مجله علوم گیاهان زراعی ایران
سال پنجاه و پنجم شماره 1 (بهار 1403)

Spreading hedgeparsley is a weed of wheat fields which thier seed bank is increasing in Kermanshah province. The aim of this study was to investigate the effect of time, burial depth, and seed shape in the field. This study was conducted as a factorial experiment in a completely randomized design with 3 replications. Both hairy and non-hairy forms of spreading hedgeparsley seeds were placed in different depths of storage (control), zero (soil surface), 5, 10, 20, and 40 cm of soil, and then seeds digged out from soil at 3, 6, 9, and 12 months burial time. The results showed that the effect of time, burial depth, and seed shape treatments on germination was significant in the field. The highest percentage of spreading hedgeparsley seed germination was observed in the first 3 months after burial. In general, the percentage of seed germination decreased by time. At a depth of 5 cm in the soil due to the favorable environmental conditions such as temperature, light and oxygen, the highest germination percentage was observed. Seed germination percentage decreased with increasing depth. The percentage of germination of spreading hedgeparsley seeds was higher than that of spinyseeds due to the level of contact of seeds with light, temperature and humidity.

In order to investigate the changes in weed flora in the irrigated wheat fields of Isfahan county over a 15-year period (from 2019 to 2004), a systematic sampling of weeds was conducted in 100 farms with W pattern during wheat tillering to stem elongation stages. In 2004, the dominant weed species was winter wild oat (Avena ludoviciana) with a abundance index of 76.1; however, in 2019 three weed species, including winter wild oat, wild barley (Hordeum spontaneum), and littleseed canarygrass (Phalaris minor) were recognized as the dominant species with abundance indices of 70.1, 42.3, and 28.6, respectively. In 2004, the dominant broadleaf weed species were lambsquarters (Chenopodium album) with a dominance index of 67.9 and prostrate knotweed (Polygonum aviculare) with a dominance index of 31.96. However, in 2019, the highest dominance indices were observed in lambsquarters, prostrate knotweed, and Flixweed (Descurainia Sophia) with abundance indices of 78.4, 38.5, and 39.04, respectively. The correlation between weed distribution and soil factors (nitrogen, phosphorus, potassium, soil texture, and electrical conductivity), crop rotation, and herbicides was examined using canonical correspondence analysis (CCA). Littleseed canarygrass, wild barley, field brome (Bromus commutatus), licorice (Glycyrrhiza glabra), hoary cress (Cardaria draba), and yellow sweet clover (Melilotus officinalis) showed the highest correlation with soil nitrogen levels.

Water deficit stress is considered as one of the most important factors affecting soil microbial activities in dry and semi-dry ecosystems, which reduces microbial activity by limiting access to nutrients. To evaluate the effect of water stress (30%, 50%, 70%, and 100% of field capacity), urea chemical fertilizer (100, 200, and 300 kg/ha), and the impact of biological fertilizers (inoculation with mycorrhiza alone, co-inoculation with mycorrhiza and nitrogen-fixing bacteria, co-inoculation with mycorrhiza and azospirillum, and control) on the yield characteristics of Zea mays hybrid Sc706, a field experiment was conducted as a split-split plot in a randomized complete block design with three replications in two cropping seasons (2018-2019 and 2019-2020) on a farm in Firoozabad, Fars province, Iran. Dual and triple interactions of water stress, urea chemical fertilizer, and biological fertilizer showed significant differences in all yield characteristics. In most traits, the application of urea chemical fertilizer (200 and 300 kg/ha) along with biological fertilizers (mycorrhiza-azospirillum and mycorrhiza-nitrogen-fixing bacteria treatments) produced the best results. Overall, it can be concluded that the use of 200 and 300 kg/ha of urea fertilizer along with a combination of biological fertilizers, mycorrhiza-azospirillum and mycorrhiza-nitrogen-fixing bacteria, can be suitable options for improving the yield and morpho-physiological characteristics of corn under regional conditions.

After soybean and oil palm, rapeseed has the third place in supplying vegetable oil in the world, so that it accounts for 14.7% of the total production of vegetable oil. The current research was carried out using modeling approach in order to simulate the replacement of wheat cultivation with rapeseed cultivation in terms of water and economic productivity in four locations (Aleshtar, Khorramabad, Pol-e Dokhtar, and Kuhdasht) in Lorestan province. APSIM model was used to simulate the growth and yield of wheat and rapeseed crops. The model validation results showed that it accurately simulates wheat and rapeseed grain yield with nRMSE of 8.6%. The results showed that wheat cultivation (3524.4 kg) had a higher grain yield than rapeseed cultivation (2750.2 kg). In addition, wheat cultivation system (1.45 kg m-3) compared with rapeseed cultivation (1.15 kg m-3) had higher water productivity. However, the difference between these two cultivation systems in terms of irrigation productivity was not considerable (0.11 kg m3). Also, economic productivity and net income of rapeseed cultivation system were 0.220 million tomans per cubic meter and 59.9 million tomans per hectare, respectively, while they were 0.014 million tomans per cubic meter and 41.1 million tomans per hectare, respectively, for wheat cultivation system. In general, the results approved that moving from wheat cultivation to rapeseed cultivation can be environmentally and economically sustainable in the agro-ecosystems of Lorestan province, especially in Khorramabad county.

Considering the high production potential of quinoa plant, especially under stressful conditions such as drought and salinity, it is necessary to introduce new and high-yielding genotypes for cultivation in different regions of Iran. The objective of this research was to evaluate the diversity of 26 new and foreign quinoa genotypes in terms of morphophenological characteristics. The experiment was carried out in a completely randomized design with three replications in greenhouse of Rice Research Institute of Iran (RRII), Rasht, in 2021. The results of analysis of variance showed that there was a very significant statistical difference among the studied genotypes for all measured traits. Factor analysis using the principal components method identified three main and independent factors that explained 39.19, 24.63, and 15.94%, respectively, and in total about 80% of the total variance. In addition, cluster analysis based on Ward's minimum variance grouped the studied 26 quinoa genotypes into three separate clusters; including 14, 7, and 5 genotypes, which very largely corresponded to grouping of the principal components. In total, the results of the current study showed that among the studied 26 quinoa genotypes, genotype No. 12 with 1000-grain weight, panicle length, and grain yield higher than the other genotypes as well as dwarfism and earliness characteristics was the most valuable genotype of this experiment. Furthermore, genotypes No. 4, 8, 17, and 18 for grain yield, genotypes No. 7, 13, and 15 for earliness, and genotype No. 14 for dwarfism, were the promising genotypes of this research, which can be used to transfer earliness and dwarfism to high-yielding genotypes in future breeding programs.

Pearl Millet (Pennisetum glaucum L.) is one of the most important crops in arid and semi-arid regions that are cultivated for grain and forage. Due to cross pollination and high heterosis, the development of hybrid varieties is the most important breeding method of pearl millet. In order to study the preliminary yield comparison of hybrid cultivars and investigate the possibility of replacing open-pollinated cultivars with hybrid cultivars, 11 promising pearl millet hybrid cultivars with a check variety (Mehran cultivar) were planted in the randomized complete block design with three replications in Karaj, Isfahan and Zabul. The days to 50% flowering, plant height, stem diameter, leaves number, panicle length, panicle thickness, tiller number, fresh fodder yield, dry matter yield, 1000 seed weight, and seed yield were evaluated. The results of combined variance analysis and mean comparisons showed that there is considerable genetic diversity for the studied traits. The results showed that the cultivars H294, H444, H504, H604, H824, and H794 had the highest grain yield compared to the total mean of the experiment. In addition, five cultivars H543, H333, H353, H563, and H604 were above of total average in terms of fodder production and had good potential to be used in the field as commercial cultivars with the aim of fodder and seed production.

In conditions where don't have enough water for irrigation, intercropping of forage plants is one of the ways to achieve sustainable agriculture. Biochemical and physical properties of soil tillage system can affect the yield of plants in intercropping. Therefore, with the aim of investigating the forage yield and competitive indices of intercropping, this experiment was performed in the cropping seasons of 2020-2021. Treatments included conventional, minimum, and no tillage system. Intercropping patterns also included monoculture of forage sorghum and maize, alternate row cultivation maize and forage sorghum and alternate cultivation on planting rows. The results showed that the highest plant height (295 cm) and leaf area (6.88) was obtained in intercropping and conventional tillage. The highest forage yield was also observed in sorghum monoculture. However, the land equivalent ratio of mix intercropping with 1.17 showed the superiority of intercropping over monoculture. Evaluation of competitive indicators such as dominance index, relative crowding coefficient, and competitive ratio showed that forage maize is the predominant plant in intercropping conditions. The system productivity index with 8.11 showed that intermediate cultivation on planting rows was superior to other treatments in conventional tillage conditions. The results showed that in conventional tillage and intercropping conditions, acceptable yield was obtained; this advantage can increase water efficiency and use of sorghum in intercropping.

The development of herbicide-resistant weed species is a threat to the agricultural industry in Iran and the world. The first step in managing this issue is the identification of herbicide-resistant populations. In this study, 124 and 45 grass weed accessions, including winter wild oat, annual ryegrass, and littleseed canarygrass, were collected from wheat and canola fields, respectively, in different provinces of Iran. The accessions were screened using commonly used herbicides at the three- to four-leaf stage. The weed accessions collected from wheat fields were exposed to the recommended field dose of clodinafop-propargyl, pinoxaden, mesosulfuron-methyl+iodosulfuron-methyl-Na, and mesosulfuron-methyl+iodosulfuron-methyl-Na+diflufenican. Similarly, the canola grass weeds were treated with haloxyfop-R-methyl, sethoxydim, cycloxydim, and clethodim. The experiment was carried out based on a completely randomized design with four replications under controlled greenhouse conditions. Four weeks after spraying, the fresh weight of the populations was measured. The results showed that 52, 9, 19, and 17% of grass weeds in wheat fields were resistant to clodinafop-propargyl, pinoxaden, mesosulfuron-methyl+iodosulfuron-methyl-Na, and mesosulfuron-methyl+iodosulfuron-methyl-Na+diflufenican, respectively. Morover, 47, 47, and 22% of the canola grass weeds showed resistance to haloxyfop-R-methyl, sethoxydim, and clethodim, respectively; while they were susceptible to cycloxydim. Cross-resistance to selective herbicides in canola was observed in 36% of the tested grass weed species. Additionally, multiple resistance to both ACCase and ALS inhibitors in wheat fields was identified in 13% of winter wild oat and 82% of annual ryegrass populations, respectively. It is recommended to avoid the use of herbicides with the same mechanism of action for controlling grass weeds in areas where the wheat and canola rotation system is prevalent

This study aimed to investigate the response of four ecotypes of milk thistle from Isfahan, Kohgiluyeh va Boyer Ahmad, Khuzestan-Omidiyeh, and Hungary to three irrigation regimes (irrigation after 40%, 60%, and 80% maximum allowable depletion of available soil water (evaluated in 2020-2021 under five different planting dates (September 27th, October 17th, November 6th, November 26th, and March 10th) at the research farm of Isfahan University of Technology in Iran. The experiment was conducted as a combined analysis of a split-plot based on randomized complete block design with three replications. The results showed that the highest and the lowest grain yield and shoot dry weight of milk thistle plants were obtained under the October 17th and March 10th planting dates, respectively. Water deficit at both levels decreased grain yield, shoot dry weight, number of flowers per plant, plant height, flowering degree-days, and physiological maturity degree-days, but increased grain and shoot water use efficiencies. The "Kohgiluyeh and Boyer Ahmad" ecotype exhibited the highest seed yield, shoot dry weight, seed/shoot water use efficiency, and harvest index, making it a promising candidate for breeding programs aimed at creating adaptive cultivars of the milk thistle plant. Based on the study's findings, it can be concluded that milk thistle should be planted in the fall season from late September to mid-November under similar climate conditions.

Rapid and efficient recovery from water deficit stress may be one of the key determinants of drought adaptation in plants. The present study was designed to investigate drought stress tolerance and recovery in promising lentil lines at the flowering stage. For this, a factorial experiment based on the completely randomized design was conducted with three replications. The factors included 6 lentil lines, drought stress (control (irrigation at 80% FC or 20% moisture depletion), medium stress (irrigation at 55% FC or 45% moisture depletion), and severe stress (irrigation at 30% FC or 70% moisture depletion)), and three sampling times (three and six days after drought, and recovery (two days after re-irrigation)). Drought stress caused a decrease in chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, protein, yield, and yield components. The reduction of these traits was more remarkable at six days after stress. However, during the recovery time remarkable increase was observed in these traits. The results showed that the correlation between H2O2 and MDA was significant and positive. Furthermore, drought stress increased the amount of proline, H2O2, and MDA, which resulted in an increase in the activity of antioxidant enzymes (catalase, polyphenol oxidase, and peroxidase). An increase in the intensity and duration of the drought stress also caused an increase in H2O2 and MDA content and the activity of antioxidant enzymes. In addition, in the recovery conditions, a significant reduction in the destructive effects of stress (H2O2, MDA content) and the activity of antioxidant enzymes was visible. The results of the present study indicated that the effects of drought stress on lentil lines yield and yield components (seed number, number of pods, 100-seed weight, and seed yield) were varied. Drought stress at the flowering stage decreased the number of seeds and pods per plant, and 100-seed weight, which led to yield losses. Although line 2 had the highest yield under normal and drought stress conditions, line 1 exhibited the lowest yield under stress conditions. Based on the results of this experiment, line 2 seems to be a suitable line for culture in the regions challenged with water deficit stress.

This study was conducted to investigate the effect of foliar application of amino acids on yield and yield components of oil rapeseed under late-season drought stress conditions. The experiment was conducted as factorial based on a randomized complete blocks design in the research farm of the Faculty of Agriculture at Tarbiat Modares University during the 2021-22 growing season. The experimental treatments were irrigation regimes at three levels (normal irrigation, withholding irrigation from 50% flowering stage, and withholding irrigation from pod forming) and foliar spraying at five levels (no foliar, foliar spraying 0, 1, 2, and 3 g amino acids per liter of distilled water). The results showed that plant height, shoot dry weight, 1000-seed weight, harvest index, and biological and grain yield, number of seeds per pod, and the number of pods per plant were significantly affected by the interaction of irrigation regimes and foliar spraying. The highest plant height (166.5 cm), 1000-seed weight (3.58 g), number of pods per plant (131.4) and grain yield (4514 kg ha-1) were obtained by foliar spraying of two g amino acids per litre under normal irrigation conditions. According to the results, foliar spraying 2 g amino acids per liter had the most positive effect on the yield and yield components of oil rapeseed in all irrigation regimes (normal irrigation, withholding irrigation from 50% flowering stage, and withholding irrigation from pod forming). Therefore, upon approving in future research it could be recommended to use foliar spraying with 2 g amino acids per liter in oil rapeseed cultivation.