Iranian Journal of Field Crops Research
Year:2010 | Volume:8 | Issue:3|Papers Count:22

In order to study the effect of amounts and methods of nitrogen application on quantitative and qualitative characteristics of forage sorghum (Sorghum bicolor (L.) moench var. speed feed) an experiment was conducted as split plot based on compeletely randomized block design with 3 replications. In this study 3 amounts nitrogen fertilizer including (80.5, 161 and 241.5 kg/ha) were used as main plots and 3 methods of nitrogen application including in one stage (total fertilizer applied after planting), two stage (one-half fertilizer applied after planting and one-half after first harvest) and three stage (one-third fertilizer applied after planting, one-third after first harvest and one-third after 6 to 8 leaves regrowth) as sub plot. Results showed that the effect of amounts and methods of nitrogen application in first, second and sum of two harvests on dry matter forage yield and protein yield was significant. Methods of nitrogen application in two and three stage were better than one stage, and nitrogen amounts of 80.5 and 161 kg/ha were better than 241.5 kg/ha, which provide better condition for crop development and growth, because the crop used better of environmental factors than the other treatments. The effect of amounts and methods of nitrogen application were not significant on plant height and number of tiller.Effect of amounts and distribution method of nitrogen fertilizer was significant on percentage fiber and ash at first harvest and protein percentage of second harvest. The highest protein percentage and ash and the lowest fiber percentage were obtained from 80.5 (N) kg/ha and application in three stages. Interaction between amounts and methods of nitrogen was not significant on studied traits, other than on protein percentage at first application and ash percentage at second harvest. The results showed that the maximum yield quantitative and qualitative were obtained by using of nitrogen fertilizer amount of 80.5 kg/ha by two or three stage application.

In order to evaluate the effect of different planting ratios on yield and yield components of sesame and chickpea in intercropping, an experiment was conducted in Research Farm of Faculty of Agriculture, Ferdowsi University of Mashhad in 2007. The treatments were arranged in split plots based on randomized complete block design with three replications, consisting of two planting methods namely row planting and mixed planting as main plot and five planting ratios including chickpea monoculture, sesame monoculture, 10% chickpea+100% sesame, 20% chickpea+100% sesame, 30% chickpea+100% sesame as sub plot. The results showed that the highest sesame yield of 1.8 t/ha was obtained in 20% chickpea+100% sesame intercropping at row planting pattern and the lowest yield of 0.74 ton/ha was obtained from 10% chickpea+100% sesame ratio with mixed planting. Land equivalent ratio (RYT) showed that with 20% chickpea+100% sesame, 30% chickpea+100% sesame and 10% chickpea+100% sesame ratio the yield was respectively 39% (RYT=1.39), 28% (RYT=1.28) and 24% (RYT=1.24) more than monoculture. This could be attributed to better utilization of environmental resourses by these combinations of the crops.

This study was conducted with 18 advanced durum genotypes and two check cultivars, Zardak (durum check) and Sardari (Bread wheat check), under rainfed and supplemental irrigation in field and also under stress (polyethylene glycol) and non-stress (distilled water) conditions in laboratory in Sararood station during growing seasons 2004-5 and 2005-6. The genotypes were significantly varied based on analysis of variance and mean comparison for the studied agro-physiologic traits. In the both growing seasons, the genotypes No.9, 15 and 19 had the highest grain yield under rain-fed condition. Tthe genotypes No.13 and 16 for 2004-05 and the genotypes No.8, 12 and 19 for 2005-06 had the highest grain yield performance under supplemental irrigation.The genotype No-16 with the highest yield across environments had the highest STI and TOL, whereas the genotype No.8 with the lowest yield had the lowest TOL and relatively low STI. The results of path-coefficient analysis for grain yield under rain-fed condition showed that the traits of DHE, DM, FL, Ped.L/PLH, PLH, RWC, SL had positive direct effect on yield and the others traits had negative direct effect. The genotype No.19 had the highest coleoptile and rootlet length and for these two traits genotypes No.6 and 17 were in lowest. The genotype No.19 had the highest PIS and PIN and genotype No.3 had the lowest. The genotypes No.3, 9, 11, 14 and 20 had the higher GSI under stress than non-stress conditions. The STI as a field criterion had significant positive correlation with the traits of Root.L. and Root. No., which indicating selection based on Root. L. and Root.No. in laboratory condition may be useful and recommended for screening in field condition.

In order to investigate of phenological and morphological characteristics, yield components and yield of cold tolerant chickpea genotypes in fall sowing, 9 cold tolerant chickpea genotypes and Karaj 12-60-31 as a control were evaluated in Experimental Field of College of Agriculture, Ferdowsi University of Mashhad in 2006-2007.The experiment was carried out based on randomized complete block design with four replications. The planting date was 25 October and three times of irrigation was done as supplementary irrigation at planting stage, 20 days after that and at flowering stage. The control was ruined at seedling stage due to the hard cold. Based on the results, the differences among the genotypes for all of measured traits including growth duration, plant height, number and length of branches, yield components (pod number per plant, seed number per pod and 100 seeds weight), seed yield and biological yield were significant (P≤0.05). There were positive and significant correlations between seed yield and vegetative (r=0.71**) and reproductive (r=0.68**) periods. MCC291, MCC349 and MCC207 produced the highest seed yield with 231, 229 and 217 g.m-2, respectively. Totally, it appears that some of genotypes have appropriate yield potential for fall sowing under supplementary irrigation at Mashhad.

To study the effects of soil solarization, barley straw mulch and hand weeding on weed seedbank, a field experiment was conducted at Research Farm of College of Agriculture, Ferdowsi University of Mashhad during 2007-2008 growing season. This experiment was based on a randomized complete block arranged as a split-split plot design with three replications. Clear and black polyethylene, and non-solarized control were arranged on main plots. A different straw mulch rates (0, 300 and 600 gm-2), and weeding treatment were in the sub-plots and sub-sub plots, respectively. A total of 19 weed species was recorded in all treatments which were mainly annual broad leave species. Results indicated that solarization with clear sheets had 1.8 times less seed density than the control plots. Application of straw mulch decreased weed seed population. Also, hand weeding was effective in reducing weed seeds. Weed seedbank density in no-weeding plots was 3 times greater than weed control plots.The interaction between soil solarization, straw mulch and weeding on seedbank size was significant. The lowest number of weed seeds was observed in clear polyethylene, 300 gm-2 straw mulch and weeding.

The important factors for high seed yielding genotypes selection, involve of those characteristics that affecting on seed per plants. In order to evaluation and selection the fittest lentil genotypes in sistan region, an experiment with 10 genotyps were carried out in agricultural research farm at Agricultural research Institute of Zabol University, in 2006-2007 by complete randomize blocks design in three replications.The results showed significantly differences (p<0.01) among genotypes (G) for all traits, in exception of growth stage before cool season. The survival percent was over than 80 percent for all genotypes, after cool season. Maximum and Minimum yield obtained by MLC225 and MLC29 (1088 and 304 kg/ha respectively).There was a high positive correlation between pod per plant and seed yield. Therefore MLC225 because of having Maximum seed yield, greatest height (32.8cm), and greatest length of growth duration, Maximum pod number per plant and seed per plant was the best genotype in this experimental condition. MLC25 and MLC138 with 917 and 880 Kg/ha were in second and third ranks.

In this research, the effect of drought stress on antioxidant enzymes, membrane stability and essential oil percentage in Balm (Melissa officinalis L.) has been evaluted under field conditions. Experimental design was complete randomized block design with 4 replications. The treatments included: T1 (control, non stress), T2 (80%FC), T3 (60%FC), T4 (40%FC) and T5 (20%FC). Results showed that there was a significant differences (P<0.01) between treatments on evaluated traits such as catalase, nitrate reductase, peroxides, membrane stability and percentage of essential oil. The mean comparison of treatments showed that amount of product catalase content that produced in T5 (%20FC) with 31.09 mmol decayed H2O2 per second was higher than other treatments. It was also well defined that nitrate reductase in T4 (40%FC) with the mean of 3.543 mmol produced nitrate per fresh weight, was higher than other treatments. There was not any significant differences between T4 and T5 for their peroxidase contents but they had higher peroxidase that other treatments. Mean comparisons of membrane stability between treatments, showed that in moderate stress condition, the membrane stability increased in comparison with control treatment but in treatments with higher drought stress, the membrane stability has been decreased. The percentage of essential oils of collected samples from natural rangelands of Tehran, Ardebil and Esfahan provinces was compared with cultivated plants in the field. Results of analysis variance of collected plants from natural rangeland showed a significant differences between treatments for plant height, stem diameter and percentage of essential oil at %5 probability level. The mean comparison showed that samples collected from Ardebil with %0.3961 essential oil, Esfehan with 36.60 cm plant height and Ardebil with 2.867 mm stem diameter were superior over other treatments. It could be concluded that Balm has a high adaptation to different climatic condition.

Nitrogen use efficiency and root morphology of different potato (Solanum tuberosum L.) cultivars were compared in two field and greenhouse trials and root morphology response to nitrogen concentration was investigated. In field experiment, treatments consisted of four nitrogen application rates (0, 90, 180 and 270 kg ha-1) and six potato cultivars (Fontane, Kuras, Agria, Miriam, Cosmos and Picasso). Greenhouse experiment was conducted at sand culture method and effects of different nitrogen concentrations (100, 200 and 300 mg l-1) on root morphological characteristics were studied. Different nitrogen application rates affected total tuber yield and nitrogen efficiency of potato cultivars. Maximum tuber yield was obtained in 270 kg ha-1 N treatment. There was no significant difference between tuber yields in 180 and 270 kg ha-1 N treatments. Nitrogen use efficiency and agronomic efficiency of potato cultivars decreased with increasing nitrogen application. Cosmos, Kuras and Picasso had the highest yield, nitrogen use efficiency and agronomic efficiency among potato cultivars. In greenhouse trial, different nitrogen concentrations had significant effects on all root morphological characteristics, except root average diameter. In all potato cultivars, root volume, root fresh weight, root dry weight, total root area, total root length and shoot dry weight increased and root/shoot ratio and specific root weight decreased with increasing nitrogen concentration. Potato cultivars differed in root morphological traits and cultivars with higher nitrogen efficiency had larger and stronger root system in all nitrogen concentrations.

In order to evaluate the effect of increase plant density on stalk yield and sucrose content in two sweet sorghum cultivars, an experiment was conducted at Research Farm of Isfahan University located at Zaghmar village. A split plot layout within a randomized complete block design with tree replication was used. Main plots were plant densities (100, 200, 300, 400, 500 and 600 thousand plant/ha) and subplots were cultivars (Rio and Keller). The effect of plant density at hard dough harvest stage on plant height, stem diameter, number of tillers, stem fresh weight and juice yield were significant but had no significant effect on brix, sucrose percentage and purity. The highest juice yield and purity were produced by 400 thousand plants/ha. Keller was significantly superior for plant height, stem diameter, stem fresh weight, juice yield and brix at hard dough harvest stage as compared to Rio. Number of tiller per plant of Rio was significantly more than Keller. There were no significant difference between two cultivars for sucrose percentage and purity but sucrose percentage in Keller had highest as compared to Rio. Maximum stem fresh weight, juice yield, sucrose percentage and purity were obtained at hard dough harvest stag. On the basis of the results obtained, 400 thousand plant/ha plant density, Keller cultivar and hard dough harvest stage might be suitable for sweet sorghum production under the condition similar to the present study.

In order to evaluate the electrolyte leakage as an indicator for cold injury in eight sugar beet (Beta vulgaris L.) cultivars including Rasoul, Shirin, IC, 7233 (national cultivars), Afshari, Paolina, Rhizofort and Laetitia (foreign cultivars), a trial carried out at Crop Physiology Lab. of Agriculture College of Ferdowsi University of Mashhad in 2006. In this study beet cultivars, with 8 freezing temperatures (0, -2, -4, -6, -8, -10, -12 and -16 oC) as a complete randomized design in a factorial arrangement with three replications. Plants were kept until 4-5 leaf stage in natural environment, then transferred to the thermogradient freezer. The cell membrane stability of beet cultivars was measured through electrolyte leakage and the lethal temperature 50 (LT50) of leaf samples based on electrolyte leakage percent also were determined. Results showed that there were significant differences (p £0.01) among freezing temperatures and cultivars for electrolyte leakage and LT50. As temperature decreased below -4 oC, electrolyte leakage of all genotypes were increased. Among beet cultivars, IC cultivar had the highest, and 7233 cultivar had the lowest cold tolerance according to the LT50. Also in grouping sugar beet as local and foreign cultivars, there were no significant different in electrolyte leakage among cultivars.According to the high correlation between electrolyte leakage percent and LT50 (r=-0.81), it seems that using this index for evaluation of freezing tolerance injury in sugar beet could be useful.

Humic acid is an organic acid without environmental destructive effects that is applied for increasing germination rate and wheat establishment. In order to evaluate effects of different levels of humic acid on germination of four wheat cultivars, an experiment was conducted in 2008 at Research Laboratory of Faculty of Agriculture, Ferdowsi University of Mashhad. A randomized completely block design with four replications used with factorial combination of humic acid concentration (0, 36, 54, and 72 mg/l) and wheat cultivars (Sayons, Chamran, Pishtaz and Sabalan). Results showed that all traits except germination rate were significantly different (p<0.01). Treatment with 54mg/l humic acid concentration showed the highest germination rate, seedling vigor index, radicle length, plumule dry weight and radicle length to plumule length ratio. Cultivars were significantly different in all traits except germination rate. The best humic acid concentration for increasing germination rate, radicle length, radicle dry weight and also decreasing mean germination time was 54mg/l.Pishtaz and Sayonz were the best dry land and irrigated cultivars in response to humic acid respectively.

In order to study the effects on salinity and silicon application on yield and yield components of purslane (Portulaca oleracea L.), an experiment was conducted in a completely randomized desgin with three replications and two factors consisted of four different levels of salinity using NaCl (0, 7, 14, 21dS/m) and two levels of silicon (application of one mMol sodium silicate and not application). Increasing salinity concentration significantly caused a negative effect on seed yield. But yield components such as number and weight of seed were more sensitive than number of capsul in main stem in final seed yield. Application of silicon increased seed yield in control but was not significant in salinity levels and leaves and stem biomass. Seed yield and total seed weight in branches was significantly decresed. Weight of 1000 seed in main stem and branches was not significantly different in salinity levels. As a result, purslane could be extremely tolerated to saline conditions, so it seems that it can be cultivated in saline soils and arid regions. Also applied silicon can be increase yield and plant tolerance to environmental stress.

Salicylic acid (SA) or orthohydroxybenzoic acid play a major role in regulation of many physiological processes e.g. growth, development, ion absorption and germination of plats. In order to evaluate the effects of prepriming Fennel seed with salicylic acid in salinity stress condition, on germination and growth characteristics of Fennel, an experiment was conducted in a factorial arrangement based on completely randomized design with three replications. The experimental treatments were salicylic acid with 7 levels (0, 0.1, 0.5, 1, 1.5, 2 and 4 mM) and salinity with 5 levels (0, 0.3, 0.5, 1 and 1.5 percentage). All salicylic acid and salinity treatments had significant effect on percentage and speed germination, length of radicle and hypocotyle, dry weight of radicle, hypocotyle and seedling and radicle / hypocotyle ratio (R/H). One mM salicylic acid had the highest percentage and speed of germination, length of radicle and hypocotyle and dry weight of radicle, hypocotyle and seedling.The highest radicle/hypocotyle ratio was obtained at 1.5 mM salicylic acid. Four mM salicylic acid didn' t have significant effect on all maintained parameters. With no salinity stress (control), salicylic acid didn’t have any significant effect on all parameters, but when there was salinity stress, prepriming increased all studied characteristics significantly. Therefore, based on our results it seems that salinity resistance of Fennel seeds at germination stage will increase by treating seeds with on mM salicylic acid.

Shiitake mushroom [Lentinula edodes (Berk) Singer/Pegler] has the second production class among the most important edible mushrooms. For a long time this mushroom has draw attention due to its unique flavor and taste and also therapeutic properties. Dِue to the importance of this mushroom in the world and also the effect of substrate on the production of this medicinal mushroom, a research were conducted in randomized complete block design with 6 replications on 4 different substrate formulations including: 1) sawdust, wheat bran, millet, 2) sawdust, wheat bran, molasses, chalk, calcium super phosphate, 3) sawdust, wheat bran, tea waste, 4) sawdust, saccharose, citric acid, chalk and calcium carbonate onL.edodes production for determining the suitable substarte on early fruiting, yield, biological effeciency, average mushroom numbers and weights per block.Results showed that substrate formulation 1 caused earlier fruiting than others (58 days from incubation time), this formulation also had the highest yield (112/3 g/log) and biological effeciency (35/09%) between the others formula. mashroom number was the most in substrate formulation 1 (16/67 n/log) and the highest mushroom wieght was obtained from formulation 4 (14/33 g/per mushroom). there wasn’t any significant differences at (p £0.05) between substrate formulation 1 and 2.

This research was conducted to evaluate the impacts of climate change on rainfed wheat growth and yield at country level. Weather data generated by a General Circulation model based on the ICCP scenarios for the target years of 2025 and 2050. Daily weather data including minimum and maximum temperatures, precipitation and radiation were used as the inputs of a growth simulation model for rainfed after calibration and validation for predicting wheat yield under current climatic conditions. Using the model, the impacts of climate change on wheat growth and yield was predicted and compared with the current data. The simulation results indicated that leaf area index and absorbed radiation by wheat canopy was reduced under climatic conditions of the target years. Reduction of absorbed radiation resulted to a lower crop growth rate and consequently drastic reduction in dry matter production. Estimated drought stress index for the future climate conditions showed that reduction of crop growth rate was mainly resulted from water shortage due to increased evapotranspiration. Reduction of the length of growth period together with a considerable decline of harvest index resulted in a significant reduction of rainfed wheat yield despite the positive effects of increased CO2 concentration and this negative impacts on wheat yield was intensified from 2025 towards 2050. Simulation results showed that the potential impact of climate change on rainfed wheat yield was more pronounced in Eastern regions of the country compared to the Western production areas. The overall country level reduction of rainfed wheat yield was estimated in the range of 16 to 25 % and 22 to 32% for the years 2025 and 2050, respectively.

This research was conducted for evaluation of germination treatments and favorite planting date of three medicinal plant species including Dorema (Dorema ammoniacum), Asafetida (Ferula assa-foetida) and Galbanum (Ferula gummosa) in Agricultural College of Ferdowsi University of Mashhad in 2008. Effect of different levels of temperature and washing on germination percent and rate of species were evaluated in first experiment. Temperature in 6 levels including 1, 4, 7, 10, 13 and 20 °C and seeds treatment in 3 levels including drench, washing and extract were surveyed. In the second experiment, emergence condition of species in four planting dates including first December, first January, first April and first May in pot and out door conditions were evaluated. Result showed that, optimum temperature for germination of Dorema, Asafetida and Galbanum plants were 7.83, 8.27 and 3.14oC, respectively. Further, germination percent of each plant had a positive and significant relation (p<0.01) with its germination rate. The emergence percent of the three species in autumn and winter planting dates (first December and first January) was significantly higher than their emergence percent in spring planting dates (first April and first May).

In order to investigate the effects of methanol application on some physiological properties of soybean under low water stress, a factorial experiment was conducted at Research Field of Faculty of Agriculture and Natural Resources, Islamic Azad University-Karaj Branch, Karaj, Iran, during 2008, based on a randomized complete block design with three replications. The first factor was consisted of different levels of methanol equal to 0 (control), 7, 14, 21, 28 and 35 volumetric percentage (v/v), which were used as foliar applications at three times during growth season of soybean, with 15 days intervals. The second factor was water stress conditions in two levels, based on depletion of 40 and 70% of available soil moisture. Some traits such as grain yield (GY), relative water content (RWC), chlorophyll fluorescence parameters, and chlorophyll content were measured, one day before and after the third methanol application. Results showed that chlorophyll content (Chl), GY, electrolytes leakage (EL) at second sampling, photochemical capacity of PSII (Fv/Fm), maximum and variable fluorescence (Fm and FV, respectively) were affected by water stress significantly (p<0.05). As drought severity was increased, mean values of Fv/Fm, Chl and RWC tend to decline, whereas minimum (initial) fluorescence (F0) and El were increased. Methanol foliar application influenced significantly (p<0.05) Chl, GY, Fv/Fm, Fm, Fv, and RWC. There was a positive, high correlation between GY with Fm, Fv/Fm, and also Chl and RWC in both samplings. It seems applying methanol on water stressed soybean plants can reduce harmful effects of drought and improve plant potential to cope with stress.

To evaluate physiological traits and traits related to grain quality of 18 triticale lines including 9 doubled haploid (DH) and 9 corresponding F6 lines, an experiment was conducted at research farm of College of Agriculture, Isfahan University of Technology located in Lavark- Najaf Abad in 2007. A randomized complete block design with 4 replications was used. Protein content, flour protein, gliadine, glutenin- secalin, SDS sedimentation volume, test weight, length, wide and area of flag leaf, chlorophyll content and grain yield were evaluated. The tested DH and F6 lines were significantly differed for most of studied traits with the exception of the SDS sedimentation volume, test weight, gliadine and length of flag leaf. F6 lines were superior that DH line for grain quality related traits. Significant and positive correlations were observed between grain yield and with length of flag leaf, while grain yield had a negative correlation with protein percentage and protein content, measured by spectrophotometer. The highest genetic coefficient of variation was observed for chlorophyll and the lowest one was for test weight, wide and length of flag leaf. The highest and the lowest broad heritability estimates were 99% for chlorophyll content and 28% for SDS sedimentation volume, respectively. Overall, F6 lines performed superior than DH lines for quantity-related and physiological traits.

In order to evaluate the response of weed seeds to light, two experiments, at two different locations were conducted at Ferdowsi university of Mashhad in 2009. At the first experiment, field was ploughed in day and night. Weed density was evaluated 70 d after plough, with 1×1 quadrate. At the second experiment, at night treatment, ploughing, potato planting and weeding with cultivator were done at night. Weed sampling was done twice at 43 and 130 days after planting with 1×1 quadrate and weeds were identified and counted. Result showed pigweed (Amaranthus retroflexus L.), sowthistle (Sonchus oleraceus L.), crabgrass (Digitaria sanguinalis (L.) scop), jimsonweed (Datura stramonium L.) and mallow (Hibiscus trionum L.) did not observed at night plough, in contrast, night plough has no significance influence on common lambsquarters (Chenopodium album L.), and black nightshade (Solanum nigrum L.). Only common lambsquarters had similar appearance in two treatments, indicating insusceptibility of this weed to time of plough. Interestingly, at the second experiment, result was very similar. Potato yield was higher at night treatment, but not significant. This research showed that some cultural practice like plough, planting and weeding with cultivator in night can reduce weed density and weed dry matter.

This study was conducted in order to evaluation effect of drought stress on some morph-physiological traits correlated with yield in ten-grain sorghum genotypes kept at National Plant Gene Bank of Iran. Field experiments were in 3 different conditions including normal condition and two water deficit conditions in vegetative and reproductive stage in Torogh Agricultural Research Station (Khorasan Razavi Agricultural and Natural Resource Research Center, Mashhad-Iran) using complete randomized block design with 3 replications.In non stress experiment, irrigation operated normally and for 2 another experiments (1) drought stress treated in vegetative period (from 4 leaves up to flowering stage) and (2) drought stress treated in reproductive period (from flowering up to maturity), irrigation was stopped during of stress period. Traits were analyzed included: time of flowering, plant height, and number of fertile tillers, stem diameter, length of panicle, shoot dry matter, seed yield per plant, and 100 seed weight. The results of this study showed genotypes had significant difference (p<0.01) in all traits except seed yield per plant and100 seed weight in three conditions. Highest yield per plant was obtained on normal condition and this trait were decreased 11 and 42.4 percent in reproductive and vegetative period drought stress experiments compared to normal condition. Days to flowering and plant height had significant and positive correlation with biological yield per plant at all conditions. Results of multiple linear regression analysis revealed that days to flowering as a independent variable described and determined changes of biological yield per plant in normal condition as dependent variable truly (P<0.01, R2Adj=0.85) and drought stress in reproductive and vegetative period (p<0.01, R2Adj=0.79 and R2Adj=0.53) respectively. Cluster analysis with ward method at three conditions showed different groups of genotypes in each dendrogram, that indicated significant genetic variation for these investigated traits among sorghum genotypes under well watered and drought condition and it might be possible to used these characters in sorghum breeding programs.