مجله فنآوری زیستی در کشاورزی
سال هشتم شماره 4 (زمستان 1387)

Soil and water salinity is one of the most important problems of agriculture in Iran. Application of chemical fertilizers, particularly phosphorus (P) fertilizers, may lead to improve the yield quality and quantity. The effects of salinity and P on growth, chemical composition and water use efficiency (WUE) of canola (Brassica napus L.) were investigated. The experimental treatments were five saline water levels [non-saline water (EC= 0.3 dS/m), 3, 6, 9, and 12 dS/m] and four applied phosphorus rates (0, 20, 40, and 80 mg/kg soil as KH2PO4). This experiment was factorially arranged in a randomized complete block design with three replicates. The results indicated that the dry matter and grain yields of canola were decreased significantly by increasing salinity levels. Application of 20 and 40 mg P/kg soil increased grain end dry matter yield, respectively. The applied saline water increased Cl, Na, B, and P concentrations and decreased Ca, K and N in plant. On the other hand, application of P decreased Cl concentration of plant significantly. The water use efficiency, at first, was increased and then decreased by increasing salinity levels. Application of phosphorus in high levels resulted in decreasing WUE.

In order to investigate the effect of weed free periods on light absorption and use efficiency of seed production and commercial fields of potato an experimental was conducted in Agricultural faculty of Bu Ali Sina University in 2006. This experiment was a factorial experiment based on a randomized complete bloke design with three replications. Experiment 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 m-2 and weed ّfree periods at seven levels, witch in the five levels, weeds were controlled for 10, 20, 30, 40 and 50 days after crop emergence and then weeds were allowed to grow until harvest, In addition two control treatments (full- season weeded and full- season infested) were taken. Each plot consisted from four rows (eight meter per row) with a row spacing of 75 cm. In order to determine light absorption by potato canopy, amount of light in the top and under the canopy was measured 10 days after crop emergence and repeated 10 days interval for 8 times. Weeds were removed before light measurement in the infested treatments. Sampling of weed and potato was done at the same time of light measurement to determine leaf area index of potato and total dry matter of weeds. The results showed that by increasing weed free periods, leaf area index, light absorption and use efficiency, light extension coefficient and number of potato branches per unit area, increased and total weed dry matter, decreased. The effect of weed free periods on above mentioned trials in commercial field's potato plant density (5. 33 plant m-2) was more than seed protection field's plant density (6. 66 plant m-2).

The experiment was conducted to determine metabolizable energy contents of soybean (SBM), canola (CM) and sunflower (SFM) meals from differences manufactory processing oil seeds. Nine samples of SBM, four samples of CM and four samples of SFM were evaluated using conventional addition method (CAM) with adult cockerels for a seven days experimental period consisting 4 days pre-collection and 3 days collection periods. The results have indicated that apparent metabolizable energy (AME), nitrogen-corrected apparent metabolizable energy (AMEn), true metabolizable energy (TME) and nitrogen-corrected metabolizable energy (TMEn) were different within samples of SBM, CM and SFM meals (P<0.05). The averages of AME, AMEn, TME, TMEn values for SBM, were 2439.12, 2439.14, 2636.16 and 2636.27; for CM were 2058.07, 2058.58, 2177.72 and 2177.94; and for SFM were 1426.80, 1426.87, 1587.35 and 1587.46 kcal/kg, respectively. The result of experiment confirms that amount of metabolizable energy content of soybean, canola and sunflower meals can be influenced by chemical nutrients, variables and manufactory processing respectively.

Application of micronutrient fertilizers is an effective strategy for increasing yield and quality properties of wheat. This study was conducted to evaluate the effect of Fe and Zn fertilizer on wheat yield and quality properties at Moghan Agricultural and natural resource research center during 2007-2008. The experimental design was done as factorial arrangement based on randomized complete block design with three replicates. Studied factors were cultivars (three levels) and foliage application of Fe and Zn or no application (control). Plant characteristics such as plant height, number of ear per plant, number of seeds in main ear, 1000 kernel weight, biomass, seed yield, protein content, Fe, Zn and Mn concentration were studied. The MSTATC software package was used to analyze all the data and means were separated by the least significant difference (LSD) test at P< 0.01. Results showed that seed yield, Fe, Zn and Mn content were significant different among cultivars. Foliage application of Fe and Zn had significant effect on seed yield, tiller number, fertile tiller number, protein, Fe, Zn and Mn content at P< 0.01. interact effect of cultivar×micronutrient application was significant on seed yield, Fe, Zn and Mn content. Among cultivars, the maximum seed yield was obtained with Arta cultivar. Foliage application of Fe and Zn increased wheat yield over 12 percent.

Although iron effect on growth and yield of different plants has been intensively investigated, there is limited information on its effect on grain yield and seed oil content of sunflower, particularly under saline condition. In this study, the effects of soil application of Fe-EDDHA (two rates of 10 and 20 kg ha-1) and foliar spray of FeSO4 (0.5% in two intervals at 10-leaf and flowering stage) on growth, grain yield and seed oil content of sunflower were investigated. A treatment with no Fe application was considered as a control treatment. The biennial results showed that soil application of 20 kg FeEDDHA ha-1 had no significant effect on shoot matter yield of sunflower while significantly increased grain yield in comparison with control. In contrast, foliar application of FeSO4 had no significant (P <0.05) effect on seed yield and shoot dry matter yield. Seed oil content was also not affected by foliar application treatment. Regardless of the application method, increasing the fertilizer rate had no significant effect on seed oil content. Soil application of FeEDDHA significantly increased the head diameter and 1000- kernel weight but reduced the plant height. Conclusively, the result of this experiment showed that soil application of 20 kg Fe-EDDHA ha-1 increased plant tolerance to salinity and resulted higher grain yield and oil seed content as compared to control.

When allow for continuum in components of Landscape-Soil system, studies must be on basis of hierarchy scale. Data of Landscape-Soil system has straight relation with spatial information. For this reason, analysis of terrain properties has increasingly overlapped with Geographical Information System (GIS). A Digital Terrain Analysis (DTA) model derived from Digital Elevation Model (DEM). (DTA) model indexes are served to study of geomorphic surfaces and landforms in toposequence. Area of 278ha is studied in region of Ayej terrestrial dam, Jouneqan east, province of Chaharmahal and Bakhtiary in Iran. Some properties of geomorphic levels is measured by remote sensing and digital terrain modeling (DTM), such interpolation and slicing methods. Then digital terrestrial indexes, as Stream Power Index (SPI), Sediment Transport Index (STI), and Wetness Index (WI) obtained of (DEM) for six transects or sequences in study area. Every spatial situation that (SPI) to be increased, velocity and volume of flood-water were upward, as (STI) increased and (WI) reduced in its minimum. For all of sequences (STI) confirmed correlation with (SPI) closely, except 4 sequence. In sequence 4, (WI) harmonized with (STI) and traversed process of climb. Therefore sediment accumulation and water influence caused more development soils in sequence 4. In sequences 1, 2, 3, 3, 5, and 6 increased (SPI) and (STI) harmonious, reduced (WI), and caused less development soils. Percentage of slope, water influence and volume sediments are the most affected factors on configuration of landscape and landform in study area. Goal of this research was primary study landscape analysis by multiattribute and multiobjective methods, as soil survey realized for land suitability evaluation.

Performing different tillage methods with different tractors can produce an immediate effect because of the varying degrees of physical manipulation. Our objective was to investigate some soil physical properties response to short-term tillage application using different tractors on a fine loamy, mixed, mesic Calcixerollic Xerochrepts soil in Hamadan. Two tillage systems [chisel plow (CP), and moldboard plow (MP)] and three tractors [John Deer (J), Romania (R) and Massey Ferguson (MF)] were evaluated using a factorial split-plot design with three replications. Within row zone (RZ) and traffic zone (TZ) soil samples were collected from four layers to a depth of 30 cm by the end of wheat growth season, and compared for total porosity (TP), macroporosity (Macro-P), microporosity (Micro-P) and saturated hydraulic conductivity (Ks). The results showed that MP significantly increased TP and Macro-P. Tillage plus tractor influenced the TP in the RZ. The TP ranking was MF>J>R with CP at all the successive layers but this order was not observed with MP. While the impacts of tillage treatments on Macro-P within both TZ and RZ were significant, the change within TZ was not considerable. The Micro-P was also significantly affected within TZ. The Ks and Macro-P were higher within TZ with CP than MP, while Micro–P was decreased with CP. It was concluded that the performance of conservational tillage system using MF had beneficial effect on the selected soil physical properties.

River confluence is an important element of river system. The entrance flow from the minor branch to the main channel causes extensive variation in flow pattern which result a deep scour hole and formation of point bar. These phenomena can accelerate the rate of bank erosion, bring problems for navigation and may causes failure of the bridges or structure nearby. Despite of these, due to three dimensional structures of flow and sediment at river confluence, systematic study for understanding the mechanism of flow and sediments are very few. There for the main purpose of this study to conduct a comprehensive literature review and experimental program to study the effects of confluence angle on erosion and sedimentation pattern. To reach such goals first using the dimensional analysis, general non- dimensional equations were developed. Then many experimental tests were conducted for three confluence angles of 60, 75 and 90 degree and different hydraulic conditions. The experimental tests showed that as the confluence angle is increase, the scour hole and point bar dimensions increases. Using the experimental data, the effects of each non-dimensional parameters on scour hole depth were investigated and finally relations were developed for prediction the scour and point bar dimensions.

Deficit – irrigation is an optimum approach of water application under water deficit or expense. In this research, the effect of deficit-irrigation has been investigated for corn plant (variety of single cross 704). The experiment carried out in case of randomized complete block design which has 13 treatments and 3 repeats. The first treatment was without any irrigation and next treatments have increase of 10 % of full water requirement respect to previous one up to 120%. The results showed full irrigation (82.4 cm application water depth in unit area) had maximum yield of 77360 kg/ha, and dry-farming and deficit-irrigation by application water depth of up to 30% of water requirement had only loose of money for farmer. Furthermore, Maximum pure benefit was related to treatment with 10% decrease in full irrigation. The highest value for gross and pure income belonged to treatments by 50% and by 30% decreases in requirement water depth respectively. In general, results showed irrigation by application depth more than requirement depth not only decreased the benefits but also the yields. In case of limitation in water resources and permission to increase area of farming, the highest value in pure benefit will obtain in treatment by full irrigation.

Drought is a threaded factor in world produce and application of breeding method is proposal for selection of tolerant and adapted cultivators under drought stress. In order to calculated of correlation coefficient and path analysis some traits that relationship with grain yield in 15 genotypes of Chiti beans under non-stress and drought stress conditions were studied using randomized complete block design with three replications in experimental field, Faculty of Karaj Agricultural in 2004 crossing season. Irrigation was each seven days and each ten days on non-stress and drought stress conditions respectively. In this experiment were measured some of traits such as physiological characteristics (date to flowering, filling duration and seed maturity), morphological seed traits (length, weight and seed diameter) and quantitative traits (No. seed/pod per plant, 100 seed weight and pod weight). By stepwise regression introduced best model for two conditions. In regression model pod weight was the first trait that had highest R2 coefficient (R2=0.919) but second trait had lowest share under non-stress and drought stress conditions. Results of simple phenotypical correlation showed pod weight had highest correlation with seed yield on non-stress and drought stress conditions in 1% probability (r=0.95) and this result confirmed regression model. Path analysis In non-stress condition showed greatest direct effect by weight pod (r=1.035) and days to 50% flowering (r= -0.201) respectively. Path analysis In stress condition showed greatest direct effect by weight pod (r= 0.902) and number of seed per pod (r= 0.159). Total results showed for breeding programs, it is better that weight pod selected in Chiti bean. Also protein percentage not alternative trait under drought stress in Chiti beans.

Clutch size variation of a leaf mining moth Cemiostoma aceris (Fuchs) was investigated on two host plants, Populus euphratica Olivier and Salix elaeagnus Scop. Female moth’s oviposited egg clutches with different size on the two host plants and that clutch size was correlated with leaf area between host species. Therefore, females are adjusting clutch size in response to variation in resource availability for offspring. Positive correlation was also found between clutch size and leaf area within host species, however, the relationship was weak. Expected clutch size was determined from estimates of leaf area consumed by a larva until pupation. Females laid significantly smaller clutches than the expected size that could be supported by a single leaf on both host plants. It was discussed how the females determined clutch size in response to resource availability.