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1.
The objective of this study was to evaluate the effects of elemental sulphur (S) and farmyard manure on soil pH, EC and N, S, P concentrations of tomato grown in a calcareous sandy loam soil. For this purpose, a pot experiment was conducted in greenhouse conditions. Sulphur was applied at 0, 50, 100, 150, 200, 400 mg kg~ and farmyard manure at 0, 3 ton da^-1 to the soil. Three weeks after applications, tomato seedlings were planted and 8 weeks later, the plants were harvested to determine N, S, P concentrations and dry matter yield. Soil pH and EC were determined in the soil samples taken at 3 different periods. Effects of sulphur and farmyard manure applications were not significant on N, P concentrations and dry matter yield of tomato plant. S concentration of tomato plant was increased by sulphur alone. Soil pH was decreased and soil EC was increased in both 2^nd and 3^rd soil sampling period by the sulphur applications. As a result of farmyard manure application, soil pH decreased in the 2^nd soil sampling period but increased in the 3^rd soil sampling period. Also, soil EC was significantly increased in 1^st and 3^rd soil sampling period. Farmyard manure had no significant effect on S supply to tomato plant. The N:S ratio of tomato plant was decreased by sulphur alone. However, the sulphur with farmyard manure applications decreased N:S ratio in lesser extend compared to the S applications.  相似文献   

2.
M.  M.  Adilov 《农业科学与技术》2010,(4):103-106
The results of the three-year researches which had the purpose to establish an optimum depth of seeding at sowing and rational norm of seeding of red beetroot seeds at under-winter sowing in conditions of mid-loamy typical grey soils of the central climatic zone of Uzbekistan are stated in article. The researches were spent at statement of field experiences in quadruple frequency with the area of a registration allotment 10 M^-1. Crops were carried out in the first decade of December against mulching surfaces of ridges by humus and without mulching. Crops were carried out on ridges in width of 70 sm tape-two-lined with distance between tapes of 50 sm, between lines-20 sm and distance between plants in a line of 12-13 sm, at density of standing of 228-230 thousand plants/hectares. Experiences were spent with zoned in Uzbekistan multi-seedling grade of a red beetroot "Bordo 237". Experiences were accompanied by phenological supervision, biometric accounts, the account of field germination of seeds, density of standing of plants and definition of size and quality of a crop. Results of researches were exposed to the statistical analysis by a dispersive method. It has been revealed that at under-winter sowing of a red beetroot the effective way providing acceleration of shoots occurrence, formations of high-grade density of standing and increase of productivity of root crops is mulching the surfaces of ridges by humus. It is defined that optimum depth of seeding at sowing both at application of mulching and without it is the depth of seeding 4 sm. It is established that the most rational norm of seeding of the seeds, providing high-grade density of standing, is at cultivation with application of mulching 8 kg/ha, and at cultivation without mulching 8-10 kg/ha. Application of mulching the surfaces of ridges by humus, depths of seeding of 4 sm and norms of seeding of seeds of 8-10 kg/ha in conditions of under-winter sowing in comparison with cultivation without mulching and depth of seeding 2 sm and norms of seeding of 6 kg/ha provides an acceleration of receipt of fresh production of a red beetroot for 12-14 days and considerably raises root crops productivity. Application of agro receptions improved by us is the important reserve of acceleration of receipt of red beetroot early production and increase of its manufacture.  相似文献   

3.
The quality office is complex and made up of many components such as nutritional quality, appearance, cooking quality and eating quality. The cultivar is one of the main factors that could affect to the grain quality office. The aim of this work was to analyze and compare the cooking quality parameters of six different japonica varieties of rice grown in Spain (Senia, Gleva, Bahia, Maratelli, Guadiamar and Bomba). This work focused on the study of the cooking quality of rice, because it is one of the most important factors related to grain quality in Spain. It was evaluated using five characteristics: amylose content, gel consistency, degree of spreading, gelatinization temperature and pasting parameters. The amylose content ranged from 11.60% to 21.46%, with the Gleva cultivar having the lowest amylose content and with Bomba having the highest. The gel consistency varied between 5.44 cm and 9.81 cm. Regarding the alkali test, the Maratelli cultivar had the highest dispersion and transparency. Maratelli had the lowest gelatinization temperature (61.67±0.08 ℃), and Senia had the highest gelatinization temperature (67.05±0.02 ℃). Finally, the pasting parameters showed significant differences among cultivars with different viscosities.  相似文献   

4.
It is predicted that the current atmospheric CO2 concentration will be doubled and global mean temperature will increase by 1.5-6°C by the end of this century. Although a number of studies have addressed the separate effects of CO2 and temperature on plant-insect interactions, few have concerned with their combined impacts. In the current study, a factorial experiment was carried out to examine the effect of a doubling CO2 concentration and a 3℃ temperature increase on a complete generation of the brown planthopper (Nilaparvata lugens) on rice (Oryza sativa). Both elevated CO2 and temperature increased rice stem height and biomass of stem parts. Leaf chlorophyll content increased under elevated CO2, but only in ambient temperature treatment. Water content of stem parts was reduced under elevated temperature, but only when coupled with elevated CO2. Elevated CO2 alone increased biomass of root and elevated temperature alone enhanced leaf area and reduced ratio of root to stem parts. Brown planthopper (BPH) nymphal development was accelerated, and weight of and honeydew excretion by the F1 adults was reduced under elevated temperature only. Longevity of brachypterous females was affected by a signiifcant interaction between CO2 and temperature. At elevated temperature, CO2 had no effect on female longevity, but at ambient temperature, the females lived shorter under elevated CO2. Female fecundity was higher at elevated than at ambient temperature and higher at elevated CO2 than at ambient CO2. These results indicate that the combined effects of elevated temperature and CO2 may enhance the brown planthopper population size.  相似文献   

5.
E.  O.  Idowu 《农业科学与技术》2011,(4):472-475
The protein, carbohydrate and lipid contents of the food ingested and their absorption in the intestine ofHepsetus odoe in Ado-Ekiti Reservoir, Ekiti State, Nigeria were investigated. Samples were analysed chemically for protein, fat and carbohydrate using the official methods of analysis described by the Association of Official Analytical Chemist. The ingested food had mean total protein, mean total carbohydrate and mean total lipid of 60.2% - 8.55%, 15.4% ± 1.9% and 15.6% ±1.1% of the organic content respectively. Calculated mean total percentages absorbed were 72.4% protein, 52% carbohydrate and 51.5% lipid. The foregut had the highest percentage absorption while the hindgut had the lowest for all the nutrients. Different sizes of fish showed different dietary protein, carbohydrate and lipid contents. Absorptive capacity for these components of the food also varied with fish size.  相似文献   

6.
Some engineering properties of sunflower seed and its kernel, Shahroodi variety as a case study, were investigated at various moisture content levels (3-14% d.b.) for three size categories (large, medium and small). With increase of moisture content from 3 to 14% d.b., all the main dimensions (length, width and thickness), geometric mean diameter, porosity, true density, terminal velocity and static coefficient of friction increased while bulk density and rupture force for both sunflower seed and its kernel decreased for all size categories. The results showed that the highest value of static coefficient of friction for both seed and kernel was on the rubber surface, followed by plywood, polyethylene, galvanized iron, and finally aluminium surfaces. The seeds required less compressive force to dehull when loaded under the horizontal as compared to the vertical orientation. But for kernels, the trend was the opposite. Also, the compressive forces needed to initiate rupture of sunflower seed hulls were higher (47.1-94.72 N) than those required to rupture the kernel (8.5-13.4 N) in both orientations.  相似文献   

7.
The objective of this study was to investigate the effect of moisture content, size and loading orientation on mechanical properties such as force, deformation and energy absorbed per unit volume for fracturing Iranian sunflower seed and its kernel (Azargol as a case study) under quasi-static loading. Sunflower seeds and their kernels were quasi-statically loaded in horizontal and vertical orientations with moisture content in three levels: 3%, 7% and 14%, and size category in three levels: small, medium and large. The obtained results showed that rupture force for both sunflower seed and its kernel decreased with increasing moisture content while the absorbed energy and deformation at rupture point increased for all size categories in both horizontal and vertical loading orientations. Also, seeds in the vertical orientation developed hull cracks at a higher level of force than those loaded in the horizontal orientation. However, for the kernels it was the opposite. In addition, the average forces required to cause kernel rupture were lower (11.64-39.9 N) than those required to rupture the seed (30.06-117.46 N) in both orientations. Seeds loaded in a vertical orientation absorbed more energy (87.67 mJ) prior to rupture than those loaded in the horizontal (46.60 mJ) orientation. However, for the kernels it was the opposite.  相似文献   

8.
Sowing time of wheat in south eastern Australia varies from autumn to early winter, depending on the seasonal 'break'. Wheat yields are often reduced by frost damage at flowering time and by heat-and/or water-stress during grain filling. Selecting suitable varieties for specific sowing times is a complex decision farmers make because these varietal phenology and climate risks have to be assessed together. In order to help farmers make decisions, they need tools that simulate and analyse agronomically-suitable sowing dates (ASSD) for a given variety of wheat. The hypothesis underlining this study is the integration of a wheat phenology model with historical climate data is an effective approach to modelling the ASSD of current varieties used in the wheat growing areas of Southern NSW. The parameters of the wheat phenology model were based on data from five years of field experimentation across 15 sites. Data from four sites were used to examine varietal suitability in relation to sowing time and its associated risks of frost and heat damage. The optimum ASSD for any variety at 72 locations across Southern NSW was investigated. The results showed that there were substantial spatial variations in the ASSD across the target region. ASSD for a late maturing wheat genotype (EGA Gregory) can range from early March to late April, while the earliest acceptable sowing date for an early maturing spring wheat genotype (H46) can range from early to late May. The wide range of spatial variation in the earliest and latest sowing dates, as well as the varied length of sowing opportunities, highlighted the importance of being able to apply a modelling approach which can integrate information on crop phenology with climate risk for a given location. This approach would allow better decision-making on suitable varieties and sowing dates in order to minimise the risk of frost and heat damage affecting crop yield.  相似文献   

9.
Experiments were conducted to analyze the initial tree crop interaction between Jatropha curcas and wheat by planting the perennial component in East-West orientation with 8-2 m distance and wheat as intercrop at National Research Centre for Agroforestry (NRCAF), Jhansi during July, 2007 to April, 2009. During planting of Jatropha the interaction to wheat was non-significant and influence of orientation is also nil. Eighteen months after plating Jatropha had attained the mean height of 124.56 cm, collar diameter of 6.37 cm, number of branches of 11.25, canopy diameter of 98.5 cm and yielded 18.5 g seeds per plant. During 18 MAP also observations revealed the non-significant influence of Jatropha on wheat. Observations also indicated the progress in wheat growth and yield attributes with the increase of distances from tree base and it follow the order of 0.5 m〈1.0 m〈2.0 m〈3.0, 4.0 m and open. Nearly, 62% and 14% yield loss in wheat grain was observed at 0.5 m and lm distance from the tree base respectively compare with open. Comparison ofwheat-Jatropha agrisilviculture system and sole wheat cropping indicated the net grain yield reduction up to 13.5% by agrisilviculture system. The comparison of wheat and straw yields between the two years clearly indicating that the system and sole cropping have not much differed while the influence of climatic factor is witnessed by the variation of yields over years. It revealed that the initial above ground interaction between Jatropha and wheat was due to the space that can be managed by the pruning of branches which is a recommended cultural practice of Jatropha.  相似文献   

10.
Biochar is a potential micro-environment for soil microorganisms but evidence to support this suggestion is limited. We explored imaging techniques to visualize and quantify fungal colonization of habitable spaces in a biochar made from a woody feedstock. In addition to characterization of the biochar, it was necessary to optimize preparation and observation methodologies for examining fungal colonization of the biochar. Biochar surfaces and pores were investigated using several microscopy techniques. Biochar particles were compared in soilless media and after deposition in soil. Scanning electron microscopy (SEM) observations and characterization of the biochar demonstrated structural heterogeneity within and among biochar particles. Fungal colonization in and on biochar particles was observed using light, fluorescence and electron microscopy. Fluorescent brightener RR 2200 was more effective than Calcofluor White as a hyphal stain. Biochar retrieved from soil and observed using fluorescence microscopy exhibited distinct hyphal networks on external biochar surfaces. The extent of hyphal colonization of biochar incubated in soil was much less than for biochar artificially inoculated with fungi in a soilless medium. The location of fungal hyphae was more clearly visible using SEM than with fluorescence microscopy. Observations of biochar particles colonized by hyphae from soil posed a range of difficulties including obstruction by the presence of soil particles on biochar surfaces and inside pores. Extensive hyphal colonization of the surface of the biochar in the soilless medium contrasted with limited hyphal colonization of pores within the biochar. Both visualization and quantification of hyphal colonization of surfaces and pores of biochar were restricted by two-dimensional imaging associated with uneven biochar surfaces and variable biochar pore structure. There was very little colonization ofbiochar from hyphae in the agricultural soil used in this study.  相似文献   

11.
Phosphorus (P) is a major growth-limiting nutrient, and unlike the case of nitrogen (N), there is no large atmospheric source that can be made biologically available. Moreover, P governs crucial role in plant as it stimulates root development and growth, gives plant rapid and vigorous start leading to better tillering and essential for many metabolic processes for seed formation. Soil microbes play very important role in bio-weathering and biodegradation. The microorganisms produce low molecular mass organic acids, which attack the phosphate structure and transform phosphorus from non-utilizable to the utilizable for the plants form. The test of the relative efficiency of isolated strains is carried out by selecting the microorganisms that are capable of producing a halo/clear zone on a plate owing to the production of organic acids into the surrounding medium. It is a well-known fact that as the particle size of rock phosphate decreases, the microbe mediated solubilization of rock phosphate increases in soil. In the present investigation, microbial solubilization of nano rock phosphate (〈 100 nm) particles was studied. Experimental results revealed that Pseudomonas striata solubilized 11.45% of the total P after 24 h of incubation from nano rock phosphate particles while 28.95% and 21.19% of the total P was solubilized by Aspergillus niger (black pigmented) and Aspergillus niger (green pigmented), respectively. It was also observed that Aspergillus niger has the higher ability to dissolve Udaipur rock phosphate than Pseudomonas striata.  相似文献   

12.
Oleanolic acid (OA) and ursolic acid (UA) are isomeric tritcrpenes that are difficult to separate chromatographically. Studies have indicated that both OA and UA have antifertility properties in several livestock species, suppressing attainment of puberty, gonad function and gamete production. Being able to determine the presence and quantity of the OA and UA in moringa and pawpaw seeds will allow for calculation of optimal inclusion levels of these acids in animal diets for antifertility-activity. The purpose of the study was thus to quantify the levels of OA and UA in Moringa and pawpaw seed powder by means of ultra-high performance liquid chromatography with electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS). Only OA was detected in moringa seeds at a concentration level of 0.508 p.g/g + 0.032 pg/g dry weight. UA and OA could not be detected in pawpaw seeds used in this study. The presence of OA in moringa seeds suggest that the seeds can be included in tilapia diets as a potential antifertility treatment to control precocious breeding in tilapia culture in small scale farming systems in Sub-Saharan Africa. Further studies are warranted to determine the levels of OA and UA composition in moringa seeds from other parts of the Sub-Saharan Africa (other than Zambia).  相似文献   

13.
The experiment was conducted during the short dry and the short rainy seasons in 2008. A botanical inventory and relative frequencies of forage selected by Djallonke sheep grazing were developed by observation and hand-plucking. Chemical composition and in vitro organic matter digestibility (IVOMD) of hand-plucked material was determined. From July to October, woody plants are a major component of the sheep diet. Sheep selected 40 woody plants and 21 species of herbaceous. During the dry season, grazing occurred more frequently in the fallows. The most frequent woody species belonged to Elaeis guineensis and Fagara zanthoxyloides. At the rainy season, a high proportion of Panicum maximum and Eleucine indica were sampled. Crude protein was high in woody leaves at the dry season. Crude fibre were more variable in herbaceous than in woody and herbaceous were generally higher in the levels of fibre. Chromolaena odorata, Citrus sinensis, Vitex doniana were very high in IVOMD. Spondias mombin, Moringa oleifera, Persea americana, Psidium guajava, Dialium guineense presented lowest values in IVOMD. Among herbaceous, Andropogon gayanus and Panicum maximum still presented a high value of IVOMD at the dry season. High proteins suggest woody with potential as nitrogen supplements to ruminants fed low quality forage during the dry season.  相似文献   

14.
The main objective of this research is to estimate the different types of demand elasticities for the main fresh vegetables consumed in Jordan. The estimated elasticities can be used to measure the impacts of agricultural policies and can be used to predict future consumption in the context of food security in terms of access, availability, stability, and food quality. The reported demand estimates were obtained through the estimation of a Linear Approximate Almost Ideal Demand Systems (LA/AIDS) for Jordan fresh vegetable crops demand system using the most recent cross-sectional data of household expenditure survey in 2005. A censored regression method for the system of equations was used to analyze fresh vegetables consumption patterns. This method allows for inclusion of a large number of zero consumption for some foods through two-step demand system estimation. All of the own-price demand elasticities have the correct negative signs and statistically significant. According to the expenditure elasticity, tomato, cucumber, and potato are the necessity goods. The mean budget shares indicate that consumers spend 30 percent of their allocated budget to vegetables on tomatoes and potatoes. The green bean elasticity is the highest indicating that demand for beans is highly responsive to any changes in the price. The expenditure elasticities reveal that the demand on all vegetables is expected to grow over the coming few years. High own-price elasticities of all vegetables studied suggests that any changes in the prices of these crops could bring about a significant shift in fruits and vegetable constanption patterns.  相似文献   

15.
The study area is located in a Mediterranean region, so the effects of the climate variations are very important. The authors contribution to this subject is based on the compilation of many results obtained from dissertations and theses that are carried out under their supervision. The main tool used, in addition to other methods, is the water hydrochemistry as it is proved very useful in obtaining good results and helpful in getting objective interpretations regarding the presence and absence of salinity. Several factors are undertaken to show the presence of salts in waters in the plain, the lithology of the geological formations shows that they are composed of alluvium sediments where the permeability is quite high, and this enables hydraulic communication between the fresh water of the aquifer and saline water of the sea. The study of climate shows a decrease of precipitation which favors an important decrease of recharge rate to the aquifer, and hence a decrease of water resource. The strontium which is a good indicator for the origin of salinity shows a variation that indicates a variation in the distribution of the salinity, and therefore diverse origins of salinity all over the studied area. This can infer the presence of marine invasion in the down-stream part of the aquifer, whereas elsewhere salinity is caused by the presence of evaporitic formation, mainly by the argillaceous matrix in the bottom of the lake. in the up-stream part of the aquifer. In the lake, salinity is explained  相似文献   

16.
The results of researches aimed to establish the optimum growing space and density of standing of plants at cultivation of cauliflower seeds in Uzbekistan are stated in the article. Researches were spent in the suburb of Tashkent with a mid-early grade "Domestic". In experiences were compared 5 densities of standing (31746, 35714, 40806, 47620 and 57142 pieces/hectare) received at planting of sprouts with row-spacing of 70 sm and distance between plants in a row 25, 30, 35, 40 and 45 sm. Experiences were pawned in quadruple frequency with the area of an allotment 10 M2. 60-65 day sprouts were planted under film tunnel shelters on February 11-12. Film shelters were kept over plants till the end of March. Seed plants were grown up without formation. Experiences were accompanied by phonological control, calculation of leaves quantity, an establishment of average weight of a head, definition of quantity of the plants, which have given seeds, the account of a crop of seeds from a bush and of a unit of area. It has been defined that reception of seeds of a cauliflower at cultivation under film tunnels is quite possible in Uzbekistan. It is established that with representation of the big growing space the plants form more leaves, earlier and larger form the heads, develop the testicles acceleration and increase their seed efficiency. It has been revealed that the more plants thickness is, the bigger share of them does not give seeds. In this connection the greatest crop of seeds has been received at growing space 70x45 sm at which 31.7 thousand Pl/ha had been planted. It is proved that in the conditions of Uzbekistan it is possible to cultivate high-grade seeds of cauliflower with productivity of 127-147 kg/ha.  相似文献   

17.
Leafhopper Cicadulina bipunctata is represented the main insect as a pathogen for phytoplasma disease occurring by insect-transmitted plant viruses in date palm orchards. Therefore, it is important to investigate the potential effect of some insecticides against such insect. The adults of leafhopper C. bipunctata were collected from date palm orchards in Alhasa, Eastern province, Saudi Arabia. Three insecticides from different classes--beta-cyfluthrin (pyrethroids), imidacloprid (neonicotinoids) and abamectin (natural compounds)--have been evaluated in vivo against adults C. bipunctata. This stage was exposed to residual film of various concentrations of each insecticide on transparent plastic cups using a Potter precision laboratory spray tower. Bioassay test showed that both beta-cyfluthrin and imidacloprid caused 100% mortality by 500 ppm at 24 h after treatment, whereas abamectin gave the same mortality by 50 ppm at the same time. Toxicity values revealed that abameetin was the most potent insecticide compared with beta-cyfluthrin and imidacloprid, where the lethal concentrations LC50 and LC95 were 24.58 ppm and 116.73 ppm at 3 h after treatment, respectively. Therefore, abamectin can be a possible candidate to be applied on date palm or ground grass by the Ministry of Agriculture after successful field experiments.  相似文献   

18.
Partial root-zone irrigation (PRI) has been proved to be an optimal water-saving irrigation technology, however, few studies were done on water transportation and distribution under PRI. The present study was performed to investigate the water transportation and distribution among the wet and dry root-zones and the shoot using deuterium water (D2O) in 1/4 root-zone PRI experiment. It also aimed to determine and analyze the D2O relative abundance within different types of roots and shoots. The results indicated that water could be transported from roots in wet root-zone to roots in dry root-zone and shoots within 2 h after irrigation. Water transportation in roots of wet-zone was carried out by absorbing root, 1-2 mm root, 2-5 mm root, and〉5 mm root progressively, while through a reverse process in three dry root-zones. In shoots, water was transported to trunk, central trunk, annual branches, shoot and leaf progressively. Thus in the young apple trees subjected to PRI, water was distributed ifrst in the roots, including the roots in the wet and dry root-zones, to satisfy the water need of roots itself, and then transported to the shoot within hours of irrigation.  相似文献   

19.
This communication brings scientific evidence to explain the basis for efficacy of camel milk, especially on diseases where the immune system is compromised. Camels (Camelu sdromedarius) have very small and active antibodies, nanaobodies. Their special properties are being used by the USA Department of Homeland Security as bio-receptors to determine which substance could be used in a biological warfare attack. The antibodies are part of the "protective proteins" in camel milk. These include potent antibacterial, antiviral and antifungal properties. Camel milk antibodies are, in fact, "nanobodies". They are not destroyed in their passage through the stomach. These nanobodies are responsible for data concerning the use of camel milk in autoimmune diseases. Various diseases treated with camel milk are presented, as is the mode of action. The effect of pasteurization on activity of camel milk is presented as a way to overcome the need for heat. This is accomplished by presenting "pathogen-free" camel milk. The antibodies are part of the "protective proteins" in camel milk. These include potent antibacterial, antiviral and antifungal properties. The effect of pasteurization on activity of camel milk is presented as a way to overcome the need for heat. This is accomplished by presenting "pathogen-free" camel milk.  相似文献   

20.
In field and laboratory conditions the reproductive potential (survival at different stages of development) of the Colorado potato beetle has been measured, the dependence of the parameters of insects fertility on varietal features of the feed has been investigated, the food activity of the representatives of insects from four areas of the Southern Urals has been measured, the intensity and time of hypersensitivity reactions on potato leaves has been defined. In laboratory experiments, the level of activity of hydrolytic enzymes in insects and the level of activity of these enzymes inhibitors in the leaves of three potato varieties differing in their resistance to the Colorado potato beetle have been determined. The results show that the insects-representatives of different samples have different food activity in relation to different potato varieties. High mortality rates were revealed at feeding with leaves of potato of the Bashkir variety characterized by a high level of hydrolases inhibitors and relatively rapid development of necrotic reactions after the appearance of eggs laying on the leaves. We suppose that the neerogenetic barrier appearing in the form of necrosis is the major cause of the fetal mortality of insects. The level of the content of inhibitors inactivating larvae digestive enzymes affects the survival of insects at postembryonic stages. The speed of the necrosis emergence, the level of activity of digestive enzymes inhibitors in potato can be considered as criteria for the selection of breeding material for resistance to the Colorado potato beetle.  相似文献   

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