In addition to pests, cacti pose a great danger. diseases, caused by bacteria, molds and viruses. No less dangerous and diseases of improper care. To help your cacti in a timely manner, you need to know about these diseases and how to combat them. We bring to your attention the most popular diseases affecting cactus and methods for their treatment.
Phytophthora
Phytophthora cactus - a fungal disease caused by fungi of the genus Phytophora, is transferred to the plant from infected land. Under the influence of mold fungi, cactus tissues become a limp mass. The roots of the cacti and the base of the stalks rot from this disease. A strongly affected plant can be saved only by rooting the upper healthy part or by transplanting it onto healthy roots. When a lesion is less serious, they are struggling with it, removing rotten parts and sprinkling cutting areas with sulfur or coal powder. And it is recommended to transplant the cactus into sterilized soil, to which a little sand is added.
Important! Spores of the phytophthora fungus easily fall into any lesions and wounds of the stem. The probability of cactus disease increases if the soil is wetted, especially in cool weather.
Dry rot
The cause of dry rot plants are mold fungi. Dry, with dull stems cactus - a sign of dry rot. To overcome it is very difficult, because often the diagnosis is established in the later stages of the lesion. But you can take preventive measures - to process the plant at least three times a year with fungicides.
Mottled rust
It is caused by fungal infections of cacti, but can also be caused by bacteria and viruses. The stems of the plant cover rusty spots, crusts, stains, which are not worth removing, because scars remain in their places. The likelihood of spotty rust increases with temperature drops, sunburn, and cold water irrigation. To fight it is necessary to treat cacti with fungicides that will not allow further spread of rust on the cactus body. Another type of cacti spotting is antrocnosis, from which round, dry, dented spots of light brown or darker color appear on the body of the cactus. You can fight by applying Bordeaux mixture, colloidal sulfur or copper sulfate solution.
Stem rot
RRibkovaya disease, affecting, as a rule, young cacti. Their stems are bent, and the surface of the stems is covered with velvety green bloom - ripening spores of the fungus. Just a couple of days it will take a fungus to destroy all the seedlings. Stem rot ripens well at low temperature and high humidity. Diseased plants must be removed.
Did you know? Cows that feed on cacti give more milk. Therefore, Mexican farmers feed their cows with needle-dried opuntia.
Fusarium
The disease, caused by fungi of the genus Fusarium, often affects segmented cacti. The disease spreads gradually, first the roots, then gets into the conducting system, reaches the top, and the plant fades. A typical sign of fusarium are red-brown conductive vessels at the cut. In addition, the stems are covered with pink or purple bloom, wrinkling and falling. Excess moisture in the soil and high humidity - ideal conditions for the development of fusarium. If the cactus is sick with fusarium, then it should be destroyed, but as a preventive measure, you should follow the irrigation regime and moderate temperature, prevent mechanical damage to the plant, use only steamed soil, avoid excess nitrogen, water it with foundation, and do not treat.
Cancer stems and roots
Disease leading to abnormal growth of cactus roots and stems. The process may be local or generalized. In the second case, the plant dies completely. Sometimes the cause of cancer are viruses that fight off plant cells. There are no effective methods to fight against cancer of roots and stems. The plant must be destroyed.
Diseases improper care
In addition to viral, bacterial and fungal diseases of cacti, there are also so-called physiological diseases, diseases of improper care. These include burns (chemical and solar), frostbite, lack of light, flooding, crushing, excess and lack of nitrogen, lack of phosphorus, alkalization of the soil, and others.
Did you know? On the shores of the Mediterranean in Monte Carlo is the world's only garden of cacti, represented by hundreds of species of cacti growing under the open sky.
Yellowing stalks
This disease is caused by both bacteria and viruses, and the lack of trace elements and nutrients in the soil. The spread of the disease begins at the ends of the shoots, and it can be determined by a change in color at the ends of the stems — a healthy green color changes to a painful yellow. Sometimes the disease becomes chronic and lasts for years. If the cactus has turned yellow, then, probably, the only method to overcome this disease is to increase the natural protective reactions with the help of fertilizing.
Sunburn
Large white, pale yellow or brown spots on the cactus, which do not heal for a long time, may indicate sunburn. Often, sunburns of cacti appear in the spring, when the cactus after winter is exposed to bright sunlight on the street. It is impossible to cure them, and in order to avoid this, it is recommended that many species of cacti pritenyat, gradually accustom them to the bright sun.
Chemical burns
Such cacti burns are possible due to improper use of pest control chemicals.
Important! All purchased drugs should be used strictly according to the instructions, which indicate the rules of their dilution.
Frostbite
As a rule, frostbite can get a cactus in winter with a sharp decrease in temperature. If the plant is completely frostbite, then it becomes translucent, and if it is only partially frostbitten, transparent spots appear. When the cactus is frostbite completely, then it cannot be cured, and when partially - it is necessary to thaw it out gradually. The first few days you need to keep the temperature at 0 ° C, and then slowly raise it.
Lack of light
When the cactus lacks light, it grows (etiolized) - its stem is stretched, the trunk color turns pale, the length of the spines and their number decreases, and there are no underdeveloped spars on the growth. To fix this, the cactus is required to be placed in a more illuminated place, and you can also root the cut off tip. In order to prevent create optimal lighting mode for the plant.
Soil alkalization
HSoil alkalization occurs due to the watering of cacti with hard water, which most often contains calcium salts in excess. As a result, your cactus is blackened or its stems begin to blush. It will help to get rid of this problem only transplanting plants.
Excess nitrogen in soil
Excess nitrogen in the soil leads to abnormally increased plant growth, which is not accompanied by flowering. This happens much more often if fertilizers with a high nitrogen content are used. The main symptoms of nitrogen overload in the soil are the slow development of spines against the background of intensive stem growth, rotting of the roots, reactions to changes in the temperature regime, the plant is subjected to various infections. The solution to this problem will be the transfer of cactus into the soil, which is not so rich in nutrients.
Did you know? In ancient times, Latin American doctors used sterilized cacti needles to sew wounds.
Diseases of cacti a lot. Protecting cactus from a variety of diseases should consist in regular preventive and curative actions.
