Most often there are such diseases of red currant: anthracnose, powdery American dew, septoriosis. Let us consider them in more detail.
This berry bush is most affected by the fungus pseudo pectora. The peak of this disease of red currant, called anthracnose, falls on the middle or end of the summer season. The disease is caused by a violation of the physiological functions of the plant, leading to a slowdown in its development and, as a result, a decrease in the crop in the coming year. From this disease of red currants, leaves are mostly affected, occasionally cuttings or berries. On the affected areas appear very small, with the size of one millimeter, brown spots, which subsequently turn black. With a strong defeat, the shrub reduces its growth by one-third, and the crop - by half.
The degree of disease of this garden culture by anthracnose depends not only on the weather, the grade and age of the plant, but also the contamination of the area on which the red currant grows. Diseases (photos of them usually depict practically naked plants) are expressed in the drying of leaves and their premature fall. Most often this can be observed with stagnation of moisture, as well as in wet and cool weather, as the spores of the fungus are spread by rainwater. It is necessary to struggle with anthracnose by spraying. The ideal medicine is a one-percent solution of the Bordeaux liquid.
The causative agent of such red currant disease as septoriosis is the organism Ribis Desm. On the leaves of garden culture, rounded or angular spots are formed, at first brown, and then white. On the edges of lesions, brown bands are formed. The leaves dry and fall off.
Agrotechnical and chemical measures to control septoriosis are the same as in anthracnose. Microorganism spheroteka morsuvė can cause a disease of red currant, called American powdery mildew. The disease covers not only the foliage of the garden bush, but also its petioles, shoots, buds and, of course, berries. First, the symptoms of the disease are observed on the apical shoots. The underside of their leaves along the veins in the lateral lobes is covered with a mealy white coating gradually turning into a dense felt coat with a brown color. The degree of defeat of the bush depends on the weather, varietal characteristics and infestation of the site. From this disease of red currant sharply decreases its winter hardiness. In addition, the leaves become ugly, twisted. The soft winter with the abundance of snow contributes to the spread of American powdery mildew, creating a greenhouse effect. With a dense planting from this red currant disease, almost all other berries, such as gooseberry or raspberry, can die.
Agrotechnicians recommend conducting periodic preventive maintenance of this disease, feeding up garden cultures with nitrogen fertilizers. Of chemicals for combating American dew, the most suitable solution is soda ash with the addition of soap. Sprinkle twice a day, ten days apart, about fifteen or twenty days before the harvest.
The fight against red currant disease should include preliminary prevention.