桑园草害及预防

桑园的杂草种类很多。以江苏、浙江地区为例,春季以双子叶杂草为主,如荠菜、一年蓬、马齿苋、蒲公英、小旋花、水花生等;夏秋季以单子叶杂草占多数,如马唐、香附子、狗牙根、牛筋草和白茅等。这些杂草在每年6～8月份,约占桑园杂草总量的70％。杂草具有惊人的繁殖力,再生能力强、早熟。因此,桑园除草,是桑园管理的一项重要工作,这对幼龄桑来说更为重要。     

苜蓿草地的化学除草法

在人工建植草地田间管理工作中，杂草是影响牧草生长和产草量的重要原因，特别是幼苗期更严重。小面积种植采用播种前旋耕、耙地、调节播种期中耕除草措施就可以控制杂草危害，大面积种植应以化学除草为主。在进行化学除草之前，首先要掌握苜蓿     

桑园化学除草试验初报

<正> 桑园杂草种类繁多,聚生极多的有十余种。春季以双子叶杂草为主,如小蓟、小旋花、猪殃殃、野苔子、刺苋、青蒿、辣蓼、婆婆纳等;夏秋季则单子叶杂草居多,如马唐、牛筋草、狗牙根、白茅、香附子等;有些杂草,如葎草、水花生等春、夏、秋均生长旺盛。上述杂草滋长极快,不仅消耗土壤中大量的养分和水分,影响桑树生长,而且会诱致桑树病虫害的发生和蔓延。在桑园管理中,除草是一项重要而繁重的任务,但是,在生产实践中,往往因劳力不足或天气影响,杂草不易及时清除干净。国内外的许多报道表明,桑园化     

智利:控制杂草可大幅提高蓝莓产量

不使用除草剂的除草举措(如防杂草网、锯末、稻草覆盖等)可使蓝莓增产56.6%。Projar的园艺工程师维拉尔巴(Alvaro Villalba )指出,在智利蓝莓种植区域的几年试验表明,每三周一次的人工除草区域和杂草肆意生长的区域相比,前者的蓝莓产量显著增加。虽然种植稻草和人工除草有助于提高蓝莓产量,但使用除草剂和拉防杂草网的种植区,其蓝莓产量更高,可见拉防杂草网的有效性,可代替化学药剂的使用。     

上海辰山植物园杂草的调查与防治CSCD

作为上海重要的大型公园绿地,辰山植物园在满足人们休闲游憩的同时,还具有引种、保育华东区系植物遗传种质资源的的核心功能,由此引起的限制使用杂草化学除草剂与杂草蔓延之间的矛盾表现突出。为解决矛盾,采用样方法调查植物园杂草种类、发生时期及分布情况,发现辰山植物园原生植物保育区山体专类园杂草有108种,中心人工专类园有49种,其中,两种植被类型共有的杂草为19种。菊科(Asteraceae)、禾本科(Gramineae)杂草占杂草种类的大多数,分别为15.2%和11.6%。杂草主要发生在春夏季的3月和夏秋季的7月,杂草发生时间符合“双子叶杂草-单子叶杂草-双子叶杂草”“多年生杂草-一年生杂草-多年生杂草”的全年性发生规律。在调查、分析杂草发生基础上,根据杂草危害等级,通过物理、化学综合防治措施对比2种本底草坪草种的防治效果,得到以结缕草品种‘Belair’建植的草坪在7月可达到杂草防除最佳效果。     

上海辰山植物园杂草的调查与防治

作为上海重要的大型公园绿地,辰山植物园在满足人们休闲游憩的同时,还具有引种、保育华东区系植物遗传种质资源的的核心功能,由此引起的限制使用杂草化学除草剂与杂草蔓延之间的矛盾表现突出。为解决矛盾,采用样方法调查植物园杂草种类、发生时期及分布情况,发现辰山植物园原生植物保育区山体专类园杂草有108种,中心人工专类园有49种,其中,两种植被类型共有的杂草为19种。菊科（Asteraceae）、禾本科（Gramineae）杂草占杂草种类的大多数,分别为15.2%和11.6%。杂草主要发生在春夏季的3月和夏秋季的7月,杂草发生时间符合“双子叶杂草-单子叶杂草-双子叶杂草”“多年生杂草-一年生杂草-多年生杂草”的全年性发生规律。在调查、分析杂草发生基础上,根据杂草危害等级,通过物理、化学综合防治措施对比2种本底草坪草种的防治效果,得到以结缕草品种‘Belair’建植的草坪在7月可达到杂草防除最佳效果。     

苜蓿的杂草防治——一种刈割后的除草技术

苜蓿的杂草防除是草地生产上亟待解决的重要问题之一。我国北方夏季高温、多雨,苜蓿刈割后杂草生长极为迅速,因此,后期的苜蓿地杂草随着刈割次数的增加而增多,并由此使老苜蓿地比新苜蓿地杂草多,许多2—4年生的正在生产高峰时期的苜蓿地因杂草太多不得不翻耕。由于苜蓿本身也是双子叶植物,使用除莠剂除草有许多困难。本文报导的苜蓿地用百草枯除草法简单易行,使用的器械、药品都不难解决,值得有关生产和科研部门参考、试用。     

农田作物杂草的综合治理

<正>杂草的综合治理的目的是在增加作物产量及经济效益的同时,减少除草措施对环境条件的压力、对大豆生长的影响,保持产量的稳定。1农作措施除草耕作措施影响杂草种子在土壤中的分布、籽实寿命及出苗,从而影响着杂草的发生。连续免耕,如果没有好的控草措施,无疑会加重杂草发生。但免耕使杂草种子集中在表土层,促进了表土层草籽出土和深层草籽休眠,再配合有效的杂草控制措施,如合理施用杂草剂等,可以使土壤种子库的杂草种子     

草坪主要单子叶杂草防除

概述了目前草坪单子叶杂草的防除进展和存在的问题。明确主要恶性单子叶杂草的生物学特性和发生规律,提高草坪的管理水平、选择和培育适合当地生长的草坪草种,采用混播栽培管理措施和合理运用化学方法来综合防除单子叶杂草。创造有利于草坪草生长而不利于单子叶杂草生长发育的环境,使杂草在竞争中自然淘汰。     

苜蓿草地杂草防除方法

苜蓿草地杂草群落主要为稗草和藜、蓼、苋混合型。防除的综合防治措施简要介绍如下1结合选地和整地预防草害选择杂草少的地块种植苜蓿,如果是杂草繁多的生茬地,最好先种玉米等作物2～3年,经除草净地后再种植苜蓿。播种前预先深翻整地。深翻可将表层土壤中的大部分杂草籽深埋,使之不能发芽出土。另一方面,预先深翻、整地后,让地表杂草种子提前发芽。对土壤墒情好、多年生杂草占有比例大的地块,如果在苜蓿播种前再浅耕一次,可消灭已发芽的杂草。通过深翻和浅耕还可去除多年生杂草的地下根茎,减轻多年生杂草的危害。用腐熟后的农家肥作基肥,防…     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.     

Mechanism of Action of Probiotic Function of Lactobacilli

乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制.     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …