نشریه علوم به زراعی گیاهی
سال سیزدهم شماره 1 (بهار و تابستان 1402)

This research was conducted in order to investigate the effect of iron nanoparticle (INp) and Putrescine (Pu) on some Camelina traits as a factorial design in a randomized complete block design with three replications at Baye-Kola Agricultural Research Station (BARS) in 2021. The treatments included INp (0, 20, 40 and 60 ppm) and putrescine (0, 0.5, 1 and 1.5 mM). Variance analysis showed that the factors were significant on the amount of photosynthetic pigments and morphological traits. The results of the comparison of the simple effect of the treatments showed that the highest amount of chlorophyll a and carotenoid was in the vegetative stage and carotenoid in the reproductive stage at 60 ppm of INp and the highest amount of chlorophyll a at 1 mM Pu and the highest am ount of carotenoid at 1.5 mM Pu. The highest amounts of chlorophyll b and total pigments were observed in the vegetative stage in the treatment combination of 40 ppm INp with 1.5 mM Pu and in the reproductive stage in the treatment combination of 60 ppm INp with 1 mM Pu. The highest amount of yield, number of seeds per capsule and also, the high value of 1000 seed weight and plant height were observed in the treatment combination of 40 ppm INp with 1 mM Pu. In general, the interaction effect of 60 ppm of INp and different concentration of Pu had the best results, and the spraying of these stimulants can improve the yield of the Camelina plant.

In order to investigate the effect of soil amendments on yield components, yield and oil percentage of rapeseed (Brassica napus L.), a field experiment was conducted as a randomized complete block design with three replications at the farmer's field located in Amol during 2021. The experimental treatments include the application of soil amendments at eight levels of control or non use of amendments, biochar, silicon nanoparticles, zinc nanoparticles, biochar + silicon nanoparticles, biochar + zinc nanoparticles, silicon nanoparticles + zinc nanoparticles, and the application of biochar + silicon nanoparticles + zinc nanoparticles. The results indicated that the application of all soil amendments improved the yield components, yield and oil content of rapeseed compared with the control treatment or non-use of amendments. In general, the combined application of amendments had better impacts on the studied traits than the individual application of each amendment. Also, among the individual treatments, the application of zinc oxide nanoparticles had the greatest effect in improving yield components and seed yield. The highest plant height (144.33 cm), number of silique per plant (240) and seed yield (3263.7 kg.ha-1) were obtained when all three amendments were used simultaneously. No statistically significant difference was observed between individual and combined treatments of amendments in terms of seed oil content. According to the results of the present study, the simultaneous use of soil amendments can have an effective role in improving the quantitative and qualitative characteristics of rapeseed.

In order to investigate the effect of using superabsorbent polymer on some growth parameters and performance of chickpea under drought stress conditions, a factorial experiment was carried out in the form of a randomized complete block design with four replications in the crop year of 2021 in Horand region of East Azarbaijan province. The experimental treatments include three levels of irrigation (full irrigation as a control, mild water restriction or irrigation interruption in the pod setting stage, and severe water restriction or irrigation interruption in the flowering stage) and different amounts of superabsorbent (no use of superabsorbent, 50, 100 and 150 kg/ha), respectively. The results of the analysis of variance of the studied traits showed that the application of stress and the effect of using superabsorbent polymer on all the evaluated traits were significant at the probability level of 1%. The interaction of drought stress and superabsorbent polymer on plant height, leaf chlorophyll content, number of pods per plant, grain yield and biological yield at the probability level of 1% and had no significant effect on other traits. so that the highest grain yield (1710.94 kg.ha-1) was given to the treatment (full irrigation and 150 kg.ha-1). The results showed that with increasing drought stress, the values of physiological traits such as chlorophyll content and relative water content of leaves decreased, but proline content of leaves increased. If the use of superabsorbent significantly increased the physiological traits. According to the obtained results, the superabsorbent reduced the damage caused by drought.

It is necessary to investigate the effect of drought stress and the presence or absence of weeds on the growth and yield of important crops such as corn and sorghum. For this purpose, a field study was conducted in the educational farm of Ferdowsi University of Mashhad in the crop year of 2014 in the form of two separate experiments for two forage corn plants KS260 and forage sorghum of Speedfeed in factorial form in the form of a randomized complete block design with 3 replicates. The first treatment was irrigation levels of 65%, 75%, 85% and 100% of the percentage of water requirement of the reference plant (evaporation pan)and the second treatment was weed control management (weeding and not weeding). In this project, the growth indices of corn and sorghum were measured and the effect of different levels of irrigation on these indices was investigated. the lowest yield of wet and dry fodder was observed in corn and sorghum under extreme water deficit conditions., Weeding corn and sorghum fields increased about 35% of fresh and dry weight of corn fodder and 25% increase of fresh weight of fodder and 100% of dry weight of sorghum fodder. Weeding in all conditions reduces the competition of these species with crops and increases the growth indicators of forage, including leaf surface durability (49% corn and 11% sorghum), relative growth rate (9% corn and 22% sorghum). , net growth rate (23% corn and 25% sorghum) and height (12% corn and 15% sorghum).

In order to investigate the effect of different levels of tillage and residues on the yield and yield components of wheat (cv. Mehregan), a research was conducted in 2015 cropping season in south west of Iran. The study was consisted of a strip-plot experiment, using Randomized Complete Block Design (RCBD) with three replications. The investigated treatments included tillage in three levels (including conventional tillage, protective tillage and no tillage) as horizontal plots and plant residues in three levels (including zero, 30 and 60% wheat residues) as vertical plots. The results showed that the tillage treatment had significant effect on yield and yield components, harvest index, percentage and yield of protein. The highest grain yield (with an average of 477.5g.m-2) was obtained from the conservation tillage treatment and the lowest (with an average of 340.3g.m-2) from the no-tillage treatment. Also, the application of plant residues significantly affected yield and yield components, biological yield, harvest index, percentage and yield of protein. The highest grain yield (with an average of 480.7g.m-2) was obtained in the conservation tillage method with the application of 30% residues on the soil surface. Based on the results and considering the positive effects of conservation tillage method, it was suggested to use 30% of residues in this tillage method in Izeh region in order to increase wheat yield.

This research was conducted with aim of investigating the effects of organic and chemical fertilizers along with silicon on morpho-physiological characteristics and yield of purple coneflower (Echinacea purpurea L.), in Mazandaran,, Amol during 2022. The experiment was cconducted as a split-plot in a randomized complete block design with three replications. The experimental treatments include the application of organic and chemical fertilizers at four levels (control, manure, vermicompost and chemical fertilizer) as the main plot and silicon at three levels (control, potassium silicate and nano-Si) were considered as sub plot. The results indicated that the most growth characteristics like plant height, number of flowers per plant and leaf area were obtained by chemical fertilizer. The highest dry weight of plant organ was achieved with use of chemical fertilizers. The highest dry weight of flowers (429.3 g.m-2) was obtained by chemical fertilizer, which was not significantly different from the use of vermicompost (417.3 g.m-2). The application of both sources of silicon led to improvement in the number of flowers per plant, leaf area, and concentration of chlorophylls compared with control, although the application of nano-Si had higher improvement effects compared with potassium silicate. The nano-Si increased the dry weight of flowers by 9.6 and 7.4% compared with non-application of silicon and potassium silicate, respectively. Therefore, according to the findings of the present study, application of vermicompost organic fertilizer is introduced as a suitable alternative to chemical fertilizers, as well as nano-Si application to improve the morpho-physiological characteristics and yield of purple coneflower.