JOURNAL OF RESEARCH IN AGRICULTURAL SCIENCE
Year:2009 | Volume:4 | Issue:2|Papers Count:16

A field experiment was conducted in Karaj to study the effects of a few nitrogen sources on wheat (Pishtaz var.) yield and quality. Treatments consisted of, T1= Blank (without N fertilizer); T2= Sulfur coated urea (SCU ;(T3=Ammonium nitrate and T4= Urea. The experimental design was a completely randomized block design with three replications. Nitrogen rate was 180 kg N ha-1. Wheat grain yield increased with application of N fertilizers and the highest grain yield was obtained with T3 and it was significantly different with blank and SCU was significant. Difference between SCU and blank on grain yield was significant but it wasn't significant between Ammonium nitrate and urea. T3 had the highest grain N concentration and it was significantly different to other treatments. Ammonium nitrate had the highest N uptake efficiency (NUE). SCU produced 18.7 kg grain per kg N and in Ammonium Nitrate it was 29.8. Correlation between N uptake and grain yield was positive. Increasing the N uptake enhanced elements uptake. Results showed that in conditions similar to this experiment and with this materials, SCU cannot prepare N to winter wheat, in necessary amounts.

in order to study the sowing date,seed size and planting depth on yield components and yield of Corn (Zea mays) K.S.c500, A split-split plot experiment in a compeletely randomized design was conducted at Islamic Azad university, Khoramabad branch during 2003-2004.the two sowing data (Second and 12th of august) were allocated in the main plots and planting depth at three levels as 2, 4.5 and 7cm,and seed size (5.8-6mm, 4.9-7.1 mm, 7.9-8.1mm and mixed seed) were assigned in sub and sub-sub plots, respictvely. Result showed that seed size and planting depth had significant effects on exegence and plant growth, development and yield. Sowing Date and depth of planting had significant effect on plant yield. Depth of sowing (7cm) with seed size (5.8-6mm, 6.9-7.1 mm) was superior for plants yield and depth of planting (4.5cm) with mixed seed and depth of planting (2cm) with mixed seed get second and third place for plant yield. Small seeds (5.8-6mm) ubsorbed high soil moisture (high Ratio of surface to volume) and had suitable emerging with high yield (planting depth, 7cm). Depth of planting (7cm) had maximum stem elonyation rate in all seed size. High temperature stress had no important effect on water adsorption (planting depth, 7cm).The interaction effect between time of sowing, planting depth and seed size for plant height was significant. Depth of planting (2cm) with seed size (7.9-8.1 mm), depth of planting (4.5cm) with mixed seed and depth of planting (7cm), with seed size (5.8-6cm) producted maximum number of seed per row.

Water deficiency is the first limiting factor in soybean production in semi-arid regions. Therefore, increasing soybean grain yield requires the selection of resistant and adapted genotypes to dry or water deficit conditions of Iran. In this investigation, in order to evaluate the drought tolerance of indeterminate soybean genotypes, an expriment was performed in a Factorial based on completely randomized design with three replications. The expriment factors included 6 genotypes of soybean and 3 levels of drought stress (control, flowering and seed filling stages). Six drought tolerance indices of MP, GMP, TOL, SSI, STI and HARM were assessed on the basis of grain yield in stress and non-stress conditions. Stress intensity for flowering stage was low (SI=0.291) while high for seed filling stage (SI=0.429). Based on the results of principle components, two first components totally explained 99.9% of variation among data. The first and second components were named drought tolerance and stress susceptiblity component respectively. Based on the results of correlation between drought resistance indices and grain yield in stress and non-stress environments, indices of MP, GMP, HARM and STI were recognized as best indices for selection of tolerant genotypes. Based on the bi-plot graph, cultivars Williams and Hack in flowering stage and cultivar Williams in seed filling stage were recognized at a tolerant cultivars.

This experiment was conducted in 2005-2006 at the Isfahan Agricultural Research Station to evaluat the effects of delay cropping on Growth Indices canola cultivars; a split-plot layout within a completely randomized block design with three replication was used. Main plots were two cropping dates (27 September was normal cropping and 27 October was delayed cropping), subplots were inclusive of species B. napus (Option 500, Hyola 330, date of cropping Hyola401, Sargol, Modena, SLM 046, Opera, Zarfam and RGS003). Effect was significant on growth indexes such as maxium leaf area index (LAI), maxium total dry weight (TDM) and maxium crop growth rate (CGR), so that delayed cropping reduced them, but sowing date didn’t affect maxium net assimilation rate (NAR). Effect of cultivars was significant on growth indexes such as LAI, TDM, NAR and CGR. cultivars Zarfam and SLM046 had the most LAI, TDM and CGR and cultivar Opera had the most NAR. The intraction effect between sowing date and cultivar was significant on LAI, TDM, NAR, CGR and grain yield.

This study was conducted to investigate the effect of water stress and different levels of N2 fertilizer on yield and water use efficiency in sugar beet (Variety BP) in Khorasan Razavi agricultural and natural resources research center in 2006. The treatments included: irrigation at three levels (without water stress, initial water stress, constant water stress) and different rates of N2 fertilizer at four levels (without fertilizer, 50, 100 and 150 N2 kg/ha), which was done in a split plot experimental base in a completely randomized block design with four replicates. The results showed that the Treatments and different rates of N2 fertilizer had a significant effect on root yield and gross sugar percentage (P<0.01), but there was no significant effect on the sugar percent of mollass, net and gross sugar yield. Water use efficiency were significant in treatments (P<0.05). The results showed that in treatment without water stress by increasing N2 rate. The root had a better yield was more in comparison with water stress condition. Regarding the root yield, treatments without water stress with 150 Kg N2/ ha had the highest yield. Water stress treatments particularly constant water stress, caused the most water use efficiency.

This study was conducted to evaluate the effect of sheep manure compost (direct and residual) combined with application of chemical fertilizer (N, P, K) in order to reduce application of chemical fertilizers and to obtain the optimum use of organic and chemical fertilizer in corn planted during 2002-2005 at Safi-Abad agricultural research center, Dezful. The experimental design was a completely randomized block with factorial arrangement. The treatments were at four levels of chemical fertilizers consisting of 50, 75, 100 and 125% of recommended rates on the basis of soil testing which were used from urea, triple super phosphate and potassium sulphate and four levels of sheep manure compost including of 0, 5, 10 and 20 t/ha. The results showed that the main effect of chemical fertilizers with the residual effect of sheep manure compost on grain corn, 1000-grain weight and uptake of N, P and K by grain were significant. Application of sheep manure compost increased soil organic carbon and available P and K significantly. Therefore, with regard to the condition of this experiment and economic analysis of the results, use of 50% chemical fertilizers (N, P, K) in combination with 5 t/ha sheep manure compost is recommended for corn production.

Cultivation of edible mushrooms (Pleurotus spp.) is an appropriate solution to converting waste remainders of the agricultural processing and complementary industries to valuable foodstuff. In this study, some materials such as wood chips, boll, sugar beet pulp and palm fiber were employed as substrate and some types of additives including wheat and rice bran, soybean cake powder, and carrot residue were used as food complement for cultivating edible P. florida. The results revealed the shortest period of edible mushroom growth to be for those raised on palm substrate supplemented with food complement of soybean cake powder (27.33 days); the highest mean weight of the fruiting bodies on sugar beet pulp was supplemented with a mixture of soybean cake powder and rice bran (34.5 g); and also the highest crop yield and biological efficiency of the edible mushroom on sugar beet pulp substrate was supplemented with rice bran (680.7 g and 136.1% respectively).

This experiment was conducted to investigate the effects of plant growth regulators on the quantitative and quality traits of Shahani date fruits, in two consequent years as factorial experiment in RCBD arrangement with 4 replications. Clusters of palms were pollinated with distinct and equal pollen, and then were treated with different concentrations of Benzyl Adenine (BA), Gibberellic acid (GA3), Naphthaleneacetic acid (NAA) and 2, 4-Dichlorophenoxiacetic acid (2,4-D) alone or in combination together, at two stages: Hababook and Keimeri. At the ripening stage traits including: ripening percentage, TSS, pH, water content, fruit and seed weight, length and diameter were measured. The results showed that fruit sized increased in treatments had 2,4-D and seed size increased in GA3 and BA. TSS in control treatment was more than other treatments. Treatments having auxin and GA3 had a delayed ripening than other treatments. Generally, treatments having BA with low concentrations of auxin and GA3 were suitable for improvement of quantitative and qualitative traits of Shahani date fruits.

In order to investigate the effect of plant growth regulator and planting system on yield and quality of hybrid cucumber a glass house experiment was conducted in Yazd. Two growth regulators namely auxin, Naphthalene acetic acid (NAA) at the rate of 0, 25, 50, 100 mg/l and Ethephon (Chloro ethyl phosphonic acid) (CEPA), at a concentration of 0, 50, 150, 250 mg/l were sprayed on plants when they had 4 to 6 leaves. Two methods of planting were used, direct seeding and transplanting plants were spaced 60 cm apart on rows 120 cm apart. Plans were regularly watered and fertilized as normal. The criteria measured were: the beginning time of flowering, flower No, fruit No, fruit length, fruit weight, plant height, number of nodes, intern ode height and yield per plant. The results indicated that auxin and Ethephon significantly increased yield compared whit control. The interaction of planting system and hormones was significant on yield. The best treatment which produced of highest was 100mg/l NAA when combined with 250mg/l CEPA combined with the transplanting system.

Support of domestic product and export could have a powerful presence in the international trade. In this study the comparative advantage of apricot product in East Azerbaijan province was investigated by using DRC index and policy analysis matrix (PAM). Also revealed comparative advantage (RCA) and revealed symmetric comparative advantage (RSCA) as export comparative advantage of apricot in Iran were analyzed. Data were collected from Jahade-Keshavarzi organization and yearly foreign trade database. Results show for a few years there is comparative advantage and regarding to DRC=0.6, there is comparative advantage for production. According to the findings during 1994-2000 periods Iran has comparative advantage in export although in recent years it did not observe.

The comparative advantages and competitiveness and effective protection coefficient of Lorestan's major agricultural crops was assessed were assessed using a policy analysis matrix (PAM) and 1383-1384 production cost data released by ministry of Jihad-e-Agriculture. The following commodities: were considered irrigated and rain-fed Wheat, irrigated and rain-fed barley, irrigated corn, paddy (rice), irrigated and rain-fed chickpeas, irrigated and rain-fed lentil, sugar beet, tomato, cucumber, potato, irrigated beans, irrigated and rain-fed rapeseed. The economic profitability is estimated by domestic cost resources ratio (DRC), the finding demonstrate that Lorestan province has a comparative advantage in major agricultural crops, and a disadvantage in paddy (rice) and rain-fed wheat. Vegetables (potato, cucumber, and tomato), oilseed crops, corn and pulses are more profitable than other crops, within the grain sector. Within the selected commodities, cucumber, potato, tomato has a more comparative advantage than the others. The nominal protection coefficient (NPC) measures the level of protection for the tradable output by looking at the ratio of the revenue at private price above the revenue at social (shadow) price for all crops smaller than one (except paddy), meaning that the price in the international market is higher than the local market by the same former ratios. On the other hand, the implication that all crops production system is the tax imposed by the government. NPCI measures the level of protection for the tradable input by looking at the ratio of the tradable input cost at private price above the tradable Input cost at shadow price for all crops smaller than one indicating that the policies are reducing input costs for all commodities. The values of the effective protection coefficient (EPC) compares the added value at private price to added value at shadow price, for wheat, barley, sugar beet, rapeseed and paddy is above one indicates that the system benefit from protection. For other crops EPC is below one which means that the system is the tax imposed. The value of social cost benefit (SCB) ratios led to only a slight change in commodity ranking compared to the estimated DRCs.

Lands of Islamic Azad University of Khorasgan on piedmont plains of Baghe Rezvan mount were studied. These lands are representative of the area with much salt, gypsum and lime and surveying them is useful for the area. Morphologically, alternation in texture, structure, gravel contents, color, gypsum and lime contents are representative of lithologic discontinuity in the soils. With the respect to the fact all soils are derived from the Baghe Rezvan mountains, and have the same parent materials, these alterations are attributed to different floods, erosions and deposition that are products of change in climate in time. In the limestone, sandstone, conglomera and shale's of lithologic formation of Baghe Rezvan mount there are illite, kaolinite, chlorite, feldspars and quartz. All of these minerals were found in the soils. Besides these there were vermiculite-chlorite, paligorskite and in difractograms. Presence of dryness with lime and gypsum were prepared genesis and coexistence of palygorskite. Micro morphological studies showed that there were much coarse lime gravels and little fine materials. In thin sections some dense non continuous and nonsense non continuous gypsum infillings were seen. Presence of alternative layers of lime and clay as hypocoatings and quasicoatings on lime gravels show that there were changes in weathering in some periods. There were quartz, cert., epidot. amphibole, pyroxene, feldspars, primary chlorite and calcite, and some fragments of fossil lime-stones from cretaceous and siltstones in thin sections too.