How to prevent poplar mosaic virus disease? Poplar mosaic disease symptoms and prevention methods

Poplar mosaic virus disease (the virus belongs to Caryophyllus caryophyllus cryptovirus group) causes the deformation and atrophy of the diseased plants after the damage of the trees, and the top tips are dried up, and the growth can be reduced by 30% to 50%.

Symptoms] The affected leaves appear lumpy greenish, and then yellow-green spots, mostly distributed along the small veins, and the leaf veins are transparent. In the later stage of growth, the whole leaf turns yellow-green, and some special susceptible clones are deformed. Some clones have smaller leaves after being damaged, 1 2 shorter than normal leaves, 1 3 1 4 narrow, and the plants are short.

Pathogenesis] poplar mosaic virus disease can infect a variety of plants through inoculation. Different poplar varieties and clones have different susceptibility levels. The highly susceptible ones include I-63 51, I-69 55 and I-72 51, the mildly susceptible ones include Shalanyang, Xiaomei Yang, Jianyang, etc., and the resistant ones are Mass Yang, I-154 and Peking Yang.

Diseases can be transmitted by grafting, root grafting, and human activities (pruning, etc.). Mosaic virus disease mostly occurs in spring and autumn, and the disease is not significant in summer in the high temperature season. The disease of trees varies according to age, and the disease of one-year-old seedlings is serious, while that of large trees is not significant.

Control methods] Cultivating disease-resistant varieties is the key measure for the prevention and control of this disease. Disease-free plants were selected as propagation materials; Eliminate diseased strains and reduce the source of infection; Strengthen the quarantine of nurseries, and prohibit diseased cuttings or diseased plants from leaving the nursery.

The treatment of viral diseases is not possible without this patented product of biopesticides. It was widely used 20 years ago.

The symptoms of poplar mosaic disease are mainly manifested on the leaves, and the affected leaves will initially appear dusty and green spots, and then these spots will turn into irregular yellow-green spots, which are generally distributed along the veins of the leaflets. Poplar mosaic disease is generally caused by infection with viruses, and can generally be controlled with non-toxic high-lipid film concentrated emulsion, and if there are aphids, anti-aphid and menacarb are used to kill aphids.

Poplar mosaic disease symptoms.

The symptoms of poplar mosaic disease are mainly manifested on the leaves, and the affected leaves will initially appear greenish dots, after which these spots will turn into irregular yellow-green spots, which are generally distributed along the veins of the leaflets.

Poplar mosaic disease hazards.

The diseased leaves of poplar mosaic virus disease were shorter than those of normal leaves1 2, and the contents of nitrogen, phosphorus and potassium were significantly reduced, the growth of seedlings was hindered by silver ants, and the growth amount was reduced by at least 30%, the proportion and strength of wood of severely diseased plants were reduced, and the wood structure was also abnormal, and the younger the age, the more severe the symptoms.

Causes of poplar mosaic disease.

Poplar mosaic disease is generally caused by infection with viruses, which can be transmitted by grafting, and if produced in forestry, mainly with poisonous cuttings.

What medicine is used for poplar mosaic disease.

Poplar mosaic disease can generally use non-toxic high-lipid film concentrated emulsion, if there are aphids, use anti-aphid and menacarb two agents, or choose other high-efficiency, low-toxicity agent spray to kill aphids.

Poplar mosaic disease control methodsMosaic disease treatment methods.

After the emergence of poplar mosaic disease, it is necessary to strengthen the quarantine of seedlings, prohibit the transfer of vaccines and scion in and out, destroy the epidemic on the spot, reduce the source of poison, remove weeds, and reduce the places where aphids live.

Mosaic disease precautions.

In order to prevent mosaic disease in poplars, it is necessary to pay attention to strengthening quarantine and forecasting, find the epidemic, spray drugs on diseased plants, and mainly control the harm of seedling aphids and eliminate diseased plants.

Mosaic virus has a wide range of hosts, infecting 40 to 50 species of flowers. Some flowers are propagated by vegetative roots, and the virus is passed down from generation to generation, increasing year by year. The leaves of the diseased plants are reduced, and the leaves produce yellow-green uneven mosaic and leaf markings along the leaf veins, or produce yellow spots or yellow-green and dark green stripes, and some infected plants such as canna yellow-green stripes gradually turn brown necrosis, and the leaves are torn and broken along the necrotic parts.

The leaves are deformed, the corolla is small, and it is not even normal. Some ornamental plants sometimes have markings on their flowers. Mosaic viruses can be transmitted by sap, cotton aphids, peach aphids, corn aphids, potato long-tube aphids, leafhoppers and other insects with stinging and sucking mouthparts.

If the tools are not sterilized, it is easy for the plants to be infected with viruses. Mosaic disease occurs throughout the year, but spreads most rapidly during the dry season when the density of winged aphids is high. Diseased plants should be uprooted immediately during the growing season; removal of wild host plants such as weeds; Tools should be disinfected with alcohol, etc.; control of aphids and other poison-carrying insects; In the onset period, it can be sprayed with 40% dimethoate 1000 1500 times or deltamethrin EC 4000 10000 times.

Prevention and treatment should be done as soon as possible, and the initial spraying should be cured up to three times.

In late spring, when the symptoms of the disease are obvious, the seedlings of black poplar and poplar are quarantined at the place of origin, and the seedlings are removed and burned when they are found, and the diseased seedlings are prohibited from leaving the nursery. It is forbidden to purchase poplar seedlings from the affected area, especially poplar seedlings of black poplar and poplar sylvestris. When planting trees, it is forbidden to plant seedlings infected with the disease.

When raising seedlings, it is forbidden to use propagation materials such as cuttings and scion with the virus to cultivate seedlings.

If it is determined to be mosaic disease, look for this plant-derived biopesticide series: 30% suspension willow.

Virus name: poplarmosaicvirus (popmv). Virus purification:

Frozen wild tobacco leaves, finely ground in disodium phosphate buffer (containing 1 mmol l disodium ethylenediaminetetraacetic acid, sodium sulfite), the extract was heated to 50, centrifuged at low speed, ammonium sulfate was added to 30% 45% saturation to precipitate the virus, and then suspended in the buffer. The virus was further purified by sucrose density gradient centrifugation or clarification of the extract with chloroform, followed by molecular rejection chromatography on a column containing 2% agarose particles. Viruses tend to aggregate, and it is difficult to resuspend viruses that have been deposited by ultracentrifugation (Biddle &Tinsley, 1971).

Virions: slightly curved threads, about 675 nm long. The settlement coefficient is 165s.