نشریه بوم شناسی کشاورزی
سال دوم شماره 2 (تابستان 1389)

Cultivated area, yield and production trend of wheat ¬¬¬(Triticum aestivum L.), barley¬ (Hordeum vulgare L.), potato ¬(Solanum tuberosum L.), alfalfa (Medicago sativa L.) and chickpea (Cicer arietinum L.) as the main crops of Kurdistan province were studied during 1983-2006 using time series analysis and the situation of future were predicted for 2006-2021 period. The results showed that the cultivated area of irrigated wheat (18%), rainfed wheat (10.3%), rainfed barley (30.1%), rainfed chickpea (48.2%), potato (42.4%) and alfalfa (9.2%) will be increased; while the cultivated area of rainfed barley (31.1%) and irrigated chickpea (100%) will be reduced. The yield of irrigated wheat (36.3%), rainfed wheat (43.5%), irrigated barley (30.2%), rainfed barley (23%), irrigated chickpea (10.6%), potato (9.3%) and alfalfa (14.5%) will be increased and yield of rainfed chickpea (36.8%) will be reduced until year 1400. Therefore, the amount of production of all crops except irrigated chickpea will be increased during oncoming 15 years. On the basis of results, the rate of irrigated wheat, dryland wheat, irrigated barley, dryland barley, dryland chickpea, potato, and alfalfa production will be 270, 1000, 20, 20, 30, 530, and 270 thousand tones, respectively, and the amount of irrigated chickpea production will be zero at 2021. The reason for reduction of irrigated chickpea production will reduce of cultivated area. Based on results of this study the increasing of yield and cultivated area have a more important role in the increasing of cereal and alfalfa production and irrigated chickpea and potato production, respectively. Thus it can be concluded that although amount of crops production in province will improve during oncoming 15 years, however, due to limitation in arable lands in that province, more efforts should be focused on improving management methods in order to increase crops yield. It is emphasized that the results of this study are the basis of past trend and the effects of some factors such as climate change and administration politics in agriculture was ignored.

A greenhouse experiment was conducted using completely randomised design (factorial) with three replications to study the residual effect of organic manures (municipal solid waste compost and cow manure), zinc (0 and 50 kgha-1) and boron (0 and 10 kg.ha-1) by using ZnSO4 and H3BO3 salts respectively, (applied earlier for millet (Panicum italicum L.) crop) on soil properties and chemical composition of wheat (Triticum aestivum L.). Results showed that the residual effect of Zn increased total plant dry weight, available Fe and Zn concentrations of soil and plant significantly. While, available B concentration in plant decreased by 30.9% with increasing Zn application. The residual effect of B at 10 kg.ha-1, increased Fe, Cu and B contents of plant by 2%, 1.4% and 65.6%, respectively. While no significant effect was noted with respect to plant Zn content. Irrespective of Zn and B availability, application of residual organic matter significantly increased Fe, Zn, Cu and B contents of plant. Interaction effects of Zn, B and organic manures resulted in a significant Zn, Fe, B and Cu contents of plant. It is concluded that the residual effects of organic matter, Zinc and boron applied for previous millet crop, showed significant impacts in improving soil productivity and crop quality.

In order to study the effect of strip intercropping of maize (Zea mays L.) and bean (Phaseolus vulgaris L.) on the dry matter yield and land equivalent ratio (LER) in weedy and weed free treatments, an experiment was conducted at the Agricultural Station of College of Agriculture, Ferdowsi University of Mashhad, Iran. Treatments were strip width of 2, 3, 4 and 5 rows and sole cropping of each crop. In addition two levels of weedy and weed free as strips were also included. Results indicated that treatments affected dry matter accumulation of maize and bean. The highest dry matter accumulation found in two strip widths and sole crop showed the lowest. Thus by increasing strip width dry matter was decreased. Weeds decreased dry matter accumulation by reduction of both rate and content of dry matter. Increasing of strip width reduced dry matter yield of maize and bean, and two strip widths showed the highest dry matter yield. Dry matter yield in intercropping treatments were more than sole crops in all side rows. In side rows, weeds reduced biological yield of sole stand of maize, bean and intercropped by 18.7, 23.5 and 20.3 percent compared to weed free treatments respectively. In central rows these values were 29.6, 21.3 and 27.3 percent, respectively. Land equivalent ratio in strip intercropped was more than sole crops and was reduced with increasing strip width. Intercropped LER in weedy treatment enhanced 29 percent in side rows and 21 percent in central row

In order to evaluate the application of methanol on yield and yield components of soybean (Glycine max L., var. L 17) in field conditions, experiments were conducted based on a randomized complete block design with three replications at the Field Research from Faculty of Agricultural of Islamic Azad University Karaj, Iran, during 2008. Sprayed aqueous solutions were zero (control), 7, 14, 21, 28 and 35% (v/v) methanol by there times during growth season of soybean with 15 days intervals on shoot of soybean. In this study soybean grain yield, biomass HI, 1000 grain weigh, height plants, number of branch, diameter of stem, number of pod on plant, number of hollow pod were measured. Results of the experiment indicated that there are significant differences (p>0.05) between sprayed of solution methanol on all parameters. Results also showed the effect of aqueous solution 14, 21 and 28% (v/v) methanol on measured parameters was greater than other treatments. Foliar application of 14% and 21%, (v/v) methanol increased leaf area index, crop growth rate, pod growth rate, leaf area duration, pod yield, seed yield, weight of 1000 kernel, mature pods per plants. The lowest grain yield obtained in control plots and 35% (v/v) methanol treatments

Soil and water sources salinity are important constrains which threat the sustainable agriculture production in Iran. In order to evaluate the effect of different antioxidants and salinity levels on germination and seedling properties of two medicinal species (Cnicus benedictus L.), and (Cichorium intybus L.), an experiment was conducted using a factorial based on completely randomized design with four replications at Special Crops Laboratory of Ferdowsi University of Mashhad. The studied factor for each plant included: seed priming at 4 levels including control (distilled water), ascorbic acid (40 mM), gibberlic acid (75 mg.lit-1) and salicylic acid (1.5 mM), and five salinity levels according to electrical conductivity by adding NaCl to distilled water (control, 5,10,15 and 20 ds.m-1). According to results, pretreatment with salicylic acid improved all of the germination and seedling properties in Cnicus benedictus L. but gibberlic acid could to improved germination and seedling properties in Cichorium intybus L. species. There were strong correlation between germination rate and radical and caulicle length especially on Cichorium intybus species. Generally, seed priming with gibberlic acid and salicylic acid could improve germination and seedling properties of these two species. Both species showed a reliable tolerance to NaCl salinity at germination stage, and germination was 60% compared with control at 20 ds.m-1 treatment.

In order to understand the effect of plant density and different fertilizers on sesame (Sesamum indicum L.) production, an experiment was conducted as a factorial arrangement based on completely randomized block design with three replications. The experimental treatments were fertilizers in four levels (cow manure (30 t.ha-1), municipal compost (30 t.ha-1), chemical fertilizer (250 kg ammonium phosphate + 100 kg urea) and control (no-fertilizer)) and plant density in four levels (20, 30, 40 and 50 plant.m-2). The results showed that all treatments increased the plant height, number of capsule per plant, plant biomass, seed yield, seed weight and number of seed per plant compared to control, significantly. The highest amount of the traits was obtained in manure treatment. The seed yield was increased by increasing plant density, but decreased the plant height, number of capsule per plant, plant biomass, seed yield and weight and number of seed per plant, significantly. 1000-seed weight, harvest index and weight of seed per capsule had no affected by treatments. Our result indicated that the density of 40 plant.m-2 among using manure was the most appropriate of cropping pattern in our experiment.

In order to study the effects of different levels of drought stress and plant growth promoting rhizobacteria on the germination indices of seeds harvested from wheat (Tritium aestivum L.) cv. Sayonz in the field treated with different levels of nitrogen, in controlled conditions, a factorial layout based on completely randomized design with three replications, was conducted. Treatments included the seeds that collected from field that received amount of 0, 120, 240 and 360 Kg.ha-1 nitrogen fertilizer, types of biofertilizer (nitragin, biophosphouros and control) and different levels of drought stress (0, -4, -8 and -12 bar). The results showed that simple effects of levels of biofertilizers and levels of drought stress were significant on the all germination characteristics of wheat, except for mean germination time, radicle length to plumule ratio and dry weights of radicle to plumule ratio, while levels of nitrogen fertilizer only was significant on germination, germination rate and germination index. The interaction effects had showed that the seeds harvested from nitrogen fertilizer at 240 Kg/ha and drought stress 0 and -4 bar had the highest germination. Nitragin bifertilizer increased drought stress resistance compared with control, so that the stress level -4 bar reducing germination for seeds treated with biosphouros and non-inoculated, than plants treated with nitragin, were 40 and 79%, respectively. Effects of three nitrogen fertilizer, biofertilizer and levels of drought stress were not significant on the characteristics measured.

A total of twenty local and foreign maize (Zea mays L.) hybrids in five different maturity group were studied in Mashhad for two years (2007-2008). Temperature variations were created by two planting dates (5 May and 20 May). Results indicated that both indices, GDD and CHU, estimated heat units of different maturity hybrids and based on, created similar groups of hybrids. Both indices showed some changing in grouping of some hybrids. In general, the GDD to maturity discriminated different FAO maturity groups. Late hybrids accumulated more GDD during grain filling period. Required CHU was higher for the period to flowering than do from flowering to maturity. By increasing the maturity group, the required CHU for reproduction period increased as well. In general, based on the similar results in using both indices, regarding the simple calculation of GDD, we can recommend the use of GDD in grouping maize hybrids based on heat units in cold-temperate regions.

Canola (Brassica napus L.) is one of the most important oil seed crops. In order to evaluate the effects of integrated fertilization (chemical, manure and biofertilizers) on canola (B. napus variety Hyola 401) yield and uptake of mineral nutrients in saline soil and water, a field experiment was conducted in randomized complete blocks (RCBD) arrangement with eight treatments in three replications in Qum Province, Iran. Treatments were: (1) Control, P%100 (Phosphorus %100), (2) P%75B1 (Phosphorus %75+ Barvar biofertilizer), (3) P%75B2 (Phosphorus %75+ Nitroxin biofertilizer), (4) P%75M (Phosphorus %75+ farmyard manure), (5) P%75B1M (Phosphorus %75+ Barvar + Farmyard manure), (6) P%75B2M (Phosphorus %75+ Nitroxin+ Farmyard manure), (7) P%100B1 (Phosphorus %100 + Barvar) and (8) P%125B2 (Phosphorus %125+ Nitroxin). The results showed that the highest yield was obtained from P%75B1M. Difference between integrated fertilization of farmyard manure and other treatments was significant. Farmyard manure increased canola yield which was attributed to increase in availability of mineral nutrients, decreasing effects of salinity and toxic ions. Integrated application of 5 t. ha-1 of farmyard manure and %75 recommended chemical P increased yield and decreased fertilizer consumption. The results revealed that integrated applications of farmyard manure and chemical fertilizer and after that integrated use of bio- and chemical fertilizer are the best strategies to increase nutrient availability and improving canola yield in saline soil.

Biofertilizers are natural inputs that can be applied as complement or substituent of chemical fertilizers in sustainable agriculture. Effects of N and P bio- and chemical fertilizers on growth indices of maize (Zea mays L.) was studied on 2008 in Shushtar, Iran, based an as a factorial experiment based on completely randomized block design with three replications. Treatments consisted four levels of biological and chemical fertilizers, A1 (100% Chemical fertilizer), A2 (50% Chemical+biological fertilizer), A3 (25% Chemical+biological fertilizer), and A4 (Biological fertilizer). Results showed that integrated application of biological and chemical fertilizers increased stem length,leaf area index (LAI), dry mater (DM) accumulation, crop growth rate (CGR), relative growth rate (RGR), leaf area duration index (LAID) and leaf area ratio (LAR) in relation to chemical fertilizers, the highest and the lowest plant height was observed at 115 day after planting in A2 (186cm) and A1 (178cm), respectively. The minimum and the maximum LAI was observed at 71 day after planting in A3 (4.71) and A4 (2.3) treatments, respectively. Similar trend was observed in DM accumulation (20.37 and 12.48 t.ha-1, respectively) and net assimilation rate at 94 day after planting (19.4 and 11.3 g.m-2) and crop growth rate at 71 day after planting (44.8 and 26.5 g.m-2, respectively).

In order to evaluate the effect of sowing date and plant density on the morphological triats, yield and yield components of sweet corn (Zea mays L. var SC. 403) an experiment was conducted at the Khorasan Razavi Agricultural Research and Natural Resources Center, Mashhad, Iran during 2008. This experiment was carried out as split plot based on RCBD with four replications. The sowing date (14th June, 3th July and 24th July) and plant densities (66600, 83300 and 111000 plants.ha-1) were arranged in main and sub plots, respectively. The results showed significant differences between different sowing dates for plant height, ear height, and no. of leaves/plant, no. of leaves above ear, stem diameter, dehusked ear yield, can grains yield, no. of grain rows/ear, ear length, ear diameter, kernel depth, no. of ear.plant-1, 1000 kernel weight, ear harvest index and plant harvest index. The highest and the lowest can grains yield with 18.27 and 0.930 ton ha-1 was belonged to 14th June and 24th July sowing date, respectively. Although, delay in sowing date, led to decrease of growth period and also decrease of temperature can lead to improper transfer of photosynthetic materials and cause to grains yield decrease. The plant density had significant effects on husked ear yield, dehusked ear yield and forage yield. The highest can grains yield was harvested from the highest plant density (8.862 t.ha-1) and the lowest can grains yield derived from the lowest plant density (66600 plants.ha-1) with 7.692 t.ha-1). Finally, the interaction of sowing date and plant density was significant only for harvest index. Therefore, the sowing date 14th June and the highest plant density (111000 plants.ha-1), is recommended for summer sowing date of sweet corn in Mashhad with maximum and better can grains production.

In order to evaluate physiological and morphological characteristics and yield of soybean (Glycine max L.) cultivars under different planting ratios a field experiment was conducted based on randomized complete block design with four replications at the Gaem¬shahr Agricultural Research Centre of Mazandran Province, Iran, during 2008. Two soybean cultivars (032 and Sari) were planted in row intercropping in 3:1, 2:2, 1:3 and pure cultures variety planted as replacement method, respectively. The Results indicated that the planting ratio had significant effect on pod dispersal in different parts of main stem and yield of soybean cultivars. The pod number to one third mid in main stem into 53 percentages was more in 032 in pure stand and pod number to one third up into 56 percentages was more in Sari cultivar pure stand. Intercropping ratio showed significant effect on leaf area index (LAI) and total dry weight (TDW) soybean cultivars. Leaf area index (LAI) and total dry weight (TDW) was higher in 2:2, 1:3 and 3:1 planting ratios compared to pure stand in each cultivar. The highest Land equivalent ratios (LER) and seed yield on mean which was 4558 kg.ha-1 were belong to 2:2 planting ratio. In general the highest yield of soybean cultivars was in 2:2 planting ratio which may cause increasing in LAI and suitable pod dispersal in different parts of canopy structure of soybean cultivars.

In order to investigate the effects of corm tunic, corm weight and drought stress on saffron (Crocus sativus L.), an experiment was conducted at the greenhouse of Ferdowsi University of Mashhad, Iran. Treatment were combination of four corm weights range (2-4, 4-6, 6-8 and 8-10 g), two levels of water availability (100% field capacity and drought) and two levels of corm tunic (natural corm with tunic and without tunic) as factorial arrangement based on completely randomized block design with three replications. The corms were divided to four groups based on their weights and removed tunics of corm in tunic free treatment. Results indicated that the highest biomass produced in irrigation, corms with tunic with maximum weight. Both chlorophyll a and b contents decreased significantly under drought stress and chlorophyll b content was 50% of chlorophyll a content. Effect of corm size and corm tunic and interaction of these treatments imposed a significant effect on the leaf number per plant, leaf weight and chlorophyll content. Effect of corm tunic in 8-10 g corm size increased ch (a)/ch (b) ratio and leaf number. The relative water content was decreased in drought treatment in both tunic and tunicless treatments and the best corm weight in all treatment was 6-8g and could be useful to tolerate drought stress

In this study 18 forage corn (Zea mays L.) hybrid varieties were evaluated based on RCBD with four replications in Khorasan Razavi Agricultural and Natural Resources Research Centre, Iran, on 2008-2009. Result of analysis of variance showed that there was significantly difference between hybrids in forage yield, ear weight and ear to biomass ratio. Results of hybrids mean comparison with Duncan’s multiple range test showed that SC700 was higher than other investigated hybrids in forage yield trait. But hybrid 3 with 85.31 forage yield was the best hybrid in weight of ear and ear to biomass ratio. Though the SC704 hybrid was better than others for stem dry weight, ear dry weight and leaf area but there was not any significant difference between this hybrid and hybrid 3.

The study was performed for assess the environmental factors affecting weed species diversity and composition of wheat (Triticum aestivum L.) fields in Jajarm, North-Khorasan of Iran, in 2009. The crop management (herbicide, amount of nitrogen applied and preceding crop type) and edaphic factors (pH, texture and content of phosphorus) of 16 fields were collected. Shannon’s diversity index, species richness and Simpson’s dominance index were used as measures of species diversity. Means comparison showed that use of herbicide versus non-herbicide application, silt texture than loam texture and planting after fallow versus planting after melon significantly decreased species richness (4.92 versus 7.12, 5 versus 6.5 and 5.12 versus 6.75 for herbicide, soil texture and preceding crop type, respectively) and Shannon’s diversity index (1.08 versus 1.6, 1.1 versus 1.48 and 1.19 versus 1.49 for herbicide, soil texture and preceding crop type, respectively), but increased Simpson’s dominance index (0.43 versus 0.25, 0.41 versus 0.3 and 0.39 versus 0.29 for herbicide, soil texture and preceding crop type, respectively). Regression analysis revealed negative linear relationship between applied nitrogen and diversity components (r2= 0.45). The relationship between applied nitrogen and Simpson’s dominance index was positively linear (r2= 0.46). There wasn’t relationship between pH and phosphorus of soil with Shannon’s diversity index, species richness and Simpson’s dominance index. Redundancy analysis (RDA) resulted in patterns per weed community composition (F= 4.03, P-value= 0.001). Major changes in weed species composition in the study area were associated with application of herbicide. Using of 2, 4- D and nitrogen fertilizers lead to domination of grass in these fields. The method of variation partitioning out showed that crop factors on changes in arable weed species composition are more important edaphic variables.

To identify the impacts of chemical control of weeds on wheat aphids community, a field experiment was conducted in a completely randomized design with two factors, each in three replicates in a 20-ha wheat field. The herbicide treatment used Tribenuron methyl, a broadleaf–selective herbicide and the control treatment not treated with herbicide. All other agricultural practices were the same for both treatments during the season. Standard weekly sampling of the aphids associated with aerial parts of wheat plants commenced a week after herbicide application and continued for seven weeks. Among the seven aphid species collected in this study, Sitobion avenae, Methopolophium dirhodum and, Schizaphis graminum were the most abundant species. After square root transformation and normality test, analyzing data showed greater number of aphids in herbicide treatment than in control, but this difference was not significant. However, whether these differences can be explained by differences in density and diversity of weeds needs tritrophic interaction studies: weeds-aphids and natural enemies of aphids.