فصلنامه پژوهش های تولید گیاهی
سال بیست و هشتم شماره 1 (بهار 1400)

Rice milling parameters consist of milling recovery, broken grain percent, chalkiness and whiteness due to the effect on waste, price, marketing and final income of production. Reducing in rice grain milling parameters due to climate change and global temperature increase is one of the most important challenges in many of the world's rice planting regions, including our country, and the changes in milling recovery, regardless of agronomic management, depend on the environmental conditions of each region, especially the air temperature on grain filling stage. Therefore, the present study was conducted to investigate the effect of different local climates on milling parameters (MP) of two rice cultivars (cvs. ‘Tarom-Hashemi’ and ‘Shiroudi’) and also to estimate the relationships between MP and average air temperatures (AAT) during the grain filling stage of rice (from anthesis stage (50% of flowers opened) to harvesting time) in Babolsar, Amol and Polesefid regions in Mazandaran province.

Three field experiments were conducted separately based on the randomized complete blocks design with four replications in Babolsar (-21 m sea level, asl), Amol (+24 m asl) and Polesefid (+625 m asl) in the north of Iran on two rice cultivars ‘Tarom-Hashemi’ and ‘Shiroudi’ in 2014. All agronomic managements were done based on local recommendations in each region. Moreover, all studied traits were measured in the grain quality laboratory of Rice Research Institute of Iran, Deputy of Mazandaran (Amol) in three months after harvesting.

The results indicated that the effects of different local climates were statistically significant on percentage of milling recovery, head and broken grain and chalkiness (P < 0.01). All studied traits in Polesefid were better than them in both Amol and Babolsar which can be due to lower temperature during the grain filling stage of rice. In general, milling recovery (1.46 and 1.03 %, respectively), amount of head grain (3.58 and 3.11 mm, respectively) and whiteness (1.25 and 1.42, respectively) increased linearly per unit increase in AAT in both ‘Tarom-Hashemi’ and ‘Shiroudi’, respectively. Inversely, broken grain of rice (2.63 and 2.51%) and chalkiness content (1.65 and 4.24%) increased linearly per unit increase in temperature for ‘Tarom-Hashemi’ and ‘Shiroudi’, respectively. Milling economic benefit also decreased 8000,000 and 12,000,000 Rial ha-1 per unit increase in temperature for ‘Tarom-Hashemi’ and ‘Shiroudi’, respectively.

These results can be used for predicting the amount of rice milling wastage and estimating the effect of temperature on economic benefit under climate conditions of Mazandaran province. Based on our findings in this study, milling parameters variation were related to temperature which can be estimated in both cultivars (‘Tarom-Hashemi’ and ‘Shiroudi’) under different local climates of Mazandaran.

Fusarium head blight of wheat with causal agent of fungus Fusarium graminearum is one of the most common diseases affecting wheat. Fusarium as one of the major wheat diseases makes a significant loss on wheat yield and quality globally. Northern Iran, due to the distinct conditions of humidity and temperature is susceptible to Fusarium head disease. One of the most efficient ways to control this disease is the use of resistant, genetically modified cultivars. The annual screening of plant cultivars offers useful information on resistance of cultivars to Fusarium head disease for researchers.

In this study 21 cultivars of common wheat including irrigated and rainfed plus three resistant cultivars and susceptible in a complete block design with three repeat in two different environment were cultivated in Gorgan University educational farm in 2016. One of the settings was the disease-induced and the other was not disease-induced. In the stressed setting artificial contamination was induced with spore suspension and in the non-stressed setting Falcon fungicide was used to control the disease. Each wheat cultivar was planted on a 4.5 meter line. Lines had a 30 cm distance from each other and seeds had a distance of five cm. In this experiment, fresh fungi suspensions with a concentration of 1×108 macroconidia per milliliter were used. Fusarium spore suspension was applied to spikes at the beginning of the flowering period at the onset of the emergence of anthers. After spore suspension application, the disease indices including, the incidence of disease, severity of disease and disease index, and after harvesting, the percentage of infected seeds and performance indicators were measured.

Based on the results of analysis of variance, a significant difference between the cultivars tested at the probability level of 1% for incidence, severity of disease and percentage of contaminated grains was observed. Analysis of yield data using analysis of combined experiments showed that the cultivars Qaboos, Aftab and Layn 17 among the rainfed wheat cultivars, and Morvarid in irrigated cultivar, were the best cultivars in response to Fusarium head blight. Among the cultivars studied, Qaboos and Aftab had the least yield loss and were suitable for cultivation in areas with Fusarium head blight epidemy.

The results of this study showed that the occurrence of a biotic stress such as Fusarium head blight negatively affects the grain yield, the more resistant cultivars have lower yield loss. The results of this research can be used as a source for resistant genotypes for corrective actions. Qaboos and Aftab cultivars are introduced as resistant cultivars in areas with high risk of Fusarium epidemy. The Ehsan cultivar is a coarse grain cultivar and has a good yield in a disease-free environment, perhaps it can be found to be suitable for cultivation in areas with low humidity

Breeders are always looking for sources of diversity in different plants. Because spontaneous mutations occur rarely in environment, induced mutation is a more appropriate method for plant diversity. Therefore, the ploidy level instruction through mutagens, especially chemical mutagens in somatic cells, has the potential to improve the ability to produce new varieties with superior and desirable traits in many plant species. Plant species with more than two chromosome (polyploid) sequences are of particular importance due to increased genetic variation in their better adaptation to new environments, natural evolution and plant breeding. Accordingly, an investigation was conducted to induce in vitro polyploidy through colchicine in a new species of asiatic hybrid Lilium dandie, which has high potential for ornamental and medicinal.

In this experiment, in vitro bulb scales were treated in a completely randomized design with factorial arrangement in different concentrations of filter sterilized colchicine solution (0.01, 0.05 and 0.1%) for 6, 12 and 24 hours. Then samples were taken to regenerate and grow normally in a culture medium without growth regulators. After assessing the survival rate, ploidy levels of regenerated plantlets by direct counting of the number of root meristem chromosomes were determined. Length, width and density of leaf apertures using bachelor varnish technique and direct counting of chloroplast number of stomatal guard cells in adult and developed leaves as cytological factors between the control (diploid) and polypoid (triploid) plantlets was compared. plantlet fresh weight was also measured using scales and morphological indices of leaf length and width and root length were measured by precise ruler.

The results of this study showed that with increasing concentration and duration of treatment of colchicine, the survival rate of explants decreased. colchicine was completely effective in inducing polyploidy (triploid) L. dandie and the highest amount of polyploidy (14) occurred during 12 hours. The highest efficiency of productivity was obtained during treatment with 0.01% colchicine. In the polyploid plantlets, the stomatal density decreased significantly compared to the control, while the stomatal length and the number of chloroplasts in the stomatal guard cells showed a positive correlation with the increase in ploidy levels. Fresh weight and morphological characteristics of leaf length and width as well as root length in polyploidy plantlets were significantly increased compared to control.

The use of colchicine in polyploidy induction in L. dandie was completely successful and the highest polyploidy productivity (42.85%) was optimized for 12 hours treatment. Low density and longer stomatal length, as well as high chloroplast count in the chloroplast guard cells in polyploid plantlets, are a good indicator of polyploid plantlets screening than diploid plantlets. Fresh weight indices and morphological characteristics of leaf length and root width and plantlets length increased with increasing ploidy level.

Grain N content in barley plant is affected by N remobilization from vegetative organs to the grain during the grain filling period. The amount of N remobilization is negatively affected by the severe water stress after anthesis. Using of Azospirillum as a biofertilizer is a way for reduction the adversely effects of the severe water stress in the arid regions. Another way is increase the amount of soil organic matter (such as using of plant residues). Therefore, this study investigated the effects of wheat residues application and different N sources (biological and chemical) on N remobilization and grain N content of barley.

This research was conducted at the experimental farm of the Darab Agricultural College of Shiraz University. A split factorial experiment in a randomized complete block design with three replicates were carried out in 2017 - 2018 growing season. Treatments included: two levels of irrigation as the main plots [normal irrigation (IRN): irrigation based on the plant's water requirement up to the physiological maturity and another factor was deficit irrigation (IRDI): irrigation based on the plant's water requirement up to the anthesis stage (cutting of irrigation after anthesis)]. Also, sub plots were two levels of plant residues [1. without residue, 2. returning 30% of wheat residues to soil] and four fertilizer sources [N0, no nitrogen fertilizer (control); N100, 100 kg N ha-1; Bio + N50, Biofertilizer (Azospirillum brasilense) + 50 kg N ha-1 and Bio, Biofertilizer (Azospirillum brasilense)].

Application of N100 and Bio + N50 treatments significantly increased the N remobilization efficiency by 36% and 34%, respectively, as compared with the control (N0) under IRN. In contrast, under IRDI condition, all N sources decreased the N remobilization efficiency as compared with the control (N0). However, the amount of reduction in Bio + N50 and Bio treatments (10% and 11%, respectively) was lower than N100 (21%). The similar trend of N remobilization efficiency was observed for N harvest index in IRN and IRDI. Nitrogen harvest index showed a positive and linear relationship with N remobilization efficiency under both irrigation regimes. However, the justified variation of the N harvest index by N remobilization efficiency under IRDI was higher than (25%) the IRN conditions (R2 = 0.70 and R2 = 0.45). Also, Grain N content linearly increased with increasing N remobilization under both irrigation regimes. Application of wheat residues significantly reduced the N remobilization efficiency and grain N content in Bio + N50 and Bio treatments as compared to non-applied of residue. Also, there was no significant difference between with and without residue treatments in N remobilization efficiency and grain N content when N100 treatment was applied.

According to the environmental and economic considerations, integrated N fertilizer [Biofertilizer (Azospirillum brasilense) + 50 kg N ha-1] is recommended for normal irrigation conditions in order to maximum grain protein content achievement. In contrast, under cutting of irrigation after anthesis conditions, biofertilizer treatments (using of Azospirillum brasilense alone or using of it with integration to 50 kg N ha-1) reduced N remobilization efficiency as compared with control (N0). However, the decrement values were lower than the sole chemical N fertilizer (100 kg N ha-1). Therefore, in Southern Iran where water stress after anthesis is possible, biofertilizers is recommended. Also, using of wheat residues is not recommended for increasing N remobilization efficiency and consequently grain N content across over all irrigation and N regimes.

Olive (Olea europaea L.) is one of the important horticultural crops in Iran which is planted in subtropical regions. In most parts of these regions temperature, particularly during the summer, rises to the level of heat-stress for this plant species. There is a scarcity of information about the heat tolerance of olive cultivars and also about effective physiological and biochemical mechanisms by which they response to this stress. Therefore, understanding of these mechanisms and also going toward the selection and cultivation of high tolerant varieties are within the olive breeding objects.

To study the impact of heat stress on physiological and biochemical traits changes as well as the expression pattern of phenylalanine amonialyase (PAL) and polyphenol oxidase (PPO) genes, a factorial experiment based on a completely randomized design was carried out in 2017. One-year-old own-rooted olive plants cvs. Zard and Direh were transferred into the artificial growth chamber and exposed to the different thermal conditions following an adaptation period. Thermal treatments included 32 oC (referred to as the before-stress stage, for three months), 45 oC (referred to as the stress-stage, for one month), and 36 oC for five days which referred to as the after-stress stage. Different traits including cumulative shoot growth and dry weight, relative water content (RWC), electrolyte leakage (EL), malondialdehyde contents (MDA), the maximum quantum yield of PSII (Fv/Fm), the minimum chlorophyll fluorescence (Fo), PPO and PAL enzyme activities and their genes expression pattern were studied. Data were analyzed by SAS 9.1 software, and the mean comparisons were made by LSD (P ≤0.01).

The findings related to growth indexes, i.e., the cumulative shoot growth and dry weight, demonstrated the relative superiority of ‘Zard’ compared with that of ‘Direh’ under heat stress. The RWC was decreased significantly in leaf samples of both cultivars in response to high temperature. However, this reduction was more pronounced in ‘Direh’. The extent of injury to cell structures, based on the measurement of EL and MDA indexes, indicated that ‘Zard’ got suffer less damage than ‘Direh’ under heat stress and also recovered itself quicker at the recovery stage. Under heat stress conditions, a more and significant decrease in terms of the Fv/Fm index was shown in ‘Direh’ compared with ‘Zard’. In contrast with the Fv/Fm , the Fo index was higher significantly in ‘Zard’. The PPO and PAL activity was increased, with pronounced effect in ‘Zard’, under heat stress condition. The activity of PPO in both cultivars was declined following the heat stress at the recovery stage. The analysis of the expression patterns of genes related to PPO and PAL revealed their up-regulation in both cultivars in response to heat stress. The relative increase of PPO and PAL genes expression in ‘Zard’ and ‘Direh’ under heat stress conditions was respectively 3 and 1.5 times more than the before-stress stage.

The results here showed that olive cv. Zard had relatively more tolerance to heat stress. Also, this cultivar had a high ability to recover its physiological and biochemical traits following the heat stress at the recovery stage.

Over the past decades, the economic benefit has prompted farmers to grow rapeseed. Consequently, the global rapeseed production increased considerably, and today the crop is grown in shorter rotations than ever before. Rapeseed crops usually yield more if grown after other species than when grown after rapeseed. Crop rotation is a succession of crops grown on the same land. Pulses in crop rotations can improve the productivity of subsequent crops due to increased soil available N and other agronomic benefits. Also, Legume plants can promote C storage by enhancing the formation and stabilization of soil aggregates that protect soil organic C from mineralization. In order to evaluation of rapeseed growth and yield under nitrogen fertilizer and pre-cropping with corn and chickpea crops, an experiment was conducted.

A factorial experiment was designed based on randomized complete blocks with three replications and implemented on a sandy clay soil during 2012-13 and 2013-14 growing seasons, at the Agricultural Research Station, Faculty of Agriculture, University of Bu-Ali Sina, Hamedan, Iran. The first factor consisted of chickpea and corn (forage) and the second factor was urea fertilizer levels of 0, 40, 80, 120, 160 and 200 kg/ha. Harvest operation was done in July 2013 and 2014. Random samples 2 m2 areas were harvested by cutting the stems near ground level to determine the crop grain and straw yield. Evaluated traits include plant height, grain yield components, biological and grain yield, harvest index, chlorophyll index and percentage of grain protein and oil. SAS procedures and programs were used for the analysis of variance (ANOVA) calculations.

The results showed that all of the evaluated properties of rapeseed affected by pre-cropping and nitrogen fertilizer treatments. But, none of the rapeseed traits do not affect by pre-cropping × nitrogen fertilizer. The highest biological yield and grain yield and protein percentage were observed in chickpea pre-cropping treatment (about 924 and 263 g m-2 and 22.29%, respectively). Chickpea pre-cropping treatment increased rapeseed biological yield and grain yield and protein percentage about 14, 13 and 15 percent in comparison to corn pre-cropping treatment. Pay attention to the improved physicochemical conditions of the soil after cropping legumes such as chickpea, it is normal to improve the growth and yield characteristics of the next crop (in this study, rapeseed). Among the nitrogen fertilizer levels, the lowest rapeseed biological yield and grain yield and protein percentage (about 567 and 125 g m-2 and 19.05%, respectively) were achieved at 0 kg ha-1 N fertilizer consumption. Also, the highest rapeseed biological yield and grain yield and protein percentage (about 1311 and 342 g m-2 and 21.06%, respectively) were observed at 200 kg ha-1 N fertilizer consumption, but it had no significant difference with 160 kg/ha treatment. One of the most well-known effects of nitrogen fertilizers increased the properties of crop growth. In this study, rapeseed growth and yield characteristics such as plant height, chlorophyll index, grain yield components, biological and grain yield, harvest index, and percentage of grain protein and oil increased due to urea application.

It seems that in rapeseed farming, legumes pre-cropping such as chickpea pre-cropping is a good solution to reduce the use of nitrogen fertilizers and to contribute to environmental health. Also, attention to optimum fertilizer levels and non-overuse of fertilizers will contribute to agricultural sustainability.

Borage officinalis L. is an annual herbaceous plant that is distributed in temperate and subtropical regions, especially in the Mediterranean. Nowadays, foliar application of salicylic acid (SA) as one of the growth regulator for improving plant stresses tolerance such as drought stresses. Biochar is a carbon-rich product in the stable form that benefits from organic fertilizers and is used soil fertility. Considering the importance of medical plant cultivation especially in the drought region, investigation the effects of water deficit on Borage officinalis L has particular importance and according to previous studies on the positive effect of salicylic acid and biochar on mitigation of adverse effects of drought as well as improving water relations in soil, therefore this study aimed to investigate the effects of biochar and salicylic acid (SA) on some characteristics of Borage officinalis L under different irrigation intervals

These experiments were performed in a four replicated-split plot factorial arranged in CRBD with three factors irrigation intervals (5, 10, and 15 day) in the main plots and biochar application (0, 5 and 10 tons per hector) and foliar application of salicylic acid (0,0.5Mm) in sub plots. This study was carried out in research field of Shahrood university of technology, Shahrood, Iran during 2017-2018.

the results indicate that with increasing irrigation intervals in all biochar levels, leaf relative water content (RWC) significantly decreased and biochar application had no significant effect on drought stress. Salicylic acid increased leaf relative water content (RWC) in both irrigation intervals of 10 and 15 days compared to non-treated treatments but it had no positive effect on stress reduction due to increases irrigation intervals. As the irrigation intervals increased, flavonoid levels also declined significantly, salicylic acid partially moderating its use, but biochar application had different effects on flavonoid depending on irrigation intervals. Increasing irrigation intervals up to 10 days increased the level of anthocyanin, but with increasing irrigation intervals to 15 days, it decreased significantly. Biochare application had no significant effect on anthocyanin content (both under and without salicylic acid application) but with increasing irrigation intervals to 10 days, biochar application alone without salicylic acid caused anthocyanin content increased. Nitrogen percentage of borago officinalis.L leaf increased significantly with 5 tons/ha biochar for 5 days irrigation intervals and 10 tons/ha biochar for 15 days irrigation intervals, compared to control (non-biochar). The results also show that the application of biochar 10 tons/ha at 10 and 15 days' irrigation interval moderated the stress caused by increased irrigation interval for leaf nitrogen. Increasing irrigation intervals also reduced the number of flowering shoots, which improved by biochar and salicylic acid application.

biochar had a positive effect on the improvement of some physiological and qualitative indices of borago officinalis. L under drought stress condition, but there were no significant differences between different levels of biochar in terms of positive effects in reducing the effects of irrigation intervals on some traits, Besides, the simultaneous application of biochar and salicylic acid in most traits increased their efficiency in reducing drought stress effects.

Autumn cultivation of sugar beet is one of the strategies for increasing sugar beet production with minimum amount of water consumed due to the use of autumn and winter precipitation and avoiding the need for irrigation in very dry summer air. Rhizomania is recognized as the most destructive disease of sugar beet in the world. The aim of this study was to investigate the quantitative and qualitative characteristics and the effect of rhizomania viral disease on susceptible and tolerant cultivars of sugar beet in spring and autumn cultivation in polluted soil conditions of Torbat-e Jam region.

In this research, five domestic and foreign commercial cultivars including rhizomania-resistant and susceptible commercial cultivars were cultivated in spring and autumn in a field infected with rhizomania disease of Torbat-e Jam Sugar Factory. The experiment was conducted as split plot in a randomized complete block design with four replications in 2017-18 growing season as sowing time as main factor in two levels (spring and autumn) and cultivar as sub factor was considered at five levels (Giada, Dorothea, SBSI002, Monatunno and Rasoul). The traits studied in this study included root yield, sugar content, sugar yield, white sugar content, white sugar yield, sodium, potassium, trace nitrogen, sugar extraction coefficient, molasses sugar, disease severity and ELISA test index (OD). Analysis of variance was performed using SAS v.9.1 statistical software. Mean comparisons of traits were performed using LSD test at the probability level of 5 and 1%.

Analysis of variance showed that there was a significant difference between the two spring and autumn sowing times in terms of quantitative and qualitative yield and rhizomania damage. Also, for all studied traits, except for potassium and nitric oxide, there was a significant difference at 1% probability level between different sugar beet cultivars. The highest values were observed for root yield, sugar yield, white sugar yield and potassium, and the lowest values for severity of disease and ELISA index in Giada cultivar and autumn cultivation conditions. Whereas, Rasoul cultivar had the lowest values for sugar content, sugar yield, white sugar yield, potassium and nitrogen in spring cultivar and the highest values for disease severity and ELISA.

In general, the results showed that autumn sowing leads to improved quantitative and qualitative yield and reduced rhizomania damage in sugar beet. According to the results of this study, autumn cultivation of Giada is suitable in Torbat-e Jam region

Soil contamination by heavy metals is one of the main environmental stress in agricultural and horticultural ecosystems Green mint as a vegetable and medicinal plant are directly and indirectly in the food basket of the Iranian community. Therefore, cultivation of this plant in heavy metals polluted fields or fields irrigated with unusual waters, wastewater, effluent from factories and industrial units, increases the accumulation of heavy metals, especially arsenic in the plant. In addition to its effect on the growth characteristics of plants, it poses a serious threat to the health of consumers. Therefore, the present study was conducted to evaluate the effect of phosphate bio fertilizer on the reduction of arsenic heavy metal toxicity on physiological and biochemical properties of green mint.

In this study, the effect of phosphate bio fertilizer on increasing arsenic tolerance of green mint was evaluated on a factorial experiment in completely randomized design under greenhouse condition at University of Guilan during 2016. Treatments consisted of different levels of arsenic (0, 50, 100 mg/kg soil) and phosphate bio fertilizer (0 and 0.5 mg/kg soil). Plants were taken about two months after planting. Morphological characteristics of the plants (number of leaves, number of stems, plant height, shoot and root dry weight, shoot dry weight and leaf area) were measured using ADC modeling apparatus. Biochemical properties including leaf chlorophyll and carotenoids content, carbohydrate, antioxidant enzymes and proline activity were also measured.

The results showed that with increasing arsenic concentration from 0 to 100, root dry weight (2.65 g), plant fresh weight (2.8 g), leaf number (4.88) and caratenoids content (2.05 mg) were decreased. Phosphate bio fertilizer application also increased relative moisture content, plant fresh weight and carotenoid. The comparison of mean interaction of fertilizer × arsenic showed that the lowest plant height (11.28 cm), plant dry weight (8.28 g), and leaf area (12.052 cm2) were decreased under treatment of 100 mg/kg arsenic without phosphate bio fertilizer.

Application of phosphate bio fertilizer in different arsenic treatments increased proline content, polyphenol oxidase, peroxidase, carbohydrate, total chlorophyll, chlorophyll a, b with decreasing of arsenic concentration in roots and shoots. The results showed that phosphate bio fertilizer could partially improve the plant growth and its tolerance to arsenic stress. Keywords: Antioxidant Enzymes, Chlorophyll , Heavy metals,Bio fertilizer.

Kiwi (Actinidia deliciosa) is a dioecious plant species, requiring cross pollination for fruit production. Because of its high resistance to the lower temperature (up to –18ºC), kiwifruit is a good alternative to Citrus orchards in north part of country encountering chilling stress. This research was done to study the effects of two male cultivars on quantitative and qualitative characteristics of three female cultivars to determine of the best cross for each female cultivar.

This study was carried out as factorial experiment; female cultivars in three levels (Hayward, Bruno, Monty) and male cultivars in two levels (Tomori and Matua) based on completely randomized design with 6 treatments, 4 replicates, 24 plots and 10 flowers in each plot. Different fertilization was done between male and female cultivars. After harvest of fruits, the effect of treatments on fruit fresh weight, fruit length, fruit diameter, fruit acidity, total solid solution and fructose content in fruits were measured.

Results showed that the type of cultivar alone had a significant effect on fruit weight, length and diameter, fruit acidity, soluble solids content and fruit sugar content at 1% level. Male cultivar showed significant differences in fruit weight, fruit length, acidity and soluble solids content at 1% and fruit sugar content at 5% level but no significant effect on fruit diameter. Also, interaction effect of male and female cultivars was significant on weight, length and total solution solid of fruit in 1% level and on fruit diameter in 5% level, but it has not effect on fruit acidity and sugar. The highest fruit weight (85.24 g), fruit length (70.82 mm) and total soluble solid (13.50°Brix) were obtained from cross of Bruno and Matua cultivars. The maximum fruit diameter (46.43 mm) and fruit fructose sugar (6.08 g L-1) was observed from cross of Hayward and Matua and Monty and Tomori cultivars, respectively. The lowest fruit acidity (pH) (3.53) was obtained in cross of Monty and Matua cultivars.

Artificial pollination is a suitable approach to overcome all kinds of problems caused by pollination and fertility and increases the quality and marketability of kiwifruit. Pollination at the right time and with the right method and the right choice of male and female cultivars will improve most quantitative and qualitative traits of kiwifruit. Increasing fruit size is important to increase marketability and increase fruit sugar to enhance fruit flavor, and the main focus of such studies should be on these issues.

Cadmium contamination has decreased crops quality and quantity due to its uptake by plants and inhibition of its proper growth. Plants of Brassicacea family like black mustard have a high growth capacity in heavy metals polluted conditions. Some rhizobacteria can help to the movements of heavy metals in the soil. Plant growth regulators also have an important role in the induction of plant reactions to most of abiotic stresses such as heavy metals. The aim of this experiment was the evaluation of effect of growth promoting rhizobacteria, salicylic acid and brassinosteroid on reduction of cadmium stress effects in black mustard.

In order to study the effects of growth promoting rhizobacteria and plant growth regulators on physiological properties of black mustard under cadmium stress conditions, a factorial experiment was conducted based on randomized complete block design with four replications at research greenhouse of Mohaghegh Ardabili university. Experimental treatments included two cadmium levels (0 and 100 milligrams per kilograms of soil), three levels of rhizobacteria (control, Azospirillum, Pseudomonas) and three levels of growth regulators (control, Salicylic acid, Brasinosteroid). Before planting the seeds were inoculated with rhizobacteria and also growth regulators were sprayed in two stages during growth period on plants. After harvest some traits including MDA, proline, soluble sugars, photosynthetic pigments, membrane stability index and secondary metabolites were measured.

Results of means comparisons indicated that cadmium application by some effects including oxidative stress induction, increased MDA, proline, soluble sugars, phenol and flavonoid contents of leaves and decreased chlorophyll a and b, carotenoids and anthocyanin contents, membrane stability index and plant yield. Malondialdehyde and proline contents were reduced significantly by rhizobacteria inoculation and growth regulators application and phenol and flavonoid contents as well as plant yield were enhanced in both cadmium levels by rhizobacteria. Whereas growth regulators spray increased chlorophylls a and b contents, soluble sugars, membrane stability index, phenol, flavonoid, anthocyanin and plant yield and also the rhizobacteria enhanced soluble sugars, anthocyanin content and membrane stability index significantly. In addition, there was no significant difference between salicylic acid and brassinosteroid in all traits and pseudomonas inoculation compared to azospirillum indicated a significant superiority regarding some traits including membrane stability index and plant yield.

It can be concluded that cadmium contamination via the oxidative stress induction leaded to cell membrane destruction and increasing malondialdehyde content and also it resulted decreasing chlorophyll content of plant that is associated with increasing proline synthesis under stress condition. As a result of cadmium contamination stress, the activity of carbohydrates synthesis enzymes was increased and resulted increasing soluble sugars content and consequently increasing secondary metabolites content. By the application of rhizobacteria and plant growth regulators, the effects of oxidative stress were decreased and it leaded to enhancing membrane stability and reducing malondialdehyde content. Additionally, these treatments increased chlorophyll production and decreased proline content. By increasing chlorophyll content affected by these treatments, soluble sugars production in plants was increased and it resulted increasing secondary metabolites production in plant. Considering these results, the application of growth regulators and growth promoting rhizobacteria in order to decrease cadmium stress effects on black mustard grown in contaminated soils is recommended.

Barnyardgrass is the most important and most abundant weed of paddy fields in Iran and chemical control (butachlor) play a major role in its management. The usage of butachlor in most rice growing countries is restricted or prohibited due to health and environmental hazards, and its production and trade in Iran will be banned in the next future. Due to the dangers posed by widespread usage of herbicides integrated weed management with more weed competitive varieties to reduce herbicide dependence is taken into consideration. This study aimed to study the efficacy of some new herbicides for introducing as a substitute for butachlor and also to investigate the effect of rice cultivar on herbicide performance.

The experiment was conducted as a factorial experiment based on randomized complete block design with three replications at Rice Research Institute of Iran-Rasht in 2018. Factors included rice genotypes (Hashemi, Khazar and Line 203 “Line”) and herbicide type (recommended dosage of butachlor, clomazone, pendimethalin and flucetosulfuron herbicides). Moreover, hand weeded and weedy plot were included to the experiment as controls.

The barnyardgrass biomass and rice yield were affected by rice genotype, herbicide type and their interaction. The barnyardgrass biomass in weedy control in Khazar, Hashemi and Line cultivars was 227.7, 246 and 334 g m-2, respectively, which in Khazar and Hashemi cultivars was 57% and 16% higher, compared with line respectively, indicating different ability of cultivars to inhibit the barnyardgrass growth. The reduction in grain yield of rice in weedy control in Khazar, Hashemi and Line cultivars was 63, 74 and 87%, respectively, compared to hand weeded control. More reduction in line grain yield despite more inhibitory effect on barnyardgrass is due to late maturing of this line and longer period of interference with barnyardgrass. The dry weight of barnyardgrass in plots treated with pendimethalin was similar to or less than the treatments treated with butachlor, flucetosulfuron and clomazone. Also rice yield in all genotypes in plots treated with pendimethalin herbicide was not statistically different from that in the plots treated with butachlor and hand weeded control treatment. The good efficacy of pendimethalin in controlling barnyardgrass and producing grain yield similar to butachlor and hand weeded control indicates the potential of this herbicide to be introduced as a replacement for butachlor. Also, the yield of line in plots treated with clomazone and flucetosulfuron was statistically similar to the yield of hand weeded control plot, while the yield of Hashemi and Khazar cultivars in plots treated with the two new above mentioned herbicides were significantly lower than hand weeded control. These results indicate the competitive advantage of line over Hashemi and Khazar cultivars in barnyardgrass control.

In the last decade, more than 95 percent of paddy fields in the north of the country have been treated with butachlor herbicides for chemical control of barnyardgrass. In recent years, concerns have been raised about the adverse effects of butachlor on the health of the community and the environment, and the herbicide will be removed from the countries authorized pesticides list in the near future. Due to the good performance of pendimethalin in barnyardgrass control and the high grain yield in treated plots with this herbicide, it could be introduced as a butachlor substitute for barnyardgrass control in Iranian rice fields, although the cultivation of new competitor cultivars will also contribute to be successful.

Determining the exact sowing date is an appropriate tool in controlling the length of the phenological stages for optimizing the climate conditions and minimizing the effects of terminal heat and drought stresses. The agro-climatic indices are used to study of plant phenology and its relationship with grain yield. Agro-climatic indices are changed under climate change conditions. The response of crops to climatic conditions can be assessed at the plant phenological stages by monitoring these indices. The aim of this study was to investigate the grain yield of new wheat cultivars related to northern warm and humid agro-climatic zone (Iran) under different sowing dates based on agro-climatic indices in Gonbad area.

This experiment was conducted in Gonbad agricultural research station, Gonbad, Iran, during two cropping seasons (2017-2019) as split plot based on randomized complete block design (RCBD) with four replications. Five sowing dates of 1 November, 16 November, 1 December, 16 December and 31 December were placed in main plots and four spring wheat cultivars including Ehsan, Tirgan, Meraj and Kalateh were placed as subplots. In each phenological stage, agro-climatic indices were calculated which includes total day length (DL), photoperiod (PPD), growth day degree (GDD), photo-thermal unit (PTU), helio-thermal unit (HTU), hydro-thermal unit (HYTU), heat use efficiency (HUE), helio-thermal use efficiency (HTUE), photo-thermal use efficiency (PTUE) and hydro-thermal use efficiency (HYTUE).

The results showed that no significant differences were observed in grain yield of second (25 November) and third (10 December) sowing dates (5708.3 and 5626.4 kg ha-1, respectively) and their grain yield was significantly greater than other sowing dates. The grian filling period, number of spike per square meter and number of grain per spike were not significantly different in three primary sowing dates. The third sowing date had the highest values in terms of agro-climatic indices including growing degree days (GDD), day length (DL), photo-thermal units (PTU), hydro-thermal units (HYTU), during grain filling period. While, the second sowing date had maximum heat use efficiency (HUE), helio-thermal use efficiency (HTUE), photo-thermal use efficiency (PTUE) and hydro-thermal use efficiency (HYTUE). Grain yield (5269.8 kg ha-1) and number of spike per square meter (330.17) of Kalateh cultivar were significantly greater than other cultivars (Tirgan, Meraj and Ehsan).

The second and third sowing dates provided suitable conditions for plant height and resistance to lodging in different cultivars. Also, the two mentioned sowing dates were provided optimum conditions for different cultivars in terms of climatic parameters including temperature, day length, relative humidity and energy use efficiency, during grain filling period. The grain yield decreased due to severe plant lodging in the first sowing date and exposure to terminal heat and drought stresses and reduced the grain filling period duration in the fourth and fifth sowing dates. The growth period of Kalateh cultivar was shorter than other cultivars (no difference during grain filling period), which caused the plant to escape terminal heat and drought stresses, increasing energy use efficiency and consequently increasing grain yield compared to other cultivars. Therefore, Kalateh cultivar is very suitable and advisable for cultivation in low rainfall areas in northern Golestan province in the second and third sowing dates.

The importance of medicinal plants in the development of various societies is increasing day by day. Garden thyme is one of the most important medicinal plants that has antiseptic, antispasmodic, anti-flatulence, diaphoretic, expectorant and sedative properties. According to the evidence available to improve the quality of plant products using alcohol spraying solution, realizing the effect of this type of nutrition on the quantitative and qualitative yield of medicinal plants and determining the optimal conditions for their production requires study and research. Studies have shown that the use of alcoholic treatments of methanol and ethanol as a foliar application increases yield, accelerates growth, increases secondary metabolites, reduces the effect of drought stress and reduces water requirements in some crops and medicinal plants. Due to the fact that the amount of absorption of these alcohols by the plant is directly related to their concentration, thus, achieving the desired concentration and how to use it, can have a significant impact on the growth of the plant. Therefore, the present study was performed to investigate different levels of methanol and ethanol alcoholic treatments on some morphological, physiological and phytochemical traits of thyme medicinal plant.

This research was carried out as a factorial in the form of a complete randomized block design with 4 replications at Kelardasht. After placing the plant in the soil, four stages of foliar application were carried out with experimental treatments at one week intervals. Experimental treatments included ethanol with concentrations of 0, 10, 20, and 30% v/v, and methanol with concentrations of 0, 10, 20, and 30% by volume. Spraying of distilled water was also considered as a control treatment. Evaluated traits included morphological and physiological traits (plant height, number of internodes, internode length, stem diameter, root diameter, root height, leaf length and width and dry plant weight), and phytochemicals traits (chlorophyll a, chlorophyll b, carotenoids, anthocyanins, antioxidant activity, total phenol, total flavonoids, total sugars and non-reduced sugars). Data analysis of variance was performed using SAS software (ver 9.1).

Based on the obtained results, the use of methanol and ethanol alcoholic treatments as a foliar spray solution increased all the measured traits compared to the control (distilled water). Examination of morphological and physiological traits revealed that the highest root diameter and leaf length were related to 20% methanol and 20% ethanol treatments. The internode possessed the highest length in the treatment of 20% methanol without ethanol application. Application of 30% methanol without using ethanol also resulted in maximum root height. Also, the highest dry weight of the plant (9.02 g) was observed in the treatment of 30% methanol with 20% ethanol; which was 1.8 times the control treatment. Evaluation of phytochemical traits showed that in all traits, increasing methanol and ethanol levels resulted in the best findings. So that; the highest levels of chlorophyll a, chlorophyll b, carotenoids, total sugar, and non-reduced sugars were obtained in the 20% methanol treatment with 30% ethanol. Also, the application of 30% methanol and 10% ethanol increased the amount of anthocyanins and antioxidant activity of the plant; which it was at a statistical level with methanol treatment at 20% and ethanol at 30%. An increase in methanol levels from 20% to 30% caused an increase in total phenol content in all ethanol application levels.

In order to produce garden thyme, the application of alcohol foliar spray such as methanol and ethanol can be helpful. Therefore, in addition to increasing the production of dry matter per unit area, it is possible to produce the desired amount of secondary metabolites with high quality and lower cost.