Mahonia angustifolia leaf surface covered by powdery mildew symptoms of white powder, coverage up to 100%. Such as the young leaves of Mahonia narrow leaves infected by the disease, leaf curl phenomenon occurs. This disease is serious harm to the whole plant, then the growth has eased off, the new leaf is difficult to germination. Mahonia angustifolia powdery mildew damage can occur year-round, rapid development of disease for 3 to 6 month to reach its peak in August.
control methods:
1, do not plant too close, without prejudice to the premise of the landscape, cut off the branches and leaves serious disease, can reduce the invasion of natural resources;
2 , pay attention to the early onset of spraying time,UGG boots, such as narrow leaf Mahonia serious then sprayed powdery mildew, powdery mildew even eliminate, leaf spots will be left behind, affecting ornamental;
3, Control Pharmacy 20 % Triadimefon (powder rust Ling) 800 times, 3% Polyoxin 600 times, 47% of the United States from 2500 to 3500 grams of dilution of uniform spray.
2, black spot
harm plants: rose
Damage symptoms: spots round to nearly round spot diameter of 1.5 to 13 mm, dark brown to black, leaf yellowing caused by a large area, sometimes a green outer edge of the lesion, infected leaves fall off easily. Occurrences: bacteria in the diseased branches and diseased leaves on the winter, spread by wind and rain or by splashing water. Rainy, foggy, dew and leaf water on the night more beneficial bacteria invade; Shanghai in April began to appear in early lesions. Chemical control: spraying time to decide on the rose cultivation methods and weather conditions. Lucy Rose generally from May to begin spraying in early summer, and fall in temperature of late to stop spraying;
chemical control of chlorothalonil diluted 800 times with 75% or 70% of applications delayed 1000 times or 50% Carbendazim 500 times, every 10 days or so spray a second drug.
3, leaf spot
affected plants: leaves of Ligustrum
incidence to generate nearly circular brown spots, often with William patterns, often outside the edge yellow. Smaller initial lesion, lesion extended more than 1 cm in diameter, sometimes fused into irregular shape. Disease leaves easily fall off from the branches, resulting in serious morbidity bare area Ligustrum Zhigan phenomenon first occurred early on in April, the peak period of August 7 and 10 months; May 8 mid-mid- In mid-September and early November using the 80% dilution of spray Mancozeb 200 to 250.
4, southern blight
affected plants: repens, (red) of white clover, crossing the yellow
leaves, stems and roots near the soil surface to see Office to the white silk-like mycelium and sclerotia of about 1 mm in diameter, white sclerotia first post into a yellow, brown. Victims of yellow gold horseshoe lawn was the beginning of several centimeters in diameter, round, As the disease progresses, scalable number of irregular meter circle subtilis. Sclerotia of this disease is the main source of primary infection. Neat little home study of soil bacteria sclerotia, mycelium in the soil can be widely disseminated,UGG boots clearanc, as the source of secondary infection. This disease are high temperature (25 degrees to 35 degrees the optimum), high humidity disease, other beneficial soil rich in organic matter also the occurrence of this disease.
chemical control is 1% of iodine can be used 1000 times, 25% prochloraz 1000 ~ 1500 liquid spray.
5, iron-deficiency plant yellow disease
victims: Gardenia, camphor
of the disease in areas prone to calcareous soils, symptoms of leaf chlorosis, first place In the leaves on the branch side, starting from the leaf margin chlorosis, the leaf center development, leaf color from green to yellow, gradually increased, leaf turns yellow or light yellow, but still on green veins; after full leaf yellowing, turn yellow white, white, grayish brown to brown leaf on the edge, necrosis dry; the whole plant to the top of the worst affected leaves, lower leaves is normal or nearly normal and severe disease plots, plants gradually weakened, and finally death. This disease does not by the cultivation conditions, such as soil too sticky, too much lime quality, basic weight, low humidity, inadequate supply of iron caused by hormone is an important physiological disease.
chemical control: early disease, high-iron 500 times with a spray of leaves and irrigating roots, or soil in the use of iron chelate, 22 cm (6 inch) pots 0.2 g. Pharmaceutical treatment of patients with yellow flowers, should be conducted early in the disease occurrence, or less effective.
6, Rhizoctonia
leaf spot disease of all lawn diseases in one of the most widely distributed and can infect any known grass, causing large dead lawn. Any place where the grass can grow, there will be the occurrence of this disease and damage. Infected turf appears subtilis ring sizes, the central circle is still green, yellow edge band, show 'frog eye. . dew or humidity in a large case, the outer ring often appear hay mycelium formed by the spring, when the soil temperature rose to 15 ℃ ~ 20 ℃, the bacteria produce a large number of hyphae, when the temperature rose to about 30 ℃ 20 ℃ over night, and the humidity is high, the virus began to infect the host. warm-season Wo grass, in the hot and humid conditions,cheap UGG boots, disease occurrence and development of fast, large area of lawn began to disease, thatch thickness of the old lawn suffer heavier.
Chemical Control:
of 20 % drug grams of 600 times, 1000 times 1% of iodine uniformly spray, repeat spray 7 days time, for 2 to 3 times.
7, laurel leaf blight
symptoms: this disease pathogens and more from the leaf margin, leaf tip penetrated. began to light brown dots, later expanded into a large irregular patches, a few spots if a link, all leaves will dry up one-third to one half. lesion gray brown, sometimes curled brittle, with dark edge, slightly protruding, late leaf surface scattered many black specks.
Occurrence: pathogen mycelia or conidia device leaves in the winter killed. Vertical In the spring of suitable temperature, the spore produces a large number of conidia, spread by wind to the host plant, the disease occurred in 7 to 11 months, the hot and humid climate, poorly ventilated environment, plants growing weakness, a serious disease . pathogen growth temperature range of 10 to 33 degrees, the optimum temperature is 27 degrees.
control methods:
A: Park, diseased plants, removal of diseased leaves, concentrated fire ; and strengthen labor management, avoid soil water, increase of humus fertilizer and potash fertilizer applied to improve resistance to disease;
B: 1% incidence of iodine can be sprayed during the 1000 times 600 times, or 40% Chlorothalonil liquid spray
C: winter and spring garden with a clear 30% strength 600 ~ 800 times spraying plants to suitable moist; can play sterilization, disinfection, and enhance the role of resistance.
8, Fatsia japonica, throwing Aucuba, Azalea leaf disease focus
Fatsia japonica and throwing aucubin negative plants, impatience strong sunshine, summer day it leaves toxic severe burns, causing yellow leaves or leaf curl Kujiao seriously affect plant growth, some pathogens are Consequently, the further rise to infectious diseases, bacteria are part of the lesion can be seen fruiting bodies. azalea semi-shade plant, its focus leaf disease etiology and the similar occurrence of heavy leaves,UGG BOOTS, plant disease caused by a large number of non-normal leaves.
control methods:
A: because of sudden strong wind and rain over summer, to be timely elimination of the existing ground leaves and diseased leaves and destroyed on the spot, in order to avoid the expansion of existing bacteria infection by wind and rain damage range;
B: strengthen management, enhance the growth potential of trees to improve plant disease resistance;
C: inhibition of disease development and spread of spray, chlorothalonil 800 times, the United States 3000 to 4000 grams of dilution, spraying every 7 to 10 days time.
No comments:
Post a Comment