Grape downy mildew is the grape cultivates one of the process common disease, in China the area all has all sorts of establish to distributing and happen almost, happen in rainy and damp area especially general, it is a grape one of main disease. Happen serious when, can cause spic of a large number of lamina, young fruit, fruit to wait sere, cause massive turnout loss.
[main symptom]
Grape downy mildew can is kill grapy all green young tender organization, wait like spic of blade, bud, fruit spic, tender tip, cirrus, also can bring about Laoxie to come on sometimes, with blade fall victim the heaviest.
Blade fall victim, preexistence lamina the reverse side produces leach shape blob, blade front does not have unusual display, develop as the illness, blade front appears gradually the olive ill spot with not clear edge, blade the reverse side produces substance of form of white frost mildew, serious when, cover blade greater part, whole even part of a historical period is carried on the back, serious when, ill leaf is withered, crinkly, fall off even, cause inchoate fallen leaves.
Earlier symptom
Metaphase symptom
Later period symptom
Foliaceous back sends disease form
Tender tip fall victim, initial stage forms stain of shape of water be soiled, turn into after Brown the ill spot that caves slightly, ill spot also produces white frost mold when moisture. The new tip when getting a severe disease is screwy, grow stop, withered even dead. Axis of tendril, spic, Xie Bing sometimes also can be murdered, its symptom and tender tip are similar.
Bud reachs be murdered of young spic axis, earlier surface shows ecru pathological change, the edge is not clear, after that the surface produces substance of longer form of white frost mildew gradually, later period bud changes ecru, wilting.
Fruit spic fall victim, begin to happen from spic axis and fruit handle more, earlier spic axis and fruit handle change ecru, its surface produces substance of more few and far between form of white frost mildew gradually.
Fruit spic sends disease form
Young fruit be murdered, the surface produces substance of form of white frost mildew first more, change after that beige comes Brown, cave shrinkage, fall off even; Fall victim of bead of expand period fruit, much from fruit handle base the ministry begins to come on, brown disease spot is first, hind gradually shrinkage caves, the edge is not clear, ill spot surface can produce substance of few and far between form of white frost mildew, ill bead falls off easily; In fall victim of bead of later period fruit, also much from fruit handle base the ministry begins to happen, fashion the margin not apparent Brown cave ill spot, the surface does not produce substance of frost mildew form commonly, ill bead falls off easily, or drying shrinkage is on fruit spic.
Fruit bead sends disease form
[feature of cause of disease]
Bacterium of cause of disease gives birth to Plasmopara Viticola(Berk.et Curtis) Berl.et De Toni of odd axis mildew for the grape, belong to flagellum bacterium inferior mildew of door odd axis is belonged to. Hypha is patulous between host cell spread, form globose suck implement extend mesophyll cell to absorb nutrient. Asexuality phase produces Bao bursa stalk, the top gives birth to sporangium, move about spore is born inside. Bao bursa stalk carries air hole on the back to extend from the leaf, bao bursa stalk is fascicular, colorless, m of μ of 6~11 of × of M of size 400~780 μ , odd axis is ramose 3~6 second, general 2~3 second, ramose place close right angle, ramose extreme has 2~3 the small stalk that submits conic form, topmost move gives birth to sporangium. Sporangium is colorless, egg circle, have lacteal and protuberant, m of μ of 8~21 of × of M of size 13~39 μ , bud produces move about spore. Single born of the same parents of move about spore, kidney form, side gives birth to double flagellum, can move about, double swim phenomenon. M of μ of 6~7 of × of M of size 7.5~9.0 μ . Sexual condition produces egg spore. Egg spore is general at growing later period is formed in ill organization, brown, globose, outside the wall is very large, the surface is flowing, provide moire shape to rise and fall slightly, m of diametical 27~36 μ . Egg spore forms bud canal in the bud in water, bud is in charge of top to form pear form sporangium, be born inside and release 30~60 move about spore.
[come on the rule]
The bacteria is with egg spore in ill organization or be along with ill incomplete body in soil live through the winter, can survive 1 ～ 2 years. Immediately following in time sporangium of year of spring bud generation, sporangium produces move about spore, borrow harships to transmit host lamina to go up, invade through air hole, hypha spreads in cellular clearance, long taper giving a circle is sucked implement extend host nourishment is absorbed inside the cell, extend Bao bursa stalk from air hole next, generation sporangium, borrow harships to undertake be invadinged again catching. Of disease go Yo period has 4-13 day only on feeling ill breed, disease-resistant breed needs 20 days. Climate condition is affected with popularity to coming on very big.
This disease happens in autumn more, it is a grape the main disease of the later period in growing, the climate of cold cool moisture is helpful for coming on, ℃ of 13-33 of limits of temperature of bud of bacterium egg spore, appropriate temperature 25 ℃ , want to have enough moisture or grace at the same time. Limits of sporangium bud temperature 5- - 27 ℃ , appropriate temperature 10- - 15 ℃ , want to free water exists. Sporangium forms temperature 13- - 28 ℃ , 15 ℃ left and right sides forms sporangium most, 95-100% of requirement relative humidity. Move about spore yields temperature limits 12- - 30 ℃ , appropriate temperature 18- - 24 ℃ , must water exists. The experiment makes clear: When sporangium has bounty to exist, 40-50% of 21 ℃ bud, 10 ℃ Shi Meng is sent 95% ; Sporangium in high temperature dry condition can survive 4-6 day, can survive below microtherm 14-16 day; Move about spore is in relatively wet to young leaf can be being invaded when 70-80% , relative humidity is old when 80-100% foliaceous ability fall victim. Accordingly autumn low temperature, rainy cite the popularity that causes this disease easily.
Garden physical features of a place is low-lying, ventilated big, clip differs undesirable, density be helpful for coming on; Wearing of north and south compares thing wearing hair to get a severe disease, contrary frame establish a hair to get a severe disease than sheet, canopy is added frame get a severe disease than establishing a hair, frame is low get a severe disease than tall hair. Apply behindhand, slant it is beyond the mark to apply nitrogenous fertilizer to stimulate autumn branches and leaves dense and hair of fructification defer maturity gets a severe disease.
State of field hair disease
[hair cause of disease because]
Closely related the serious rate that grape downy mildew produces and climate condition, appropriate temperature and tall wet it is this disease happening and popular fundamental condition.
(1) cardinal number of live through the winter of bacterium of cause of disease is high. Bacterium of downy mildew cause of disease basically is with egg spore in deciduous leaf live through the winter. The area that much, heavy snow covers winter rain snow and a particular year, cardinal number of downy mildew live through the winter is high. Egg spore achieves the bud when 11 ℃ in free water temperature, generation sporangium, sporangium releases move about spore, move about spore splatters through rainwater transmission arrives on the grape, become the source is infected first, produce sporangium again, undertake be invadinged again catching.
(2) field humidity is big. The formation of Bao bursa stalk, sporangium, need 95 ％ - 100 ％ humidity. The happening of downy mildew and producing rate is decided by humidity and moisture. Any making that water separates the element that adds with humidity, can bring about downy mildew happen. Summerly fall rain is much, field humidity is big, not only offerred fulminant condition, and the growth of can exciting new tip, young leaf and the addition that organize water content, make plant more feeling is ill (disease resistance is reduced) , cause disease thereby popularity and erupt greatly. Spring, summertime festival rain, much mist, dew is much, became the main reason that causes this disease.
3, temperature is appropriate. The optimum temperature of downy mildew happening is 22~25 ℃ , be in commonly 10~30 ℃ , prep above 30 ℃ or the happening that can restrain downy mildew under 10 ℃ . In rainwater of Chu Xia, autumn much, temperature appropriate, the tall hair that also became downy mildew consequently is seasonal.
[method of prevention and cure]
(1) choose disease-resistant breed: Choose America to plant as far as possible series breed, because America is planted grape relatively Europe subspecies disease-resistant, can help advance somebody's career according to what differ the breed with means fit choice.
(2) period of live through the winter prevents and cure: Combinative winter crop has complete clear garden, annihilate loses infirmly branch tip, sweep deadwood fallen leaves, center burn down; Qiu Dong season breaks up greatly agrarian, be in plant and around region spurt the lime sulfur of 1 3-5 Baume degrees, in order to exterminate bacterium source, decrease second year invade first catch.
(3) strengthen help advance somebody's career management: Choice relief is high, soil is rich, ventilated and pervious to light good and the place that has system of good irrigation and drainage is built
Field. Reasonable fertilization, apply thenar fertilizer, top application should apply the compound fertilizer that contains nitrogen, phosphor, Potassium and microelement. Bind tendril in time, long
Leaf of damage of branch, cleared disease and travel be intermingled are careless, strengthen catchment job.
(4) drug prevents and cure: Grape downy mildew is seasonal epidemic disease, accordingly, answer to be given priority to in order to prevent, medicine of regular in season prevents.
Come on earlier, answer to be given priority to in order to use protective agent, agent of drug of optional in order to undertakes preventing and cure. Zinc of 80% Dai Sen manganese but wet sex powder 600 ～ 800 times fluid, or 75% 100 bacterium are clear but wet sex powder 600 ～ 800 times fluid, or zinc of manganese of · of frost of 58 ％ armour but wet sex powder 600 ～ 800 times fluid; Beautiful zinc of 65 ％ blessing but wet sex powder 500 times fluid; Phosphor of 90 ％ second is aluminous but wet sex powder 600 times fluid, or zinc of the 69% manganese that install a gram but the drug such as 1500 times fluid uses wet sex powder alternately, lie between 15 ～ 20 days gush, the basis sends ill case successive gush medicine 2 ～ 4.
Happen serious when, it is what control disease as soon as possible to spread, can choose protective agent to add remedial agent to undertake preventing and cure, optional in order to issues drug: 72.2% frost mildew power agent of hydrochloric acid brine 600 ～ 800 times fluid, or frost of 68.75% amine of fluorine Bi bacterium agent of mildew power in suspension 1000 ～ 1200 times fluid, or 84.51% frost mildew phosphor of power · second is aluminous solubility water agent 600 times fluid, when downy mildew happening is serious, remedial effect is outstanding. Or agent of in suspension of ester of bacterium of Mi of clever · of frost of 39% essence armour 500 times fluid, have protective effect already, also have remedial effect. Or 66.8% third mildew of Xie of dark zinc · power 700 times fluid, have effect of protection, therapy. Or 47% Xi acyl agent of in suspension of amine of bacterium of Mi of Lin · Zun 600 times fluid. When downy mildew happening is serious, remedial effect is better. Or water of cyanogen of Niao of frost of · of ketone of bacterium of 68.75% evil Zun is dispersive granule 1000 times fluid, have cure and protection double effect, do not have resistance to the action of a drug absolutely. The 15 seconds after medicine can begin to restrain the growth of bacterium of cause of disease and breed. Or ketone of second of Bi of 10% fluorine thiazole can do not have suspension agent dispersedly 1500 times fluid, grow of former to egg bacterium key link bacterium individually period is effective, it is the perfect union that prevents effect and stability. Although be below complex and changeful climate environment, the stability that still can assure to be as long as 10 days prevents effect. Or water of couplet of Dai Sen of · of 60% Bi aether is dispersive granule 1000 times fluid, melon and fruit of prevention and cure, vegetable downy mildew, have prevent a bacteria to invade, prevent a bacteria to diffuse to wait for a variety of action with the bacteria inside cleared body. Effective to disease of great majority fungus.
