Monday, September 2, 2013

Orchid Yellow Leaves with Brown Spots

Fusarium SPOT - is an infectious fungal disease caused by fungi of the genus are Musty Fusarium, most Fusarium proliferatum and Fusarium verticillioides [syn.  Fusarium moniliforme]. Both the fungus is difficult to distinguish from each groomsman, not only by the symptoms of the disease ( sometimes they are ), but also through a microscope. Main honors in size microconidia ( in Fusarium verticillioides are larger map ) in length and Chains microconidia ( in Fusarium proliferatum it more longest ). Many laboratories do not even bother with a detailed analysis of the documents and put Fusarium sp.

yellow orchid brown spot This orchid disease is most typically Dendrobium ( and natural species and hybrids ), and typically falls within the collection therethrough. The second was at risk Hybrid Cattleya, come to us from Asian countries, where it is ( in fact ) from the same Dendrobium ( s) and become infected. On the other orchids, the most common in our collections, the infection in its pure form is rare, usually it is the application to another, such as viral.

They fall into the plant through wounds or lorchid eaf pores ( stomata ), and in the course of their livelihoods form mycotoxins.  For example, virtually all types of Fusarium form zearalenone (Zearalenon), and Fusarium verticillioides also MONILIFORMIN (Moniliformin), FUZARIN C (Fusarin C) and Fumonisin (Fumonisin B1), the latter also generated and Fusarium proliferatum.

Both the fungus can harm not only the outer part of the orchid plant, but the orchid root system, especially when you consider that the nature of the plant pots do not cover it, and readily show, opening all the winds.  However, the most typical are the same for all the leaves, stems and directly themselves FLOWERS ( BUDS ).

white orchid Very often in the literature, there is the statement of fusariosis that gives the characteristic red, red-brown or reddish-violet damage.  Yes!  That is, unless you are dealing with a natural view, for example, Cattleya dowiana orchid, where most of the action of fungi was observed initially. Now genetics has stepped so far that MEZHIVIDOVYE HYBRIDS number in the thousands, and the more namesheno different gene, the less chance you have to meet the red orchid. Stains can be yellow orchid, orange, brown, black with yellow rim and many others.  Color and shape of the spots is very strongly associated with the structure of the leaves, especially on plants of the genus Phalaenopsis, they can be very original, especially in form.  The growth of stain is not very fast, this is largely dependent on the conditions in which contains orchid.

If spots appear on young orchid leaves (and they are more susceptible than mature ) or on young shoots, their appearance and the number can change dramatically as aging.  For example, you may receive BLACK MIDDLE Etched or edging. When perfectly folded climatic conditions ( hot humid climate, the temperatures are not below 25 ° C and not higher than 32 ° C) the development of the disease may be so rapid that the spot you seem primordial black and a female.

On the colors, covers, orchid flower stalks and buds Fusarium blight, as a rule, always monotonous - it's brown sunken spots, usually very small, as points.  Reproduction of this fungus occurs with white, pink or purple Conidia ( for ease of understanding - similar to the seeds ), which will eventually appear in the affected areas. They are more conducive to the rapid emergence of humid climate and water ingress.

From orchid plant to plant by Fusarium proliferatum and Fusarium verticillioides can migrate and clothing, and by means of wind, water through spray irrigation, have not been carefully disinfected sharp objects ( knives, scissors ), insects, etc.  "Seeds " mushrooms is very hardy and can persist for over a year, or even two.

They can quietly lie somewhere in the innermost corner of the window sill, and you will not even suspect it, naively believing that the disease is damaged.  REMEMBER, even the most well- publicized of fungicides do not kill these mushrooms are completely, about 30 % remains, and it will be some time, they regain their weight, and will appear again, so never relax !  At least once every 2 weeks and wash window sill inside with cleaning agents, especially when you have a lot of orchids and pots are one to one.  Do not let the fungi actively restore their numbers, sooner or later they will be lime.

In view of the persistence of pathogens TREATMENT diseased orchids rather complex and depends on how many territories " conquered " mushroom.

As in any other orchid case, what else infection bolshne and suspicious plants should be isolated from the rest. All suspicious spots should be cut to healthy green tissue, it is best to reserve at least 1 cm cut point without fail disinfectant, it will not only help the wound scar faster, but also reduce the probability of getting the new " seed " of the same mushroom.  Agree, it will be very sad, cut one spot, but bring a new dose of pathogens. Fungicide is desirable to produce after the cleave edge of the wound, with select products, where at least mentioned in the instructions that they are fit against Fusarium fungi because this group is very tenacious!

In the near future (just do not fall and winter), try to transplant your orchid plant to a new substrate, as Fusarium fungi primarily soil-borne fungus that is where they are most readily and distributed. Discard the old medium, provarkoy or roasting (if infected) 100% but will not help anything ( any part ) will still remain that will get stronger and will create a new lesion.

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