Diseases & pests

Shot hole disease

Wilsonomyces carpophilus

Shot hole disease is caused by the fungus Wilsonomyces carpophilus and attacks above all stone fruit such as cherry, plum, peach and apricot. Typical are round spots with a red brown margin on the leaves, out of which the dead tissue falls, leaving the perforated, shot riddled look of the foliage. In addition, sunken spots with gummosis appear on the shoots, along with corky spots on the fruits. Where the attack is severe the tree loses its leaves early and is weakened.

True powdery mildew

Erysiphales

You will see the true powdery mildew covering the upper leaf surfaces with a milky‑white coating that can be easily wiped off, unlike the false powdery mildew, which comes from below. It loves dry warm days with cool nights and especially weakens pumpkin family plants, causing the leaves to yellow and die.

Verticillium wilt

Verticillium dahliae

Verticillium wilt is a soil borne fungal disease that enters through the roots and blocks the plant's vascular tissue. Because water and nutrients can no longer get through, individual shoots or leaves wilt, often on one side only, and no longer recover overnight. Typical is a brown to greenish black discolouration in the wood, which you can see when you cut open an affected shoot. On maple and smoke bush a whole branch often dies back suddenly while the rest is still green. On tomato, aubergine, pepper and strawberry the plant struggles in summer heat and later collapses. The fungus forms resting bodies that survive ten years and more in the soil, which is why it keeps coming back on infected ground wherever susceptible crops are grown. The symptoms show above all in the warm summer, from June into October.

White mould (sclerotinia)

Sclerotinia sclerotiorum

White mould is caused by the fungus Sclerotinia sclerotiorum and attacks many vegetable crops, especially lettuces and beans. Typical is a cottony, white fungal growth at the base of the stem that develops into black, irregular resting bodies (sclerotia). Infected plants wilt suddenly even though the soil is moist, because the inside of the stem rots soft and watery. The sclerotia survive in the soil for years and germinate again in damp, cool weather.

White mould (Sclerotinia rot)

Sclerotinia sclerotiorum

White mould, also called Sclerotinia rot, is a fungal disease with a broad host range that attacks lettuce, beans and many other crops. A watery, soft rot with a cotton wool like white fungal coating develops at the base of the stem; inside it, black, hard resting bodies (sclerotia) form, which survive in the soil for years. Affected plants wilt suddenly and fall over.