مجله تولید گیاهان زراعی
سال دهم شماره 4 (زمستان 1396)

IntroductionSimulation crop models are a robust tool to improve crop management and to study yield limiting and reducing factors. Crop parameters related to phenology, leaf area and dry matter production and partitioning are needed to simulate crop growth and yield. Therefore, the aim of present study is to quantify the dry matter production and to estimate dry matter partitioning coefficients to different crop parts (stem, leaf and grain).
Materials and MethodsA factorial experiment was conducted based on completely randomized block design with four replicates and three sowing dates (4 April, 25 April and 16 May) and four cultivars (411, Sina, Local Isfahan and Sofeh) in Research Farm of Rafsanjan Vali-e-Asr University in 2011. Sampling was done at an interval of 5-10 days from two weeks after planting and continued up to end of the growing season. On each sampling, the leaf, stem and grain dry matter weight were measured. The truncated expolinear model was fitted on total dry matter weight (w) data over the time (t). Coefficient of dry matter partitioning to different crop parts (leaf, stem and grain) was obtained by fitting the linear regression model on dry matter weight of each part versus total dry matter weight.
ResultsResults showed that the model well described the trend of dry matter production versus days after planting. According to the model, the maximum dry matter accumulation in all three planting dates was obtained 972-1179, 576-611 and 191-277 gm-2, respectively. Coefficient of dry matter partitioning to leaves ranged from 0.45 to 0.51 in the first planting date, 0.51 to 0.60 in the second planting date and 0.44 to 0.61 in the third planting date. There was no different between the coefficients of cultivars. Coefficient of dry matter partitioning to stem in all three planting dates were 0.35-0.49, 0.24-0.44 and 0.14-0.23, respectively. There was no significant difference among the cultivars. Partitioning coefficient to grain was between 0.16 and 0.44 for the first planting date that was lower than the second planting date. In the third planting date, the coefficient was between 0.35 and 0.76 that there was a significant difference among the cultivars.
ConclusionIt was concluded that the trend of the dry matter production and partitioning is affected by environmental condition (temperature and solar radiation) and cultivar. The results showed that with delay in planting date crop growth rate and dry matter production were decreased. In such condition, coefficient of dry matter partitioning to stem was decreased and coefficient of dry matter partitioning to leaves and grain was increased.

. In order to study the interaction of sulfur (S), zinc (ZnSO4) and Thiobacillus bacterium on yield and yield components of cotton and some soil parameters, a field experiment in a factorial randomized complete block design with 12 treatments and three replications was conducted in the mahvelat city with center of Faiz abad of Razavi Khorasan province. Experimental factors included three levels of sulfur Zero, 500 and 1000 kg ha-1, Thiobacillus bacterium in two levels control and Thiobacillus bacterium application and zinc sulfate in two levels Zero and 50 kg ha-1 in the form of zinc sulphate application applied to the experimental plots. After harvesting the cotton crop soil and plant sample were separately collected from each plots for analysis of elements in soil and plant samples. Results of analysis of variances showed that, the interaction of sulfur, zinc and Thiobacillus on some agronomic and soil traits including cotton yield (5208 kg ha-1), seed cotton yield (3622 kg ha-1), boll weight (5208 kg ha-1), fertile branches number (12.52), vegetative branches number (10.98) were significant as compare to control. Number of bolls in plant with application of sulphur, zinc and thiobacillus and their interactions were significant. Soil reaction (pH), electrical conductivity and available sulfate were significant at 1% level and plant height and First boll height were significant at the 5% level. According to the comparison results, application of 1000 kg ha-1 sulfur without of Thiobacillus and zinc also treatment with the application of 1000 kg ha-1 sulfur with Thiobacillus was caused Significant increase in cotton yield and seed cotton yield compared to the control. Application of 500 kg ha-1 sulfur and also the application of 500 kg ha-1 sulfur with zinc was caused a significant increase in boll weight, but 500 kg ha-1 of sulfur with zinc caused significant reduction in plant height .The Soil traits studied, the application of 1000 kg ha-1 sulfur alone caused a significant decrease in soil reaction (7.35) , but significant increase created in electrical conductivity of the soil (16.5), the amount of adsorbed sulfate and the amount of adsorbed zinc were significant at 1 percent level of significant but amount of absorb zinc were significant at 5 percent level. However, application of 500 kg ha-1 sulfur with Thiobacillus more than alone of sulfur created significant increase in the available sulfate and adsorbed sulfate of soil. Results of data shows that all main effect on cotton seed oil were not significant.

Information on the concentration and accumulation of phosphorus (P) in the plant dry matter (DM) and the coefficients of its allocation to different plant parts can help improve the P nutrition of crops and increase the efficiency of P fertilizers. In order to investigate the effect of inoculation with Streptomyces sp. bacteria and fertilizer P rate (0, 20, 40, 60 and 80 kg P ha) on the P and DM accumulation and partitioning in wheat (cultivar Morvarid) and barley (cultivar Sahara), a factorial experiment in a completely randomized design with four replications was carried out in Gorgan University of Agricultural Sciences during 2014-2015 growing season. The amount of soil available P was 5.8 mg kg-1. Results showed that the effects of fertilizer P rate on DM accumulation, the P concentration and accumulation in all plant parts was significant (P = 0.01), statistically. Inoculation also influenced the DM accumulation in all parts except seeds, and P accumulation in all of them except the stem, but its effect on the P concentration in different parts of plant with the exception of leaf and root was not significant. As a result, it can be deduced that the rate of fertilizer phosphorus through both DM accumulation and P concentration, and inoculation only via DM accumulation affects the P accumulation. Also, the findings of this study showed a very high stability of allocation coefficients of DM and P to different parts of plant compared to DM and P accumulation and P concentration. P concentrations in the whole plant and grain in control (without P fertilizer) were 2.29 and 3.86 g P kg-1, and in the treatment of 80 kg P ha-1 were 3.89 and 6.00 g P kg-1. Also, the amount of accumulated P in a grain was 2.18 and 2.68 mg and in whole plant (shoot root) was 4.88 and 5.15 mg in wheat and barley, respectively. By increasing the rate of P fertilizer, accumulated phosphorus in all parts of the plant was increased linearly with different slopes, and reached to 6.98 and 9.08 at grain and 14.48 and 14.75 mg at whole plant of wheat and barley, respectively, when 80 kg P ha-1 was applied. The results showed a 197 and 186 percent increase in P uptake in wheat and barley, respectively, in the treatment of 80 kg P ha-1 compared to control. In both crops, at all levels of P fertilizer, the plant organs based on the amount of P accumulates were as seed > stem > leaf> root.

Drought is one of the most important factors limiting plant growth around the world. So it can be used minimum water with using natural fertilizer such as vermicompost and can be caused to reduce water evaporation from soil, protect and storage water in the soil. The interest in plant products has increased considerably all over the world because many herbal medicines are free from side effects since most medicinal plants are consumed raw, proper management of crop production is needed to achieve high quality plants. So in this regard, experiment was done to study the effect of different levels of vermicompost on morphophysiological and essential oil characteristics of Peppermint (Mentha piperita L.) under water deficit regimes.
A pot experiment was conducted as factorial based on completely randomized design with three replications at Gorgan University of Agricultural Sciences and Natural Resources greenhouse during 2016. Treatments were included Irrigation regimes in three levels (100 percent FC, control, 75percent FC and 50percent FC) and vermicompost in three levels (0, 20 and 40percent volumetric). Studied traits were included plant height, internodes distance, fresh and dry weight, number of tillers, leaf water ratio, proline, soluble sugar and essential oil percent. After planting, harvesting and growth characteristics, essential oil, soluble sugar and proline were evaluated with Clevenger, the method of Omokolo and the method of Bates, respectively.
The results showed that internodes distance, fresh and dry weight of shoot, number of tiller and leaf water ratio, were decreased by increasing drought stress. Also, with increasing drought stress, leaf water ratio decreased (2.13 percent) and prolin, soluble sugar and essential oil percent were increased 0.72, 10, 14 and 0.13 percent, respectively. Vermicompost had significant effects on all of morphological and physiological characteristic and this effect was the highest in 40 percent volumetric. Interaction effects of Irrigation regime and vermicompost had significant effects on all of morphological and physiological characteristic except of fresh weight of shoot and number of tillers. Essential oil (0.33 percent) and leaf water ratio (23.71 percent) increased in 40 percent volumetric in 50 percent FC.
Due to the results, it be expressed to reduce chemical fertilities use and achieve to sustainable agriculture, can be adjusted with vermicompost application a lot of part from drought stress effects on Peppermint. Generally, the results showed that by vermicompost application (40 percent volumetric) reduced drought damage on growth characteristics and the most essential oil.

Backgrounds and Potato is the fourth important crop worldwide. Since potato is mainly propagated vegetatively via tubers, increasing production of high quality and virus free seed potato is of great importance. Phyto-hormones regulate a wide range of processes and tuberization in potato. Due to small size and weakness of minitubers and some difficulties in plantlets establishment in the field, more studies are needed to improve plant establishment and productivity of minitubers under such conditions. Therefore, this study was carried out in order to evaluate the possibility of improving sprouting and plantlet establishment of potato minituber cultivars (Agria and Fontane) using plant growth regulators (6-benzylaminopurine- BAP, and abscisic acid- ABA).
A two-step experiment was carried out at the Ferdowsi University of Mashhad, during 2014-15. In the first experiment, foliar treatment of mother plants at stolonization or tuberization stages using plant growth regulators (BAP, ABA, and BAP, 50 µM) under controlled conditions was performed. In the second experiment, progeny minitubers were compared in terms of sprouting, plantlets establishment, and yield under field conditions. Factorial arrangement based on completely randomized design and complete block design were used for the first and second experiments, respectively. Number of sprouts per minituber, length of sprouts, day to emergence, emergence percentage, number of stems per plant, morphological traits, yield, and yield component were evaluated.
Day to emergence tended to decrease with an increase in sprout length. In both cultivars, BAP application at tuberization stage increased sprout length compared with the untreated control plants. The number of established plantlets and percentage of emergence were enhanced by treating plants using BAP or ABA compared with control plants, but the effects were different on the cultivars. The greatest emergence percentage observed in ABA-treated plants at stolonization stage, which was 39% more than the control. In addition, Fontane showed greater emergence percentage (15 %) than Agria. BAP application at tuberization stage advanced the number of sprouts in Agria, whereas, the most number of sprouts in Fontane recorded when BAP applied at tuberization stage. Good linear relationship was observed between sprout length and day to emergence (R2=0.88) and between the number of sprouts on minitubers and the number of tubers in the next generation (R2=0.53). Regardless to the cultivar, application of BAP at tuberization stage increased the number of tubers per plant.
The results indicating that application of BAP resulted in increasing the number of sprouts and shortened the days to emergence, whereas, ABA improved emergence parentage and plantlet establishment of the both cultivars. It seems that both BAP and ABA could be effectively used for improving sink strength for better supporting the sprouts growth under field conditions. In addition, it seems tha application of PGRs increase the number of sprouts per tuber which resulte in producing greater number of stems, hence, enhance the number of tubers per plant, however, the effects are different between cultivars.

Climate change can directly affect on worldwide food security because climate change processes (such as increasing of CO2 concentration and temperature and variability of precipitation) have directly affect on crops. Corn such as C4 plants that are sensitive to climate changes. Therefore to reduce the sensitivity of the maize in the face of climate change, we need to apply adaptation strategies. One of the effective strategies is the changes in sowing dates. Many of studies have shown that changes in sowing dates (particularly the use of early planting dates) can reduce the negative effects of climate change.
This research was conducted in three locations of Kermanshah Province. Accordingly, the future climate in the study areas was generated using long-term (1980-2009) climate data of the baseline (included minimum and maximum temperatures, rainfall and global radiation) and AgMIP technique under two climate scenarios (RCP4.5 and RCP8.5) for the future period of 2040 -2069. Long-term simulation experiments consisted of five sowing dates (5st April, 20st April, 5st May, 20st May, 5st June), three locations (Kermanshah, Kangavar and Eslamabad), two future climate scenarios (RCP4.5 and RCP8.5) in 30 years. In total, around 1350 simulation experiments were carried out. In this study, APSIM crop model was used for simulation of maize growth and yield. In this study, all of the simulations were conducted in potential conditions and water- and nitrogen-limited production situations were not considered in the current study. APSIM model has previously been calibrated and evaluated for SC704 cultivar (this cultivar is the most common cultivated cultivar in the Kermanshah Province). In current research, all the output data was analyzed, graphed and mapped using the R software package (R Core Team, 2016) and OriginPro9.1 (Seifert, 2014).
Average grain yield of Kermanshah Province was 11354 kg ha-1 in the baseline. Results showed that in 2050, on average grain yield was reduced 60.82 and 80.73 % (under RCP4.5 and RCP8.5, respectively) compared to baseline. In different locations, the highest and lowest grain yield in the baseline were recorded in the Kangavar with 13426 kg ha-1 and Kermanshah with 7952.4 kg ha-1. When averaged across locations, the highest grain yield in the climate change conditions was obtained in an early sowing date (5st April) with 7071.2 and 4743 kg ha-1 (under RCP4.5 and RCP8.5, respectively). In future on average (two scenarios) duration of growth period, vegetative and reproductive growth periods (4.7, 4 and 1.7 %, respectively) were decreased compared to the baseline. Also, in future, the number of grains and grain weight were reduced in Kermanshah Province so that under RCP4.5 were 56.5 and 31.8 %, respectively and under RCP8.5 were 78.5 and 59.3 %, respectively. However, these reductions in duration of growth period, vegetative and reproductive growth periods, the number of grains and grain weight were less in 5st April early sowing date than other sowing dates (especially late sowing dates).
Generally, results of the current study indicated that climate change had negative effects on maize yield and maize physiological and phonological characteristics in Kermanshah Province. However, early sowing dates might reduce these negative effects. So that in most cases, 5st April can reduce negative effects on maize yield and maize physiological and phonological characteristics in the future period.

Iran’s climate is mostly arid and semi-arid, where water availability is a major problem in crop production. In regions where water scarcity is the principal limiting factor for cultivation, farmers are interested in growing crops that are able to adapt to drought conditions. Bio-fertilizer has been identified as an alternative to chemical fertilizer in sustainable farming. Organisms that are commonly used as biofertilizers component are nitrogen fixers (N-fixer), potassium solubilizer (K-solubilizer) and phosphorus solubilizer (P- solubilizer), or with the combination of molds or fungi increased growth and yield plants. Therefore, the aim of this study was to investigate the use biofertilizer in drought stress on several agro-morphological and yield characteristics of faba bean under field condition.
In order to study the effects of different irrigation levels and biofertilizers on yield and yield components of faba bean, a field experiment was conducted as split plot based on randomized complete block design with three replications at the a farm located in West Azerbaijan province - city Nagadeh, Iran during growing season of 2013-2014. The main plots were allocated to irrigation levels (Irrigation after 50 mm (control), 100 mm (moderate water stresses) and 150 mm (severe water stresses) evaporation from class A pan) and sub-plots were allotted to biofertilizers (Azotobacter and Barvar Phosphate-2, Azotobacter Barvar Phosphate-2 and control).
Results showed that irrigation had significant effects on Plant height, number of pod per plant, number of seed per pod, 1000- seed weight, biological yield and seed yield but the interactions between irrigation levels and biofertilizers on any of the traits under study were not significant. In comparison severe stress (lowest yield and yield components), a non-stress conditions, on Plant height, number of pod per plant, number of seed per pod, 1000- seed weight, biological yield and seed yield were decreased up to 21.90, 39.83, 28.83, 26.15, 33 and 38 %, respectively. Among treatments, combined usage of biofertilizers showed the greater increasing in studied traits than individual consumption.
The results generally indicated that the inoculation with biofertilizers could not reduce the adverse effects of drought stress and could not effect on increasing of yield significantly. Therefore, to achieve optimal performance in arid and semi-arid areas, irrigation at all stages of faba bean of development recommended.

Among oilseeds that have a good compatibility with the climatic conditions of the Iran, safflower has a special place due to the drought and salinity resistance and also because of having the different spring and autumn varieties. Environmental stresses are the main factors reducing growth and crop yield. Among the environmental stresses, water stress is the main risks for the successful production of crops in Iran and the world. One of the most important applications of nanotechnology in various agricultural fields, especially regarding to the water and soil, is the application of nano-fertilizers to nourish plants. Iron is one the micro elements in plant nutrition. In the condition of iron deficiency, the amount of photosynthetic pigments such as chlorophyll content decreases.
To evaluate the effect of foliar spraying of nano-iron oxide on yield and some important agronomic traits of safflower genotypes at the low water stress conditions, an experiment was carried out in split factorial based on randomized complete block design with three replications in 2016 at the research farm of Imam Khomeini International University. The main factors include irrigation on two levels (full irrigation and water stress in the flowering stage) and nano-iron oxide spraying on two levels (application and non-application of nano-iron oxide) and sub-factor included 10 genotypes of safflower (Golmehr, Padideh, Goldasht, Sofeh, Mexican88, Sina, Mexican11, Isfahan mahali, Faraman and Kuseh).
The effect of irrigation on plant height, seed number in boll, boll number in plant and seed yield were significant. The interactions among all factors were also significant on plant height, main stem diameter, subsidiary branches number, seed number in boll, boll number in plant and seed yield. Mexican88 genotype had the maximum seed yield (499.5 gr. m2) in the conditions of non-stress and foliar application of nano-iron oxide. The highest boll number in plant (22) was observed in the genotype Sina in non-stress conditions and foliar application of nano-iron oxide. In conditions of non-stress and applying nano-iron oxide, genotype Sina had the highest plant height (74.33 cm) and was not significantly different from Kuseh, Sofeh, Golmehr and Isfahan mahali genotypes (73.6, 71.43, 69.2 and 68.5 cm, respectively). The effect of fertilizer was significant only on the subsidiary branches number. Mexican 88 genotype had the greatest subsidiary branches number at the conditions of stress and applying nano-iron oxide.
The study showed that, regarding to the most traits, Mexican 88 and Kuseh genotypes were suitable for planting in both conditions of stress and non-stress.

The free radicals amounts are increased due to drought stress and subsequently they harm plant. The drought stress-resulted free radicals are scavenged by changing in activity of antioxidants like catalase, superoxide distmutase (SOD) and guaiacol peroxidase (GP) (regressors or independent variables; Xs). This reaction is known as resistance to (protection against) oxidative stress. This protection is reflected in traits like growth and grain production (biomass and harvest index, respectively; dependent or response variables; Ys). By maximizing Ys in relation to Xs, the combination of Xs with possible highest Ys can be obtained. This optimization comes from the relations of Ys with Xs under drought stress conditions. Due to having more than one Ys here, the relation tends to be multivariate and highly complex, especially when there is no strong positive relation (correlation greater than .95) between Ys variables. In such situations, the genetic algorithm can overcome the complexity. The output of mentioned algorithm can be used by plant breeders. In another words, breeders can increase drought tolerance by genetic manipulation of plant for optimum activity of Xs. This experiment was aimed to do the mentioned optimization for Mung Bean.
The experiment was carried out in pots located in an open filed to increase the accuracy and possibility of generalizing the results to field results. Pots had 5 kg capacity in which 5 seeds of line VC1973a were planted. For thinning, 3 seedlings were removed, and left 2 ones. The filed capacity was determined using weight method. Treatment levels were 4 levels of low irrigation including irrigation at 80% (control), 65% 50%, and 35% of field capacity. At maturity stage, the harvest index and biomass (biological yield) (Ys) were measured. The concentration of antioxidant enzymes catalase, SOD, and GP (Xs) were determined at flowering stage. For maximizing the function, first partial desirability function was determined. Then general desirability function was calculated. The value of Xs for which the highest amount of Ys is attainable was obtained on the basis of genetic algorithm and using MATLAB software.
The results indicated that a function with 7 components including the main and interactive effects of Xs could predict the relation of Ys with Xs well (Adjusted R2>0.97). The standardized regression coefficient was positive for catatlase which reveals that the drought resistance (harvest index and biomass) enhances with increasing the activity of this enzyme. Like catalase, the effect of GP was additive on drought tolerance, but considering its standardized regression coefficient, this enzyme had a lower effect than catalase. Due to negative standardized regression coefficient for SOD, it could be concluded that the drought tolerance doesn’t enhance with increasing activity of SOD.
The optimized concentration of catalase, SOD, and GP was 0.956 μmol H2O2 g−1 FW, 24.23 AU g−1 FW, and 21.23 AU g−1 FW, respectively for possible maximum drought tolerance. It should be mentioned that these optimized concentrations were all among observed concentrations. Moreover, reports indicate that there is genetic diversity in activity of antioxidant enzymes (prerequisite to carry out breeding programs for attaining the optimized activity) for Mung Bean.

Background and Nowadays malnutrition due to low food diversity is a serious problem in developing countries like Iran. Due to important role of wheat in nutrition of these countries, researchers try to produce wheat grains with higher proteins, amino acids, iron and zinc content, providing essential body nutrients and as a result reduce malnutrition. Considering the role of folic acid in transfer of single carbon fragments and its effect on improvement of metabolic processes, in this research effect of external application of folic acid on the quality and yield of wheat grains were investigated.
Material and Kohdasht wheat cultivar was planted in a farm experiment conducted at research farm of Maragheh University in early spring of 2013 using randomized complete block design with three treatments with density of 500 seeds per m2. The three treatments were as follows: control (without application of folic acid), priming of seeds with 25 µM Solution of folic acid accompanying leaf spraying in steming stage. The third one was the same as second one except leaf spraying in heading stage. Folic acid spraying is carried out in the final hours of day by a pump sprayer. 100 mL of solution was sprayed per each square meter.
Finding: Results revealed that folic acid external application had following advantages compared to control: firstly, increase the yield of grain, Secondly, protein, essential amino acids, iIron content of grain is increased meaningfully and finally cause to increase the chlorophyll content in flag leaf.
In this research the effects of external application of folic acid have been studied on whole grain, but part of accumulated iron along with proteins during flour preparation process have been omitted. However considering positive impact of external application of folic acid on quality of grains and on proteins, amino acids, iron content of them, we can claim that this method was a short-term solution for both improving quality and quantity of food and reducing adverse effect of malnutrition.

Nowadays, due to population growth and changes in eating habits, there is a need to increase agricultural productions to meet consumer demand all around the world. Increasing the area under cultivation is one of the solutions for this problem, which cannot be appropriate in future because this needs to use of marginal lands with low yield and stability. Hence, increased yield is an effective strategy in this regard which can resolve the problem by decreasing yield gap. Considering the fact that there is an urgent need to increase rice production in the country as well as improving the productivity of soil resources, planning for the proper use of chemical fertilizers to achieve the maximum performance seems to be required. Accordingly, the aim of this study was to evaluate rice potential yield and yield gap in Foumanat plain using boundary line analysis, moreover, to find the relationship between soil properties and rice yield.
In order to investigate the yield gap (YG) of rice (cv. ‘Tarom Hashemi’) related to soil properties, a field experiment was carried out in Foumanat plain during two cropping seasons: 2012-13 and 2013-14. We recorded the information of 53 fields as soil samples were taken and geographic coordinates were recorded. Some soil characteristics such as total nitrogen, potassium, phosphorus, organic matter and cation-exchange capacity were measured. At the end of growing season (harvesting time) grain yield was calculated in each field (1 m-2). The boundary line method was used to calculate yield gap, optimum yield and optimum amount of soil properties for each field. Data analysis done by nonlinear regression of quadratic function, dent-like and segmented models based on PROC NLIN procedures.
Segmented functions were well able to describe the trend of pH and electrical conductivity of soil. In addition, dent-like function used to describe the process of changes in available phosphorus, available potassium, organic matter and cation exchange capacity. Also, a quadratic function was used to describe the trend of total nitrogen . The average of optimum yield and actual yield were 7. 67 and 4.81 ton ha-1, respectively, in Foumanat plain with an YG of 2.86 ton ha-1 (37.3 percent). The optimum concentration of total nitrogen, phosphorus, potassium, organic matter, cation exchange capacity, pH and electrical conductivity were 0.266 percent, 13.49-30.35 mg kg-1, 102.2-173.4 mg kg-1, 2.7-3.2 percent, 25.43-30.8 meq 100 g-1, 6.36 and 1.92 dS.m-1 respectively.
Based on the results of this study, some of the main factors for rice YG in this area could be inappropriate management of chemical fertilizer usage (nitrogen, phosphorus and potassium) as well as ignored role of organic matter and cation exchange capacity in providing essential nutrients for rice. Boundary line analysis method could clearly calculate the soil properties potential in response to yield. In general, the results of this study can help to conclude a good strategy for achieving optimal production and gap reduction due to fertility situation of the area.

Potato is the fourth most important food crop in the world that plays an important role in people feeding. This crop is a source of carbohydrates, protein and essential amino acids for human being and it is one of the important tuber plants. Low yield of crops in many countries often related to the deficiency of soil nutrients. Chemical fertilizers have an important role in improving yield and quality of potatoes. However, excessive use of chemical fertilizers is associated with many health and environmental problems and pollution in water and soil. This study was conducted to evaluate the effect of organic fertilizers and growth promoters on potato (cultivar Milva) yield to reduce the consumption of chemical fertilizers.
Experiment was conducted at the Agricultural Research Station of Gonbad Kavous University in a randomized complete block design with three replications in 2016. Treatments included the use of nitrogen, phosphorus and potassium to amount of common use of region (100 NPK), 100 NPK Humic acid (HMC), 100 NPK Equilibrate vegetative organic (EVEO), the use of nitrogen, phosphorus and potassium at a rate of half of the region convention (50 NPK) HMC, 50 NPK EVEO, application of EVEO and HMC alone. Traits of tuber number plant-1, fresh and dry weight of tubers plant-1, plant fresh weight ha-1, biological yield, tuber yield, and harvest index were measured.
the results indicated that application of HMC and EVEO with chemical fertilizers significatly increased tuber number plant-1, tuber weight plant-1, biological yield, tuber yield, and harvest index; but they had no significant effect on plant weight. The highest tuber number plant-1, dry weight of tuber plant-1, biological yield, tuber yield, and harvest index were obtained in 100 NPK EVEO; although there was no significant difference with treatments of 100 NPK HMC and 50 NPK EVEO. The lowest amount of these traits were achieved in the treatment 100 NPK. However, it had no significant difference with treatments of application of EVEO and HMC alone.
Based on these results, the use of EVEO can reduce consumption of chemical fertilizers by 50%. Also, significant difference was not observed between chemical fertilzer treatment (100 NPK) and application of EVEO and HMC alone. Therefore, use of these organic materials can increase the absorption and efficiency of nutrition and consequently reducution of the consumption of chemical fertilizers will help to reduce environmental pollution.

To study the effect of potassium, zinc and boron foliar application on physiological traits and yield of two bread wheat cultivars under optimum and late planting dates, An experiment was conducted as split-split plot based on randomized complete blocks design with 20 treatments and 3 replications in Ramhormoz city in farming year 2015-16. The experimental factors were included planting date in two levels: optimum (November 21) and late (January 5) as the main factor, nutrients foliar application in five levels: (water as a control, potassium, zinc, boron and combination potassium zinc boron (each 3 lit.h-1)) as the sub factor and two cultivars of bread wheat Pishtaz and Chamran 2 as the sub-sub factor. Solutions for foliar application were prepared by using potassium (21%), zinc-chelate (7.5%) and boron (5%). Traits measured were included leaf chlorophyll content, flag leaf relative water content, cell membrane stability, maximum quantum efficiency of PSII (Fv/Fm) and leaf proline content. The results showed that with delay in planting all above traits except leaf proline content decreased significantly due to terminal heat stress. However, the delay in planting was increased canopy temperature. Potassium, zinc and boron foliar application separately and in combination reduced harmful effects caused by the delay in planting on the traits leaf chlorophyll content, flag leaf relative water content, cell membrane stability index, maximum quantum efficiency of PSII (Fv/Fm), leaf proline content and grain yield in both wheat cultivars. As well as, foliar application these nutrients reduced canopy temperature of wheat cultivars under both optimum and late planting dates. Despite the lack of significant differences in Pishtaz and Chamran 2 wheat cultivars in canopy temperature, cell membrane stability index, maximum quantum efficiency of PSII (Fv/Fm), leaf proline content and grain yield, these cultivars showed a more appropriate response to the zinc separate application and potassium zinc boron combined application in both optimum and late planting dates, respectively. Chamran 2 cultivar under water foliar application conditions (control) indicated more yield than the Pishtaz cultivar in both planting dates. Measured physiological traits Pishtaz and Chamran 2 wheat cultivars showed improvement as a result of potassium, zinc and boron application in both planting dates. In general can be used from potassium, zinc and boron foliar application and their combined application as appropriate management strategy to reduce canopy temperature, improve physiological traits and reduce the negative effects of delay in planting date on bread wheat in Ramhormoz city.