Most frequent strawberry diseases:
Strawberry noble rot
This fungus attacks, most of all, fruits and flowers. The flowers attacked turn brown and wither and rotting spots appear on the fruits. A grey, dusty layer of conidia develops in the place attacked. The development of the disease is favoured by humid and warm weather.
Strawberry common leaf spot
The initial symptoms are small, brown spots which, as they grow, turn grey white and are encircled by a red and brown border. They appear mainly on leaves and calyx sepals, which wither when strongly attacked. Sometimes, especially under cover, the symptoms may also appear on fruits (dry, small spots around the seeds attacked).
Strawberry leaf scorch
Its symptoms – in the form of numerous small, brown spots – appear, most of all, on leaves and calyx sepals. The symptoms are first seen on older leaves. The leaves attacked turn yellow and red and quickly wither.
Strawberry Verticillium wilt: The symptoms appear most frequently on annual plants. Initially, the oldest, outer leaves wilt and die, followed by the whole plant. The mass death of plants is usually observed after a susceptible strawberry variety is planted in a strongly infected field (sites on which vegetables, potatoes or strawberries have been previously cultivated). The fungus attacks roots, from where it grows into the crown and petioles, which results in a dry, well visible necrosis of their base.
Strawberry powdery mildew
It creates a white, flour-like layer that appears most prominently on the lower side of leaves, which roll upwards in a distinct manner into a boat-like shape. The layer of mycelium and conidia may also cover other above-ground organs of the plant. Strongly attacked leaves experience the formation of extensive necroses and, sometimes, red and brown spots, well visible on the upper side of a leaf. Mildew appears with particular frequency in plants cultivated under cover and on cuttings on mother plantations.
Strawberry Colletotrichum crown rot
This fungus attacks all of the above-ground organs of the plant. The disease has been observed to occur with a much greater frequency during hot and humid summers. On a plant attacked dry, dark brown necroses are formed, on which (in humid conditions) light pink concentrations of conidia are visible. An attack on the strawberry crown, on which a dry, light brown rot develops, results in a rapid death of the plants.