Without taking effective measures to combat scab, you can lose the crop and lose seedlings. This fungal infection affects absolutely all parts of the plant: leaves, fruits, and immature branches. Most prone to the disease are apple trees, pears, plums, as well as cherries and cherries. You can recognize the disease by the presence of characteristic spots on the foliage and deformation of the fruits.
What Does Scab Defeat Look Like: Description
Fruit tree scab is a fungal disease most common and dangerous in amateur gardens throughout the summer. In September, the danger is late autumn-winter varieties of apple trees, as secondary infection manifests itself. By hitting the fruits, leaves, and shoots of apple and pear, scab not only dramatically reduces the amount of yield but also affects its quality.
Below you can find a photo and description of the scab affecting fruit trees.
Fruits, especially with early infection, are often ugly and crack. Sick fruits are not stored, they quickly fade, they are easier to colonize with rot pathogens. Affected scab ovaries or stalks usually fall off.
Severe damage to the leaves of the scab leads to premature fall of leaves, which negatively affects both the loading of fruits and the general condition of the tree: growth decreases, buds go unprepared for winter, winter hardiness decreases.
On the leaves, the scab appears in the form of rounded spots of the olive color, covered with a slightly velvety coating. The size of the spots and their number can be different and depend on the susceptibility of the variety, weather conditions and leafage. When infected in the spring and in the first half of summer, spots are usually large (8-10 and even 13 mm in diameter), with a later and especially autumn period of infection, they are much smaller (2-3 mm).
If you do not use effective means to combat scab, the disease will damage the fruits. On them, the disease also manifests itself in the form of dark, almost black (or gray-black), sharply defined spots. At the edges of the spots, you can see a light rim. When the fetus grows, the affected tissue cracks. In the case of early infection, the fruits acquire an ugly, one-sided shape.
And what does the scab look like on tree trunks and branches? On the shoots, the scab appears first in the form of small swellings on the cortex, which burst over time. The bark is covered with small cracks and peels. Shoots grow poorly and often die off.
How to Deal with the Scab That Hit Fruit Trees
How to deal with a scab on fruit trees so as not to lose crops and prevent infection of other crops?
The main method of combating scab is to protect trees from spring infection and to contain the spread of the disease in the summer. For spraying throughout the season, use fungicides (Skor, Rayek, Chorus, Abiga-Peak), which should be alternated during repeated treatments.
When growing pears, prefer scab resistant varieties in your area.
Cherries and cherries are affected by scab. Velvety olive-brown spots appear on the fruits, covered with sporulation of the pathogen. Green fruits are poorly developed, wrinkled and dry. On mature fruits, small cracks sometimes form. Velvety roundish, often merging dark olive or brownish brown spots appear on the leaves in wet weather.