Phytophthorosisis a disease caused by fungi of the genus Phytophthora. It attacks many different species of plants, both herbaceous and woody. Ingardens, symptoms of phytophthoraare most often observed on rhododendrons and conifers. This disease is very dangerous for plants, so it is worth learninghow to recognize the symptoms of phytophthoraand how tofighting phytophthorosisin the garden. We suggest the bestphytophthora spraysthat can save your plants!
Phytophthorosis on rhododendrons
How to recognize the symptoms of phytophthora?
The symptoms of phytophthora may be slightly different on different plants.The disease develops very quickly in high humidity or excessively humid soil and temperatures above 20 ° C. In garden shrubs, root rot is usually seen (very often the lesion is visible only on one side of the shoot), which spreads upwards. Single shoots die, on which leaves or needles turn yellow and brown. To make the diagnosis of the disease easier, we describe belowsymptoms of phytophthorosis characteristic for particular groups of plantswhere the disease is most common.
Phytophthora on azaleas and rhododendrons- infection can be caused by Phytophthora cinnamomi, P. citricola, P. citrophthora or P. ramorum. Formerly, this disease was referred to as root and root rot in rhododendrons and azaleas.
Symptoms of phytophthora on rhododendronsinclude inhibition of plant growth as well as wilting and browning of the apical leaves.Very oftenleaves curl along the main nerveinto a characteristic roll and hang down on the stem. Typicallysymptoms are seen on one or moreshoots, while others appear he althy. Rot may appear at the base of the affected shoot, and when the plant is excavated, you can see that the roots are weakened and their tips turn brown (in particular, fine hair roots rot).
To make sure that the plant is attacked by phytophthorosis before it dig out, you can cut off the bark at the base of the infected plant with a sharp knife. If the wood tissue is rusty red and it is clearly distinguishable from he althy tissue, it isa sign of phytophthora disease
Boxwood phytophthora- in summer, individual shrubs turn yellow, turn brown, wilt and die. This is especially visible in the case of boxwood hedges, when individual pieces fall out for some unknown reason. At the base of the shoot you can see rot spreading upwards and also to the roots."
Phytophthora on azaleas
Phytophthora on conifers- growth inhibition of several-year-old plants is observed. On one side of the plant, a slight yellowing of the needles is noticeable on individual shoots, which gradually expands, the color of the needles turns brown or reddish. Entire plants may die over time, and in the case of some conifers, such as cypress trees, they will appear burnt. At the root, browning of the tissues is observed.Decay at the base of a shoot usually initially shows up only on one side of the shoot , and with time it grows larger and moves upwards. After removing a piece of tissue with a knife, you can clearly see the border between the he althy area and the brown or reddened affected area.
Phytophthorosis - browning needles and rot of pine shoot base
Apple phytophthorosis- apple trees are attacked by Phytophthora cactorum, apple leaves in mid-summerthey usually turn gray, yellow and brown, and some of them fall off. After a detailed examination of the trunk, it turns out that at the base there are (usually only on one side of the shoot) brown spots, slightly recessed.
Heather phytophthora- single shoots turn yellow and brown, such symptoms usually appear in mid-summer, the number of dying shoots increases very quickly until the entire plant dies. Phytophthora on the heather can also manifest itself in the form of browning only the tips of the shoots, which bend into the shape of a stick and hang downwards.
Good to know!Mushrooms of the genus Phytophthora can also attack vegetable plants. In tomatoes, it is the Phytophthora infestans fungus that causes a serious and common disease, which is potato blight on tomatoes.
Fighting phytophthora
Fighting phytophthora is very difficultThe pathogen can stay in the ground and infect plants from the root.Usually, symptoms are not visible at first and we are not aware that the plants we buy may be infected. When the symptoms of phytophthora are clearly visible on the leaves and shoots, the plants often cannot be saved.
RThe development of the disease is favored by a moist and fertile substrate.On the other hand, plants are less often infected in dry and less fertile soils. Coniferous and heather plants, including azaleas and rhododendrons, are recommended to be planted in a substrate with the addition of composted pine bark. Before planting new plants, it is worth soaking their roots in a solution of Polyversum WP.
Polyversum WP is a biological preparation containing the plant-safe Pythium oligandrum fungus that parasitizes on fungi that cause phytophthora. For this reason, it is very effective in reducing the development of phytophthora.
If in the gardenwe notice plants suspected of being infected with phytophthora , they should be carefully examined. If there is root rot and root rot, the entire plant must be dug up and removed from the garden.The other plants growing nearby are watered and sprayed with Polyversum WP. If the symptoms of phytophthora appear only on single shoots or we are not 100% sure that it is phytophthora, treatment can be attempted. Sick shoots should be cut and the whole plants should be sprayed and watered with fungicide.
In places where plants infected with phytophthora grew , do not replant species susceptible to this disease for at least 4 years as the pathogen can survive in soil. It is also worth decontaminating it by watering it with a fungicide. The most frequently recommended for this purpose is Magnicur Energy 840 SL.
Otherfungicides used against phytophthorosisare: Aliette S (fights phytophthora on conifers and ornamental plants such as gerbera), Proplant 722 SL (conifers, flowering ornamental plants, vegetables such as: tomato, cucumber, lettuce).
