Phylostictosis Of Rose Leaves

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

Phylostictosis, or brown spot, is an extremely unpleasant disease of roses, which manifests itself on the leaves in the form of oval, round or irregular specks. And the speedy development of this ailment is facilitated by a temperature of more than twenty-five degrees and high humidity. Roses attacked by an unfortunate misfortune lose their decorative effect, and if their treatment is not started in time, they may even die

A few words about the disease

On the leaves of roses attacked by phyllostictosis, numerous scattered rounded specks of dark brown appear, framed by wide rims of purple-brownish shades. As the harmful misfortune develops, the center of the damaged tissues acquires a characteristic ash-gray tint. At the same time, wide purple edges do not disappear anywhere.

Also, specks of grayish-white shades can form on the leaves. In the centers of such spots, the formation of point small fruit bodies of black color occurs - this is how the wintering stage of the pathogen fungus looks like. Infected leaves, turning yellow, fall off prematurely. Almost always, the pathogen remains in fallen leaves.

Phyllosticta rosae Desm is the causative agent of phyllostictosis. And the formation of grayish-white spots on the leaves of roses is due to the harmful activity of a fungus called Phyllosticta rosarum Pass. The infection can spread through the wind (from infected rose bushes to healthy ones), through water and through infected soil.

How to fight

On pink bushes affected by phyllostictosis, it is necessary to systematically remove drying leaves or parts of them affected by a harmful disease. Typically, the speckled areas of the leaves are carefully trimmed with a sharp knife. In this case, it is necessary to capture a small part of the surface not affected by the disease. At the end of this procedure, hands and the knife are thoroughly washed, and the knife is also wiped with alcohol. Fresh leaf cuts are abundantly sprinkled with activated carbon, crushed into powder. By the way, at the very beginning of the development of an unpleasant ailment, these measures are often more than enough. And as soon as the cuts on the leaves dry out a little, you can also treat them with special compounds.

It is recommended to treat diseased roses with such fungicidal preparations as "Strobi" (4 g of the product are dissolved in ten liters of water), "Abiga-Peak" (for five liters of water - 40-50 g) and "Vectra" (2 - 3 ml of this drug).

A good effect in the fight against phyllostictosis of rose leaves is given by alternating spraying with preparations containing triazole ("Skor", "Topaz") and mancoceb ("Ridomil Gold", "Profit"). Similar treatments are carried out in compliance with a weekly interval and no more than three times.

In order to get rid of phyllostictosis, a copper-soap solution can also be used. Prepare this composition immediately before use, combining 200 - 300 g of household or potash soap with ten liters of water, as well as copper sulfate (20 - 30 g). First, soap and copper sulfate are diluted separately in a small amount of hot water. Then, a solution of copper sulfate is poured into the soap solution, stirring it continuously, in a thin stream. If hard water is used to prepare the life-saving composition, so that the solution does not curdle, about 5 g of soda should be added to the water. The resulting mixture is sprayed with diseased plants.

And for the treatment to have a greater effect, it is necessary to provide the roses with the most comfortable conditions - access to fresh air, regular moderate watering and sufficient lighting. It is important to remember that excessive waterlogging is one of the main provocateurs of most fungal diseases. When watering, it is very important to pay attention to the water temperature - it should be identical to the ambient temperature or exceed it by several degrees.