جستجوی مقالات مرتبط با کلیدواژه "thousand grain weight" در نشریات گروه "زراعت"

The highest concentration of protein is found in plant-based sources, whereas animal protein production tends to be more challenging and costly compared to plant-derived proteins. Within plant sources, legumes emerge as a primary reservoir of protein. A notable proportion of protein compounds within legumes boast relatively high nutritional value. The amount of protein in most plants of the legume family, including beans, is reported between 18 and 32%. guar or cluster bean (Cyampsis tetragonoloba (L.) Taub.) is an annual plant from the legume family, which is cultivated in dry plains as an alternative crop due to its high tolerance to drought and salt conditions. This plant, like most legumes, is important in the balance of soil mineral elements in agricultural systems due to its ability to symbiosis with nitrogen-fixing bacteria. Planting date and optimal plant density are two effective factors to achieve the potential performance of plants. Considering the importance of guar as an edible, industrial, fodder and medicinal product, it seems necessary to conduct research on the growth response of this plant to management factors, especially the date and density of plant planting. The present study was conducted with the aim of investigating the effect of planting date and row spacing on guar plant as an alternative plant for the climatic conditions of southern Kerman and other similar climates, in order to achieve the highest yield and grain quality.
 

The experiment was carried out as split plots based on the completely randomized blocks design with three replications in the research farm of South Kerman Agricultural and Natural Resources Research and Education Center (Jiroft) in two years 2018-2019. Jiroft region has a latitude of 57 degrees and 32 minutes north and a longitude of 28 minutes and 32 degrees east and is located at an altitude of 628 meters above sea level. The experimental treatments include planting date as the main factor in six levels (10 and 25 May, 9 and 24 June, 9 and 24 July) and seed planting intervals as secondary factors in four levels (20, 30, 40 and 50 cm).
 

The results showed that the maximum dry weight of leaves and stems, the number of leaves in the secondary stem, the height of the plant and the length of the pod were observed on the date of 24 June and the row spacing was 50 cm, and in all planting dates, increasing the row spacing led to an increase in the mentioned traits. The comparative analysis of average planting dates reveals that the highest metrics were achieved on June 9th. This includes a 43% increase in the number of pods per plant, a 23% increase in the number of grains per pod, a 66% increase in biological yield, a 45% increase in grain yield, and an 18% increase in harvest index. The highest leaf surface index (15%) and number of leaves in the main stem (91%) was observed on the 24 June. In general, with the delay in planting after early June (9 June) to late June (24 June), the yield and yield components of guar gradually decreased and reached the lowest value. The results comparing the mean effect of row spacing showed the highest number of pod per plant and seeds per pod at 50 cm row spacing, but the highest grain yield was obtained at 30 and 40 cm row spacing.
 

In general, among the planting dates, guar planting in June to early July in Jiroft region is the best planting date. While, early planting (May) and late planting (late July) were not favorable for guar and led to a decrease in plant yield. Therefore, in order to obtain the best yield and agronomic characteristics of guar plant in the south of Kerman province and similar conditions, it is recommended to cultivate this plant from early June to early July and at a row distance of 30 to 40 cm, because in the mentioned dates and row spacing, the plant makes the best use of environmental factors and with the reduction of competition between the plants, its performance and components increase Because.

Khuzestan, as one of the most important corn-producing provinces of Iran, lacks improved cultivars compatible with extremely hot and dry conditions and relies on foreign cultivars, including the old single cross 704 variety. To prepare suitable cultivars for Khuzestan, lines should be produced and evaluated in the region that can be used in the production of hybrid and open-pollinated cultivars.

To identify and improve the important and effective traits on maize grain yield, 289 corn lines, which were bred in Khuzestan, were crossed with the hybrid single cross 704 and evaluated in two cropping seasons (summer 2016 and spring 2017). The experiment was carried out with a simple lattice square design of 17 × 17 and two replications at the Safi-Abad of Dezful Agricultural Research Center in 2016 and 2017. The traits measured from the growing stage to harvest were plant height, tassel length, tassel branch number/plant, stem diameter, number of leaves / plant, ear diameter, grain depth, ear length, number of rows/ear, grain number/row, 100-grain weight, grain yield, biological yield, and harvest index based on the guidelines of the corn and fodder plant department of the Iranian seed breeding and preparation research institute. The yield based on 14% seed moisture along with other traits was measured and calculated from the two middle lines of each experimental plot. The genetic parameters in this research were calculated using the mathematical expectation of the mean square as the basic design of random complete blocks in the form of genetic relationships. To analyze the correlation between the traits and to identify the common factors affecting the studied traits, decomposition into factors was used with the principal component analysis and varimax rotation. Eventually, the analysis of variance (ANOVA) of data and calculation of correlation coefficients between variables were done using SAS Ver 9.20 software and analysis into factors with StatGraphics Ver 19.0 software.

The results of ANOVA showed an acceptable genetic diversity among promising maize lines in terms of all studied traits, except for ear length, number of rows/grain, and number of grain/row. The results of the composite analysis in two cropping seasons revealed that the effect of genotype was significant on all studied traits at the level of 1%, suggesting significant genetic diversity among the studied genotypes for all traits. The significance of the genotype × season interaction effect for all studied traits at the 1% level indicates the different responses of genotypes in summer and spring. The highest and the lowest genetic and phenotypic variances in summer and spring belonged to biological yield and seed depth traits, respectively. The ranges of genetic diversity in the studied traits in summer and spring ranged from 1.96 to 32.72 and from 7.63 to 29.88, respectively. Among the studied traits, the highest genetic and phenotypic diversities were observed in the number of tassel branches/plant trait (32.72 and 33.35, respectively). The highest heritability rates in spring were observed for biological yield (97.69%), grain yield (97.43%), grain depth (97.06%), ear length (96.30%), and plant height (95.74%). On the other hand, the highest amount of heritability along with the highest amount of genetic improvement was observed for the biological yield and grain yield traits, both of which can be considered the most important criteria for selecting parental lines in breeding programs based on this study. The results of the analysis of correlation coefficients for the studied traits in summer indicated that the grain number/row (0.81), biological yield (0.72), ear diameter (0.62), and grain depth (0.52) produced medium to high grain yields among the studied traits. In spring, the biological yield (0.86), 100-grain weight (0.65), grain number/row (0.64), ear length (0.64), and ear diameter (0.63) had medium to high effects on the seed yield.The results of analysis in the factor analysis in summer and spring revealed that five hidden and independent factors justified 71.40 and 72.27% of the total data changes, respectively. Five hidden factors for summer were the share of grain yield from the total dry matter (33.10%), plant height factor (15.80), ear diameter component factor (8.80), tassel height factor (7.50), and grain weight factor (7.20).

The two factors, namely the share of grain yield from total dry matter and the plant height factor, account for more than 61% of the total justifiable variation of 14 traits in 289 lines. These two factors enable us to define and recognize differences and similarities between the lines that grow in spring conditions in Khuzestan.

Maize (Zea mays L.) is ranked fourth among cereals in terms of area under cultivation and grain yield after wheat, barley and rice. Water scarcity or water stress is one of the most limiting factors in crop growth and crop yield, which reduces the average yield by 50% and even higher values. Water stress in corn through adverse effects on inoculation and grain filling, reduced plant photosynthesis, reduced amount of material grown and as a result of grain shrinkage, reduced leaf area and disrupting physiological processes, reduces the number of grains per ear, weight Thousands of seeds, bio-yield and grain yield. Conservation tillage is one of the inevitable methods of conservation agriculture by which the effect of water stress on plant growth and yield can be reduced. In agro-ecosystems, conservation tillage, while preserving and improving water resources and the environment, improves crop production and makes it sustainable. Since Iran is located in the arid and semi-arid region of the world and drought has a negative impact on the yield of its products, the study of water stress and strategies to deal with it is of particular importance; Therefore, the purpose of this study was to investigate the yield response and yield components of maize to tillage systems and irrigation regimes in Karaj.
 

In order to evaluate the effect of different tillage systems and irrigation regimes on corn yield, an experiment was conducted as split-plot in the form of randomized complete blocks with three replications in the research farm of the University of Tehran (longitude 35 degrees East, latitude 35 degrees and 48 Minute North) in 2016. The main factor in this experiment was tillage with two levels (no-tillage and conventional tillage) and the second factor was irrigation with three levels (without water stress, moderate water stress and severe water stress based on 75, 110 and 150 mm evaporation from Evaporation pan surface, respectively). Irrigation was done using plastic tapes (type) and the irrigation volume was controlled by the meter. Irrigation treatments were applied from the 4-leaf stage. The distance between the main, sub-factors and blocks (replicates) was 10, 2 and 10 meters, respectively, and there were six 10-meter planting lines within each experimental plot. Also, the distance between rows of corn in the plots was 75 cm and the distance between plants per row was 15.5 cm (density of 86,000 plants per hectare). To determine the water requirement, the Class A evaporation pan method was used and using daily meteorological data, Equations 1 and 2 were used:ETC = KC × ET0 = (Eq.  1) ET0 = K p × E pan  (Eq. 2) in them, ETc = Evapotranspiration of the desired crop (mm.day-1), KC= Plant coefficient, ET0= Reference evapotranspiration (mm.day-1), Kp= Plate coefficient (without unit), E pan= Evaporation of the pan (mm.day-1)

The results showed that the effect of tillage and tillage interaction at irrigation levels on any of the traits was not significant, but the effect of irrigation regimes on plant height, number of seeds per ear, 1000-seed weight, ear weight, grain yield, Biological yield, harvest index and water use efficiency were significant. The highest plant height was obtained in conditions without water stress (217 cm). Also, the highest number of seeds per ear was obtained under normal irrigation conditions, so that the application of severe stress reduced the number of seeds per ear by 26%. Severe water stress reduced the weight of 1000 seeds by 12%. Also, the weight of ear decreased by 38% compared to normal irrigation in severe stress and reached 151 g. The highest grain yield in normal irrigation was 12471 kg.ha-1, which severe stress reduced grain yield by almost 40%. A similar trend was observed in biological yield, with severe water stress reducing by 29%. In terms of water use efficiency, severe water stress increased it to 2.21 kg.m-3, which showed a growth of 31% compared to normal irrigation.

The results of this study showed that the tillage system had no significant effect on any of the traits, but water stress had a negative effect on all traits except water use efficiency, so that plant height, 1000-seed weight, Number of seeds per ear, ear weight, grain yield, biological yield and harvest index decreased sharply but water use efficiency increased compared to treatment without water stress. Based on the results of this study, corn irrigation based on 75 mm of evaporation from the evaporation pan surface in similar climatic conditions is recommended.

In order to investigate the effect of nitrogen fertilizer levels and planting density on the yield and yield components wheat cultivar of Qabus, a study was conducted in the two cropping years of 2018-19 and 2019-2020 in the farm of Gonbad. The experiment was a split plot in a randomized complete block design with three replications. Nitrogen fertilizer treatments included zero, 100, 200 and 300 kg / ha of urea source were in main plots and planting density levels included 150, 225, 300, 375, 450 and 525 seeds per square meter were in subplots. The results of analysis of variance showed that in both years of experiment, grain yield, number of spikes per square meter and number of seeds per spike were affected by different levels of nitrogen fertilizer, different levels of plant planting density and fertilizer interaction at planting density at 1% but the interaction of grain weight per spike in both years of the experiment was not affected by fertilizer levels and planting density levels. The results of comparing the mean interaction of treatments showed that the combination of fertilizer levels of 300 kg / ha and density of 300 plants per square meter in the first year of the experiment with grain yield of 4957 kg / ha and fertilizer levels of 200 kg / ha and density of 375 plants per square meter in The second year of experiment with grain yield of 4408 kg / ha had the highest value

In order to study the effect of different tillage systems and irrigation levels on corn yield, an experiment was conducted as split plot in the form of randomized complete blocks with three replications in the research farm of the University of Tehran in 2016. The main factor in this experiment was tillage with two levels (no tillage and conventional tillage) and the secondary factor was irrigation levels with three levels (without water stress, moderate water stress and severe water stress based on 75, 110 and 150 mm evaporation from Evaporation pan surface, respectively) was considered. The results showed that the effect of tillage on grain yield and water use efficiency was significant at 1 and 5% probability level, respectively. Also, the effect of irrigation levels on plant height, grain number per panicle, grain yield, biological yield and water use efficiency was significant at 1% probability level and on 1000-grain weight at 5% probability level. Maximum plant height(100.38 cm), number of seeds per panicle (2408), 1000-seed weight (31.33 gr), grain yield (5843 kg.ha-1),and biological yield (11575 kg.ha-1) was obtained from irrigation based on no water stress treatment (75 mm evaporation from the surface of the evaporation pan) and the maximum water use efficiency (1.15 kg.m-3) was found from severe drought stress (150 mm evaporation from the surface of the evaporation pan). Also, no tillage method increased grain yield (16.25%) and water use efficiency (13.72%) compared to conventional tillage method.

In order to investigate the effects of nitrogen rate and time of irrigation on the grain yield and grain yield components of wheat, one experimental as split plot was carried out as split plot design based on randomized complete block design with four replications in research farm of Aliabad Katoul Emam Khomeini agriculture high school during 2018-2019 and 2019-2020. Irrigation time was in main plot (no irrigation, irrigation at stage 33 zadoks, irrigation at stage 70 zadoks) and nitrogen rate was in sub plot (zero, 57.5 kg N/ha, 115 kg N/ha from urea source). Significant interaction wasn’t observed between irrigation treatments and nitrogen rates in almost all traits. The highest yield was obtained by using a supplementary irrigation in stage 70 of Zadox and consumption of 115 kg of pure nitrogen. Grain yield had a positive correlation with biological yield, spike length, spike weight, number of seeds per spike and seed weight per spike. Factor analysis revealed that the first two factors explained 74.5% of the total variation. The results of stepwise regression analysis showed that only the spike weight trait entered the model and alone justified 80.7% of the grain yield variation.

Water use efficiency Increasing is an effective way to optimal water use and to achieve sustainable production in a water deficit crisis. In this regard, the effect of drought stress through four irrigation regimes (after 80 (control), 110, 140 and 170 millimeter evaporation) on four sorghum varieties (Sepideh, Kimia, Payam and KGS32) was studied in the summer of 2016 and 2017 in Khorramabad, Iran. Results showed that the morphological characteristics of plant such as plant height and grain yield components decreased with increasing drought stress. Maximum number of grain per head (2286.9 seeds) from Sepideh and maximum thousand-kernel weight (23.8 g) were obtained from Payam variety in the first year under normal irrigation conditions. The highest grain yield was obtained under normal irrigation conditions with an average of 8230.5 kg ha-1 and the lowest grain yield was obtained from irrigation after 170 mm evaporation with an average of 3917.5 kg ha-1. The highest water use efficiency for grain yield (1.55 kg m-3) was obtained from Sepideh variety in the after 110 millimeter evaporation irrigation regime. Totally, Sapieh variety at after 110 millimeter evaporation irrigation regime saves irrigation water, while producing optimal economic performance and is recommended for temperate region of Khorramabad and similar areas.

Association mapping is a technique with high resolution for QTL mapping based on linkage disequilibrium and has shown more promising for describing genetically complex traits. In addition, it is a powerful tool for describing complex agronomic traits and identifying alleles that can contribute to enhance the desired traits. In this study, whole genome association mapping was used in a set of 148 spring barley cultivars. Phenotypic evaluation was conducted at Zahak Agricultural Research Station, Iran, using alpha-lattice design with two replications, for two croppinhg cycle (2014-2015 and 2015-2016). Traits such as days to anthesis, days to physiological maturity, grain filling period, flag leaf length, flag leaf width, grain number per main spike, thousand grain weight and grain yield were measured. Association analysis between the markers and phenotypic traits was performed with a mixed linear model (MLM with K+Q). In total 28 QTLs were identified which were related to the measured traits. A stable QTL was detected on chromosome 5H (74.76 cM) for days to anthesis. Three QTLs were detected on chromosomes 4H (125.08 cM and 120.64 cM) and 5H (74.76 cM) for grain filling period. One QTL on chromosome 2H (10.87 cM) was associated with days to anthesis, grain filling period and 1000 grain weight. One QTL on chromosome 4H (125.08 cM) was also associated with days to anthesis, grain filling period as well as flag leaf length and 1000 grain weight. Common genetic locations for these traits could be due to pleiotropic effects or genetic linkage.

This study was performed for the evaluation of the effect of Azotobacter and nitrogen levels on morphological traits, plant nitrogen uptake rate, seed oil and yield and nitrogen use efficiency of six safflower (Carthamus tinctorius L.) genotypes under rainfed conditions, as a factorial experiment based on a randomized complete block design with three replications, during 2015-2016 and 2016-2017 growing seasons. Experimental factors were seed inoculation with Azotobacter and urea chemical fertilizer application (Non-inoculated with Azotobacter and urea as control, seed inoculation with Azotobacter, inoculation with Azotobacter + 50% N and inoculation with Azotobacter + 100% N) and six genotypes of safflower (312-S6-692, PI-401478, PI-253895, PI-306974, padide and sina). The combined analysis of variance for two years showed that the main effects of fertilizer and genotype had significant effect on all of the traits. The interaction of nitrogen × genotype was significant on root volume, leaf are index, number of lateral branches, grain nitrogen, straw nitrogen and total nitrogen uptake. Result showed that inoculation with aztobacter + 50% use of nitrogen had higher nitrogen use efficiency than aztobacter + 100% use of nitrogen. However, there was no significant difference in the grain yield between those fertilizer treatments. Sina with the highest values of grain yield (1203 kg.ha-1) and nitrogen use efficiency (17.49 kg.kg) was considered as superior variety. Therefore, with the aim of reducing environmental pollution by excessive use of N chemical fertilizer, application of Azotobacter is suitable for safflower production under daryland conditions.

In order to investigate the effects of foliar application of 6-benzylaminopurine on physiological traits, yield and yield components of quinoa (cultivar Q26) an factorial experiment has been conducted, based on randomized complete block design with four replications at the research farm of Agriculture Faculty, the University of Zanjan, during cropping seasons of 2017. The experimental factors include optimal irrigation (-0.4 MPa) and drought stress (-1.5 MPa) as primary factor and foliar 6-benzylaminopurine in three levels (0, 50, and 100 μM) as the secondary one. Irrigation treatment has significant effect on all traits, except chlorophyll b and cartenoide. Drought stress increases electrolyte leakage (EL), proline, and Harvest index (HI) though it has a declingin effect on other traits. The effect of irrigation and hormone interaction has been considerable, except for chlorophyll b, total chlorophyll, thousand weight grain, and biomass yield. The highest grain yield (215.75 g.m2) in optimal irrigation is observed in 50 μM and in drought stress condition with 149.76 g.m2, obtained in 100 μM of cytokinin. The maximum harvest index (25.6%) can be observed in the control treatment of drought stress. Results show that applying cytokinin reduces the unfavorable effects on quinoa; therefore, this hormone’s foliar can be a solution to enhance the grain yield of quinoa under drought stress conditions.

Salinity stress is one of the limiting factors in crop production especially in agricultural lands of arid and semi-arid regions. Under salinity stress, the availability of nutrients is reduced due to poor soil conditions. In contrast, the use of these elements by foliar spray is an appropriate method to increase the efficiency of nutrients absorption. Application of some elements by foliar spray reduces the negative effects of salinity. According to the reports regarding the positive effects of nitrogen, calcium and potassium as inducers of salt tolerance, this study was designed to investigate the response of cumin plant in hydroponic conditions to salinity stress and foliar spray of the above mentioned elements.

This research was conducted in 1395 in a research greenhouse in Fasa, Iran. A factorial experiment was conducted in a completely randomized design with three replications. The first factor was salinity stress in three levels including control (semi Hoagland solution), semi Hoagland solution + 75 mM sodium chloride and semi Hoagland solution + 150 mM sodium chloride. The second factor was foliar spray treatments consisted of control (distilled water), calcium nitrate, potassium nitrate, ammonium nitrate and calcium nitrate + potassium nitrate which were prepared with concentrations of 5/857, 7.214 and 2.857 kg per 1000 liters of water, respectively. These concentrations were selected in such a way that the nitrogen concentration used in all of them was equal. Salinity treatments were applied to Hoagland solution. Spraying of the desired compounds was carried out every two weeks until the end of the flowering stage.

The results showed that increasing in salinity stress reduced plant dry weight and leaves chlorophyll content in cumin. Foliar spray of calcium nitrate + potassium nitrate and calcium nitrate alone could somehow prevent the adverse effects of salinity on cumin. Compared to control, salinity level of 75 mM did not reduce the leaf relative water content in cumin. But increasing the salt stress to 150 mM reduced the relative water content of the leaves. While increase in salinity stress increased ion leakage, compared to control foliar spray of calcium nitrate, potassium nitrate, ammonium nitrate and calcium nitrate + potassium nitrate could reduce ion leakage in cumin. At salinity level of 75 mM sodium chloride, foliar spray of calcium, potassium and ammonium and at 150 mM sodium chloride, calcium spray could somewhat neutralize the adverse effects of salinity stress on chlorophyll a. The results showed that salt stress increased the sodium content of the cumin shoot. In fact, salinity stress disturbs the cationic balance of cumin and prevents the absorption nutrient elements and provides the possibility of more sodium absorption by cumin. In all salinity treatments, compared to control, foliar spray of the utilized compounds increased the number of umbel per plant. Calcium and potassium sprays with a competitive effect reduced the sodium absorption and to some extent could play a role in improving the yield components of cumin.

Overall, the results of this study showed that increase in salt stress caused disturbance in leaf relative water content, ion leakage and chlorophyll content of cumin. However, foliar spray of calcium nitrate and potassium nitrate increased leaf relative water content and reduced ion leakage in cumin. Also, increase in salt stress caused a disturbance in cationic balance and prevented other cations such as calcium, potassium and magnesium to be absorbed while allowed cumin to absorb more sodium. Finally, the use of various spray combinations could improve the number of umbrellas per plant, the number of seeds per umbrella and the weight of 1,000 seeds of cumin in 75 mM salt stress conditions.

In order to investigate the effect of humic acid foliar application on drought stress effects of Niger (Guizotia abyssinica (L.F) Cass), a split plot experiment was done in a randomized complete block design with three replications at the research farm of the faculty of agriculture/Shahrekord University in 2016. The main factor consisted of four drought stress levels (60 (control), 100, 140 and 180 mm evaporation from evaporation pan) and the sub factor was including four humic acid levels (0, 2, 4 and 6 liters per hectare). The results showed that the effect of drought stress and humic acid was significant on plant height, number of lateral branches, number of head per unit area, 1000 grain weight, grain yield, biological yield, harvest index, chlorophyll, carotenoids and proline (at 1% level of probability). Drought stress caused decreasing and humic acid caused increasing in all traits except of proline. The interaction effect of drought stress and humic acid on number of head per unit area, grain yield, harvest index, proline (at 1% level of probability) and on plant height (at 5% level of probability) was significant.The maximum plant height, number of heads per unit area, grain yield and harvest index were obtained at control with six liters humic acid application per hectare, and the maximum amount of proline was observed at the treatment of 180 mm evaporation with no humic acid application. It is recommended to use 100 mm evaporation regime with 4 liters humic acid application per hectare for more economic profit.

Biofilmed bacteria that possess growth promoting properties can help crops such as wheat to survive in water stress conditions. In this regard, a factorial experiment with randomized complete block design (RCBD) was carried out to evaluate the effects of biofilm bacteria on yield and its components of wheat in rain-fed condition. Factors were including biofilmed bacterial isolates (including no bacteria, and isolates 16-1, 38-2 and 1-54), different wheat varieties (Kohdasht and Chamran), and water application (applying 20, 50, and 80 % of available water content) which were applied in 3 replications in research greenhouse of university of Maragheh. Studied isolates were selected among 120 biofilm isolates which were isolated from Graminae’s roots resistant to drought in the Hashtrood region. Results revealed that bacteria had positive effects on yield component of wheat in all applied water conditions. Bacteria’s application also prevented the deduction in some of yield components which usually occurs due to water stress condition. However, the results revealed that the effects of bacterial application were higher in Chamran variety compared to Kohdasht variety. Root’s wet and dry weights, root’s tissues density, water holding percentage of root and root/shoot ratio were affected by water stress condition. Bacterial inoculation decreased root’s wet and dry weights and tissues density. In contrast, Bacterial inoculation considerably increased water holding percentage. In general, the results suggest that biofilmed bacteria are suitable to deduct the effects of drought stresses.

Background and Wheat is one of most important crops, which has special place in people’s nutrition in developing countries such as Iran. Also, due to reducing food diversity and lack of receiving enough micronutrient such as iron, malnutrition and anemia are among the most challenging nutritional problems of these societies. Nowadays scientists try to not only improve the quality and quantity of wheat but also increase the accumulated micronutrients such as iron in wheat and help to reduce malnutrition. Due to role of folate in transfer of single carbon fragments, in this research effect of folic acid foliar application at different growth stages were investigated on wheat grains quality and quantity.
Material and In order to evaluate the effect of folate foliar application on yield and iron content of wheat at different growth stages, an experiment was conducted at Maragheh University reseach farm in 2013 using randomized complete block design. In this regard, wheat cultivar namely Kohdasht planted with 500 seeds per m2 at 3 - 5 cm depth. Then, wheat seedlings was sprayed with 50 μM folate at shooting, heading, milky, dough and combination of above mentioned stages during last hours of daytime.
Findings: Results revealed that folate foliar application at different phonological stages of wheat caused to increase plant height, flag leaf area, and number of tillers compared with control, while it had no effect on number of spikelets per spike. In contrast, the percentage of sterile florets per spike significantly decreased in treated seedlings at all growth stages except heading stage. Also folate foliar application cause to increase the number of grains per spike at all growth stages except milky grain stage compared with control. In addition Folate foliar spray significantly affected 1000 seed weight only at milky and dough as well as combination of above mentioned stages. Because of folate foliar spray, biological and grain yield showed a significant increase in all phenological stages compared with control. Also, folate foliar application cause to significantly increase the content of grain iron except stem elongation stage compared with control.
As a conclusion, it can be stated that folate foliar application led to Increase wheat yield at all growth stages. But for achieving desirable quantitative and qualitative yield, it is better that folate get used to at last stages of wheat biological cycle. In addition, due to the positive effect of folate on the qualitative and quantitative aspects of food security, could be considered in breeding programs.

Drought tension is one of the most important determinants of crop production, therefore, this study aimed to investigate the effect of drought tension on wheat genotypes, as a completely randomized factorial statistically design was conducted under greenhouse conditions. The experimental treatments has consisted of three levels of drought tension (85, 60 and 35 percent of field capacity) and eight genotypes of wheat (Omid, Zarea, Mihan, ZSZOBKAYKA, JS3l7G217, Solh, G13CA2242O4P, and FAA3P4FCCC). The results indicated that there was significant difference between wheat genotypes in terms of remobilization of dry matter from the stem, leaf, peduncle, the whole plant and spike. Also, the efficiency of the remobilized dry matter of shoot, leaf and total and proportion of transferred dry matter from stem and total, was significant. Zare genotype was allocated the highest dry matter transferred of stem and leaves. Omid and JS3l7G217 genotypes had the highest efficiency of dry matter transferred from stem and Omid and Zare genotypes had the highest efficiency of dry matter transferred from peduncle.The highest proportion of transferred dry matter of leaf to seed was observed of genotypes Zarea and G13CA2242O4P. Also, wheat genotypes had significant differences in terms of plant height, peduncle length, number of grain per spike, one-thousand grain weight, and grain yield and harvest index. The highest plant height was allocated to genotypes Solh, Mihan and JS3l7G217 and the maximum spike length was belonged to genotypes FAA3P4FCCC and ZSZOBKAYKA under 85% field capacity. The highest and lowest one-thousand seed weight were obtained from genotypes Solh and JS3l7G217, respectively. Genotype ZSZOBKAYKA by producing 1.53 gram grain per plant under 85% field capacity and JS3l7G217 genotype by 0.39 gram per plant under 35% field capacity devoted the highest and lowest grain yield.

In order to study the influence of different levels of nitrogen and early and medium maturity cultivars on yield and yield components of sweet corn, an experiment was conducted in Yasouj region during summer 2011. The experiment was arranged in split plots based on randomized complete block design with two factors and three replications. Main plot included four levels of nitrogen fertilizer (0, 50, 100, 150 Kg N ha-1) and sub plots included two early and medium maturity cultivars. Results showed that interaction of nitrogen and cultivar was significant on fresh ear yield. Application of 150 kg N ha-1 at medium maturity cultivar produced the highest fresh ear (1892 gr m-2) that was significant difference with other treatment. The treatment of 100 kg N ha-1 had the highest effect on grain yield (521.27 gr m-2) and medium maturity cultivar with of grain yield equals 498.57 gr m-2 was showed a higher yield than early cultivar. The highest thousand grain weight (141.99 gr) was obtained at 150 kg N ha-1 treatment. Also the highest fresh forage yield (2436.8 gr m-2) related to application of 150 kg N ha-1. Generally it seems that application of medium maturity cultivar and 150 kg N ha-1 due to maximum yield.

Sweet corn is the one of the most important types of corn. There is a high amount of sugar in the endosperm of sweet corn than dent corn. Baby corn is the ear of corn that is being harvested in the silking stage before the end of pollination. This crop has an interesting using methods as salad, conserve production and vegetative consumption. Both two sweet and baby corn is obtained from one plant in different growth stages and could be harvested from one corn hybrid. Best yield and quality of baby corn is obtained from sweet corn hybrids, because of high amounts of sugar in the grains and ears. Sweet corn and baby corn could be harvested at early dough stage (with about 30 % of humidity) and early silking stage before the pollination is completed, respectively. Plant density is the most important factor in growing corn, especially in sweet and baby corn. Khuzestan province is one of the main regions of corn production in Iran. In Khuzestan, forage and silage corn have the most production among the summer crops. Corn is planted in two planting date in Khuzestan: early spring and early summer. Spring corn planting produces little grain yield due to Simultaneity of silking stage with hot early summer days. Because of little production and little research about sweet and baby corn, this study was performed and designed.
In order to investigate the effects of plant density and harvesting method on sweet corn and baby corn yield, an experiment was performed during 2012-13, in research farm of Ramin Agriculture and Natural Resources University of Khuzestan, located in southwest of Iran. In this experiment, four plant densities (7, 9, 11 and 13 plants.m-2) and two harvesting methods (baby corn and sweet corn) were investigated in an RCB statistical design with four replications. The KSC 403 hybrid was used and investigated in the experiment, as a sweet corn hybrid. Statistical analysis was performed using SAS 9.1 through GlM procedure. Means of all treatments were comprised using least significant difference (LSD) at 5 % probability level.
The effects of plant density on yield components of baby corn was significant. Increasing the plant densities increased the ear number and percentage of non-standard ears. The Highest yield of ear without husk, standard and non-standard were obtained (2649.5, 766.97, and 3043.9 kg.ha-1, respectively) with 13 plants.m-2. In sweet corn, increasing plant density from 7 to 13 plants.m-2, decreased row per ear, grain per row and thousand grain weight. Highest grain yield (1232.5 kg ha-1) and green ear (12607.2 kg ha-1) of sweet corn were obtained with plant density of 9.m-2.
Analysis of correlation showed that in both baby and sweet corn, there were positive and significant correlations between yield and its components. There was the high number of non-standard ears in all experimental treatments. In sweet corn, the standard ear without husk yield has positive and significant correlation with all traits except the percentage of standard ear and sheathed ear weight. In addition, unsuitable climate conditions during silking stage reduced the yield of sweet corn through the high number of aborted florets. Yield of sweet corn yield showed negative and significant correlation with grain row per ear and grain per row. However, increasing the ear number.m-2 increased yield in higher plant densities up to 9 plant.m-2 density.
Generally, the baby corn had high yield with good quality in this region, but, standard ear percent of the baby corn of the hybrid KSC 403 was very low. On the other hand, sweet corn grain yield was low due to high air temperatures during pollination and maturity stages.

In current study, the effect of planting method and density was examined on yield, yield components as well as seed oil percentage of rapeseed (Hyola401) at three tillage systems in rice-field at Amol, Mazandaran during 2011-12. The treatments consisted of tillage systems at three levels: no-tillage, minimum tillage and conventional tillage as main factor, planting method at two levels: hand-sowing and row planter as sub factor and seeding density at three levels: 6, 9 and 12 kg ha-1 as sub-sub factor. The results showed that in all treatments the highest seed yield was obtained by applying minimum tillage method; so that grain yield at minimum tillage was greater by 20.8% and 96.4% compared to conventional and no tillage systems, respectively. The seeding methods (hand-sowing and row planter) had no significant effect on seed yield. The mean squares of oil seed percentage and 1000 seed weight in any of applied treatment were no significant suggesting the stability of these traits in relation to applied treatments. Overall, use of 9 kg ha-1 seed, especially by row planter under conservation systems was necessary for achieving the best result.

To investigate the yield and correlation between agronomic traits and yield, seven rice cultivars (Fajr, Sahel, Cadoos, Shafagh, Nemat, Neda and Domsiah) were studied using RCBD design with 4 replications at Sangdivar village, Kalat Nader (2010-2011). Based on ANOVA, significant differences were observed among the studied genotypes. Also it was observed that the number of fertile tiller, plant height, number of seeds per panicle and weight of 1000 grains had significant and positive phenotypic and genotypic correlation with grain yield, while other traits had no significant phenotypic and genotypic correlation with yield. According to compare mean and correlations matrix, and due to higher number of fertile tiller, plant height, number of seeds per panicle and weight of 1000 grains, Fajr and Nemat cultivars had better yield than those in other cultivars. As well, path analysis verified positive and direct effects of 1000 grains weight and plant height on yield. So selection of superior genotype concerning yield can be indirectly performed through mentioned traits.