Bacterial and virus diseases of grapes

The material is devoted to symptoms of a disease of grapes: infectious xloroz, korotkouzly, wood borozdchatost, twisting of leaves, infectious usykhaniye and to measures of fight against them.

Virus and bacterial diseases are transmitted by the inoculations, the cutting tool, nematodes

Virus and bakterialyyony diseases are transmitted by the priyovivka, a cutting instruyoment, nematodes.

Infectious xlo­roz (panashyur, pestrolistost, yellow mosaic). Vesyona young growing lis­tya and escapes almost polnos­tyu become colourless and zhel­teyut. Pozhelteniye of a leaf begins, as a rule, on veins (lose coloring earlier, than the sites of a fabric of a leaf remote from them). Poyozhelteniye begins with stayory leaves and then raspro­stranyaetsya on leaves moloyody. Edges of yellow leaves dry out. The leaves which have grown later, are covered with chaotically scattered yellow spots. Clusters small, with goroshashhimisya berries. Growth of bushes constantly dies away and they perish.

Korotkouzliye. At a poyorazheniye this virus, a rasyopuskaniye of kidneys the disjointed. Leaves settle down almost veryotikalno, early ostanavlivaet­sya growth of green escapes, kus­ty are oppressed, interstices uko­rocheny and in zigzag fashion is­krivleny. Often escapes de­formirovany, with double knots, fastsiatsiya and a vilchatost, with strongly developed stepsons. The form of leaves of many grades changes: they become dissymetric, cloves on them are extended and za­ostreny (remind a fan form) or, on the contrary, netipichyono are approximated, petiolar vy­emki are expanded. Patients ku­sty poorly fructify. Sotsveyotiya the small. At strong illness razyovitiya a flower in a sotsveyotiya dry up and fall down or are badly pollinated, berries not za­vyazyvayutsya, inflorescences uvyada­yut. Polupuyosty clusters with underdeveloped berries are often formed.

Borozdchatost dreve­siny. Generally imparted bushes are surprised this to a boyoleznye. In a junction of components of an inoculation obrazu­yutsya the extended pressed grooves directed along an axis of escape. The bark in a place of a rasyopolozheniye of furrows utolshhena and more friable, than on sites with not struck fabric, easily exfoliates from wood. Productivity falls. Bushes ot­stayut in growth, prezhdevremenyono perish.

Twisting of leaves.

Illness symptoms nachinayut­sya at the end of July – the beginning avgu­sta, then by September usili­vayutsya. The main sign – edges of leaves are lowered down and braided. Depending on a grade, the premature pozhelteniye or reddening of leaves is thus observed. Along the main veins green coloring remains in the form of uzyoky strips. Plates of leaves of sick bushes utolshhayutsya, become leathery, gruby­mi to the touch, crumble. Uxud­shaetsya coloring of the ripened berries (it faded), a sakharisyotost lowered, acidity raised. Many imparted grades are ill without seen pri­znakov diseases that za­trudnyaet identification of porazhenyony bushes and promotes an illness rasyoprostraneniye. The Uroyozhaynost of sick bushes is lower, than at the healthy. In the beginning zak­ruchivayutsya bottom leaves. Moyolodye leaves on the ends of annual escapes don’t change a form. On a measure a zakruchivayoniya of leaves, more and more pro­yavlyaetsya xloroz edges of listoyovy plates.

Symptoms of a lack of potassium are very similar to twisting. Difference that at nedostat­ke potassium the first signs of a skruyochivaniye appear on leaves of an average zone of escape.

Infectious usykhaniye. Escapes ukorachivayut­sya, knots approach, leaves are deformed. Growth pobe­gov is strongly oppressed, the crop sharply falls, for the 3-5th year after emergence of an illness ku­sty perish.

Fight measures

a) Use for a razyomnozheniye of only a sertifitsiyorovanny healthy posayodochny material.

b) Observance of karantinyony actions for a preduyoprezhdeniye of drift of an infection on healthy plantings.

v) Destruction by a raskorchyovka of sick rayosteniye (leaves, escapes, skeyoletny parts, roots, scraps to burn); a raskorchyovanny posayodochny hole, the soil to pickle.

g) Soil fumigation pro­tiv nematodes.

E.Klyuchikov.

(On Dachnik newspaper materials).