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infested
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     The rates of infested water exposure and occurrences of new infection and reinfection were reduced from9.5 % and1 9.4% to6 .7% and7.1 % ,being 42 .0 % and 6 6 .1 % 1 ower than those in the control group,respectively;
     水接触率和血吸虫感染率分别由9.5%和 19.4 %下降到 6.7%和 7.1% ,比对照组分别减少 4 2 .0 %和 66.1% ;
短句来源
     and the proportion of women taking their children in contacting infested waterand the infection rate of the children aged 3- 5 were reduced from 5 4.8% and 1 7.6 % to 6 .3% and 2 .7% ,being 87.9% and 86 . 0 % lower than those in the control group,respectively.
     携子女接触水率和 3岁- 5岁儿童血吸虫感染率分别由 54.8%和 17.6%下降到 6.3%和 2 .7% ,比对照组同龄组儿童分别减少 87.9%和 86.0 %。 对照组在同期内上述各项指标均无明显变化。
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     There was adecrease of 62. 7% of persous in contacting with infested water in the educated group but anincrease of 11. 76% in the control.
     实验组接触水人数比干预前减少62.07%,对照组则上升11.76%;
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     In addition, the rate of contacting infested water due to swimming in experimental group was reduced from 10.05% to 2.28%, which was 78.29% lower than those in control group.
     游泳接触水率由10.05%下降到2.28%,比对照组下降了78.29%;
短句来源
     However tha rate of contacting infested water due to fishing in experimental group was increased from 25.06% to 36.94%, and the total rate of contacting infested water and the prevalence of schistosomiasis was not reduced as compared with that before education.
     但实验组捕鱼接触水率由25..06%上升到36.94%,总水接触率和血吸虫感染率未见下降。
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  “infested”译为未确定词的双语例句
     the infested rate on trees 69.92 percent and the maximum to 88.32 percent;
     株被害率平均为69.92%,最高达88.32%;
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     The cotton leaves infested with eggs of different ages were dipped in 0.5, 5.0 a.
     将各日龄的卵用0.5,5 a.
短句来源
     The mortality from the SsNPV insecticide produced the year of the infested larvae is 94% and the LC50 is 3.15×10 3PIB/ml.
     以当年生产的病毒杀虫剂为标准试剂,感染幼虫死亡率为94%、LC50为3.15×103PIB/ml。
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     It is also confirmed that sheep, yaks, Ochotona curzonae and Lepus oiostolus in Zeku County were infested by AE with the prevalence of 5.36% , 4.69%, 3.45% and 12.50%, respectively.
     泽库县绵羊、牦牛、高原鼠兔和灰尾兔有多房棘球蚴的感染 ,感染率分别为 5.36%、4.69%、3.45%和 1 2 .50 % ;
短句来源
     In group Ⅴ(fed "dry well" water plus moldy food infested with Aspergillus niger), papilloma (23.5%, 4/17) and early carcinoma (5.9%, 1/19) of forestomach were found.
     第5组(喂饲旱井水加黑曲霉霉食的大鼠)诱发了前胃乳头状瘤(23.5%,4/17)和早期癌(5.9%,1/19)。
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  相似匹配句对
     Oocysts Excretion Regulation in Cryptosporidium Infested Cow
     隐孢子虫感染奶牛的卵囊排出规律
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     Rice plants could be infested in the seedling stage;
     水稻在秧苗期开始受侵染。
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  infested
PR Proteins in Plants Infested with the Root-Knot Nematode Meloidogyne incognita(Kofoid et White, 1919) Chitwood 1949
      
The involvement of phenylalanine ammonia-lyase and salicylic acid in the induction of resistance of tomato plants infested with
      
More often we encountered infested crabs of a medium size, with a carapace width of 25-29 mm.
      
In the summer period the proportion of infested crabs in different habitats ranged from 7 to 84%.
      
torrentium were infested with the endosymbiotic bacterium Wolbachia pipientis.
      
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Following a series of experiments conducted in East China Agricultural Re-search Institute (Nanking) during the past years,the "red arsenic",a well-knownraw-drug (containing approximately 90% of As_2O_3,9% of AS_2S_2 and 1% of mis-cellaneous substances),is found to be acceptable as seed disinfectant for the controlof cereal smuts.This raw-drug is not only excellent in effectiveness,but alsoeasily obtainable in this country. Incidence of infection of wheat bunt in the plots receiving 3 different treatments,namely,red...

Following a series of experiments conducted in East China Agricultural Re-search Institute (Nanking) during the past years,the "red arsenic",a well-knownraw-drug (containing approximately 90% of As_2O_3,9% of AS_2S_2 and 1% of mis-cellaneous substances),is found to be acceptable as seed disinfectant for the controlof cereal smuts.This raw-drug is not only excellent in effectiveness,but alsoeasily obtainable in this country. Incidence of infection of wheat bunt in the plots receiving 3 different treatments,namely,red arsenic (inoculated seed grains dusted at the rate of 0.05 % by weight),copper carbonate (0.3%),ethyl mercury phosphate (0.05%),during the last 4years,averaged 0.2%,1.4% and 2.7%,respectively against 44.8% in the control.The corresponding figures for the flag smut of wheat were respectively 3.1%,0.8%,5.0% against 20.5%; for the covered smut of barley,0.9%,1.1%,0.9% against1.6%; for the kernel smut of oats,6.8%,3.1%,0.5% against 41.4%.The resultsmake us believe that this native raw-drug is not inferior,in some cases even su-perior,to other fungicides now extensively manufactured and considered efficientin preventing the various cereal smuts.But in the control of the covered smut ofbarley,as we have already shown elsewhere,another native raw-drag,sulphur ismore effective.In the last 3 years,field experiments were carried out to studywhether arsenic gives beneficial effect on the germination of seed and on the yieldof grain.Arsenic was applied as dust to the clean seed wheat following thestandard hot water treatment.Data showed that the number of seedlings in asingle 12-ft.row ranged 368-400 from treated seed as compared with 362-386 fromuntreated seed.Yield of grain also increased 4.7 to 23.6 per cent.It is,there-fore,evident that this fungicidal dust,when properly used,is at least not injuriousto seed wheat.The following points,however,must be borne in mind when thearsenic treatment is put into practice: (1) The dosage should not be higher than0.05 per cent and lower than 0.005 per cent by weight of seed grain.Otherwise, ??it would be either injurious to seed germination or ineffective for disease control.(2) Arsenic can be applied only to thoroughly dried seed grain. Seed wheat con-taining 24% of moisture when treatment was made, lost its vitality in a very fewdays, while that with less than 12% moisture can be stored for one month withoutspoilage. (3) Arsenic reduced germination of seed grain after storage at the highertemperatures. Under laboratory conditions, seeds, treated during hot summer whenthe air temperature ranged between 31 and 35℃, largely lost their germinativecapacity within half a month, but seeds, treated in cooler season when air tempera-ture dropped below 22℃, germinated as untreated ones after being stored for 3months or longer. (4) The relative humidity during storage played the most im-portant role in causing arsenic injury to the seeds. Seeds of wheat containingproper moisture (around 12%) dusted with arsenic at correct rate (0.05% byweight), failed to germinate after being stored for 5 days at temperatures above30℃ under 100% r.b.; but there was little or no injury after a storage period ofover 7 months at 37℃ under 18% r.h. (5) The length of storage period is alsoa factor in causing arsenic injury, and at the same time affecting the efficiency ofthe treatment. Seeds dusted with arsenic at a dosage of 0.05% during mid-summer(July of 1953) retained their germinative capacity within 0.5 month, but no seedsgerminated after 2.5 months' storage. On the other hand, almost complete controlof disease was obtained from thoroughly infested seed grain dusted with 0.0125%of arsenic and stored for 60 days, but similarly treated seeds which were sownimmediately, gave 45.15% infection as compared with 72.77% in the check plot.Consequently, the proper method of using arsenic against cereal smuts is to dustthoroughly dried seed grain at the rate of 0.05-0.0125% by weight and to storetreated seeds under cool (below 25℃) and rather dry (around 80% of r.h.) con-ditions for a period of about one month. According to the results obtained from experiments conducted under bothlaboratory and field conditions, it is found that there is no synergism nor antago-nism between arsenic and such filling materials as ashes, slake lime, talc, charcoalpowder, and calcium phosphate; and that neither soil temperature nor soil moistureact as factors influencing the germination of treated seeds.

(一)用紅砒粉末作為種子消毒處理藥劑,對於幼苗感染性的小麥腥黑穗、小麥稈黑穗及燕麥堅黑穗等,有極良好的防治效果。但對大麥堅黑穗及條斑病,則不見功。(二)紅砒使用得法,對於麥種絕對無害;而且對於大麥、小麥的清潔種子,有積極的增產作用;惟對於燕麥還未能肯定。(三)紅砒粉末的拌種用量,當以種子重的0.025—0.05%為準簧僦?.005%,仍有殺菌效果。(四)為了增大藥物的容積,使得微量的紅砒粉末能够均勻週到地沾着每一麥粒,可用滑石粉、木灰末、甚至消石灰、草木灰或過磷酸鈣來稀释。(五)麥種拌砒後,須經一定期間的貯藏後播種,方顯出其强大的殺菌防病效果珉S拌隨種,則效果较少。至貯藏期間的久暫,則當因季節和用量等等而異。大致可以一個月為度。(六)紅砒使用不得其法,易起藥害。而藥害有無的關键,主耍在於拌砒後貯藏中的濕度,其次才是温度。如充分乾燥,在酷暑的氣候條件(37℃)下,貯藏7個月,尚??無妨礙。至於播種時的地温土濕,則關係極微。(七)紅砒的藥害與麥種處理當時的含水量有密切關係.含水量多,極為蝛U;含水量在12%以下,即安全無礙。(八)在自然狀况下用紅砒處理麥種,應當避去炎夏季節。又麥種拌砒前,必須充分晒乾。拌砒後...

(一)用紅砒粉末作為種子消毒處理藥劑,對於幼苗感染性的小麥腥黑穗、小麥稈黑穗及燕麥堅黑穗等,有極良好的防治效果。但對大麥堅黑穗及條斑病,則不見功。(二)紅砒使用得法,對於麥種絕對無害;而且對於大麥、小麥的清潔種子,有積極的增產作用;惟對於燕麥還未能肯定。(三)紅砒粉末的拌種用量,當以種子重的0.025—0.05%為準簧僦?.005%,仍有殺菌效果。(四)為了增大藥物的容積,使得微量的紅砒粉末能够均勻週到地沾着每一麥粒,可用滑石粉、木灰末、甚至消石灰、草木灰或過磷酸鈣來稀释。(五)麥種拌砒後,須經一定期間的貯藏後播種,方顯出其强大的殺菌防病效果珉S拌隨種,則效果较少。至貯藏期間的久暫,則當因季節和用量等等而異。大致可以一個月為度。(六)紅砒使用不得其法,易起藥害。而藥害有無的關键,主耍在於拌砒後貯藏中的濕度,其次才是温度。如充分乾燥,在酷暑的氣候條件(37℃)下,貯藏7個月,尚??無妨礙。至於播種時的地温土濕,則關係極微。(七)紅砒的藥害與麥種處理當時的含水量有密切關係.含水量多,極為蝛U;含水量在12%以下,即安全無礙。(八)在自然狀况下用紅砒處理麥種,應當避去炎夏季節。又麥種拌砒前,必須充分晒乾。拌砒後,必須貯置高燥處所。

Sugar cane borers infest the cane and cause a considerable injury to the plant in China. Four species of sugar-cane borers are commonly found in Kwangtung Province, viz. Diatraea venosata Wk., Chilo infuscatellus Snellen, Eucosma schistaceana Snellen and Sesamia inferens Wk.Trichogramma evanescens Westw. occurs in nature as an egg parasite of the sugar-cane borers.The present experiment on breeding Trichogramma centres around the ways of increasing its viability.The quality and the quantity of the nutrient...

Sugar cane borers infest the cane and cause a considerable injury to the plant in China. Four species of sugar-cane borers are commonly found in Kwangtung Province, viz. Diatraea venosata Wk., Chilo infuscatellus Snellen, Eucosma schistaceana Snellen and Sesamia inferens Wk.Trichogramma evanescens Westw. occurs in nature as an egg parasite of the sugar-cane borers.The present experiment on breeding Trichogramma centres around the ways of increasing its viability.The quality and the quantity of the nutrient for the larvae and adults of Trichogramma play an important role in relation to their viability. The contents of the egg of Sitotroga cerealella Oliv. which has been commonly used as a host of the Trichogramma are of poor nutrient quality and quantity for the larvae of this parasite. The eggs of Angoumois grain moth are so small that only one adult Trichogramma emerges from each egg. Such adults are usually smaller in size, less active and with lower reproductive potentiality as compared with those that emerge from the field hosts; besides, the female sex ratio gradually decreases in the successive generations.From the results of an experiment on Trichogramma breeding, it is found that the eggs of Attacus cynthia ricini Boisd. and of Dendrolimus sp. are the most suitable hosts for the propagation of Trichogramma evanescens. The adults of the parasites emerging from such eggs are generally large in size, very active and possess high reproductive potentiality; besides, the female sex ratio remains unchanged in the successive generations. Evidently, the quality and the quantity of the egg contents of these two species of insects fulfil the nutritional requirements for the development of the Trichogramma larvae and they are recommended as hosts for Trichogramma propagationThe average number of adult Trichogramma emerging from a single egg of Dendrolimus sp. and that of Attacus cynthia ricini is 27.3 and 28 respectively with the respective maximum reaching 52 and 59 in the present record. If too many adults emerge from a single egg, both their size and reproductive potentiality would decrease and, moreover, the number of the male individuals would increase and the adult life would shorten. Undoubtedly, all these features are unfavourable for the utilization of the parasites for control of the insect pest as far as the effectiveness of the parasites is concerned. From the standpoint of increasing viability of the parasite, regulation of the number of parasites in the egg during the procedure of propagation of Trichogramma is necessary. Regulation of the number of parasites in the egg means regulation of the quantity of the nutrient for the parasites. The method of checking the occurrence of superparasitism is to regulate the ratio of the number of female Trichogramma and host eggs to 1:1 through the procedure of propagation; the period of oviposition should not exceed one day.The quality of nutrient for adult Trichogramma greatly affects its longivity and reproductive potentiality. The result of a nutritional experiment shows that honey is the most suitable nutrient for it. The adults fed with honey have the longivity increased 8.6 times and the number of the offspring 14.7 times as compared with those fed with distilled water.Cold storage effectively reduces the speed of development of the immature stage of Trichogramma. The mature larvae about to pupate within the host eggs maintain their life for 57 days under 4—7℃ and all of them will come out as adults at room tempeature. The fresh eggs of Dendrolimus sp. and of Attacus cynthia ricini kept in cold storage of 0— 4℃ for 97 days and 61 days respectively are still usable for rearing Trichogramma.In order to increase the adaptability of Trichogramma to the environment of the sugarcane field, the rearing procedure is suggested to proceed in the field or in an indoor environment with fluctuating temperature and humidity. The continuous artificial rearing should not exceed five generations before the liberation of the parasites.The distance of dispersion of Trichogramma eva

甘蔗是我国最重要的糖料作物,甘蔗害虫以甘蔗螟虫最普遍,分怖亦最廣。廣东珠江三角洲常见的甘蔗螟虫共有四种:条螟或称斑点螟(Diatraea venosata Wk.)、二点螟(Chilo infuscatellus Snellen)、黄螟(Eucosma schistaceana Snellen)和大螟(Sesamiainferens Wk.)。甘蔗螟虫为害的结果,形成枯心苗和蛀(?),影响甘蔗生长发育,减低蔗糖成份,易受风折,而且造成甘蔗赤腐病菌入侵条件。 甘蔗螟虫的为害虽重,但目前还没有一套完整的防治方法,也还没有一种很有效的方法。本试验目的,是利用赤眼蜂来防治甘蔗螟虫。试验内容是赤眼蜂的寄主的选择和繁殖、赤眼蜂的繁殖及保存、赤眼蜂田间放播初步试验和甘蔗螟虫田间发生情况的调查。现将各项试验结果简要地分述如下: 赤眼蜂能否利用成功,要看培育出来的赤眼蜂是否具有高度的生活力。赤眼蜂的生活力可用下列四个标准去量度:(1)蜂体大小,(2)繁殖能力,(3)成虫寿命,(4)对田间环境的適应性。此外,繁殖出来的赤眼蜂雌性此率不应此自然界的减低。 赤眼蜂的生活力,首先和寄主有很大关系。如果寄主卵的内含物的质和量都適合 於赤...

甘蔗是我国最重要的糖料作物,甘蔗害虫以甘蔗螟虫最普遍,分怖亦最廣。廣东珠江三角洲常见的甘蔗螟虫共有四种:条螟或称斑点螟(Diatraea venosata Wk.)、二点螟(Chilo infuscatellus Snellen)、黄螟(Eucosma schistaceana Snellen)和大螟(Sesamiainferens Wk.)。甘蔗螟虫为害的结果,形成枯心苗和蛀(?),影响甘蔗生长发育,减低蔗糖成份,易受风折,而且造成甘蔗赤腐病菌入侵条件。 甘蔗螟虫的为害虽重,但目前还没有一套完整的防治方法,也还没有一种很有效的方法。本试验目的,是利用赤眼蜂来防治甘蔗螟虫。试验内容是赤眼蜂的寄主的选择和繁殖、赤眼蜂的繁殖及保存、赤眼蜂田间放播初步试验和甘蔗螟虫田间发生情况的调查。现将各项试验结果简要地分述如下: 赤眼蜂能否利用成功,要看培育出来的赤眼蜂是否具有高度的生活力。赤眼蜂的生活力可用下列四个标准去量度:(1)蜂体大小,(2)繁殖能力,(3)成虫寿命,(4)对田间环境的適应性。此外,繁殖出来的赤眼蜂雌性此率不应此自然界的减低。 赤眼蜂的生活力,首先和寄主有很大关系。如果寄主卵的内含物的质和量都適合 於赤眼蜂幼虫营养之需,羽化出来的成虫体积大,繁殖力强,寿命也有延长的趣势。关於赤眼蜂的寄主,我们管用过17种鳞翅目昆虫的卵供其寄生,结果以松毛虫(Dendro

Sweet-potato wilt,a dangerous disease of sweet potatoes,has made itsappearance for more than 10 years in several districts of the south-easternKwangsi and south-western Kwangtung.During recent years it has been found tocause a heavy loss of sweet potato crop in these two provinces. Sweet-potato wilt is a kind of wilt disease which infects the fibrovascular ??bundles of the plant.It begins to infect the vine cuttings and those parts thatare in close contact with the sick-soil.The infected parts first show the...

Sweet-potato wilt,a dangerous disease of sweet potatoes,has made itsappearance for more than 10 years in several districts of the south-easternKwangsi and south-western Kwangtung.During recent years it has been found tocause a heavy loss of sweet potato crop in these two provinces. Sweet-potato wilt is a kind of wilt disease which infects the fibrovascular ??bundles of the plant.It begins to infect the vine cuttings and those parts thatare in close contact with the sick-soil.The infected parts first show the water-soaked appearance and then extend upwardly,and eventually become blackenedand rotted.As a rule,ths leaves of the infected plants show an abnormal coloror pale yellow,and drooping appearance.In the meantime,the root tips of theadventitious roots of the vines lose their cortex and begin to lot.Wilting followsquite rapidly and finally the entire plant dies.If the disease infects the plantafter the potatoes beginning to form,it may extend throughout the vine and in-to the roots,causing the enlarged roots to show brown streaks and finally blackenedand rotted with pungent odor. The cause of the disease may appropriately be considered as due to bacteriaand Fusarium spp.Four types of bacteria,i.e.white smooth type,yellow smoothtype,white rough type and yellow rough type,are able to cause the disease.Atleast four kinds of Fusarium,i.e.white aerial mycelium type,white mycelium withred of a purple tint substratum type,pink mycelium with red of a purple tint sub-stratum type and without aerial mycelium type are responsible for the disease.Which is the main cause of the disease? Either bacteria or Fusarium alone or theboth in combination is able to cause the disease,further tests should be madebefore a definite conclusion may be drawn. The dissemination of the wilt organisms may appropriately be considered inthree ways,namely,(1) by infested roots and vines,(2) by sick-soil,and (3) byinsects,as the sweet-potato weevil (Gycas formicarius Fabr.).The former twoways of dissemination are more definite than the latter,however,further testsand observations should be made. According to the results of 2-years field experiments in Tsen-shi and Peh-liustations,it shows that different varieties of sweet-potato possess different resis-tance to the disease.Among several varieties tested,it is found that Tai-nung No.3being a promising one,because it yields very high and is highly resistant to thedisease and to the drought.Although it is occasionally found to be susceptibleto the disease in the experiment field of Tsen-shi and is more commonly foundin the experiment field of Lin-kwei.The second variety is Tai-nung No.46 dueto its high degree of disease resistance. The results of preliminary tests indicate that the method of reproduction byold vines would decrease both in disease resistance and in yield within the samevariety. From tests conducted in two different fields,i.e.one at dry land and the ??other in the rice field,it shows that the discrepancies were found in the occur-rence of the disease and also in the relation of the method of manuring to thepercent of infection. Dipping cuttings in different disinfectants did not show any significant results.There are discrepancies in both plowed and sunned field test and two methodsof setting the vines test.These may be due to methods of treatment,landand varieties used for experiment being different. According to the results of date of planting tests in Peh-liu,it indicates thatthe occurrence and the development of the disease are closely related to the highhumidity and the high temperature.These climatic factors affect the health ofthe early growth of the plant which in turn would increase the disease resistance.It is suggested that the most suitable date for planting sweet-potato in Peh-liu isin the first decade of August. In comparing the weather records of the three districts—Lin-kwei,Peh-liu andTsen-shi—in relation to the date of early and last occurrences of the disease,itshows that an average air temperature of 23.4-28.4℃ is most suitable for the oc-currence of the disease,and an average relative humidity of 80 per cent is alsoneeded for the infection of the disease.Based on these facts,we may say thatsweet-potatoes in Lin-kwei are capable to be easily infected by the wilt organisms.except the last date of the infection would be preceded 10-20 clays.Any otherregions with similar climatic factors,it is also very possible to be infected. According to the results of 2-years experiments and facts from surveys,sug-gestive control measures are proposed: (1) excluding the disease by regulationthrough the use of quarantines enforced by an inspection station empowered torestrict or eradicate diseased roots and vines to prevent them from becomingsources of infection in disease-free districts; (2) selection of disease resistant varie-ties in combination with cultural practices such as the use of more ash,suitableamount of lime and manure,and suitable date of planting to enable plants toescape or resist the disease.For the present time,we suggest that the use of Tai-nung No.3 in Tsen-shi and Peh-liu may meet the requirement,and promotingthe method of root reproduction in place of an old method of reproduction byrepeating vine cuttings from old vines can prevent the degeneration of the plantand decrease the infection of the disease.

甘薯瘟是一种具有十余年历史的病害,不仅严重地威胁着广西东南部几县的甘薯生产,同时也严重影响了广东西南部和广西毗鄰的几个县的甘薯生产。甘薯瘟是一种枯萎类型的病害,是侵染維管束的脉管病害,首先侵染插条与土壤接触部位,先呈水漬狀,继而变黑腐爛并向上發展,叶色不正常或呈黄色而萎垂。此时薯藤的不定根根尖脫皮并开始腐爛,最后全株枯死。如在結薯块后才受病,除薯藤显现枯萎現象外,可向薯塊發展而呈褐色条斑,最后变黑腐烂,發出刺鼻臭辣气味。瘟薯的病原初步認为是由细菌和镰刀菌所致。细菌中可分为白色粘滑型,黄色粘滑型,白色干绉型和黄色干绉型;鐮刀菌中包括白色气生菌丝型,白色菌丝基層稍呈紫紅色型,粉紅色菌丝基層呈紫紅色型,无气生菌丝型等。但究以哪类为主导,抑系并發性呢?仍須进一步研究。薯瘟病原的傳播,初步認为有三种方式:带病薯块和薯苗,病土,及昆虫(如小象鼻虫等),其中以前二种較为肯定,后一种則仅属可能,仍有待+于进一步試驗观察。甘薯各品种間确具有不同的抗病性能,如台农三号的抗病性較强而产量最高,又能抗旱,台农46号的抗病性最高,但产量則較低,因而台农三号是最有希望的品种,但在岑溪試驗地,会略有發現蔓割病(可能是薯瘟病原之一),临桂試...

甘薯瘟是一种具有十余年历史的病害,不仅严重地威胁着广西东南部几县的甘薯生产,同时也严重影响了广东西南部和广西毗鄰的几个县的甘薯生产。甘薯瘟是一种枯萎类型的病害,是侵染維管束的脉管病害,首先侵染插条与土壤接触部位,先呈水漬狀,继而变黑腐爛并向上發展,叶色不正常或呈黄色而萎垂。此时薯藤的不定根根尖脫皮并开始腐爛,最后全株枯死。如在結薯块后才受病,除薯藤显现枯萎現象外,可向薯塊發展而呈褐色条斑,最后变黑腐烂,發出刺鼻臭辣气味。瘟薯的病原初步認为是由细菌和镰刀菌所致。细菌中可分为白色粘滑型,黄色粘滑型,白色干绉型和黄色干绉型;鐮刀菌中包括白色气生菌丝型,白色菌丝基層稍呈紫紅色型,粉紅色菌丝基層呈紫紅色型,无气生菌丝型等。但究以哪类为主导,抑系并發性呢?仍須进一步研究。薯瘟病原的傳播,初步認为有三种方式:带病薯块和薯苗,病土,及昆虫(如小象鼻虫等),其中以前二种較为肯定,后一种則仅属可能,仍有待+于进一步試驗观察。甘薯各品种間确具有不同的抗病性能,如台农三号的抗病性較强而产量最高,又能抗旱,台农46号的抗病性最高,但产量則較低,因而台农三号是最有希望的品种,但在岑溪試驗地,会略有發現蔓割病(可能是薯瘟病原之一),临桂試驗田也会發生过多次。老藤繁殖会降低同一品种的抗病性和产量,值得我們注意。在旱地和水田不同試驗地上所得結果,可初步说明發病情况很不一致,追肥与不追肥处理的發病率也不一致。藥剂处理种苗效应不显著,翻晒土壤及二种种植法試驗结果不一致,想与試驗方法、試驗地不同和供試品种不同有密切关系。薯瘟的發生与發展和高温潮湿有密切关系,而这些气候因素对于植株的早期生??長壮健及增强抗病性也有关系。初步建議,在北流地区以立秋(8月上旬)种植較为适当。从临桂雁山、北流和岑溪三处的气候記录,和薯瘟开始發生与最后發生日期的記录看来,可以初步說平均气温23.4—28.4℃最适于薯瘟的發生。相对湿度平均在80%以上亦适于本病的發生。由此可見,在临桂雁山地区,薯瘟可能是容易發生的,不过停止發病日期会提早10—20天。其他地区如有相似气温与湿度情况,那也是会發生薯瘟的。根据二年試驗結果和調查所得情况,初步提出防治薯瘟的办法如次:(1)应采取种薯和种苗的檢疫措施,禁止病区的种薯运往無病地区,以防蔓延;(2)选育抗病品种为主,結合先进的栽培管理法;多施草木灰,适当施用石灰,根外追肥,适期种植等,以增强植株的抗病性,避免病害的侵染,保証丰产。目前在岑溪及北流地区,可先推广种植“台农三号”品种,并提倡以薯塊育苗,切勿采用老藤繁殖,以避免植株的衰退,减少薯瘟的發生。

 
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