JOURNAL OF RESEARCH IN AGRICULTURAL SCIENCE
Year:2008 | Volume:4 | Issue:1|Papers Count:13

This experiment was conducted to study the effect of NaCl salinity during germination and seedling growth of twenty-four chickpea genotypes in greenhouse conditions. The study was conducted as a factorial experiment with 3 replications in completely randomized design at three steps. The first step was germination test (0, 50 and 100 mM) the second was screening test (0, 40, 60, 80 and 100 mM) and finally, the morphological and physiological traits were studied (0, 30, 60 and 90mM). The results of germination rate (GR) and final germination percentage (FGP) showed that FLIP95-64C genotype and FLIP82-150C had maximum and minimum germinations, respectively. All the genotypes had emerged up to 76% at 50 mM NaCl/L. The screening results indicated that FLIP95-50C had the highest tolerance to salt stress (EC=4.32ds/m) and the lowest salt tolerance related to FLIP95-57C and FLIP93-174C (EC=1.02ds/m). The results of the third section of experiment showed that seedlings weight decreased by increasing the salinity but the more sensitive genotype (FLIP 95-57C) was affected adversely by NaCl. In addition, tolerance genotype had longer length of rootlets. The results also indicated that concentrations of Na and Cl ions were lower in tolerant genotypes than in the sensitive one. This may serve to believe that tolerance genotype of chickpea contains a mechanism which can exclude toxic ions. Finally, the results showed that plant responses to salinity were different at germination and seedling stages.

In order to determine of the best drought resistance indices and identify the resistance genotypes, 10 spring safflower cultivars were sown under drought and non-drought conditions based in a completely randomized block design with three replications on the research farm of Islamic Azad University of Khorasgan. Analysis of variance revealed a significant difference and genetic variability between cultivars for drought resistance indices. Assessment of simple correlation coefficients among drought resistance indices and seed yield of cultivars showed that GMP and STI help identify cultivars with have high potential yield and tolerant to drought stress. Therefore, these were recognized as the best resistance indices. Comparison of the mean of cultivars for the geometric mean of productivity (GMP) and stress tolerance index (STI) and biplot display designed that Sterling, Nebrasks10, land race Koseh and Gila the most resistant cultivars and U.S.10 were the most sensitive to drought stress. Classification of cultivars using cluster analysis revealed that crossing U.S.10 with Isfahan28, Arak2811 and C111 cultivars with maximum genetic distance are recommended for genetic improvement of drought resistance in spring safflower cultivars.

Half diallel crosses of nine Iranian wheat cultivars were used to estimate the correlation between grain yield and some agronomic traits. Parents with F2 generations were evaluated in a randomized complete block design with three replications. Plant grain yield and some agronomic traits including flag leaf length, flag leaf width, plant height, tiller number, grain number per main spike, main spike length, grain weight per main spike, peduncle length and peduncle weight were measured. Estimations revealed negative correlation between grain yield and other traits except for grain weight per main spike and peduncle length. The direct and indirect effects of traits were obtained by path analysis. The results of path analysis and stepwise regression indicated that grain weight per main spike, tiller number, plant height and peduncle weight explained the main part of the grain yield variation.

In order to investigate the effect of planting date and various levels of the nitrogenous fertilizer on the effective substances, biological yield and production of chamomile, an experiment was conducted during 2004-2005 on the research farm of faculty of agriculture of Islamic Azad University Khorasgan Branch. In this experiment three planting dates (6 March, 20 March and 5 April) and three levels of nitrogenous fertilizer (75, 150 and 225 kg per hectare) were evaluated as Urea fertilizer. The number of flower, dry and wet weight of flower in three cuttings, the number of days to budding, the number of days to 50% flowering, the number of days to 100% flowering, the height and the diameter of stems, and the number of branches, tillers, and the percentage of essence and the weight of essence were measured. The results showed that the various planting dates with regard to the number of total number of flowers, the total wet weight, the total dry weight, the numbers of days to flowering, the number of days to 50% flowering, the number of days to 100% flowering, the height of stem and the diameter of stem had a significant difference at one percent probability and the percentage of essence had a significant difference at five percent probability. On the first planting date, the effect of the earlier planting dates on the number of days to the budding date was two weeks longer. The delay in the planting date had no significant effect on the stems, tillers, branches and percentage of essence and the weight of essence. The effect of the level of nitrogen on the number of days to 50 percent of flowering and the number of branches were significant at 5 percent probability, and the rest of the characters were not affected by the level of nitrogen in the soil. There was a significant interaction between the planting date and the level of nitrogen on the number of flowers in the first cutting, wet weight of flowers and the percentage of essence. There was a significant interaction between planting date and the level of nitrogen on the percentage of essence. The highest number of flowers were obtained on the first planting date using more than 75 kg nitrogenous fertilizer per hectare. The best percentage of the essence was related to the third planting date and 150 kg nitrogenous fertilizer per hectare. It is expected that the greatest rate of treatment in chamomile is obtained by planting the crop on the first of March, according to the earlier planting dates and the use of nitrogenous fertilizer, lower than 75 kg per hectare.

In order to evaluate the allelopathic effects of two crops extracts (rye and wheat) on germination and early growth of lambsquarter and black nightshade, an experiment was conducted with a factorial arrangement based on completely randomized design with three replications in Seed Library Research of Tehran university. Treatments were: extract concentrations (0 (control), 5, 10, 25 and 40), weed species (lambsquarter and black nightshade) and crop plants (wheat and rye). Interactions of weed species × crop plants had no significant effect on radicle and plumle length. Also Interactions of weed species × crop plants× extract concentrations had no significant effect on the radicle length of weed species. The effects of other treatments and their interactions on germination percentage, germination rate, radicle length and plumle length were significant. The germination percentage of black nightshade was susceptible to allelopathic matter when compared with lambsquarter. The extract of the above two crops had more inhibitory effects on germination rate than the germination percentage. Low concentrations of extracts caused a higher reduction in germination rate. Early growth of lambsquarter was more tolerant than black nightshade to allelopathic mater. Root length was more sensitive than shoot length to extracts.

In order to determine the effect of water stress and different soil nitrogen on absorption of some macro and micro nutrients in corn plant KSC 704, a field experiment was carried out in a completely randomized block design with factorial layout in three replications in 2004. Treatments consisted of: 150, 300 and 450 kg N/ha as urea sources and water stress consisted of T0 (non water stress), T1 (water stress in vegetative stage before pollination and 50% flowering), T2 (water stress in reproductive stage two weeks before tasseling and at a time when 50% of tassel appeared), T3 (water stress in grain filling period expressly after the end of pollination and milk development). The results showed that nitrogen fertilizer affected amount of phosphorus, potassium, manganese and iron absorption (P<0.01). Different levels of irrigation also affected the amount of phosphorus, nitrogen, potassium, zinc, manganese, iron and copper. Increasing nitrogen fertilizer, enhanced nitrogen, phosphorus, potassium and manganese absorption but absorption of iron decreased. Among different water stress treatments, the most and lowest decreasing effect on absorption of nitrogen, phosphorus and potassium respectively, were related to T0 and T2. The water stress, increased potassium, zinc and copper absorption but it caused a decrease in manganese absorption. Manganese and iron absorption are negatively related.

In this research, the effect of secondary treated wastewater (TW) of Shahinshahr Wastewater Treatment Plant on some characteristic of turfgrass with three soil textures was studied. Experiment was performed in pot in a completely randomized block with a factorial design, with three factors and three replications for a period of 10 months. The first factor was a mixture of water and TW (100%water, 75% water and 25% TW, 50% water and 50% TW and 100% TW), the second factor was soil texture (sandy loam, loam and clay loam) and the third factor was varieties of Zoysiagrass (DALZM1, DALZM2, DALZM3, DALZJ1 and Mayko). Using TW increased turfgrass’s color, height and yield. The maximum color and height observed using a mixture of 75% TW and 25% water, and the maximum yield was obtained in irrigation with 100% TW. The highest color (5.53) was associated with DALZM3 variety, and DALZJ1 variety had the maximum height (12.5 cm) and yield (180.7 g per pot). Interaction of percentage of TW and variety indicated that the highest color (5.73) was obtained in DALZM3 variety using 100% TW, and DALZJ1 variety had the highest height (13.5 cm) and yield (248.3 g per pot) using 75% TW and 25% water. Therefore, using TW has no negative effect on measured characteristics.

Two separate experiments were conducted to determine the time of flower induction and the effects of foliar application of N (Urea), Zn (Zinc sulphate) and B (Boric acid) on the qualitative characteristics and yield of grape ‘Siah’ during 2004-2006, in Sisakht region. In the first experiment from June to September every two weeks interval girdling and defoliation was imposed on 3 branches and 3 vines. During the following spring, it was found that flower induction occurs in early July in this area. In the second experiment, the effect of foliar application of N, Zn and B with 8 treatments (control, N, Zn, B, N+B, N+B, B+Zn and N+Zn+B, at the concentration of 0.5% each) in a completely randomized block design with 4 replicates were studied. The Results showed that effect of foliar application treatments on the %TSS, %TA, TSS/TA, pH and yield were significant (P≤%1). Application of combination treatment (N+B, 0.5%) increased the fruit quality than other treatments. Also application of all foliar treatments increased the yield in the year of treatment and in later year than untreated control.

In order to determine the suitable medium, concentrations and types of plant growth regulators, experiments were conducted by using different concentrations of 6-benzyladenin (BA) (0, 0.5, 1 and 1.5 mg/L) and Indole-3-butiric acid (IBA) (0, 0.005, 0.01 and 0.02 mg/L) on Jasminum grandiflorum and two media MS and 1/2 MS in in vitro culture. Explants of single node containing buds of the above species were disinfected by 20% clorax for 15 min. In this research, the bud growth percentage and proliferation rate were measured. In vitro shoots were rooted in MS medium containing different concentrations of IBA (0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75 and 2 mg). Over all, 1/2MS medium was superior to MS medium 1 mg/L BA + 0.005 mg/L IBA. And 1 or 1.25 mg/L IBA for rooting.

Yellow rust caused by Puccinia striiformis f. sp. tritici, is a globally important fungal disease of wheat (especially in Central and Western Asia) that cause significant annual yield losses. Its varies from one area to another, depending on climate and predominant cultivars. In order to control disease, use and production of resistant cultivars is the best method. For this purpose, the reaction evaluation of 20 promising wheat genotypes of cold zone with a susceptible check was conducted on yellow rust in Ardabil. Each genotype was planted in two 1 m rows 30 cm apart under mist irrigation and artificial inoculation. The experiment was conducted in 2001 - 2003 cropping years, based on completely randomized block design with three replications. To increase disease development, a susceptible cultivar (Bolani) was sowed among lines (10 entry intervals) and also as borders of Nursery. Besides, the artificial inoculation of the nursery was carried out using a mixture of spores and talcum powder at sun set and Gs36 stage by means of a duster. The disease severity and infection type were recorded respectively based on the modified Cobb, s scale and Roelfs et al. method. Then, coefficients of infection (CI) were calculated by combination of disease severity and infection type. The results showed that there are significant differences among lines. The lines of C-80-3, C-80-4, C-80-5, C-80-11, C-80-12, C-80-16 and C-80-20 were highly resistant, where as, C-80-2, C-80-13, C-80-18 and C-80-21 (check) lines were susceptible. The rest of lines were moderately resistant or moderately susceptible that located between two mentioned above groups.

In this research was carried out on determination of LD50 value of chitin synthesis inhibitor compounds (Lufenuron 25% EC and diflubenzuron 25% WP) on second larval instars of the Colorado potato beetle Leptinotarsa decemlineata (Say). Was invest igated. The eggs of the insect were collected from fields where located around Urmia University and Nazlo village. Second larval instar was separated by measuring of head capsule width and used in bioassay. In order to, determination of LD50 potatoes planted in plastic vases were used. To study the susceptibility of larvae, with measuring of their feed level, treatment cages were made and definite rates of poison solution were used, then larvae were released in these cages individually. In bioassays, LD50 values of mentioned compounds on second larval instars were determined. The data were analyzed with log-probit transformation using the MSTATC software. The LD50 values of lufenuron and diflubenzuron on second larval instars were estimated 139. 56 and 913. 67 ppm respectively. The results showed that lufenuron was more effective than diflubenzuron to control the pest. On the basis of collected data in this research and the selective nature of chitin synthesis inhibitor compounds we can conclude that these compounds can be used for reasonable control of Colorado potato beetle.

The present study was conducted in order to determine the proper extender for poultry semen among Beltsville, Ringer and milk and the comparison of various proportions of different extenders applied for dilution (semen-over-extender ratios 1:1 and 1:2) and its impact on fertility and semen storage period (non-storage or 24-hour storage). This study was carried out in the Isfahan Center for Breeding and Production of Native Hens. The study consisted of eleven treatments and each treatment included three roosters as replicate and 24 hens. Collected semen was diluted in 1:1 and 1:2 ratios by various extenders and insemination was conducted immediately or after a 24-hour storage period at 5 degrees of centigrade. The results indicated that following a 24-hour storage period, fertility declined and that the effect of various insemination periods on fertility proved to be significant (P<0.01). There was no significant difference between the 1:1 and 1:2 ratios for the extenders (P<0.05). Among the extenders, when using non-stored semen, employment of the1:1 Ringer extenders produced the highest fertility and there was no significant difference between the Beltsville and control extender. However, using milk as extender lowered the fertility. In conclusion, none of the applied extenders are proper for semen storage and application of Ringer as extender resulted in the highest fertility.