Stains on orchid leavescan come in a variety of shapes and colors. The most common are black, yellow or white spots on the orchid leaves. Sometimes they are grayish or brown, dry or watery. Each type of stain on orchid leaves indicates a different cause of their formation - care errors, disease or pest. Seewhere do stains on orchid leaves come fromand how to treat orchids with stains on leaves!
Stains on orchid leaves
Black spots on orchid leaves
Black, dry and rough to the touch, extensive spots on the leaves of the orchidare caused by sunburn.They are formed in places of direct sunlight. Such damage is irreversible because the leaf parenchyma has been destroyed. Toavoid burns to orchid leaves , avoid exposing plants to direct sunlight. They feel much better in places with diffused light than on a strongly lit window sill.
Black-brown, convex and air-filled, light ring-shaped, streaky or irregular, often very numerous and yellow (chlorotic),gradually darkening and tissue-damaging spots visible on orchid leavesare symptoms viral diseases. Viral diseases are very common in orchids. Unfortunately, viral diseases cannot be cured. If we observe the above-mentioned symptoms on our orchids, we should remove such copies as soon as possible. Viral diseases are transmitted by pests (especially aphids). Therefore, fighting pests of houseplants plays an important role in the fight against viral diseases of orchids.
Yellow spots on orchid leaves
Numerous appearingsmall, yellowish spots covering the entire surface of the orchid leaf in mosaicand the slightly dusty underside of the leaf are symptoms of mite feeding. They are very troublesome pests, often inhabiting potted plants. The species most frequently attacking orchids is the orchid spider mite (Tenuipalpus pacificus). It was brought to Poland together with orchid seedlings imported from China in 2008. Therefore, when purchasing orchids, carefully inspect the selected specimen for visible leaf mite feeding symptoms.
The effects of spider mites feeding on orchid leaves
Similar symptoms are caused by the spider mite (Tetranyus urticae). The spider mite infestation is favored by high temperature and low air humidity.To get rid of mites from orchidswash leaves with lukewarm water with a few drops of washing-up liquid.The lower side of the leaf blade can be smeared with vegetable oil. The oil covering the body of the spider mites will limit their access to air. We can also use garlic clove extract or onion husk extract. In case of a strong infestation, we should reach for insecticides, e.g. Agrocover Spray.
Yellow spots on the leaves of the orchidmay also be a symptom of feeding scales. Shields are small insects whose body is hidden under a hard shell. They are saturated with plant juices, which at the same time excrete honeydew, i.e. honey dew, which covers the leaf surfaces and promotes fungal infection. The species that often attacks orchids is the citrus plant (Coccus hesperidum), which inhabits plants in greenhouses. We remove scales from orchid leaves mechanically, using a cotton swab soaked in denatured alcohol or water with gray soap. After thorough cleaning of the orchid leaves, spray the plants with Target Agricolle prophylactically. Mealybugs on orchids are controlled in a similar way.These pests resemble wool fluff and their harmfulness is similar to that of scalefish.
Sometimes the hard and convex spots on the leaves of an orchid are the shells of insects, such as scales, bowls and mealybugs
Brown and brown spots on orchid leaves
Whendark green, small, slightly recessed spots appear on the orchid leaves , which turn brown and brown and spread over the entire leaf surface, these are symptoms of phytophthora (Phytophthora sp.) . It is a fungal disease that develops very quickly in low temperature and high air humidity. Red, brown spots on orchid leaves are a symptom of rot, caused by fungi of the genus Pythium. In high temperatures and high humidity, Pythium fungi kill orchids in a matter of days! In order to avoid infection by fungi, it is necessary to provide orchids with optimal growing conditions.In sick plantsremove and destroy all infected leavesSpray the remaining parts of the plant with Biosept Active.
White spots on orchid leaves
Metallic shimmering,silver-white spots on the upper sideand black lumps on the underside of orchid leaves indicate the presence of thrips. They are small (3 mm) insects with a variable body color - from white to black. The species inhabiting orchids is the oriental thrips (Thrips palmi). They are not frequently ascending pests. Orchids are attacked by them at the place of breeding or in stores. When we notice the characteristic symptoms of thrips feeding, we place blue sticky boards attracting these insects in the orchid pots or near them. Spraying is also necessary. To combat thrips on orchids, use the Target Agricolle preparation.
Bright spots on orchid leaves
Ifthere are round or irregular, slightly sunken, light spots on the orchid leavesthat gradually turn brown and expand into irregular shapes, it means that we are dealing with bacterial blotch Phalaenopsis leaves (Pseudomonas cattleyae).Too intensive irrigation of orchids favors the development of this disease.Leaves with symptoms of the diseasecut off with a sharp tool right at the root. The cut wound is left to dry and the whole plant is transplanted into a new pot and fresh substrate. We limit watering and sprinkling the plant. Avoid soaking the leaves when watering as the bacteria are transferred with the water. Spray the adjacent orchids prophylactically with Biochikol 020 PC or the aforementioned Biosept Active.
MSc Eng. Agnieszka Lach
