نشریه پژوهشهای زراعی ایران
سال پنجم شماره 1 (پیاپی 9، بهار و تابستان 1386)

The purpose of this research was to determine the optimal level of nitrogen fertilizer and planting date for cumin (Cuminum cyminum L.) planting in Kooshkak region located in Doroodzan Dam Areas which represents a typical semiarid region. This research was carried out in the fall and winter 2000 and using a factorial experiment with two factors based on completely randomized block design with nitrogen fertilizer at three rates (0, 30, and 60 kg N ha-1) and sowing date (Nov. 6th, Dec. 21th, Feb. 6th, and March 6th) in four replications. The effects of different nitrogen rates were significant on plant height, number of umbrella per plant and number of seed per umbrella, but it was not significant on number of seeds per plant, 1000-seed weight, biological yield, seed yield and harvest index. The effects of sowing dates were significant on number of seeds per umbrella, number of seeds per plant; 1000-seed weight, biological yield and seed yield; but it was not significant on plant height and harvest index. The interaction of nitrogen rates and sowing dates were significant on plant height, number of umbrella per plant and seed yield, but it was not significant on number of seeds per umbrella, number of seeds per plant, 1000-seed weight, biological yield and harvest index. It was concluded that for obtaining the high cumin yield, application of 30 kg N ha-1 and the late planting date (February 6th and March 6th) due to probable winter cold, are recommended for this region.

Using organic matter, such as, peat and vermicompost as soil amendment, increases aeration, water infiltration, water holding capacity and nutrients of soil. A greenhouse experiment was performed to study the effect of organic materials on plant growth characteristics, total biomass and grain weight of chickpea with four treatments; 1) Soil + 3% peat (PS), 2) Sterile soil + 3% peat (SPS), 3) Soil + vermicompost (1:6) (VCS), 4) control (C) in a completely randomized design with four replications. The results showed that the maximum germination percentage, number of branch and number of pod per plant were observed in SPS treatment due to the avoidance of harmful microbial impacts. Plant height in this treatment reduced, whereas, no significant differences in total dry matter per plant and dry weight of chickpea per plant were observed compared to control. Plant growth consist of plant height, number of branch and number of pod per plant in vermicompost and soil + peat treatment reduced in the early stages probably because of plant - microbes interaction effects. Application of vermicompost increased fresh and dry weight, pod dry weight and single grain weight, probably due to more plant nutrient availability in this treatment when compared with other treatments.

Interest has increased towards hemp (Cannabis sativa L.) fibre production due to renewed demand for natural fibre in the world. A Study was conducted in 2005 at Shirvan in Northern Khorasan province, Iran, to determine the effects of three plant populations (30, 90 and 150 plant per m2) and three rates of nitrogen application (50, 150 and 250 kg N per ha) on final stand, stalk height, basal stalk diameter, total stalk yield as well as fibre content from stalk and fibre yield in male and female plants. A split plot experimental with three replications was used. The result indicated that due to enhanced competition for light at higher population on density and N2 level plant mortality was higher than other treatment Morphological characteristics were highly correlated with plant sexual, plant population and nitrogen fertilizer. Highest stem, leaf and inflorescence yield were obtained at 250 plant m-2 when 150 kg N ha-1 was used. Lowest plant density did not show self-thinning but reduced above ground dry matter. Shoot dry matter increased with increasing plant density and nitrogen supply. Apparently, fibre content was greater at medium density and lowest nitrogen fertilizer, however, fibre yield was greatest at highest plant population and nitrogen fertilizer. In terms of fibre yield, approximate 31.7% of the fibre was located in the bottom parts, 22.4% in the middle and only 9.9% in the top part of the stem. The results suggest that hemp can yield large quantities of useful fibre at Shirvan when planted in proper plant densities and suitable nitrogen fertilize

Seed priming (osmopriming) consists of imbibing seeds in an osmotic solution that allows pregerminative metabolism to proceed, but prevents radicle emergence. This treatment can increase rate, percentage and uniformity of germination or seedling emergence. The aim of this study was to investigate the effect of seed priming on germination and seedling development of fennel. The experiment was conducted in Petri-dishes using a factorial arrangement based on completely randomized design with three replications. Seeds of fennel were osmotically primed in -1, -1.5 and -2 MPa NaCl, KCl, KNO3 and polyethylene glycol 6000 for 24, 48 and 72 hours at 20○C. Priming with all of the osmoticums increased germination percentage significantly. Seeds primed with NaCl had 97% higher germination percentage than non-primed control seeds. Also, primed seeds with NaCl, KCl and PEG resulted in higher germination rate, greater seedling fresh weights and longer seedling root and shoot lengths than was the case for non-primed seeds. In this study increasing the duration of seed priming had negative effect on measured characteristics. Priming with NaCl and KCl had better results than other treatments. In this case, evaluation of the effect of seed priming on emergence and growth of fennel in farm condition is necessary.

The exotic plant, Swallow- wort, a twining perennial of the Milkweed family, has become increasingly invasive in some place of Iran, especially orchards. Increased knowledge of wort germination biology would facilitate development of an optimum control program. Germination of Swallow wort seeds as affected by environmental factors was studied under controlled-environment growth chamber conditions. The following studies were conducted in plant Pests & Diseases Research Institute during the years 2003-4: 1- Effect of constant temperature on germination that including 10, 15, 18, 20, 25, 30, 35 and 40˚C; 2- Effect of light on constant germination; 3- Effect of temperature fluctuations on seed germination: 15/7, 20/12, 25/17 and 30/22˚C. All experiments were conducted with 8 replications. Swallow wort seeds showed no dormancy when detachment from mother plant. Seed germination was strongly influenced by temperature. Light did not play a crucial role on seed germination of this weed. Therefore Swallow wort seeds were not photoblastic and temperature fluctuations did not increase seed germination of Swallow wort. The above characteristics are very important in making swallowwort an invasive weed. Having precise information of these traits enables us to a better management and control of this troublesome weed.

In recent years, biological fertilizers have received special attention by scientists in sustainable and low input agriculture. In order to study the effects of arbuscular mycorrhizal fungi and free living nitrogen fixing bacteria on growth and photosynthesis characteristics of corn in conventional and ecological cropping systems, a field experiment was conducted at the Research Farm of Ferdowsi University of Mashhad during year 2006. A split plots arrangement based on randomized complete block design with three replications was used. Treatments consisted four cropping systems (1- High input conventional system, 2- Medium input conventional system, 3- Low input conventional system and 4- Ecological system) and four inoculations (1- Mycorrhiza fungus, Glomus intraradices, 2- Bacteria, Azotobacter paspali and Azospirillum brasilense, 3- Dual inoculation, Fungus plus bacteria, and 4- No-inoculation, control), which were allocated to main plots and sub plots, respectively. All agronomic practices and inputs application during planting and nursing for each of cropping systems were conducted according to regional traditions. Results showed that the effect of inoculation on photosynthesis rates of corn was significant, as the highest photosynthesis rate obtained in dual inoculation. Single inoculation (fungus or bacteria) was ranked second. The effect of all inoculations on corn dry matter production was significant and dual inoculation produced the highest dry matter yield. The cropping systems have significant effect on corn yield and the difference between medium input conventional system and high input conventional system was significant, but the high input, low input and ecological cropping systems showed no differences. Inoculants affected the SPAD readings, and dual inoculation showed the highest SPAD readings. This study showed that utilization of low input conventional and ecological systems in combination with use of dual inoculation of arbuscular mycorrhizal fungus and free living nitrogen fixing bacteria could be a suitable replacement for high input conventional systems and chemical fertilizers

Four osmotica (water, hydrochloric acid (HCl 0.5 N), (HCl 0.1 N), sodium chloride 1.5 N and polyethylene glycol-6000 (PEG 6000) were used for priming of four varieties of sugar beet (Beta vulgaris) namely KWS, Universe, Afshari and Orbise. The type of experiment was Factorial on the basis of completely randomized design with three replications. Fifthy seeds were washed by distilled water, HCl, PEG 6000 and NaCl and then each of the above treatments were applied for two hours. The most promising treatments in terms of the rate and percentage of germination were water and HCl. Radicle and coleoptil lengths were shorter in NaCl and PEG is comparison with HCl and water. Varieties of KWS, Universe and Orbice had longer shoots that shows the restage of them was more than other varieties and the treatment of HCl increased the percentage and rate of germination

In order to investigate the effects of irrigation regimes and seeding rate on quantity of Isabgol (Plantago ovata) a field experiment was conducted at the Agricultural Research Station, Fersdowsi University of Mashhad, in April 2004. For this purpose a spilt-plot experiment based on complete randomized block design with three replications was used. Three irrigation intervals (every 7, 14 and 21 days) allocated in main plots and three seeding rates, 8, 12 and 16 Kg/ha allocated to sub plots. The results indicated that plant dry weight, plant height, number of spikes per plant and seed weight per spike were significantly affected by irrigation intervals and decreased irrigation intervals caused to increasing the above parameters. The effect of treatments on spike length and seed yield, was not significant. Effect of seeding rates on spike length, number of seeds per spike and seed yield was significant. However, the highest seed yield was obtained at the highest seeding rate (16 Kg/ha). Effect of seeding rates on plant dry weight, plant height and number of spike per plant, was not significant. The effect of different irrigation regimes and density on seed quality characters was studied in a complete randomized block design with three replications. The results indicated that effects of treatments on the amount of mucilage was significant and the highest amount of mucilage was produced at higher seeding rate (16 Kg/ha).

In order to investigate potssium leachate test for evaluation alfalfa (Medicago sativa L.) seed vigor, seeds of four cultivars: Hamedani, Yazdi, Maopa and Garayonge were kept for 0, 2, 3 and 4 days in accelerated aging conditions with 41oC temperature and %100 relative humidity. Then germination percentage and seedling length was measured in standard germination test. Afterwards one gram seeds of each cultivar in various aging treatments were soaked in 50 ml distilled water for 60, 90 and 120 minutes. Then the amount of electricl condutivity and potassium were measured and results were compared with germination percentage and seedling length. Results showed that each accelerated aging treatments can be used for distinguish differences between of alfalfa cultivars seed vigors. Also results of potassium leachate test as well as electrical condutivity test in imbibition priods used in this expriment can be used for ranking alfalfa seed vigor. On the basis of results, 60 minutes imbibition were sufficient for these tests.If the results of this experiment will confirmed with field experiments,both electrical conductivity and potassium leachate tests after 60 minutes seed imbibition will the fastest methodes for evaluation alfalfa seeds viability and vigor.

In order to determine freezing tolerance of 14 wheat cultivars including Anza, Bezostaja, Pishtaz, Tous, Zagros, Zarrin, Shahryar, Falat, Qods, Glenson, Maron, Navid, Niknejad and MV-17 that were grown on field, samples of each cultivar after hardening in the field were harvested in 4-6 leave stages and trimmed to 2cm above and below the crowns and put on the thermogradient freezer. After freezing in the range of 0 to -20 oC, samples were transferred to the greenhouse and planted in the pots. Survival percentage, height, leaf area, chlorophyll content, dry weight, LT50 and DMT50 were determined after 3 weeks. Survival percentage after freezing was different in cultivars

In order to study the effect of drought and salinity stress on quantitative and qualitative yield in reproductive growth stage of safflower (Carthamus tinctorius L.), an experiment was conducted on two successive years 2003 and 2004 growing season in Field Research Station of Ferdowsi University of Mashhad, Iran. A split plot design using the base of randomized complete block design applied, where level of irrigation including complete irrigation during whole growing season (control), cutting irrigation at flowering (medium stress) and cutting irrigation at heading bud formation (high stress) as main plot, and safflower cultivars including Isfahan, Arak, and KH as subplot. Source of irrigation water was saline water pumped from the deep well with electrical conductivity (EC) of 4.9 dS/m. Result shows that cutting irrigation at heading bud formation caused a significant reduction in plant height, head number per plant, number of seed per head, seed weight, seed yield, oil yield and chlorophyll content. The highest seed and oil yield in both years obtained from KH cultivar and the lowest seed and oil yield was belonging to Isfahan cultivar. Overall results showed that in non- stress conditions Arak variety showed the best growth and yield performances, while in drought stress conditions KH variety is a better alternative. All three cultivars of safflower complete their life cycle with a satisfactorily yield in the presence of salinity.

Global warming will affect all climatic variables and particularly rainfall patterns. The purpose of present investigation was to predict climatic parameters of Iran under future climate change and to compare them with the present conditions. For this reason, UKMO General Circulation Model was used for the year 2025 and 2050. By running the model, minimum and maximum monthly temperature and also maximum monthly rainfall for the representative climate stations were calculated and finally the effects of climate change on these variables based on pre-determined scenarios was evaluated. The results showed that averaged over all stations, mean temperature increase for spring in the year 2025 and 2050 will be 3.1 and 3.9, for summer 3.8 and 4.7, for autumn 2.3 and 3 and for winter 2.0 and 2.4 ºC, respectively. This increase will be more pronounced from North to the South and from East to the West parts of the country. Mean decrease in autumn rainfall for the target years of 2025 and 2050 will be 8 and 11 percent, respectively. This decrease is negligible for summer months. Length of dry season for the years 2025 and 2050 will be increased, respectively up to 214 and 223 days due to combined effects of increased temperature and decreased rainfall.

Root and shoot characteristics of chickpea (Cicer arietinum L.) genotypes are believed to be important in drought tolerance. There is a little information about the response of genotypes root growth in hydroponics and greenhouse culture, also the relationships between root size and drought tolerance. This study was conducted to observe whether genotypes differ in root size, and to see that root size is associated with drought tolerance during early vegetative growth. We found significant differences (p0.01) in root dry weight, total root length, tap root length, root area, leaf dry weight, leaf area and shoot biomass per plant among 30 genotypes of chickpea grown in hydroponics culture for three weeks. Each of these parameters correlated with all others, positively. Among 30 genotypes, 10 genotypes with different root sizes were selected and were grown in a greenhouse in sand culture experiment under drought stress (FC %30) for three weeks. There were not linear or non-linear significant correlations between root characters in hydroponics and greenhouse environments. It seems that environmental factors are dominant on genetic factors in seedling stage and so, the expression of genotypics potential for root growth characteristics of genotypes are different in hydroponic and greenhouse conditions. In this study, the selection of genotypes with vigorous roots system in hydroponic condition did not lead to genotypes with the same root characters in greenhouse environment. The genotype×drought interactions for root characters of chickpea seedlings in 30 days were not significant (p

In order to correlate corm size and storage period of corms to allocation of assimilates in different parts of the plant an experiment was conducted during growth period of 2004 and 2005 in Faculty of Agriculture, Ferdowsi University of Mashhad. Treatments were four groups of corm size (3-6, 6-9, 9-12 and 12-15 g) either stored for a period of time before planting or sown directly without storage. Experiment was conducted in a Complete Randomized Block design with three replications. Results indicated that storing corms before planting had a negative effect on number, area, length and width of leaf and also on weight of leaf, weight of main shoot, weight of leaves of lateral shoots and total weight of plant. However, weight of corm, number and weight of lateral shoots and area of lateral leaf was not affected by storing the corms. Nevertheless, in the second year, number, length and weight of leaf on main shoot, number of cormlet, number, area and weight of leaf on lateral shoots, total weight of plant, corm weight, weight of main shoot and weight of lateral buds was reduced while leaf width were not affected. Effect of corm size on almost all measured parameters was positive and with increasing corm weight an increasing trend was observed in the above parameters. No flower was observed on corms which were stored, while corms which planted after lifting produced flowers and Larger corms of 9-12 and 12-15 g were superior in terms of number of flowers per unit area and also weight of flower and stigma per unit area. Corms with 9-15 grams planted immediately after lifting the corms produced higher yield.

In order to evaluate the electrolyte leakage as an indicator of freezing injury in colza (Brassica napus L.) genotypes under controlled conditions, a trial carried out at the green¬house of College of Agriculture, Ferdowsi University of Mashhad. In this study 10 rapeseed genotypes, with 5 temperatures (0, -4, -8, -12 and -16 °C) on subplot and acclimation and non acclimation on main plot were evaluated on RCD factorial split plot with two replications. Plants were kept until 3-5 leaf stage in green¬house condition with 23/16 2 °C (day/night) and natural photoperiod. Pots were subjected to acclimation (for three weeks) or non acclimation that plants immediately frozen.For acclimation treatment after three weeks freezing was done in thermogradient freezer. The cell membrane integrity was measured through electrolyte leakage and the lethal temperature 50 (LT50) of samples also were determined. There were significant differences (p

Agroecosystem Health investigating requires a holistic approach based on its biophysical, socio-economic and human community dimensions. In order to assess Agroecosystem Health in Mahhad, this research was conducted for the period of 1982 to 2002. The assessment necessitates the selection of indicators which represent various aspects of the agroecosystem. The purpose of this study was to establish a conceptual framework that facilitates the assessment of Agroecosyetem Health. The first step was to develop a set of indicators. Data on structural, functional, and organizational indicators were collected from official documents and statistics and also questionnaires. Results showed that from 1982 to 1997 Health Index (HI) decreased and the lowest HI was in 1997 and after that trend of HI was improved. Sensitivity analysis showed that functional criteria had the highest correlation with HI. To improve the HI in short term, the most effective parameters would be functional indices such as chemicals, water use efficiency, soil degradation, machinery costs, and education indices. The index of people’s concern on environmental issues showed that 69% are concerned about the environment. This could be a good reason for the governmental and non-governmental organizations to focus on environmental health and try to improve the level of HI. The index of government’s financial support to agricultural section has decreased from 1982 to 1997

In order to evaluate competition ability of Grain maize (Zea mays L.) against redroot pigweed (Amaranthus retroflexus L.) a field experiment was conducted at Esfahan on 2003. In this research the effect of corn spatial arrangement on yield and yield components of corn (647 Three Way Cross hybrids) under different levels of redroot pigweed infestation was investigated. Treatments were arranged in a factorial split experiment based on RCBD with three replications. Factorial arrangement of corn densities (74000 and 111000 plant ha-1) and planting patterns (single row, rectangular twin row and zigzag twin row) formed the main plots. Split-plots referred to pigweed densities (0, 4, 8 and 12 plant m-1). Results showed that both grain and biological yield of corn increased as corn density rates increased but rows number per cob, number of grains per row of cob and 1000 grains weight decreased. The effects of planting arrangement on yield and yield components despite rows grain in cob, 1000 seeds weight and harvest index were statistically significant. Corn grain yield and yield components decreased significantly by increasing pigweed density. The effect of redroot pigweed density on corn grain and biological yield loss was predicted using Cousence hyperbolic yield equation. It showed that maximum grain yield loss and biological yield loss happened in single row arrangement and low corn density. Rows number per cob and grain numbers per row in higher corn density treatment showed lower reduction slopes under pigweed competition. In addition, grain rows numbers per cob and corn harvest index in twin arrangement treatments decreased lower than single row treatment under pigweed competition. The results of this research indicated that corn competition ability against redroot pigweed could be increased using dense population (1/5 fold of general density) and zigzag twin row arrangement.