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1.
通过对不同群体结构茶园十年的试验研究,结果表明,在亩植0.4—1.2万株的范围内,建园初一、二年,随着茶树密度的增加,茶树的生物总产量和经济利用系数提高,有利于提早投产,提前收益。从种植后的第三年开始,群体和个体的矛盾日益显露,茶树表现出明显的边际生长优势;输导根增加,吸收根减少;叶片光合效率降低;个体生物产量差异显著;茶园表层土壤容重加大,孔隙度降低,透水性减弱;中下层土壤含水量减少,旱季容易出现水分亏缺,因而使各处理间的经济利用系数日益接近,密植的增产效应逐年消失。从种植后的第八、九年开始,产量持平,  相似文献   

2.
The results are reported of an examination of detailed measurements on the ingestive behaviour of calves and lambs in response to variations in the surface characteristics of swards under strip-grazing and continuous stocking managements. It is shown that intake per bite and the short-term rate of herbage intake were both sensitive to the height of the surface horizon above ground level but, at least under strip-grazing management, not to variations in herbage density in the grazed horizon. The rate of biting was less sensitive to variations in sward conditions, particularly under strip-grazing.
Both intake per bite and rate of intake were more sensitive to variations in grazing height under strip-grazing, where sward changes were rapid, than under continuous stocking, where they were slow. Under continuous stocking, ingestive behaviour was more sensitive to changes in sward conditions in lambs than in calves.  相似文献   

3.
This paper is intended to determine the optimal processing parameters applied to the dyeing procedure so that the desired color strength of a raw fabric can be achieved. Moreover, the processing parameters are also used for constructing a system to predict the fabric quality. The fabric selected is the nylon and Lycra blend. The dyestuff used for dyeing is acid dyestuff and the dyeing method is one-bath-two-section. The Taguchi quality method is applied for parameter design. The analysis of variance (ANOVA) is applied to arrange the optimal condition, significant factors and the percentage contributions. In the experiment, according to the target value, a confirmation experiment is conducted to evaluate the reliability. Furthermore, the genetic algorithm (GA) is combined with the back propagation neural network (BPNN) in order to establish the forecasting system for searching the best connecting weights of BPNN. It can be shown that this combination not only enhances the efficiency of the learning algorithm, but also decreases the dependency of the initial condition during the network training. Most of all, the robustness of the learning algorithm will be increased and the quality characteristic of fabric will be precisely predicted.  相似文献   

4.
杨瑞林 《中国麻业》2003,25(6):304-306
农产品质量安全问题受到了党和政府的极大关注。这也是应对入世挑战。提高我国农产品市场竞争力的一个重要方面。麻类产品在提高质量的同时，应加强安全生产监管，对生产中使用的农药、化肥、除草剂、重金属、化工原料、化学辅料等要严加控制；应推行市场准入制，加强对产品中有毒有害物质的检测；应完善质量保障体系，健全标准体系。打破欧盟的“技术壁垒”，建立我国的技术壁垒措施。  相似文献   

5.
为探究越冬期不同的覆盖材料对茶园土壤温度及茶叶产量、品质的影响,寻求效果佳的防冻材料,研究采用稻草、白膜、黑膜、稻谷壳和防草布等5种材料在茶园行间进行地表覆盖,比较不同材料覆盖后对土壤温度和茶叶产量、品质,以及春茶萌发时间的影响。结果表明,相较于未进行覆盖的对照,5种覆盖处理均能提高土壤温度,平均增温1.5~2.9℃,且覆盖后可使茶叶产量提高4.3%~13.6%,春茶萌发时间提早2~4 d,其中增温效果稻草和稻谷壳优于其他材料。使用稻草和稻谷壳覆盖后,茶叶水浸出物、咖啡碱、茶多酚、氨基酸含量均有所提高。综合比较来看,稻草和稻谷壳的增温效果较黑膜、白膜和防草布更好,而且能提高茶叶产量与品质,更适合作为茶园越冬期防冻的覆盖材料。  相似文献   

6.
秸秆还田与覆膜对土壤理化特性及玉米生长发育的影响   总被引：5，自引：0，他引：5  
试验研究秸秆还田对不同覆膜时期的全膜双垄沟播玉米生长发育与土壤理化特性的影响。结果表明,经秸秆还田后全膜双垄沟播耕层土壤养分含量变化依次表现为整株还田>秸秆粉碎>免耕留茬,不同覆膜时间对土壤养分变化影响不明显;秸秆还田土壤容重明显降低但免耕留茬一膜两年用处理土壤容重增大。在玉米生育前期经秸秆还田后的土壤温度与水分均显著低于对照,其株高、茎粗与叶面积均小于对照;在玉米生育后期秸秆腐解后对土壤水分起到一个补偿效应。玉米产量表现为秋覆膜整株秸秆还田>顶凌覆膜整株秸秆还田>秋覆膜秸秆粉碎还田>顶凌覆膜秸秆粉碎还田>免耕留茬一膜两年用,秸秆还田后玉米产量较对照有增产趋势,而免耕留茬一膜两年用有减产倾向,但处理间差异不显著。  相似文献   

7.
The leaves ofCoriandrum sativum contain 51.4µg of betacarotene (85.6 IU) per gram and 361mg L-ascorbic acid per 100g on a dry weight basis. The vitamin C in the plant did not change significantly for three days when the cut stems were placed in water and maintained at a temperature of 17 °C. Cooking for 5 minutes lowered the vitamin C content in 4 and 10 volumes of water by 41 to 49% and 61 to 67%, respectively. Cooking for 10 minutes in the same amount of water increased the loss by a few percentage points.  相似文献   

8.
《Plant Production Science》2013,16(4):391-399
Abstract

To study the physio-chemical and microbial properties of green tea waste-rice bran compost (GRC), and feasibility of GRC as the alternative of agrochemicals for quality spinach production, five types of compost were prepared by mixing green tea waste and rice bran. The compost temperature was increased by adding rice bran to the green tea waste. The compost GC made from green tea waste alone contained a relatively large amount of nitrogen (7.55%). On the other hand, the compost RC made from rice bran alone contained a relatively large amount of minerals, such as phosphorus (0.49%), potassium (4.96%) and magnesium (2.28%). Addition of rice bran increased the total number of bacteria, viable bacteria and organic matter decomposing bacteria as well as actinomycetes population in the mature compost. The frequency of organic matter decomposing bacteria in GRC was in the following order: cellulolytic bacteria < pectolytic bacteria < lipolytic bacteria < amilolytic bacteria except RC. The growth of spinach was significantly increased over the untreated control (only soil) when GRC was applied in the field and growth pattern was depended on the nature of the composting materials. The highest fresh weight of 27.5 g plant-1 and 45.4 g plant-1 were obtained by applying the compost with 30% green tea waste + 70% rice bran (GRC-3) under field condition in autumn of 2004 and 2005, respectively. The highest growth enhance effect was also obtained from GRC-3 when three spinach varieties were grown with GRC under greenhouse condition. The amount of nitrate and oxalate in the spinach grown with GRC were ranged from 114.0 to 146.0 mg 100 g-1 and 612.0 to 748.0 mg 100 g-1 fresh weight, respectively. These values were below from the safety standard of health level of nitrate and oxalate for spinach. The amount of ascorbic acid, glutamic acid and iron in the spinach were increased by applying the compost. Among the five combinations of GRC, GRC-3 provided the best results in spinach production.  相似文献   

9.
The root cap (RC) is a multilayered dome of spindle-shaped parenchyma cells that overlies the growing root tip. It is present in the roots of almost all crop species. This paper briefly reviews some topics on the structure and function of the RC in the major crop species such as maize and rice. Special attention is placed on its contribution to the root system formation, that is, the elongation and growth direction of axile roots. The cells produced in the RC meristem are pushed forward as new cells form beneath them, and eventually the cells on the periphery of the RC fall off. The life cycle of RC cells of maize has been studied extensively and ranges from one to seven days. Approximately 4,000 to 21,000 cells are present in a complete maize RC, and 1,400 to 3,200 sloughed cells can be found in the rhizosphere soil per day per root. These cells, called root border cells (RBCs), mix with RC mucilage and play important roles for the root growth in soil. The RBC-mucilage complex effectively reduces the resistance roots experience during penetration into field soil, about 30–40% of the resistance being reduced by the presence of RC alone. The RC is also a tissue integral to gravitropism, and is known to determine the direction of root growth. The size of amyloplasts and coumellae in RCs has a strong influence on determining the growth angle of axile roots. The function of the individual regions of the RC and how the RC tissues and cells are formed should be studied further to advance our understanding regarding the critical roles of the RC in crop root growth.  相似文献   

10.
玉米花丝和穗轴中可溶性糖、淀粉变化规律的研究   总被引：1，自引：3，他引：1  
在一般大田环境中,控制玉米果穗的授粉情况,研究果穗在套袋和自然授粉时可溶性糖和淀粉在花丝和穗轴中的变化情况。结果表明:花丝和穗轴中的可溶性糖、淀粉浓度均呈单峰变化,可溶性糖以及花丝中淀粉浓度峰值出现在吐丝后第5天,而穗轴中的淀粉浓度峰值出现时间提前2天。花丝不同部位间可溶性糖浓度由基部向顶部依次下降。而积累量随着生育进程的推进而上升,但后期花丝中的物质含量相对稳定。从总体来说,无论套袋还是自然授粉的果穗,各物质变化趋势一致,但后期授粉果穗的可溶性糖和淀粉积累量高于套袋果穗。  相似文献   

11.
为了解安徽省淮北及黄淮麦区的小麦加工品质,以52个安徽省小麦产业体系展示品种为材料,分析了供试小麦品种HMW-GS的组成和分布、谷蛋白聚合体(GMP)含量、小麦蛋白质含量、Zeleny沉降值及湿面筋含量。结果表明,52个供试小麦品种的HMW-GS变异类型众多,共发现13种变异类型,包含6种优质亚基类型;共出现了21种HMW-GS组合。按照GMP、蛋白质、湿面筋含量及Zeleny沉降值可将52个供试品种分为4类。供试品种的品质评分介于4~10分之间,平均7.4分。基因位点Glu-A1含有1亚基的品种,GMP含量高于含有Null亚基的品种。  相似文献   

12.
Strains of Phytophthora megasperma insensitive to the fungicide metalaxyl showed limited cross-resistance to the structurally related fungicide cyprofuram and to metolachlor, a herbicide with antifungal properties. The three compounds each inhibited nucleic acid synthesis, but the wide variation in resistance factors and in the degree of nucleic acid inhibition at the concentrations inhibiting mycelial growth by 50% indicated that cyprofuram and metolachlor possess alternative mechanisms of toxicity. Studies with protoplasts suggested that cyprofuram has a direct effect on the plasma membrane which may be important against those resistant strains where nucleic acid synthesis is least affected. Metolachlor also was extremely effective in causing protoplast lysis. Sporangia production by P. palmivora was stimulated by low concentrations of cyprofuram, and germination was delayed. As with other ‘acylalanine-type’ fungicides, inhibition of nucleic acid synthesis is considered to be the main mode of action. Some degree of cross-resistance between cyprofuram and other acylalanines is likely to occur in the field but the dual mode of action of cyprofuram might delay its onset. The effect of increased sporogenesis on the development of resistance is more difficult to assess.  相似文献   

13.
以郑单1002为材料,设置灌浆中后期(灌浆36 d)不同穗部及穗下不同数量的去叶处理,研究去叶后对玉米群体光合性能、冠层结构、产量以及子粒含水率等的影响。结果表明,穗部叶及穗部以下叶保留3~4片叶,产量不降低;去叶较多情况下表现为减产;不保留穗位叶较对照减产了12.36%,子粒千粒重下降是导致减产的主要原因。去叶后直接导致玉米群体叶面积指数下降,无截取散射略微增加;保留3~4片叶处理,叶片光合性能表现出一定补偿效应,净光合速率高于对照处理,羧化效率略有升高;去叶处理降低灌浆后期子粒含水率,不保留穗位叶片处理较对照处理相比,在灌浆44、52、60 d,子粒含水率分别下降了8.14、8.75、17.84个百分点。  相似文献   

14.
The nutrient composition, ofColocasia esculenta flowers (CF) and leaves (CL), and the green fruits ofSolanum melongena (SM) were carried out as a means to determine their nutritional potential. Results showed that these food materials had high moisture and fiber levels which ranged between 888 and 906 g·kg–1; and 204 and 303 g·kg–1 dry weight (dw) for moisture and fiber respectively. The calorific values were between 3889 and 4001 kcals·kg–1 dw, while the total lipids ranged from 53 in CF to 71 g·kg–1 dw in SM. The leaves ofColocasia esculenta had the highest crude protein value of 307 g·kg–1 dw. The flowers had 149 g·kg–1 dw while SM had 138 g·kg–1 dw. The amino acid profile in the flowers and leaves ofColocasia esculenta in contrast to SM were balanced comparable to the reference FAO pattern. Ash values were high (ranging from 76 in SM to 98 g·kg–1 in CL) with potassium being the principal element. Iron and Zinc levels were also high especially in CF (with 303 and 82 mg·kg–1 dw respectively). These foods also contained moderate quantities of calcium, phosphorus and magnesium but were poor in manganese and copper.  相似文献   

15.
Various two-step extraction procedures with and without application of ultrasound in the first extraction step were used to isolate the xylan component of corn cobs in polymeric form. The obtained immunogenic water-soluble (ws-X) and the biologically inactive water-insoluble (wis-X) xylan fractions were characterised by yield, composition, structural and molecular properties. The yield of ws-X was strongly affected by the alkali concentration and extraction temperature, particularly in the ultrasound-assisted procedures. The results indicate a higher efficiency of the ultrasonic extraction procedures expressed in the shortening of extraction time, and lowering of the alkali concentration and extraction temperature. In contrast to the molecular properties, there were no significant differences between the sugar composition and main structural features of the ws-X fractions obtained by extraction in 5% NaOH with and without application of ultrasound. At similar levels of yield, the biological activity of the ultrasonically extracted ws-X preparations was higher.  相似文献   

16.
Plant Foods for Human Nutrition - The objective is to verify if gluten-free (GF) and gluten-containing (G) breads differ in their sodium content and lipid profile. Samples of GF...  相似文献   

17.
玉米种质资源的交流和保护   总被引：1，自引：0，他引：1  
滕海涛 《玉米科学》2009,17(4):21-23
分析了玉米种质资源对育种的重要意义。种质资源和植物新品种间具有一定的内在关系,但是又互相区别。公共研究机构是玉米种质资源的主要提供者,企业间的玉米种质资源合理有序交流是发展的趋势。指出资源价值评价和评估体系的规范建设是平等分享种质资源的核心环节,种质资源的合理分享将有助于育种产业的健康和长远发展。  相似文献   

18.
The main object of the experiment was to assess the effect of the relative proportion of non-protein nitrogen (NPN) to total nitrogen in silage on digestion in the sheep. Four unwilted perennial ryegrass silages were made with the addition of formic acid at 0, 2·2, 4·2 and 5·2 litres t-1 to provide foods with NPN proportions reducing from 0·26 to 0·20 of the total N. The digestion of the silages was studied in a 4 × 4 Latin Square experiment with sheep cannulated in the rumen, proximal duodenum and terminal ileum.
Results for organic matter (OM), cellulose and N showed no major difference between silages in their digestion in the rumen, small intestine and caecum and colon, though small differences ( P <0·25) in rumen fermentation pattern and in the proportion of digestible OM disappearing in the small intestine were observed. Concentrations of ammonia N in the rumen and rates of rumen bacterial protein synthesis did not differ significantly between silages and there were no treatment effects on the passage of individual amino acids to the small intestine. The results indicate that the proportions of NPN to total N in the silages examined had little influence on the efficiency of silage N utilization in the rumen or on the passage of undegraded dietary protein to the small intestine.  相似文献   

19.
通过架设防虫网、人工养蝇、引蝇访花并选择不同天气类型观察苍蝇、蜂和其他种类昆虫在杧果(Mangifera indica)花穗上的活动情况,研究杧果传粉的主导因子、人工养蝇和引蝇访花对提高杧果授粉受精率的效果,以及在不同天气类型情况下温度对主要传粉昆虫苍蝇访花活动的影响。结果表明,杧果主要传粉媒介为昆虫,其中苍蝇在杧果传粉中起主要作用,其次为蜂。苍蝇在杧果花穗上的活动主要受温度影响,不同天气类型对苍蝇访花活动也有影响,在晴天天气条件下苍蝇在花穗上的活动时间和温度范围都较大。人工养蝇和引蝇访花可大幅度提高杧果受精发育果的比例。  相似文献   

20.
The Potato Murrain on the European Continent and the Revolutions of 1848   总被引：1，自引：1，他引：0  
The tale of the Irish Famine, 1845–1849, following the outbreak of potato late blight, has been told repeatedly, but the parallel story of the Continental Famine, 1845–1847, has not yet been recorded. The Continental Famine was caused by poor harvests of potatoes, due to the same late blight, but also of grain, due to frost, drought, rust, voles, inopportune rains, floods and hailstorms. The Continental Famine was enhanced by hoarding, speculation, and poor governance. Hunger was followed by infectious diseases. The demographic effects of hunger and diseases are difficult to disentangle. The number of excess deaths due to the Continental Famine cannot yet be determined with any precision, but clearly it approaches that of the Irish Famine. The harvest failures of 1845 and 1846 and the resulting famines came on top of rural pauperisation and urban discontent, and thus contributed to the revolutions of 1848 on the European Continent. The statement ‘an epidemic of potato late blight caused an epidemic of revolutions’ is, perhaps, exaggerated but it contains a grain of truth.  相似文献   

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