Continue the cooperation with Marcus V. Locatelli, this is another interesting article
published on its website and freely translated. Obviously everyone who find some mistakes or had observations, is invited to post a comment.
The bacterioses in Phalaenopsis, has the most causal agent cited in literature (at least so that I could find) the bacteria Pectobacterium carotovora, whose most common symptoms of infection are soft rot in leaves (pectolytic enzymes released by Pectobacterium carotovora in the internal tissue of the plant, mesophyll, pectates of Ca degrade the middle lamella which is the “cement” that unites in plants one cell to another) and soft rot in pseudobulbos, that rot is also called anasarca (ponding regions and bad smell). In addition to this agent, cited were other bacteria with the potential to cause disease in orchids in general, such as Pseudomonas sp., Erwinia carotovora, Erwinia chrysanthemi and Acidovorax avenae pathovar cattleyae, but to properly identify it is necessary biochemical tests more complex.
Bacterioses in plants has no cure, they are systemic diseases. Thus, the best control is given by prevention. There are some antibiotics for agricultural use, but absolutely discouraged, at great risk of human contamination and environmental that its use brings with it.
It is known that unlike some of fungi, bacteria are not actively penetrate the body of the plant, because of lack of biochemical artifacts such as enzymes that when released on the surface of a leaf, for example, degrade the cuticle of the same thereby decreasing the mechanical resistance to penetration once existed.
Thus, his best control is given controlling the agents, the vectors, who would literally put the bacteria into the body of the plant, especially insects and mites.
Now here we will talk about the mites are microscopic beings, as shown in the photo below (withdrawal of Wikipedia), a mite very common in our homes.
The phytophagous mites feed is the juice to mobile rasp cells with their appropriate oral appliance. Surely, open wounds that serve as entry to the viruses and bacteria.
The mites of gender Brevipalpus (family Tenuipalpidae), for example, are important vectors of viruses in the Brazilian citrus industry, demanding millions of dollars every year for its control.
In the case of the mite of citrus leprosis, Brevipalpus phoenicis here in our tropical climate, and sub-tropical, the population increase occurs from the months of April / May, declines in again from October / November, they develop themselves better in the driest environments, and the increasing of rainfall in some ways control this phenomenon.
The photos below show symptoms of cellular scraping by mites (in bas-relief) in the leaves of Phalaenopsis, and the black eyes and yellow spots (without bas-relief), symptoms of a possible bacterial infection.
As a measure of control to mites, cited were those related to the cultural treatment, such as avoiding the accumulation of dust on the surface of the leaves, which serve to protect the mites, and always keep the orchidarium as airy as possible.
When it comes to chemical control, although there is some product registered in Brazil for the cultivation of orchids (new!) And away from me prescribe a product that is not registered by the competent authorities, I’m risking my record on Tuesday revoked before create even withdraw it, but I know that staff has used acaricides the basis of phosphorous, clorodifenilsulfona, dinitrophenol and chlorine, both dangerous products that need extreme caution as to the application, from the use of individual protection equipment (EPIs) by people who use the spray, and some time, specified in the package leaflet of each, to avoid having contact with the plants and sprayed areas.
Recalling also that, although the main vector of diseases in crop plants is the beast man, through practices such as discovered, excessive injuries with cutting tools and the use of these immediately of a plant to another, without a necessary disinfestation, water, contaminated irrigation of origin, and irrigation on a little embasada, purchase of seedlings or any other product employed in the cultivation of dubious origin, and plants in very trouble benches, plants rasped in plants and so on.
Finally, what should be borne in mind is not letting injuries in plants exposed for a long time, spraying a little cinnamon powder (which has phenols that microbicides are substances in general) and pincelar syrup broth (mixture of copper sulphate, carbonate of calcium and water) helps to seal a surface open for a cut.
Below, a photo of a Phalaenopsis demonstrably convicted, the golden circular spots are symptoms of viral disease (caused by CyMV – Cymbidium Mosaic Virus) and the leaves on the right, it is possible to notice symptoms of anasarca.