Orchids from Green Drop Home. Diseases and pests : Viral diseases.

Headlines

Good time to you!

Orchid fleck virus (Primary Stage)

Viral diseases.

   The word «virus» comes from the Latin «virus» - poison. A virus does not have its own metabolism, and reproduction, they need to get in the cells of plants. In these cells, they can not enter active, since it is not in a position to self to get through their shell. To do this they need «assistant», and they entirely dependent on the so-called vectors, which are implementing them in a cell. They may be pests in the first place. We know that, drink cell sap from plants, aphid and Thrips palmi can carry viruses into cells or conducting vessels. Disputes fungi may also move or introduce viruses into the cells.
   Once inside the plant viruses are starting to spread further through the conducting vessels. Known today many viral diseases, so-called virozy received its name from the main host plant, they staggering. In doing so, the name often appears as external signs of injury, such as tobacco mosaic virus, indicating that the plants appear similar to a mosaic of light spots.
   Viruses cause discoloration (stripes, spots, different dash intensity of color or clarified sections) or leaf deformation. Affected plants cease to grow, there is a tendency to degenerate.
   Some typical of viral lesions diseases such as deformed growth, coupled with a neoplasm (eg, «Broom Witch»), agent may not be viruses, and mycoplasma.
   External damage caused by viruses may appear very diverse. First, depending on the virus, the external signs of injury may be more or less pronounced. Secondly, with good care and constant feeding fertilizer plants could «mask» viral diseases. In this case, the defeat apparently little or no apparent only at the young sprouts can be seen very weak symptoms of the disease. When it came to viroza, there has been more or less typical pattern. Do your plants will be a delay of growth of leaves or whole plants in general. It also drew the attention of deformation of the leaves or flowers. On flower color discoloration can occur, for example, discontinuous coloring, but the plant does not kill.
   The most typical manifestation of the same virus an appearance on the leaves and stems spots, stripes, lines of different intensity or clarified sections of tissue in the form of spots or rings. In the first case, the cause of defeat is the mosaic virus, the second - the virus that causes circular spots.
   With respect to virus prevention plays a major role. This includes the destruction of all possible vectors of viruses (see above). Avoid any damage to plants, because the wound - this is an open door for viruses. Alcohol wash cutting tools, which jump from diseased plants to healthy. Do not use diseased plants for cuttings.
   In the world of orchids at this time is known and described about 20 different viruses. The external manifestation of viruses is directly dependent on the type of orchid, its varieties and conditions. Very often affect several plant viruses at the same time, which is very difficult to diagnose diseases of the external.
   Viruses can be a slow developing and very rapid, which in a relatively short time may completely destroy all the plantations in huge greenhouses. Some viruses can be located inside the plant for years, apparently not giving no signs of life.
   Precise identification of the virus is possible only in the laboratories of the expert division, as the process of recognition of viruses is a long and laborious.

Cymbidium mosaic virus.

Cymbidium mosaic virus on Phalaenopsis

   This virus, although named Cymbidium mosaic virus (CyMB), but less than it affects not only the Cymbidium, but the rest of orchids. The most vulnerable this disease are the Cattleya and Phalaenopsis, somewhat less frequently it occurs on Laelia and Paphiopedilum.
   The manifestation of this virus, usually begins with the young leaves of plants, which are beginning to appear of different sizes and forms of light (white, yellow or light green) areas.

Phalaenopsis

   The most typical manifestation of Cymbidium mosaic virus in Phalaenopsis is the color of young leaves of normal green begins to turn into a marble. In light of the emerging leaves of different sizes. They can be both large and small, as a round or oval, etc. As we get older leaves, these bright areas become depressed black spots. First blackening occurs on the inner side, and then on the outside. Leave greatly weakened and eventually fall off. CyMB evident not only in the leaves of Phalaenopsis, but its colors. However, there is one feature - the virus manifests itself only in dark varieties Phalaenopsis, for example, a violet. The form of the flower shape and color also becomes marble. However, it should be noted that this expression of the virus occurs very rarely.

Cymbidium

Cymbidium mosaic virus on Cymbidium (Primary Stage)

   Manifestation CyMB at the Cymbidium also begins with a young leaf. First, in the middle of the leaves (right on the bend) appear long light-green stripes, which over time becomes convex. As the disease previously bright areas become black. This is seen as on the outside of the leaves, and on the inside. Then the sheet is weakened and fall off. Along with the changing colors of leaves changing color, and deformed flowers orchids.


Cattleya

Cymbidium mosaic virus on Cattleya (inner side of the leave)

   In contrast to the above orchid, Cattleya CyMB appears to have grown up on the leaves. First, they appear depressed dark brown or black spots, which can be either round or elongated oval, sometimes along with the more rounded shapes appear very long (from one end of the sheet to another) bulged strips. Circles and rings can merge with each other in fancy designs, however, the heart of such images remains green. As the disease is changing color and the new sprouts, flowers and orchids. New shoots appear lighter, while the flowers are covered with black spots, which over time are connected in line.

Odontoglossum ringspot virus (ORV).

Odontoglossum ringspot virus on Calanthe

   At the initial stage of the virus on the outside of the leaves of Odontoglossum appear light green or yellow ring, usually the middle of which is green. As the disease tissue in the affected area becomes depressed and black, and the plot inside the ring is still green. Often, when, on the contrary, become black inside the ring, a ring remained light green or yellow, or when all black ring (and its rim, and core) in full.
   Very often CyMB and ORV affect plants at the same time, and can cause unpredictable changes in form and color of leaves of orchids.

Orchid fleck virus.

Orchid fleck virus (Final Stage)

   Unlike CyMB and ORV, the virus appears in the old leaves of orchids. The most susceptible to the disease Phalaenopsis, Paphiopedilum, Cymbidium, Coelogyne and Oncidium. Young leaves are a long time without visible signs of injury, but on older leaves on their inner side, at first appear, circles and stripes. As the disease affected areas dry up and become outwardly similar to the white-gray, clear otcherchennye, bulged spots, which are usually seen only on the outside of the leaf. Over time, they settle various types of fungal disease and the stain cherneyut. This virus can be very long, is located in the plant juices, without any external manifestation. Impetus to the further development of infection is stressful to the plant situation, such as insufficient lighting, temperature maintenance, insufficient or, conversely, excessive watering, or over food plant nitrogen fertilizers.

Taiwan-Virus.

Taiwan-Virus

   This virus affects mostly young seedlings only Phalaenopsis, which comes from Asia. The external manifestations of the virus is very diverse. Nevertheless, the virus most often outwardly manifested in the form of light changes in color of leaves on a bright, sometimes even white. Spots as the rules vague, scattered, somewhat reminiscent of cloudy sky. Until now, the moment the virus is still very poorly understood. According to the structure of the studied virus, there are assumptions that it belongs to the group Tospo. On the colors of the virus is not.

Methods of combat.

   There are no drugs for the treatment of viral diseases in plants is still not there. Affected plants virozom destroyed. If the patient virozom plant does not look very ugly, it can even be left to grow, particularly by removing the external adversely kind of. However, in this case there is a serious risk of infection with the emergence of insect pests that are carriers of the virus. Diseased plants can infect other species of plants! In each case, decide what you do with a sick plant. Reproduction of the educational fabric cuttings (in vitro) guarantees the absence of virus in plants.
   Before you buy orchids must be very carefully inspected for the presence of changing color as the leaves, and flowers, and if there is the slightest suspicion, that a plant in no case should recover, as well as facing him in the neighborhood orchids, as they are already may be contaminated.
   From plant to plant viruses are transmitted slowly, however, sucking the juice insects (such as spider mites) can greatly help this process. The best prevention of pests - this is a thorough inspection of plants, watering through the soul and sufficient humidity. If we plant pests must be immediately isolated from the rest.
   In addition, viruses can pass through cutting items (knives, scissors, etc.), so when working with orchids should always carefully monitor the disinfection of knives and scissors. Moreover, it sometimes happens that a plant is infected with a virus, but the external signs have not been shown.
   Viral diseases are often confused with lack of nutrients, as well as in connection with those on the leaves of orchids are also often occur on different pictures of mazaiki. Regular feeding of orchids useful substances such as potassium, phosphorus, iron, etc., will prevent confusion in this matter.

Our recomendation.

   Fight against Aphididae and Thysanoptera, which are dangerous carriers of viral diseases.

Prevention.

   As for humans, as well as for plants, prevention - best treatment. In the first sign of any disease, even if you can not diagnose it, when the first symptoms of which, or even if you feel suspicious, separate this plant from the rest of the collection jar.
   It's so many collection perished during the night, from the fact that owner waved his hand and decided to remove the suspicious pot in quarantine in the morning.
   All new, all that just bought, even if bought at the trusted place, still must go through quarantine. For how long? Not less than a week, better than a month. Still in the first two weeks, especially when the plant arrived without roots, do not water until new roots begin to grow. Only spray. And do not feed, but it is understandable.
   For the quarantine, you can certainly build a orhidarium, but if it is not possible - put the pot on a shelf. If this is not possible - cover a polyethylene bag, but it should be that the plant would not suffocated and not rot.
   Ideally, for each pot should be his separate tool set. If you can not - wipe all alcohol, bleach.
   Just brought plant should be transplanted. Old ground, send to the compost in the garden. Even if the plant has come from your most reliable supplier, even if from our shop, pots, substrates should be theirs. Not "ready for use", but their own. It can be scary in other case.
   Preventive methods are the same for humans, and for the plant.

By Greendrop Greendrop