نشریه فیزیولوژی گیاهان زراعی
پیاپی 57 (بهار 1402)

This research was carried in cropping years 2017-18 and 2018-19 to study the effect of plant density on morphological traits, flowering pattern, boll production and seed cotton yield of new cotton cultivars in Varamin region of Iran. In this research, five cotton cultivars including Varamin, Shirpan603, Cocker100, NO200 and SP731 in three plant densities were evaluated using a factorial experiment in a randomized complete block design with three replications. In this study, the number of flowers and flowering date in cultivars for 11 weeks (1 July to 15 September) were counted. The results of analysis of variance showed that the differences between cultivars were significant for plant height, number of nodes, number of flowers, number of bolls and fiber and seed cotton yield at 1% level. The results also showed that there is a significant difference between the years of project implementation for plant height, number of bolls and fiber and seed cotton yield at the level of 1%. The mean of plant height for the first and second years were 93.2 and 119.9 cm and the average number of bolls per plant were 15.9 and 11.41 and the seed cotton yield were 5242 and 4050 kg/ha, respectively. In this study cultivars did not differ significantly in terms of number of days from planting to flowering, number of days from flowering to harvest and early ripening. Investigation of flowering process in 11 weeks showed that the peak of flowering for both years of research was the eleventh week after planting with an average of 41.8 and 44.6 flowers per plant. Most of the bolls were produced from the flowers of the eleventh week for first year and from the flowers of the tenth week for second year. The cumulative growing degree days during the vegetative and reproductive growth period for two years of experiment was significantly different.  So that at the end of the seventeenth week after planting (last week of flowering) the cumulative growing degree days in the first and second years was 1734.9 and 1245.5, respectively, Which can be one of the important reasons in reducing the number of bolls and fiber and seed cotton yield in the second year.

Salinity is one of the most destructive environmental stresses, which affect almost every aspect of physiology and biochemistry of a plant. It is a serious threat for crop yield especially in arid and semi-arid regions. Several strategies have been suggested in order to decrease the toxic effects caused by salinity on plant growth, among them use of silicon and bio fertilizers play important role in yield improvement. In this regard, an experiment was carried out as factorial based on randomized complete block design with three replications in research greenhouse University of Mohaghegh Ardabili  in 2021. The investigated factors were included salinity levels [no application of salinity as control, application of 30 and 60 mM salinity (1.8, 2.76 and 5.53 dS.m-1 respectively)], bio and organic fertilizers (no application as control, vermicompost, mycorrhiza, both application of vermicompost and mycorrhiza) and nanosilicon foliar application (foliar application with water as control, foliar application of 30 and 60 mg.L-1 of nanosilicon). The results showed that both application of vermicompost and mycorrhiza, foliar application of 60 mg.L-1 of nano silicon under no salinity decreased dry matter remobilization from the stem (209.01%) and aerial parts to grain (80.49%), but increased stomata conductance (50.47%), flag leaf protein (26.17%), current photosynthesis (153.41%), the contribution of current photosynthesis in grain yield (89.56%) and  grain yield (88.88%) compared to no appllication bio and organic fertilizers and nanosilicon under 60 mM salinity conditions. Based on the results this study, it can be suggested  that the application of bio and organic fertilizers and nanosilicon can increase the grain yield of triticale under salinity conditions due to improving stomata conductance and current photosynthesis.

In order to investigate the effect of humic acid on some of physiological characteristics and agronomic traits of rapeseed (Brassica napus L.) cultivars under drought stress conditions, the present experiment was carried out as Split-split plot design randomized complete blocks design with 4 replications in Kaleybar city in 2019. The main plot, sub plot and Sub-sub plot included irrigation after 60, 90 and 120 mm water evaporation from class A evaporation pan, bean cultivars divided into 4 categories of Hayola 420, Sarigol, Traper and RJS003, and humic acid application on 5 levels (0, 100, 200, 300 and 400 mg.Lit), respectively. The results showed that the simple effects of drought stress, humic acid and cultivars traits measured at a probability level of 1%. The interaction between water stress and humic acid on chlorophyll content, plant height, number of pods per plant, grain yield and oil yield were significant. The effect of dual interaction (drought stress × humic acid and drought stress × cultivars) on chlorophyll index, plant height, number of pods per plant, grain yield and oil yield were significant. With increasing drought stress, the relative moisture content (20.54%), number of grains per pod (25.32%), 1000-grain weight (16.58%) and oil content (6.75%) decreased; While increasing the proline concentration (35.13%). The highest oil yield and grain yield were allocated to 60 mm of evaporation and 400 mg/l of humic acid and the lowest amount of oil and grain yield was assigned to 120 mm of evaporation and no use of humic acid. Humic acid increased the relative moisture content, number of seeds per pod, 1000-seed weight and oil percentage and decreased the amount of proline (26.31%). As a result, spraying 400 mg/l humic acid at different levels of drought stress improved physiological characteristics and increased production components compared to the control (no spraying). In the four cultivars evaluated, Hayola 420 cultivar had the highest grain yield and yield components. According to the results, humic acid reduces damages caused by drought stress.

Replacing biological inputs that are prepared through natural processes instead of chemical inputs in strengthening the growth and development of crops and increasing their yield is one of the principles of organic and sustainable agriculture. In this regard, in order to investigate the effects of the use of bio-active growth solution on yield and yield components of chickpea (Mansour cultivar), an experiment was carried out in the form of a randomized complete block design in three replications at the Dryland Agricultural Research Sub-Institute for two years from the fall of 2019. Each replication includes 13 treatments including the application of each of the concentrations of 0.5, 1, 1.5 and 2 liters of the mentioned fertilizer in the three stages of the beginning of vegetative growth, the beginning of pod formation and the beginning of vegetative growth + the beginning of pod formation along with the control treatment (no foliar spraying). The results showed that seed yield, biological yield, number of pods per plant, number of seeds per pod and 100-seeds weight were affected by foliar application. The concentration of 1 and 1.5 liters per hectare of the solution in the two stages of the beginning of vegetative growth and the beginning of podding had the greatest effect on the yield and yield components of chickpea. Under the mentioned treatments, the grain yield with an average of 774.8 kg per hectare, the number of 13.6 pods per plant, 0.95 seeds per plant and the 35.1 g for 100-seeds weight were superior to the control. Economically, it is recommended to use a concentration of one liter per hectare compared to a concentration of 1.5 liters per hectare as the best concentration of bioactive solution to improve the yield and yield components of chickpea.

The present study was conducted biennially in the cropping years of 2019 and 2020 in Savad-Koh lands. The experiment was performed as a factorial experiment in a randomized complete block design with three replications. The first factor of Rhizobium leguminosarum bv. Viciae inoculation with faba bean at two levels (inoculation with R-Etli strain and non- inoculation); and the second factor of fertilizer treatments at five levels including: cattle manure 30 t ha-1 (CM), vermicompost 10 tons per hectare (VM), azolla vermicompost 10 t ha-1 (VA), chemical fertilizer treatment based on soil analysis (NPK), and control treatment (C). Was. The results showed that fertilizer treatments were significant in most bacterial interaction traits. In both years of experiment, vermicompost treatments, especially Azolla vermicompost had the highest number of pods (39.7 in the first year and 46.3 in the second year), number of seeds (181.9 in the first year and 205.2 in the second year), yield Pods (1377.4 and 1503 g m-2 in the first and second years, respectively) and grain yield (429 and 1503 g m-2, respectively, in the first and second years) were inoculated with R. leguminosarum and in terms of nitrogen uptake, Phosphorus and potassium showed significant superiority even over NPK treatment. The results suggest that the main source of vermicompost production has a great effect on growth, nutrient uptake and grain yield and by inoculation with appropriate nitrogen-fixing bacteria has a synergy on agronomic traits. Therefore, this nutrition method can be used as one of the nutrient management strategies in sustainable faba bean production.

Considering the importance of cultivating rainfed oil plants and the possibility of introducing them in rotation with wheat, in the present study, the reactions of the morpho-physiological traits of safflower (Carthamus tinctorius) in response to different types of tillage in rainfed conditions were evaluated. The experiment was conducted based on a randomized complete block design with three replications at Saral Rainfed Agricultural Research Station of Kurdistan during 2017-2019 seasons. The treatments were no-tillage, reduced tillage, and conventional tillage systems. The results of this experiment showed that the types of tillage caused changes in the morpho-physiological traits of the safflower. The highest yield (796 kg/ha) was obtained from no-tilllage system, which showed an increase of 24.8 and 40 percent compared to reduce tillage and no-tillage, respectively. In the no-tillage system, relative water content (69%), chlorophyll (2.01 mg/gr fresh weight of leaves) and leaf area index (2.8) were respectively higher than reduce tillage and conventional tillage. The highest amount of catalase and superoxide dismutase enzymes (0.085 and 0.72 units mg protein per minute, respectively) was observed in the leaves of plants cultivated by conventional system. In conventional tillage, the root colonization and sporulation were decreased significantly compared to the other two tillage systems. Finally, the physiological and biochemical traits related to yield in no-tillage and reduce tillage showed a more favorable and stable situation than conventional tillage.

In order to evaluate the diversity of oat genotypes (Avena sativa L.) in response to cold stress, 21 oat genotypes were studied in the Faculty of Agricultural Sciences and Engineering of Razi University, Kermanshah in 2015-2016 under controlled conditions in the greenhouse. Two separate experiments were conducted to determine the 50% plant lethality temperature (LT50) and the effect of short-term cold stress on physiological characteristics and antioxidant enzymes, in the form of a completely randomized design. Variance analysis of LT50 showed that there is a significant genetic variation between the investigated genotypes in terms of LT50 level. The average of LT50 trait showed that the genotypes (Ozark), (UFRGSP 948886), (UPF775456), (Euro), (GA Mitchell), (Mortlock), (OH1022), (Brusher), (Wallaroo) and (Kalott) had the highest LT50 value and can be considered as cold tolerant genotypes, and (Quoll) and (Nasta) genotypes had the lowest values. A positive and significant correlation was observed between the catalase enzyme and chlorophyll content and between the peroxidase enzyme and ion leakage rate. The Ozark and UFRGS 948886 genotypes were placed in the group with the maximum mean LT50, chlorophyll content, carotenoid content, catalase enzyme, peroxidase enzyme and minimum ion leakage rate in the cluster analysis. Therefore, it could be stated that the genotypes of this group have better conditions in terms of cold tolerance than other genotypes.