نشریه به زراعی نهال و بذر
سال بیست و هفتم شماره 4 (1390)

To classify the wheat breeding research stations of Iran, 15 lines/cultivars with different growth habits and vernalization requirements were grown in three sowing dates (12 Oct., 01 Nov. and 21 Nov.) in 18 research field stations in 2005-2008 cropping seasons. Experiments were carried out as split plot arrangements in randomized complete block design with three replications. Sowing dates were assigned to main plots and genotypes were randomized in sub-plots. Grain yield from all filed stations in three years were analyzed to determine the suitable sowing date for each location. Combined analysis of variance showed that the first date of sowing (Oct. 12) was suitable for most of the locations except Zarghan and Isfahan where the first and second dates of sowing were not significantly different. The third date of sowing was not suitable for any of test locations. Cluster analysis based on mean of the days to heading of genotypes in each date of sowing grouped 18 research stations into three groups:1) Varamin, Mashhad, Karaj, Zarghan, Isfahan, Khorramabad and Neishabour. 2) Ardebil, Arak, Hamadan, Miandoab, Kermanshah (Islamabad), Qazvin, Zanjan, Khoy, Jolgeh Rokh and Eqlid. 3) Darab. In the first and third groups spring wheat genotypes had higher grain yield, whereas in the second group winter and facultative wheat genotypes performed better.

To determine the suitable row spacing and rate of nitrogen fertilizer for rapeseed cv. Hayola 308, a factorial experiment based on randomized complete block design with three replications was carried out in paddy fields of Rice Research Institute of Iran, Rasht, Iran, in 2003-2004 and 2004-2005 growing seasons. Row spacing at three levels: 20, 25 and 30 cm and four nitrogen fertilizer rates, based on soil testing and Water and Soil Research Institute recommendations, including: 0.7R, 1.0R, 1.3R and 1.6R from urea source. The R factor was determined as 140 Kg urea ha-1. Some important agronomic characteristics such as number of secondary branches per plant, number of siliques per plant, number of seeds per silique, silique length, 1000-seed weight, grain yield, oil content and oil yield were measured and recorded. Combined analysis of variance showed no significant differences between row spacing for grain yield. However, row spacing of 20 cm with an average seed yield of 1947 kgha-1 was relatively superior to other row spacings. Among the nitrogen rates, the highest seed yield was obtained from fertilizer rates of 1.6 R with 2189 kg ha-1. No significant differences were observed among treatments for oil content. Increasing in nitrogen application didn’t decrease the oil content. Results clearly showed that row spacing of 20 cm with average of 887.4 kg ha-1 had the highest oil yield. Nitrogen rate of 1.6R showed maximum number of secondary branches per plant (4.3), number of siliques per plant (89.7), 1000-seed weight (4.719g) and oil yield (1001 kgha-1). Row spacing of 20 cm and nitrogen rate of 1.6R had the highest seed yield, oil content and oil yield. Since there was not significant differences between 1.3R and 1.6R nitrogen rates at 20 cm row spacing for seed and oil yields, the combination of 1.3R nitrogen fertilizer and 20 cm row spacing is recommended. This recommendation package would decrease application and leaching of nitrogen and is more environmental friendly.

To determine whether Kochia can grow on marginal land irrigated with saline water, it was grown with six levels of saline water (1.5, 7, 14, 21, 28, and 35 dS/m) and three levels of applied water (AW) (25, 75, and 125 percent of the water requirement) in 2008 and four levels of applied water (50, 75, 100, and 125 percent) in 2009. Results showed that kochia produced considerable amounts of biomass (34 and 14 t DM ha-1) in 2009 and 2008 under suitable conditions, respectively. Under severe drought and salinity, kochia still could produce up to 16 and 8 t DM ha-1 in 2009 and 2008, respectively. Salinity tolerance of kochia was improved by increasing water application. Results of water depletion from different soil layers showed that Kochia could uptake more water from the 30-60 cm soil depth. The soil salinity (ECe) in this depth was lower in comparison to the 0-30 cm soil depth. Additionally, the water uptake from the 30-60 cm soil depth improved the level of salt tolerance of Kochia. The highest salt accumulation was observed in 60-90 cm soil depth. Results of this study demonstrated that Kochia should be considered as a forage crop or for production of biofuel using saline water in semi-arid areas.

To study the effect of different levels of irrigation on quantitative and quality traits and water productivity of three commercial grapevine cultivars, this research was carried out in stripe block arrangment in randomized complete block design with three cultivares (Qzel-ouzum, Rishbaba and Rasha) and three levels of irrigation treatments (100%, 75% and 50% water requirments) in three replications. At fruit ripenning stage, different traits as weight, length and width of bunch and the quality traits including TSS, TA, pH of the fruit and the volume of the fruit juice were recorded. Combined analysis of variance indicated that different levels of irrigation had significant effect on TSS, TA, pH, juice volume, berry weight and width, bunch width and weight, annual vegetetive growth and fruit yield. The highest and lowest fruit yield were obtained by 100% and 50% irrigation, respectivly. However, effect of 25% deficit irrigation on fruit yield was not significant. Deficit irrigation reduced the juice volume, berry weight and size. Water consumption in 100%, 75% and 50% of water requirments were 4086, 3064 and 2043 m3/ha, respectively. Water productivity of 100%, 75% and 50% irrigation were 2.8, 3.63 and 4.04 kg/m3, respectively. To increase the water productivity in vineyards with optimum fruit yield, application of 25% deficit irrigation is recommended. By decreasing of 25% water use, the water productivity will increase to 30 % without significant reduction in fruit yield. Water productivity was different for groupvine cultivars. cv. Rasha had the highest water productivity.

Drought stress is the most important factor which reduces root and shoot growth in crops. This study was performed to evaluate the effects of drought stress and starter nitrogen fertilizer on root characteristics and seed yield of four chickpea genotypes. The field experiment was laid out as split plot-factorial arrangement in randomized complete block design with three replications. Drought stress was assigned to main plots in three levels; no stress (full irrigation) moderate drought stress (irrigation at planting and early flowering) and severe drought stress (no irrigation). Nitrogen fertilizer at two levels; 0kg N/ha and 25kg N/ha and four chickpea genotypes; Azad, Bivanij, Hashem and ILC482 as factorial in sub plots. Result showed that effect of drought stress was significant on number of secondary roots, length of roots, length of primary roots, roots volume, roots dry weight, root: shoot ratio, number of root nodules, roots length density and seed yield. Effect of nitrogen fertilizer was significant only on dry weight of roots and root: shoot ratio. Genotypes were significantly different for traits except roots length density. In severe drougth stress conditions and without application of nitrogen fertilizer cv. Bivanij had the highest seed yield, number of root nodules, volume of roots and dry weight of roots.

To assess the response of two grain sorghum cultivars; Kimiya and Speedeh to different phosphorous fertilizers under deficit irrigation conditions, a field experiment was conducted in Research Farm of College of Agriculture, University of Tehran in Karaj, Iran, in 2009 and 2010 growing seasons. The treatments were arranged as split-split plots in randomized complete block design with three replications. Irrigation regimes of normal weekly irrigation (control) (IRN) and deficit irrigation (IRS) were assigned to the main plots, and sorghum cultivars (Kimiya and Speedeh) to the sub plots and phosphorus fertilizers levels: P0 (no phosphorus fertilizer), chemical phosphorus fertilizer according to soil test (P100), biological phosphorus fertilizer of a mixture of micorrhiza fungi (Glomus intraradices) and phosphate solubilizing bacteria (Pseudomonas fluorescens) (M+Ps), and integrated application of P50+ M+Ps were assigned to sub-sub plots. Results showed that in normal irrigation regime grain yield of cv. Speedeh was 9508 kg/ha while in deficit irrigation regime it produced only 7192 kg/ha. This is while cv. Kimiya had 10368 and 8795 kg/ha of grain yield in normal and deficit irrigation regimes, respectively. Integrated phosphorus fertilizer application affected grain yield under normal and deficit irrigation conditions and proved to be a suitable substitute for P100. Results also indicated that grain sorghum cv. Kimia could be suggested as a suitable cultivar for grain production under deficit irrigation conditions with integrated phosphorous fertilizers application.

Garlic (Allium sativum L.) is one of the most important vegetable crops in Iran. The most suitable sowing date and planting density are very important management practices in garlic production. Therefore, effect of sowing date and planting density on yield and yield components of white garlic of Hamadan was studied in Hamedan Agricultural and Natural Resources Research Center in 2007-2009 growing seasons. The experiment was carried out as split-plot in randomized complete block design with there replications. Sowing date at four levels; 09 October, 24 October, 09 November and 24 November were assigned to main plots, and planting density at two levels; 550 × 103 and 740 × 103 plant/ha were randomized in sub-plots. Effect of sowing date and planting density and their interaction on yield, clove weight, clove diameter, number of clovelet in each clove and number of skin layer were studied. Results showed that the best combination of sowing date and planting density was 20 October with 740000 plant/ha with yield of 24.1 tons/ha. Therefore, this combination can be recommended for production of white garlic of Hamadan under similar conditions.

To study the effect of essential oils of medicinal plants on post-harvest stability of fruits quality and decay management of Kinnow mandarin, this experiment was carried out as factorial in completely randomized design with four replications. Essential oils of Thyme, Mint, Fennel, Rosemary, Ajowan and Cummin at two levels; 500 and 750 ml/l were applied to wounded and non-wounded fruits, that had been sprayed by Botrytis cinerea spores, and then stored in common and cold stores and kept for four months. Fruit decay (%), fruit weight loss (%), TTS (%), total acid (mg/100ml) and changes in Vitamin C were measured and recorded. Store had significant effect on fruit decay. Decayed fruits in cold store (20.9%) was significantly less than in common store (32.7%). The lowest decayed fruits was observed in 750 ml/l Mint essential oil and the highest decayed fruits rate was in sprayed wounded treatment. This indicated that wounds are necessary for pathogen penetration. Fruits in cold store had significantly higher total acid content than common store. The highest total acid content was measured in 500 ml/l of Fennel essential oil and the lowest in 750 ml/l of Mint essential oil treatments. TSS (%) was significantly higher in cold store than in common store. This can be associated to higher respiration rate of fruits due to higher temperatures in common store. Non-wounded control fruits had the highest TSS (%) which could be due to low respiration rate of these fruits. Non-wounded control had no significant difference with 750 ml/l Mint essential oils. The lowest TSS (%) was measured in 500 ml/l essential oils of Ajowan. Vitamin C content was highest in 750 ml/l essential oil of thyme and lowest in 500 ml/l essential oil of Cummin. Fruits treatment with essential oils of Thyme, Fennel, Rosemary and Mint at either levels of 500 and 750 ml/l and Ajowan only at 750 ml/l level had significantly higher vitamin C content. This research showed that essential oils of medicinal plants were effective in controlling post-harvest stability of fruits quality and decay management. Essential oils of Mint and Ajowan had the highest effect at the 750ml/l level and can be recommended for post-harvest fruits decay management of Kinnow mandarin.