نشریه علوم به زراعی گیاهی
سال دوازدهم شماره 2 (پاییز و زمستان 1401)

In order to evaluate the yield and yield components of pinto bean varieties (Phaseolus vulgaris L.), under water stress, an experiment was conducted in 2016 in Damavand city in the form of a split plot design based on a randomized complete block design with 3 replications. So that water stress (A), as the main factor, includes three levels: control, mild stress and severe stress and variety (B) was considered as a subfactor, including 6 varieties of pinto beans (Ghaffar, F16, Ks21492, Ks21495, Ks21558 and Ks22102). The traits of number of pods per plant, length of pods, number of seeds per pod, weight of 100 seeds, biological yield, yield of seeds per plant and harvest index were measured and indices of drought stress tolerance were calculated. According to the results of analysis of variance, the effect of water deficit stress was significant on all studied traits, except for the traits of weight of 100 seeds, biological yield. Also, there was a significant difference between the investigated varieties in terms of all the studied traits at the probability level of 1%. The results of comparing the mean treatments showed that Ks 21495 had the highest seed yield with the highest values of the number of pods per plant and the number of seeds per pod. Based on the obtained results, mean productivity (MP), geometric mean productivity (GMP), harmonic mean (HARM) and stress tolerance index (STI) indices were the most appropriate indices for the strain-tolerant varieties.

In order to Response of agronomic traits of forage corn to simultaneous cropping with legumes, nitrogen levels and cultivator application. A factorial randomized complete block design with three replications was used. Urea manure levels [N0= without urea (Control), N1= 150 Kg ha-1 of urea, N2= 300 Kg ha-1 of urea) and simultaneous cropping treatment, (S1= cultivation of corn, S2= cultivation of corn + cultivator application, S3= cultivation of corn + cultivator application + soybean, S4= cultivation of corn + cultivator application + cowpea, S5= cultivation of corn + cultivator application + alfalfa) were assigned in plots. In this study, traits such as stem diameter, height of earing, number of ear, wet weight of ear, number of grain per m-2, harvest index, biological yield, wet weight of stem and leaf and surface of ear leaf were evaluated. The result have shown that the interaction effect of urea levels and simultaneous cropping + cultivator application treatment was significant on stem diameter, height of earing, wet weight of ear, number of grain per m-2, harvest index, biological yield and wet weight of stem and leaf. The highest and lowest of biological yield (18.13 and 9.60 ton ha-1) were obtained with the cultivation of corn + cowpea + 150 Kg ha-1 of urea + cultivator application and cultivation of corn + cowpea + cultivator application + 0 Kg ha-1 of urea manure, respectively

Experimental treatments include the seed priming including: control (soaking seeds for 24 hours in water), soaking seeds for 8, 16 and 24 hours in seed guard solution was performed in the main plots and three cultivars of rice including: Champa,, Anbarbo and high yielding cultivar i.e. LD-183 were applied in the sub-plots. The results showed that the effect of duration of priming on number of spike per square meter, number of grains per spike, 1000-grain weight, grain yield, biological yield and grain protein percentage was significant. The effect of cultivar type was significant in all measurement traits. The interaction effect of seed duration of priming and cultivar type was not significant in terms of grain yield and biological yield and significant in terms of other traits. The maximum grain yield was obtained in Anbarbo cultivar + 24 hours in seed guard solution with an average of 5621.77 and the minimum grain yield in Champa cultivar + 24 hours in normal water with an average of 32264.5 kg/ha. The maximum grain protein was obtained in 24 hours in seed guard solution with an average of 11% and the minimum grain protein in 24 hours in ordinary water with an average of 8.3%. In general, the results of experiment showed that the effect seed priming by seed guard solution with increasing production components could be effective in increasing quantitative and qualitative yield as compared to soaking the seeds in water (local custom) and it can suggested by researchers and farmers.

Drought is one of the most important nonliving stresses affecting the growth of plants, thereby limiting the agricultural yield of the plant. Measures including presenting information for improving the drought risk management, improving planning for more effective reaction to drought, investment on disaster risk reduction (DRR), and presenting an environment for minimizing the general risks lead to enhanced endurance, as well as prevention or reduction of future drought risks along with maintaining livelihoods. This research was performed in two agricultural years as split court experiments in the form of fully randomized block with four replications. Various conditions of soil humidity were considered as the main treatment at three along with the treatment of biofertilizers at seven levels, considered as secondary treatments. The study results indicated that various humidity conditions of the leaf relative water content (RWC), the greenness index of leaves (SPAD), chlorophyll a and b, as well as the grain yield became significant. With increase in the severity of stress, their values decreased suggesting their sensitivity to changes in the status of soil water and the leaf water potential. Usage of azotobacter and Phosphobacteria biofertilizers resulted in significant elevation of SPAD, RWC, chlorophyll a and b, as well as grain yield compared to the nonuse of biofertilizers. The effects of combined use of microorganisms led to compensation of the water stress damages. Generally, considering water deficit conditions and temperature elevation resulting from climate change, use of microorganisms as seed priming can considerably reduce these risks.

Changing planting density changes the nitrogen requirement in rice cultivars. To determine the effect of planting density and nitrogen fertilizer on the growth and yield of promising mutants, a field experiment was conducted in the deputy of the Rice Research Institute in Mazandaran (Amol) in the cropping years of 2020 and 2021. The experiment was performed as a factorial split plot in a randomized complete block design with three replications, that urea fertilizer levels (100, 200 and 300 kg/ha) as the main plot and two genotypes (1117 and 215) and planting density at three levels (25×25, 13×30, 18×30) as sub-plots Implemented in factorial format. The results variance homogeneity test showed the non-uniformity of the data in two crop years. The results of 2021 crop year showed that the three-way effect (nitrogen×planting density×line) was significant for six traits of plant height, panicle length, number of filled, empty and total grains total seeds per panicle, and yield. The panicle length increased with the increase of urea fertilizer consumption. The weight of 1000- grains of line 1117 was equal to 28.9 grams, but line 215 had a weight of 21.2 grams per thousand seeds. The highest number of panicles per hill was obtained in the treatment combination of line 1117 and planting density of 13x30 (17.67±0.72). The best treatment combination to achieve maximum yield was the consumption of 300 kg of urea fertilizer at a planting density of 13 × 30 for line 1117 and equivalent to 6148.83 ± 0.1 kg per hectare.

The present study was conducted to study genetic diversity in 26 rice genotypes (lRRl heat tolerant collection) in 2016 in Khuzestan Agricultural and Natural Resources Research Center as a factorial experiment based on a completely randomized design with three replications including 24 lines and 2 hybrids as the first factor and drought stress with PEG 6000 in 5 levels of zero (control), -0.3, -1.8, -3.3 and -4.8 Bar were performed as the second factor. The results of analysis of variance showed that there was a significant difference between drought levels, genotypes and their interaction in all traits at a probability level of one percent. The lowest indices of germination and seedling growth were observed at the level of -4.8 Bar. The highest positive and significant correlation (r = 0.90**) was obtained between shoot length and seedling length. In principal component analysis, the four first components accounted for 85% of the total diversity. Cluster analysis with Ward method included genotypes in three clusters. In the first cluster of lines 48, 15, 35, 44, 42, 20, 19, 5, 28, 10, 16, 4, 2, 55, 53, 31, 34, 36 and HB2 hybrid, in the second cluster of lines 25 and 23 and hybrid HB1 and in the third cluster were lines 40, 13, 41 and 21. According to the results of mean of comparison, biplot and cluster analysis of the second cluster genotypes in terms of germination rate, shoot length, root length, seedling length, seedling fresh weight, seedling dry weight, seedling Dry/wet weight ratio, seed vigor index are higher than the total average and therefore tolerate to drought. The selected genotypes can be considered in advancing breeding programs in the development of new rice cultivars with greater tolerance to drought stress.

In the present study, the influence of foliar application of salicylic acid and biofertilizers on modulating the effects of drought stress on some morphophysiological characteristics, dry matter yield and essential oil production of basil (Ocimum basilicum L.) was investigated using a factorial experiment based on a randomized complete block design in triplicate within the 2019 in Hurand . Experimental treatments included three levels of drought stress (70, 140 and 210 mm of evaporation from Class A evaporation pan) as the first factor, seed inoculation with bacteria at five levels (no inoculation as control, inoculation with Azotobacter, Pseudomonas, Azospirillum and co-inoculation with Azotobacter, Pseudomonas and Azospirillum) as the second factor and salicylic acid foliar application at four levels (0, 0.5, 1 and 1.5 mM) as the third factor. .The results of this study showed that the drought stress had an important role in reducing the basic factors in basil growth. The results showed that with increasing the intensity of drought stress, the proline content increased. So that the highest proline content (1.69 μM/g fresh weight) were obtained from the treatment of 210-mm evaporation. Based on the results obtained in this experiment can be expressed, the use of salicylic acid at a concentration of 1.5 mM and the co-inoculation of bacteria play a role in relieving the negative effects of drought stress and their administration can effectively increase the quantitative and qualitative properties of the basil.

Drought stress is one of the main reasons for the reduction of quantitative and qualitative yield in sugar beet cultivation, on the other hand, the increasing reduction in available water, especially in arid and semi-arid regions, has made the worse situation. In this situation, the use of drought-resistant cultivars is an effective way to reduce production risk. For this purpose, experiments were conducted in the form of split plots in based of RCBD statistical design with the main factor of irrigation (90 and 180 mm) and sub-genotype factor (16 hybrids and 4 genotype control varieties) in the years 2016 and 2017 at Karaj Sugar Beet Research Institute. The results showed that there is a decreasing trend in the average root yield and white sugar yield in two years under stress conditions of 28.5 and 10.5%, respectively, compared to normal irrigation conditions. However, under stress conditions, sugar content had an increasing trend, and root impurity values (sodium and nitrogen) had a decreasing trend, which was accompanied by the highest values of the sugar extraction coefficient. Also, the reduction of water consumption in stressful conditions led to an increase in the efficiency of irrigation water in stressful conditions compared to normal. In the examination of genotypes, based on two indices of tolerance and resistance to drought stress and yield index, genotypes number 1, 3, 9, 12, and 16 were identified as promising genotypes.

Since the yield of sugar beet is affected by the length of the growing period and agronomic management, to investigate the delayed cultivation, this experiment was conducted in 2015 and 2016 with two treatments of planting row spacing (Pr) with two levels of 25 and 40 cm (main plot) and three levels of plant spacing on row (Ps) using 1.7, 2.4, and 3.1 units per hectare seeds (sub-plot), it was carried out in the form of split plots with a RCBD in four replications. By adding the harvest date treatment with two levels of conventional and delayed in the second year, the statistical design was changed to split plots factorial (Ps and harvest date as factorial). The highest percentage of white sugar content (WSC) and potassium was obtained in the 40 cm row spacing. In the second year, a 37% decrease in the number of final roots compared to the first year caused a 25% decrease in root yield (RY), 31% in white sugar yield (WSY), and 21% in irrigation water use efficiency (IWUE). Contrary to the first year, the effect of Ps was not significant on traits such as RY, WSY, and IWUE, while it had no significant effect on the percentage of WSC in any of the two years. In the second year, with a delay in harvesting, the increase in WSY and IWUE was 32% and 16%, respectively. Therefore, Pr of 25 cm and Ps of 22 cm (2.4 units) is recommended for the Karaj region.

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.

The use of polyamines with an impact on a wide range of plant growth and developmental processes can in/directly influence the growth indices and metabolic performance of the plant. This experiment was performed in a randomized block design with 10 treatments including spermine, spermidine and putricin each at three levels of 50, 100 and 150 mg / l with 3 replications. Non-foliar treatment was utilized as a control treatment. The results demonstrated that foliar application with different levels of polyamines had a significant impact (P≤0.01) on traits such as root dry weight, wet and dry weight of shoots and also a significant effect (P≤0.01) on traits such as chlorophyll, a, b and total chlorophyll, height, side branch, the number of umbela and weight of 100-seeds. The highest dry weight of roots, wet and dry weight of shoots and the numbers of side branch were related to spermidine treatment 150 mg/ l, the highest chlorophyll a and b and total chlorophyll and the number of umbels related to spermine treatment 150 mg / l, the highest carotenoids related to spermine treatment 100 mg / l and The maximum weight of 100 seeds and height for putrescine treatment was 150 and 100 mg / l respectively. Based on the results of this study, it seems that spermine and spermidine have been effective on more traits. Foliar application of polyamines can also increase the quantitative and qualitative yield of the plant and change the majority of traits.