AGRICULTURAL RESEARCH
Year:2008 | Volume:7 | Issue:4 (A)|Papers Count:28

In order to evaluate of consequense of application some of biofertilizers on qualitative characteristics of soybean seed cultivars produced under water deficit stress conditions, two experiments were conducted in laboratory and field. Filed study was conducted as split factorial based ofRCBD and laboratory experiment was done as factorial on the based of CRD with four replications. Seeds were evaluated in laboratory conditions by standard germination test.Treatments were include biofertilazer(Brady rhizobium japonicum inoculation, B. japonicum+ Pseudomonas fluorescens coinoculation, B. japonicum + Glomus mosseae coinoculation), cultivar (Zalta Zalha and Clark x Hobbit line) and water deficit stress (Irrigation after 50, 100 and 150 mm evaporation from pan class A, in parents field). Results showed that water deficit stress had negative consequense on seed quality. Co-inoculation of seed cultivars withB. japonicum and P.fluorescens improved final germination percentage, primary and finally field emergence and field emergence index in water deficit stress levels. Seedling vigour index, final germination percentage and normal seedling had significant and positive correlation with primary and finally field emergence.

In order to evaluate the effect of osmopriming pretreatment of fennel seed germination, this study was done, under salt stress conditions. A factoring experiment based on completely randomized design was conducted with three replications. The experimental factors were cultivars of Soroksari and Iranian population (from Isfahan Province), six levels of osmopriming pretreatment (0, -1/15, -1/9, -3/5, -4/8, -6/5 bar), and five levels of salt stress (0, 40, 80, 120, 160 mmol/l NaCI). At the first stage, seeds were immersed in different levels of osmopriming pretreatment for 24 hours at laboratory temperature (20oC) and they were then treated with five levels of salt stress. Results showed that there were significant differences between Soroksari cultivar and Iranian population in terms of germination parameters: percent of germination, length ofradic1es, length of seedling, fresh weight and dry weight of seedlings, whereas there were no significant differences in germination speed and mean of germination period. Interaction effects of cultivar, pretreatment and salt stress was significant. The best characteristics of germination were observed at osmopriming pretreatment of -1/15 bar and salinity of 0 mmol/l NaCl. By increasing salinity, Soroksari cultivar had bettetr seed germination than Iranian population. Therefore Soroksari cultivar was more tolerance than Iranian population to salt stress.

In order to determine the appropride traits for indirect selection of com cultivars, 7 inbred lines and 7 hybrid progenies from their crossing together with 4 F2 progenies from their self-pollination were used in an experiment based on imbalance grouped design with three replication conducted in Hamedan Agricultural Research Center in 2005-06. The results indicated that positive and high significant phenotypic correlation was existed between grain yield and weight of cob without husk in all three groups. Path coefficient analysis revealed that stalk diameter and width of ear leaf had the greatest direct effect on grain yield in inbred lines, while, weight of cob without husk, width of ear leaf and cob diameter traits had high and positive direct effects on grain yield in hybrids. In F2, the weight of cob with husk and number of kernels per row had high and positive direct effects on grain yield. According to this study, it can be concluded that any group had independent traits for indirect selection toimprove grain yield, and only the width of ear leaf could be used as a common trait for selection both in inbred lines and hybrids.

Weight and growth of grain are affected by two components of dry matter accumulation and grain filling period. This research was conducted to investigate the behavior of these components under the influence of environmental and physiological changes (e.g, change in sink per ear) at Ahwaz climate condition. A spilt factorial design was set up based on randomized complete block with four replications. Three planting dates (6 November, 26 November and 16 Desamber) were main plots and randomized compound cultivar (stare, chamran and fong) and sink size (intact spikelets as control and removal of one side of ear in main stem) were subplots. Due to high temperatures during grain filling period, late planting has a negative consequence on wheat productivity in this region. Delay at sowing might cause to limit sources which may reflects yield limitation. Harvested single grain weight for first, second and third planting dates were 47.12, 44.97 and 40.39 mg respectively. On the other hand when comparing varieties, it reveals that fong cultivar despite a short grainfilling period and high source limitation obtain the most grain growth rate with single grain weight of 45.36 mg as compared with two other cultivar. But Chamran cultivar with a short period of reproductive phase and slow grain growth rate developed the lowest weight of single grain. Reduction of physiological sinks and increasing photo assimilates increasing did not affect grain filling period, but the manipulation of sink caused on increase in the growth of single grain weight, number of grain per spikelet and grain filling rate with 15.02, 11.24 and 16.15 percent respectively, compared to control. The present study showed that partial detachment of spikelets may cause a enhancement in the accumulation of soluble carbohydrates in remaining part of plant head when compared to control.

In order to evaluating drought resistance indices in lentil(Lens culinaris Medik) twenty lentil genotypes were evaluated in a split plot design with three replications under two levels of irrigation (with stress and without stress) at research farm of Zanjan University in spring of 2004. To evaluate drought tolerant genotypes on the basis of yield performance in stressed (Ys) and non-stressed (Yp) environments, quantitative measures of drought tolerancei.e mean productivity (MP), stress tolerance (TOL), geometric mean productivity (GMP), harmonic mean (HARM), stress susceptibility index (SSI), stress tolerance index (STI) and superority measure (P), were computed and studied in RCBD design baise. Results indicated significant differences among all genotypes with respect to drought indices and yield performance in both environments. The highest amounts of STI, HARM, GMP and MP were related to the genotype TN-1768 in both stressed and non-stressed conditions. Correlation analysis between yield and indices revealed that STI, HARM, GMP and MP are the best indices for screening of drought tolerant genotypes. Accordingly, genotypes TN-1768 and Ziba were selected as drought tolerant genotypes. Biplot multivariate technique located the genotypes TN-1768, Flip-97-8 and Ziba near the vectors related to STI, HARM, GMP and MP. Cluster analysis located tolerant genotypes TN-1768 and Flip-97 -8 in one group and susceptible genotypes TN-1778, ILL-7135 in another group as well.

Safflower (Carthamus tinctorious L.) is one of the most important plants in crop rotation and economical stability in semi-arid agro ecosystems. Although low yield in safflower compared to other crops, may decrease its competitive ability understanding the differences between high and low yielding cultivars under drought and the relationships between them and yield, might be important in increasing seed production. A split-plot arrangement of treatment in a randomized complete block design with three replications was used at research farm of Bu-Ali Sina University, located in Hamedan, in 2006 growing seasons. Three cultivars of spring safflower including IL-111, PI and Isfahan local cultivar under water stress at vegetative and reproductive growth stages were used. In this research some of the growth indices and physiological characteristics such as total dry matter accumulation (TDM), crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR), leaf area index (LAI), in three cultivars (IL-111, PI and Esfahan native), was evaluated.The longest growth duration was seen from Esfehan native and shortest growth duration was observed from IL-111 cultivar under water stress. Leaf area index decreased with decreasing availability of water. Maximum total dry matter and crop growth rate were observed in PI cultivar.The highest net assimilation rate also was obtained in PI cv. Significant differences were observed between three cultivars in biological yield, grain yield, yield components, seed oil percentage, oil yield and Harvest index. The lowest biomass and grain were belong to water stressed plant in vegetative and reproductive stages. Water stress at vegetative and reproductive growth stages decreased 20.7% and 31.28% of grain yield respectively in comparison with non-stress plants (control). The result showed that the maximum grain yield and oil yield were observed in PI and IL-111 cultivar under non-stress treatment. In contrast, oil percentage and oil yield in IL-111 decreased sharply under water stress at vegetative or reproductive stages. Maximum grain yield and oil yield was belong to PI under vegetative water stress.

This study has been conducted in order to identify and introduce the resistant bread wheat genotypes to drought in germination stage. Seeds of 30 genotypes with different resistance were exposed to osmotic potential levels of 0, -4, -8 and -12 bar taken from Polyethylene glycol 6000 solution. A factorial experiment based on completes randomized block design was conducted with three replications. The results showed that there was a significant difference between genotypes, osmotic potential levels and their interaction effect of osmotic potential levels x genotypes. It was also observed that with the increase in the amount of osmotic potential level amount in sensitive genotypes, a significant decrease of germination was occurred cultivars, Tabasi, Alvand, Bak cross bahare Roshan and Darab2 showed the highest percentage of germination.

Water is an important factor in crop production and is of a high value in agricultural engineering. Water shortage is the most restricting factor in irrigated areas. Because of this limitation, deficit irrigation research has a special value in optimization of water use and determination of water depths in irrigation strategy. Due to the aforementioned, a research in Khorramabad region on wheat with different levels of water use was conducted in 1380. This research was carried in RCVD using six irrigation treatments with three replicates. Irrigation interval, planting and growth conditions were the same for all treatment some results of this research are as follows: There was not significant at 1% level between yield of irrigation levels 125%, 100% and 75%, however was between yield of irrigation levels 0%, 25% and 50%. Yield of irrigation levels 0%, 25% and 50% to full irrigation had reduced 9.5%, 25.7 and 50.5% receptivity.Irrigation levels 25% and 50% had water use efficiency (WUE) of 2.48 and 1.51 (kg/m3) receptivity that were more than other levels. If the wheat cost 1900 Rials in Kilo. Yield different per hectar between irrigation levels 25% and 50% was 1162800 Rials. The results showed that irrigation level 50% with water use efficiency (WUE), yield high and an economic point of view, was the best.

To study the effect of salinity levels on physiological characteristics and antioxidant enzyme activity quantity in sesame leaf, an experiment was conducted at research greenhouse, Faculty of Agriculture during the years 2004 and 2005. A factorial experiment based on completely design with three replications was used. The treatments comprised five salinity levels, 2.4, 4.4, 6.4, 8.4 and 10.4 dS/mand four sesame population, including Giroft, Dezful, Moghan and Borazjan. Stomatal conductance respiration and relative water content was significantly decreased with increasing with levels. Theeffect of salinity stress on antioxidant enzyme Super oxid dismutase, Gatalase and glutation reductase contents in sesame leaves was significant. There were also significant differences between sesame population on active enzyme value. Borazjan and Moghan population hadthe highest activate enzyme. The active enzyme value was increased on flowering stage and decreased at ripening. It cac be concluded that between the investigated sesame population Moghan with the highest enzyme value, yield and relative water content content had the highest resistant and Borazjan was most sensitive on salimity stress.

Some plant extracts contain specific compourds showing antifungal properties. In this study, water, methanol, chloroform, acetone and ethanol were used as solvent to prepare extracts of stem, leaf and fruit of sumac. These extracts were then tested against Rhizoctonia solani, Fusarium oxysporum, Phytophthora drechsleri and Bipolaris sorokiniana and their antifungal properties was investigated by paper disc method. The results showed that methanolic extracts of stem and fruit of sumac had the most inhibitory activity against F. oxysporum and P. drechsleri, respectively.Ethanolic extract of leaf and methanolic extracts of fruit, leaf and stem had the highest inhibitory activity against R. solani.

Antifungal effects of edifenphos and triyclazole fungicides and also extracts of Artemisia annua, Sumbucus ebulus, Polygonum persicaria, Peteridium aquilinum, Melia azedarachand Saturia sp.On the control of rice blast disease were investigated. Fresh leaves of the plants were driedin shade and made into powder and then extracted using ethanolic and methanolic solvent.The effects of the extracts on the inhibition of radial growth ofPyricularia grisea was determined in laboratory by growing the fungus on potato dextrose agar (PDA) containing plant extracts and fungicides in Petri dishes. The results indicated that methanolic and ethanolic extracts of A. annua had the highest inhibitory effect on mycelial growth. After demonstration of antifungal activity of plant extracts, the field experiments were performed with stocks in comparison with edifenphos and tricyclazole. Fourteen day old rice (Binam variety) plants susceptible to blast were used for spraying the extracts and fungicides. The rice vases sprayed with different extracts were placed between the rows of infected cultivated rice in paddy field of National Institute of Rice Research (NIRR). The symptoms were appeared from day five onwards. The severity of the disease for each leaf was caculataed by digit and the mean infection for each vase was calculated accordingly. The results indicated that all extracts of the plants could prevent the fungus growth. The highest control was obtained by ethanolic and methanolic extracts of A. annua with 84.6 ± l.13 and 86.8 ± 5.42 % respectively. The control percentage of S. ebulus was 73 ± 10.2l. The fungicides, edifenphos and triyclazole prevented fungal growth by 72.5 ± 3.57 and 56.4 ± 4.34 % respectively. Our results showed that all extracts had potential for controlling rice blast agent.

Genetic diversity of 20 important Iranian sweet cherry cultivars considerable for breeding programs, together with 3 sour-sweet cherry, 1 sour cherry and 5 foreign sweet cherry cultivars were studied using micro-satellite markers. Extracted genomic DNA from sweet cherry young leaves was used for PCR and amplification. Amplified products were separated using 6% polyacrylamide gel containing 7M urea under denaturing conditions and visualized by staining with silver nitrate. Gels were then scored based on either the presence or absence of the bands, -and polymorphism information content (PIC) for each SSR marker was determined. The number of alleles per locus ranged from 6 to 9 and totally 123 alleles were identified. Genetic diversity of cherry cultivars was estimated using NTSYS software program based on the Jaccard Similarity coefficient which was considered for cluster analysis. Cluster analysis placed the 29 cultivars in five groups, showing a high diversity between the cultivars, so that the Iranian sweet cherries were alighted quite different from the foreign cherries. Foreign cherries were grouped in different branches so other sour cherry and sour-sweet cherries.

In order to determine evapotranspiration and crop coefficient of cucumber in greenhouse, this study was conducted in Research Center of Agriculture and Natural Resources of Yazd. A pot planting method was used to facilitate the accurate estimation of the water balance equation components in root zone. Cucumber seeds and grasses were planted in pots as main and reference crops respectively. Daily soil moisture changes in pots were measured by means of a TDR apparatus. Temperature, relative humidity, daylight duration and evaporation from the pan were measured and used for the evapotranspiration estimation of both main and reference crops. Maximum water requirement of cucumber in greenhouse was 6.41 mm/d and the values of Kc in 3 different (initial, middle and final) periods of growth were 0.3, 1.4 and 0.93, respectively. The results showed that the Kc value was not constant and hence it was climate condition depended. So, it is needed to calculate the Kc value individually for different climate conditions. According to the results, evapotranspiration rate in greenhouse was decreased greatly compaced to the outside condition. Due to the water shortage in Yazd province, it is necessary to develop the greenhouse planting method to increase the water use efficiency.

In order to investigate the effects of sulfur and two microelements, iron and zinc, on growth characteristics and quantitative and qualitative yield of sunflower an experiment was carried out in Research Farm of Agricultural College of Bahonar University of Kerman. The experiment was a split factorial plot and performed on the basis of randomized complete block design with three replicates. The experimental treatments were as follow: two levels of sulfur as main plots and the combination of two levels of iron (0& 1500 ppm) and two levels of zinc (0 & 1000 ppm) in a factorial arrangement as sub plots. Data analysis of variance showed that sulfur had a positive and significant effect on dry weight, leaf area, stem height, grain yield and oil percentage (P<0.01).Foliar application of iron had also positive and significant effects on grain yield, oil and protein percentage, while Zinc had a negative and significant effect on grain yield and protein percentage.The interactions of sui fur*iron, sulfur*zinc and sulfur*iron*zinc affected grain yield and oil percentage significantly. The highest grain protein (%) was belonged to sulfur*iron treatment. It seems that usage of sulfur and iron fertilizer in sunflower farms has a useful results but zinc fertilizer application in such a farm needs more investigation.

In order to determine the response of yield and yield components of potato in seed production and commercial planting densities to weed infestation periods an experiment was conducted in Agricultural Research Farm of Bu-Ali Sina University in 2006. This experiment was conducted in a factorial arrangement based on a randomized complete block design with three replications.Experimental treatments were potato plant density at two levels, 5.33 (optimum plant density of commercial fields) and 6.66 (optimum plant density of seed production fields) plant per square meter and weed infestation period at seven levels, in which at the five levels, weeds were allowed to grow for 10, 20, 30, 40 and 50 days after crop emergence and then weeds were removed manually until harvest. In addition two control treatments (weed free and weedy check) were also considered.Each plot consisted of four rows (eight meter per row) with row spacing of 75 cm. In order to calculate the total dry mass accumulation, crop sampling was started 10 days after crop emergence and repeated for 11 times, at 10 days interval. Yield and yield components were determined at harvest. The results showed that the effect of weed infestation on total dry matter accumulation trend was started 40 days after emergence and about 90 days after reached to maximum. The effect of weed infestation on total dry matter, tuber yield, number of tuber per square meter and mean of tuber weight in commercial plant density was more than seed production plant density. The number of main stem was not affected by weed infestation in both plant densities.

The knowledge of genetic characters of quantative and qualitative traits and their heritability in wheat (Triticum aestivum.L.), are the most important requirement for breeding high wheat yield varieties and disease resistance of this strategically crop. Yellow rust (strip rust) caused by puccinia striiformis f.sp.tritici is an important disease of wheat in many regions of the world. In Iran, the most severs epidemic years were 1993 and 1995. For this reason. 10 lines of wheat were studied to determine study of genes effect and combining ability in some of bread wheat genotypes to yellow rust disease. Ten parents' lines, F 1 were evaluated in a randomized complete block design with three replications in Mashhad, Torugh Agricultural Research center, two races of wheat 134E134A+ and 4EOA+were used. Latent Period (LP), Infection Type (IT) were measured in the field and Greenhouse. Analysis of for the combination indicated significant differences between races and genotypes. Diallel analyzed with method of Griffing and Haymans. The GCA and SCA for all traits were significant and showed that additive variance was more important. Test for validity of diallel hypothesis showed epistasis effects for all traits. Average degree of dominance ranged from partial to over dominance for resistance or susceptibility.

The effect of drought stress on some morphological, physiological and biochemical responses of five grapevine cultivars (Gazney, Shahani, Muscat Gordo, Flame Seedless and Bidaneh Sefid) was evaluated. One year old rooted cuttings of each cultivar were used in a factorial experiment with complete randomized blocks design, under different levels of water deficit (80%, 50% and 30% of soils available water) using gypsum blocks, in green house condition. The results showed that the plant height, number of leaves and nodes, leaf area and the percent of dry weight related to each cultivar decreased with increasing water deficit rate. The highest decrease observed in 30% of soil available water treatment. Decreasing in plant height was significant only in Flame Seedless cultivar. The highest proline accumulation occurred in Muscat Gordo and soluble carbohydrates accumulated most high in Gazney cultivar under 30% available water treatment. Flame seedless had the lowest level of proline, soluble carbohydrates and chlorophyll content. Gazney and Shahani cultivars showed no significant decrease in chlorophyll content under water deficit stress. The relative water content (RWC) of leaves decreased due to water deficit. The highest decrease observed in Gazney and Bidaneh Sefid. There was negative correlation between RWC and proline accumulation. The cultivars Gamey followed by Bidaneh Sefid and Shahani and then Muscat Gordo had better relative growth rate respectively under water deficit stress, but Flame Seedless was the most sensitive cultivar to this condition and is not recommended for cultivation in arid areas.

In this study, pathogenic variability of the Rhizoctonia isolates recovered from potato and sugar beet was examined on radish, tomato, potato and sugar beet. Results revealed a high degree of diversity in virulence of the isolates. Among plants tested, sugar beet and potato were the least and the most susceptible hosts for R. solani, respectively. Isolates of AG-4 and AG-3 caused the highest and lowest amount of disease on sugar beet respectively. Among the four hosts, tomato and radish were the most susceptible plants used in this study against the isolates of AG-4. These results indicated clearly that AG-3 isolates have a preference for potato, whereas no host preference was observed among isolates of AG-4. In other words, AG-4 isolates have the highest pathogenicity on the all plants tested. Results of this study indicated that it would be possible to separate the isolates based on their virulence on radish and tomato better than potato and sugar beet respectively. These results suggest that it is preferable .to replace sugar beet and the potato seeds with radish and tomato seeds when these types of experiments need to be done.

In hot semi-arid areas, the portion of water that might be lost due to wind drift and evaporation would be significant. Thus a proper understanding and control of factors affecting wind drift and evaporation losses (Ls) in sprinkler irrigation for developing water conservation strategies are important. The purpose of this study included proposition of the practical model and adequate estimation equation by characterize Ls in semi-portable hand-move sprinkler system under different weather conditions in south-east region of Khouzestan province. The type of field tests were conducted with single sprinkler conditions. Estimation equations showed that the Ls increases 3.26% for every increment of 1 mls of wind speed. Also, results showed that Ls exceeded beyond 19% when wind speed increased more than 3.5 m/s. This study showed that Ls were decreased largely from 21.9% to 2.8% in hot semi-arid climates when switching from day to night irrigation in the summer.

In order to enhance tuberose cut flower vase life, and their florets opening and to reduce ethylene production by flowers, a factorial experiment was conducted based on a Randomized Complete Block Design with three replications. In this study, tuberose corms were soaked in 50, 100 and 150 mg/l gibberellic acid (GA3) for 24 hours before culture. After harvesting, cut flower, they were stored in 5 and 10oC cold storage. The results showed that the above three traits were affected by the interaction of GA3 and cold storage. Interaction of 50 mg/l GA3 and cold storage (5oC) reduced ethylene considerably and was better then the control the other treatments. Furthermore, 150 mg/l GA3 and cold storage (5oC) increased the percent of florets opening to 37.2 as well as vase life to 11.3 days, which was better than the other treatments.

Pink rot and pythium leak or watery rot of potato mainly caused by P. erythroseptica and P. ultimum are two important diseases occurring in several countries. Although other species of Phytophthora may also be the causal agent pf pink rot of potato tubers. These two diseases were recently observed in some potato growing areas of Semnan province. These are more prevelant in fields with heavy soils and poor drainage. Their secondary development takes place in stores with poor storage facilities. During 2002-2003 in a survey for identification of Pythiaceous species, the causal agents of pink rot and Pythium leak of potato tubers in Semnan province of northern Iran, Phytophthora megasperma and Pythium ultimum were found to be new records from potato tubers for Iran. In this survey 40 potato fields and related stores were inspected for detection of both diseases. Using BNPRA selective medium without hymixazole, 49 isolates belonging to pythiaceae were isolated from disease speciments of some fields and stores. Results showed that 34.70% were Pythium (all having the characteristics of P. ultimum) and 65.30% were Phytophthora (majority belonging to P.cryptogea and remaining being P.erythroseptica and P.megasperma). Majority of Pythium isolates were seprated from stored potato tubers while Phytophthora isolates were mainly found on diseased tubers collected at harvesting time. Review of literature indicates that the two species P.megasperma and P.ultimum have not yet been reported from diseased potato tubers in Iran and seem to be new causal agents of pink rot and potato leak for Iran.

In this survey, among 6 isolates of Trichoderma spp., biocontrol effect of Trichoderma virens, which was more efficient than the other isolates during dual culture assays, was investigated alone and in combination with hnazalil (1 ppm) in comparison with application of imazalil and tiabendazole alone on fruit, in growth chamber and cold storage conditions, at both 20 ±1o C and 4±1o C againstPenicillium digitatum . Results showed that imazalil prohibits Trichoderma growth at the concentration of 1000 ppm on PDA culture medium. Mentioned isolate also inhibited growth and development of the pathogen by producing volatile metabolites and intracellular secretions. Application of antagonistic isolate, alone, resulted in 88% and 82.82% disease reduction at 4±1o C and 20± 10 C respectively. Results obtained from the effect of fungicides on pathogen showed that imazalil is significantly more efficient than tiabendazole. Integrated use of the isolate (5 x 107 spores per ml) with imazalil improved its biocontrol efficiency and resulted in 94.8% decay reduction in 40 C.