Journal of Agricultural Science and Sustainable Production
Year:2012 | Volume:21/2 | Issue:4|Papers Count:12

In order to investigate the effects of osmotic pretreatments on germination of tomato seeds, a factorial experiment was performed in completely randomized design with three replications in Agriculture and Natural Resources Research Center of Mazandaran province in 2011. Experimental treatments, including tomato cultivars ergon, norma and ravista and five pre-treatment, including polyethylene glycol (PEG 6000), potassium chloride (KCl) with concentrations of 5 and 10 percent, water and control respectively. The results showed that the maximum root length and shoot number were treated by pre-treatment and 10 percent concentration of PEG and ergon figure was obtained, but the maximum length of seedlings ergon figure was obtained. Most roots to shoot length ratio (R/S) under the pre-treated by PEG with concentrations of 5 and 10 percent figure was ergon. The maximum ratio of dry weight and root to shoot (R/S) respectively by making Prime water and potassium chloride (KCl) with concentrations of 10 percent were the result. Most normal germination and the total number of germinated seeds were pre-treated with a variety ravista by water and polyethylene glycol was obtained. Maximum germination rate of treated cultivars and priming were treated with PEG concentration of 10 percent and the figure was ergon. The highest and lowest percentage of germination, respectively, norma and ravista cultivars was concluded. While the maximum fresh weight of root and shoot respectively, before treatment with potassium chloride concentration of 10 percent was obtained. Most indicators with pre-treatment Vigor 1 by PEG concentration of 10 percent in number and ravista KCl concentration of 5 percent and the highest index figure norma vigor 2 also related to PEG concentrations ergon 5 percent figure was obtained.

In order to estimate relationship among rapeseed quantitative traits using correlation and regression coefficients, as well as to assess direct and indirect effects of specific traits to oil yield via path analysis, 14 rapeseed cultivars in two years were evaluated using randomized complete block design with three replications in Rice Research Institute of Iran, Rasht, Iran during 2005-2007 cropping seasons and 13 traits were measured. The results of combined analysis showed significant difference among years, genotypes and year×genotype for most studied trait that be indicated the existence of genetic variation among varieties. Oil yield had a significant positive correlation with grain yield, oil percent and grain weight, while had a significant negative correlation with DS. Results of stepwise regression analysis of oil yield showed that traits grain yield, oil percent and days to flowering had the highest effect on oil yield and was attributed 99.1% of oil yield variation. According to path analysis, grain yield and followed by oil percent had the highest direct effects on oil yield. Based on the results grain yield and grain weight was proposed as selective index to reach the high oil yield.

Wheat is the most important crop plant in Iran and self sufficiency in wheat production is one of the economical and food safety policies in the country. In spite of efforts have been carried out in this area, the mean of wheat yield in Iran is less than its world average. To identify high yielding wheat lines with optimal characteristics and determination of traits to use as selection index, 180 recombinant inbred lines derived from a cross between Norstar (winter wheat) and Zagros (spring wheat) cultivars were evaluated in a randomized complete block design with two replications. During the experiment, grain yield, number of grain per spike, 1000 grain weight, spike length, number of fertile tiller, plant height and winter survival were measured. Analysis of variance revealed significant differences among the lines for all the studied traits except winter survival and transgressive segregation was observed for grain yield, number of grain per spike, number of spike per m2, plant height and spike length. In path analysis, 1000 grain yield, number of grain per spike and number of spike per m2 with positive direct effects on grain yield determined about 93.2 of this trait variation. Considering high heritability of these characters compared with grain yield, they could be use as indices in selection of high yielding lines. Based on grain yield per m2, 14 lines were superior to Norstar (high yielding parent). Considering optimal characteristics of these lines, they could be evaluated at multi-environment experiments for selection of high yielding genotypes.

Suitable weather and environmental conditions have provided a considerable share of agricultural activities next to Industrial and services in Hamedan province of Iran which is very important for sustainable rural development of the area. This study aims to determine the comparative advantage of walnut production in Hamedan province of Iran. The policy analysis matrix model (PAM) has been used to measure the comparative advantage of walnut product for the agricultural year of 2008-2009.The research founded the existence of indirect taxation on outputs from one hand and indirect subsidy on tradable inputs on the other hand. That means the government could not effectively support the policy of import substitution policy of walnut in the state. Whereas, the domestic resource cost index shows existence of comparative advantage of walnut production in the area.

Dill (Anethum graveolens L.) is one of the most important medicinal plants with great applications in different medicinal industries. In present study, effects of biologic and chemical nitrogen fertilizers were evaluated on growth, yield and essential oil constituents of dill. The research was conducted under field condition in randomized complete block design with three replications. The treatments included chemical fertilizer (150 kg/ha urea), biofertilizer (Azospirillum/Azotobacter), combinations of biofertilizer and 50% chemical fertilizer and control. Different characteristics such as plant height, number of umbel per plant, number of umbellet per umbel, number of grain per umbelet, 100 seed weight, grain yield, biologic yield and oil percentage were recorded. According to the results, the highest height, biologic yield and grain yield components (except the number of grain per umbellet) obtained on chemical fertilizer and combinations of biofertilizer and 50% chemical fertilizer. Results showed highest harvest index and essential oil content detected in chemical fertilizer and combinations of biofertilizer and 50% chemical fertilizer. Identification of essential oil components showed that content of carvone increased with application of nitrogen fertilizers. Results indicated, application of biofertilizers enhanced yield and other plant criteria in this plant. Generally, it seems that using of biofertilizers or combinations of biofertilizer and 50% chemical fertilizer could improve dill performance in addition to reduction of environmental pollution.

In order to evaluate the effects of drought stress, poultry litter and urea fertilizers on agronomic properties of forage maize (cv. SC704), a spilt-plot experiment arranged in randomized complete blocks design was conducted with four replications at the research station of Shahrekord University in 2009. The main plots consisted of irrigation treatments at two levels, normal irrigation and irrigation stop at pollination stage for two weeks. Sub-plots were assigned to fertilizer treatments with three levels of urea fertilizer (F1=217, F2=435 and F3=652 kg ha-1), and three levels of poultry litter (F4=5.28, F5=10.57 and F6=15.86 Mg ha-1) and F0 as the control (no fertilizer) treatment. Results showed that drought stress had a significant effect on stem and ear fresh weights, ear diameter and fresh forage yield, but not on green and yellow leaf numbers, leaf area index, tasselling and silking creation, anthesis–silking interval, plant height, stem diameter, ear length and leaf fresh weight. The effects of fertilizer treatments were significant on all the measured characters with the exception of leaf numbers. The application of nitrogen resulted in an increase in forage yield, most likely due to increased leaf area index, leaves, stem and cob weights, length and diameter of cob, stem diameter, plant height and decreased anthesis–silking interval in N-fertilized treatments. Poultry litter and urea fertilizer×drought stress interactions were observed for leaf area index, leaf and stem fresh weights. The highest fresh forage yield (101 Mg ha-1) was observed in the normal irrigation and 15.86 t ha-1 of poultry litter treatments that significantly differed from other treatments. However, if a large quantity of poultry litter is unavailable, 10.57 t ha-1 of this manure that had no significant differences as compared with 652 kg ha-1 of urea fertilizer, would lead to an optimum yield.

Considering safety and environmental issues are very important in all domains of agriculture, industry and services in different countries. In the agricultural domain despite of numerous efforts to find alternative methods, millions of liters of toxic chemicals are used by chemical methods to control plant pests every year. Certainly, the most important issue in spraying is the size of drops which is influenced by several factors including pressure, nozzle hole diameter, viscosity of the chemical solution and wind speed in the area. In this study, MLP network Feed Forward modeling was used. Input consisted of two layers including nozzle diameter (three sizes) and spraying pressure (three pressure levels). Output of the artificial neural network determined by volume median diameter. In order to choose the best procedure, five methods including gradient descending, descending gradient with momentum, Levenberg-Marquart, conjugate gradient and Delta Bar Delta were used. Considering both minimum mean square error and coefficient of determination, the descending gradient with momentum was chosen. After training and validation of the network, MSE and coefficient of determination were 0.0176 and 0.90, respectively. In order to verify the results from neural network several tests were carried out and observed particle diameters were compared with values obtained from neural networks by chi-square test. The difference was not significant. These results indicate that neural networks can estimate properly the size of the droplets.

A field experiment was conducted in 2008, to investigate the effects of different irrigation treatments (I1, I2, I3 and I4: well-watering on the bases of 70mm evaporation from class A pan and irrigation disruptions at flowering stage, grain filling stage and during flowering and grain filling stages, respectively) on growth and yield of three pinto bean cultivars (Talash, Khomain and COS16). The experiment was arranged as split-plot based on randomized complete block design in 3 replications, with the irrigation treatments in main plots and pinto bean cultivars in sub-plots. Dry matter accumulation, crop growth rate, relative growth rate and grain yield per unit area decreased, due to water stress at reproductive stages. The percentage of grain yield reduction under irrigation disruption during flowering and grain filling stages compared to well-watering condition was about 40.25% .The most reduction was happened at water disruption during flowering and grain filling stages. Dry matter accumulation and crop growth rate of Talash was higher than for Khomain and COS16. Grain yield of khomain was slightly higher than that of other pinto bean cultivars. However, this difference was not statistically significant.

In order to study of some quantity and quality characteristics of two wheat cultivars under different planting method and irrigation levels conditions, an experiment was carried out in 2009-2010 in field of Ahvaz Shahid Chamran University. Experimental design was strip split plot within randomized complete block with three replications. Row factor was planting methods that include: basin, 3 line on the ridges, 6 and 9 lines on the ridges. Column factor was irrigation that includes two levels: irrigation after discharge 25% and 50% plant available water in soil, and two cultivars that include Chamran and Stare were in subplot. The test results showed that planting methods, the characteristics grain yield, straw yield and protein percent are significant differences with each other. Among planting methods, 3 line methods have significantly higher grain and straw yield compared to other methods, while 6 and 9 line methods have significantly highest protein percent. Irrigation levels have been not a significant difference. Between cultivars, Chamran have significantly higher in shrub height, grain yield and straw yield. While, Starr has higher shrub weight and greater spike length. Based on the results of this test and according to water shortages in most parts of the country, ridge planting method, specialy 3 lines on the ridges whit second level irrigation and Chamran cultivar is recommended.

In order to evaluate the effects of tillage systems and rice residue management on morphological traits and yield of winter rapeseed (Brassica napus L.) as second crop after rice in Rasht, a factorial experiment was conducted using randomized complete block design with 3 replications at Rice Research Institute of Iran (RRII, in 2003-2004 and 2004-2005 growing seasons. The experimental factors were tillage systems at 3 levels (T0: no tillage, T1: minimum tillage and T2: conventional or complete tillage) and rice residue management at 2 levels (R0: without residue and R1: with residue). The evaluated traits were time of flowering initiation, days to maturity, plant height, secondary branches number per plant, height of the lowest pod bearing branch, pod length, grain yield and dry weight of weeds (20 and 40 days after planting). The results of this experiment showed that there was a significant difference between tillage systems in terms of all the evaluated traits except pod length. Rice residue management had significant effects only on initiation of flowering, days to maturity and dry weight of weeds (40 days after planting). In addition, none of the traits showed significant response to the interaction of evaluated factors. The highest amount of grain yield with average of 2278 kg.ha-1 was related to conventional tillage system without residue treatment and the lowest amount of this trait with average of 1342 kg.ha-1 was obtained from no tillage system with residue treatment. Conventional tillage system treatment showed no significant difference with minimum tillage in terms of grain yield. Based on economical analysis, it seems that the minimum tillage treatment with or without residue have some advantageous compared with conventional tillage system which justifies its application.

To evaluate the effect of water deficit stress on yield, yield components, chlorophyll and osmolytes in Matricaria chamomilla, and the effect of super absorbent polymers on reduction of drought stress, a factorial experiment was conducted based on randomized complete block design with three replications in Faculty of Agriculture of Urmia University on 2008. Treatments included water deficit stress (irrigation after 50, 100, 150 and 200 mm evaporation from pan class A) and varying amounts of super absorbent polymer (0, 60, 120, 180, 240 and 300 kg/ha). Results of Analysis of Variance (ANOVA) showed the significant effect of irrigation on dried flower, the numbers of capitol per plant, capitol diameter and receptacle height, and non significant effect on single capitol weight and leaf soluble carbohydrates. While, the effect of super absorbent polymer on was non significant dried flower, the numbers of capitol per plant, capitol diameter, receptacle height, single capitol weight and leaf soluble carbohydrates Interaction effect between water deficit and polymer was significant on the yield of biomass, chlorophyll a, b, total chlorophyll and proline. The highest and lowest yield of dried flower (116.83 and 75.98 kg/ha), capitol diameter (0.544 and 0.497 cm) and receptacle height (0.676 and 0.568 cm) were obtained from irrigation after 50 and 200 mm evaporation from pan class A, respectively. But, the maximum and minimum numbers of capitol per plant (199.22 and 91.22) were obtained from 100 and 150 mm evaporation from pan, respectively. The highest yield of biomass (1215.55 kg/ha) was obtained from irrigation after 50 mm evaporation and 0 kg/ha of polymer application, and the lowest yield (164.44 kg/ha) was obtained from irrigation after 200 mm evaporation by using 120 kg/ha of polymer. In this research, chlorophyll a and b had the reducing trend from irrigation after 100 mm evaporation from pan. The greatest proline accumulation (4.001 mg/g dry weight) belonged to irrigation after 200 mm evaporation with 120 kg/ha of polymer, and the minimum leaf proline content (0.748 mg/g dry weight) was observed at irrigation after 100 mm evaporation with 300 kg/ha of polymer. In general, German chamomile tolerance to drought stress was through osmotic regulation of proline, and the yield of biomass was improved by super absorbent application.

In order to evaluate germination, seedling growth and seed composition of German chamomile produced at different irrigation regimes (Irrigation at 30, 60, 90, and 120mm evaporation from pan class A) a randomized complete block design with six replications was conducted in 2009-2010 at the Research Station of Faculty of Agriculture, Urmia University, Urmia-Iran. Results showed that the significant effect of irrigation on percentage, rate and index of germination, and however nitrogen and phosphorus content, and percent and yield of seed protein, but non significant effect of irrigation on time to 50% germination, root length, shoot length, seedling length, root/shoot length ratio, potassium content and seed yield. The highest germination percent (90%), rate (8.2% d-1) and index (8.5) belonged to irrigation after 60 mm evaporation from pan and the lowest germination percent (48%), rate (4.4% d-1) and index (4.8) belonged to irrigation after 120 mm evaporation. However the highest (3.43 and 21.44%) and lowest (3 and 18.74%) nitrogen and protein content were obtained from irrigation after 120 and 30 mm evaporation, respectively. The changes in protein yield were the same with protein percentage because of non significant effect of irrigation on seed yield. Thus the strongest water stress was the optimum regime for producing seed yield because of minimum water use. Concerning with phosphorus, the highest (8.08%) and lowest (6.56%) amounts were occurred at irrigation after 60 and 120 mm evaporation from pan. The binomial regression between irrigation and germination percent, rate, and index, nitrogen, phosphorus and protein percentage emphasized to results of ANOVA. Non significant correlations between content of phosphorus and germination, and potassium and germination, and however between seedling growth and nitrogen, phosphorus and potassium reserve of seed emphasized to independence of germination and seedling growth from these reserves. However, correlation between nitrogen content of seeds and germination was significant and negative.