Mar, the sub-plot consisted of factorial arrangement of different concentrations of cytokinin (0, 25 and 50 and 75 μm l-1, Kinetin), and sunflower cultivars (Qasem and Oskar). Sowing date with desired temperature considered as control and delayed and late sowing dates considered as mild and severe heat stress so that the flowering and grain filling periods faced with terminal heat stress. Results showed that terminal heat stress in delayed and late sowing dates caused a decrease in plant height, grain number per head, head diameter, 1000-grain weight, biological yield, oil percentage, and oil and grain yield. The optimum hormone concentration needed to exhibit a considerable increase in studied traits of sunflower cultivars under heat stress was 50 μm l-1,particularly, in Late sowing date sunflower plants, foliar application of cytokinin (50 μm l-1) increased grain yield (by 17% and 15%), biological yield (by 5% and 8%), and oil yield (28 and 13%), in Oscar and Qasim cultivars, respectively. Results show that foliar application of cytokinin (50 μm l-1) can be considered as a strategy to enhance the grain yield of sunflower cultivars under under heat stress conditions in tropical regions such as Khuzestan.

In order to study the vegetative characteristics, yield and seed quality of canola as influenced by silicon, sulfur and Tecamin flower, an experiment was conducted in in the farmer’s condition in the Darzian, 12 km far from Marivan during the two consecutive growing seasons 2017-18 and 2018-19 in the form of spilit- split plots in a randomized complete block design with three replications. In the main plot, silicon foliar application at two levels (0 and 2 kg/ha), in the sub-plot, sulfur foliar application at three levels (0, 1 and 2 liters per hectare) and also in the sub-sub plot, foliar application of reproductive growth biostimulant of Tecamin flower at three levels (0, 1 and 2 liters per hectare) were considered. The results of combined analysis showed that stem weight under the influence of the year showed a significant difference at the level of 5%. Silicon application affected significantly the number of axillary stems, pod weight, pod length, grain weight and seed protein and Tecamin foliar application also affected significantly all studied traits such as plant height, first pod height from the ground, number of axillary stems, stem weight, pod weight, pod length, grain weight, grain yield, oil and protein seed. Also the mentioned traits except plant height, number of axillary stems and pod length affected significantly by sulfur. Based on finding, silicon (2kg/ha) and sulfur and Tecamin (2L/ha) increased the studied characters. In this study sulfur and Tecamin increased the grain yield as: 7.42 and 14.12% compared to control, respectively. Protein seed significantly increased by silicon as 0.66%. Also oil and protein seed increased by 2 litre sulfur (3.33-3.34%) and 2 litre Tecamin (1.2-1.31%). Based on the interaction effects, silicon and sulfur foliar application as 2 L/ha were increased the oil seed by 4.03%. Also seed protein increased by 5.23% in second year by silicon and sulfur and Tecamin (2L/ha). Therfore, according to the effects of the used treatments on the seed yield and quality increasing and considering the costs of preparation and foliar application, the utilization of sulfur and Tecamin flower as 2L/ha is recommended in similar climatic condition and in canola cultivation.

Selecting the appropriate cultivar of corn and providing efficient irrigation methods in order to increase water productivity and production per unit area for optimal use of water resources in agriculture is of great importance. In this study, it was tried to evaluate and compare between drip irrigation methods (type) and furrow irrigation on 20 cultivars of maize cultivars in order to determine the most appropriate irrigation method and the best cultivar compatible with the region in order to increase yield and water use efficiency. Also reduce the amount of water consumed.

This experiment was conducted to investigate the growth, yield and water use efficiency of different corn cultivars as split plots based on a randomized complete block design with three replications in the tropical city of Dehloran in 2021. The main plots included irrigation management with two methods of drip irrigation (type) and furrow irrigation and the sub-plots included 20 varieties of corn. Vegetative traits including plant height were measured by meters, stem diameter, flag leaf area, number of cob rows, number of seeds per row and 1000-seed weight. Finally, after drying the plants, biological yield and grain yield were weighed using a digital scale. Water use efficiency was also calculated based on biological yield.

The results showed that cultivars 704 (122.3 days), BK74 (123.5 days) were known as early cultivars and NS640 (129.8 days), 89MAY70 (129.5 days) were known as late corn cultivars. Conserv cultivars (242.5 cm), 704 (225.2 cm) had the highest plant height. The highest leaf area of ​​flag was observed in cultivars AGN820 (279.5 cm2), AGN837 (274 cm2). Also, Conserv (3.33 cm), Barakat 3 (3.32 cm) cultivars had the largest stem diameter. The lowest plant height in BK66CTM cultivars (214 cm), BK65 (216.7 cm), the lowest stem diameter in BK66CTM cultivars (2.8 cm) and the lowest flag leaf area in 89MAY70 cultivars (199.2 cm2) and BC678 (199.7 cm2) were observed. Highest grain yield in cultivars AGN823 (9866.67 kg.ha-1), KSC703 (9760 kg.ha-1), AGN824 (9653.33 kg.ha-1) and lowest grain yield in BK66-CTM cultivars (5937.78 kg.ha-1) and Simon LF (6257.78 kg.ha-1) were observed, cultivars 704 with 348 g and AGN822 with AGN822 with 356.67 g had the lowest 1000-seed weight and cultivars AGN823 with 400.83, AGN824 with 393.33 g, AGN816 and Simon LF (394.17 g) had the highest 1000-seed weight, 1000-seed weight was higher in type irrigation method compared to furrow irrigation. AGN824 cultivars with 24808.87 kg.ha-1 had the highest biological yield and BK66CTM cultivars with 17644 kg.ha-1 had the lowest biological yield. the mean grain yield in type irrigation (9152 kg.ha-1) compared to the average grain yield in furrow irrigation (7980 kg.ha-1) has increased by about 14.7%. The amount of water consumption in the drip method (5966.7 m3.ha-1) compared to the amount of water consumption in the furrow method (8950 m3.ha-1) decreased by 3.3 3 shows. The effect of drip irrigation and furrow management methods on water productivity based on biological yield showed that water efficiency based on biological yield in strip drip irrigation method is equal to 3.65 kg.m3 and in furrow irrigation method is 2.25 kg.m3. Which indicates a 62.2% advantage of water efficiency in the drip strip method over the furrow method.

The general results of this study indicate the superiority of drip irrigation and the introduction of cultivars for cultivation in the tropics. The strip drip irrigation method, considering the reduction in the volume of water consumption, showed a significant increase in the yield and yield components of the corn plant. Strip drip irrigation with lower water consumption was able to produce more performance compared to leak irrigation. The strip drip irrigation method reduced irrigation water by 33.34% compared to the leak irrigation method.