Bacterial and viral diseases
Mar 17, 2018
As sad as it is to admit, there are no really high-effective means of combating these diseases. This does not mean that you should not try to resist them. Even if the plant is not always cured completely, you, most likely, will be able to prevent its death.
Wet Bacterial Rot. Like many other flower diseases, in the early stages, the first symptom of infection with wet rot is the yellowing of the leaves. It starts from their apexes, then goes to the edges, after which more specific symptoms appear: spots of purple and dark-blue on the leaves. Flowers wither and fall off. Strongly affected tubers: in the early stages of the disease, they can look outwardly healthy, but soon they become lethargic and emit yellowish-brownish mucus.
Mosaic. This virus-induced disease usually manifests itself during the flowering period. Its main symptom, which gave the name of the disease, is the appearance on the monophonic leaves of sharply delineated patches of a diverse form( sometimes merging into rings) of a lighter color. Then the variegation intensifies: the leaves turn pale and turn yellow, necrotic spots may appear, and on the petals of flowers also appear, as a rule, elongated, even dashed, specks not characteristic of the natural color of this variety. With heavier forms, the flowers are deformed, the seeds are not formed in them. Sometimes there is rosette and shortening of internodes. All this is accompanied by a general oppression of the plant.
Mosaic plants can infect aphids.
There are no effective methods of struggle.
Jaundice. The virus of jaundice is carried by some small insects. The course of the disease in adult plants and shoots differs significantly: if the plant was infected shortly before flowering, in addition to the yellowing of the leaf tips, one can not expect trouble; with the earlier infection, the development of peduncles may be delayed. And in that, and in another case, if the plant bulbous or tuberous, despite the apparently healthy appearance of underground parts, the next year a healthy normal plant can not be obtained from them.
Infection with jaundice during the period of regrowth usually ends with the death of plants. Chlorotichnye8 in appearance, frail seedlings do not form peduncles and quickly wither.
In "intermediate" cases( a fairly young plant), in addition to the symptoms of chlorosis, the total growth is delayed, branching often increases, but the inflorescences or peduncles remain underdeveloped.
Bacterial scab. Heat and moisture promote the propagation of pathogens of bacterial scab. When the disease is caused by this disease, small spots of reddish color appear on the leaves( more often at their base), which, if not taken, can turn into burnt spots( round or oval) dark from brown to black in color, and the upper part of the weakenedsheet will start to turn yellow. With high humidity, moist rot can develop in these places, up to the point where a rotten stalk breaks at the base. With less moisture, the disease develops more slowly, and the affected tissues will be hard to touch. If the bulbous plant is affected, on the bulbs also can be found foci of infection - they will be covered with sores with dried up crusts of black color with raised edges. The sores can occupy a significant part of the surface, but they do not generally extend into the interior.
A good therapeutic and prophylactic for acidophilic( acid-loving) plants is acidification of soil: scab agents prefer a slightly alkaline environment.
Variegation. This disease is typical for tulips and related species. It is also transferred by sucking pests. The symptomatology is similar to the mosaic that arises in the disease, but the order of appearance of the external signs of the disease is like the reverse: first the spots-bands appear on the petals of the flowers, turning sometimes a single-colored stain into a motley, and only then do pale oblong stains appear on the leaves. Flowers melt, deform, the plant is weakened.
Bacterial Root Cancer. Cancer of the roots of plants has nothing to do with the terrible disease of warm-blooded animals and man, and he received his name because the most typical manifestation of this disease is the formation of tumor growths on the roots of plants. The causative agent of this disease is completely not species-specific: its victims can become representatives of any plant families.
Outlet. In plant and flower literature it is not always clear what exactly is at stake: rosetchnost( i.e. shortening of internodes, convergence of leaves) is most often a symptom of a particular pathology caused not always by viruses or bacteria. But in some experts, the rosette is allocated as a separate disease, more precisely, it sometimes turns out to be the only visible sign of a viral disease without laboratory analysis. If changes in diet and watering do not change the appearance of the plant, and similar symptoms occur in neighboring plants - there is no doubt that this is viral rosette.
Dwarfism. Infectious dwarfism, like rosette, is calculated by eliminating other causes. First - food and moisture, then - the use of anti-pest agents - nematodes.