Silver leaf occurs mainly on apples and stone fruit in all growing regions but is particularly common in areas that experience damp, humid conditions. Infected trees will develop a silvery sheen which is caused by light shining through leaf cells that are damaged by toxins produced by the fungus.

Below is an article from Northwest Cherry Growers, Yakima, WA about a virus of another kind—one that potentially can have a huge impact on cherry production.

As mentioned last issue, some hints on how to improve the crop disease situation are presented here.

Alternaria leaf blotch is characterised by irregular red–brown coloured lesions on the leaves. The lesions might expand under favourable conditions, followed by yellowing of the leaves and then defoliation of the trees.

Just when your cherry patch was looking magnificent, you turn your back and suddenly those healthy green leaves are not looking so good—they are full of holes, or looking a bit tattered.Shot hole, latent infections of bacterial gummosis and necrotic ringspot virus are three diseases that come to mind.

Summer trunk canker is more common during prolonged wet, windy spring and summer seasons on soils that are poorly drained.

The incidence of brown rot and blossom blight is related to temperature and duration of wetness.

Peach leaf curl is favoured by a cool and wet spring around budswell followed by warm, humid conditions, which bring about rapid growth.

While bacterial spot is more common on susceptible varieties grown in coastal areas, it is also becoming a problem in inland production areas.

Wet conditions in late winter to early spring can activate shot hole spores that have remained dormant in bud scales and twig lesions during the previous season.

Organic Crop Protectants is thrilled to reveal their very latest innovation in plant protection, an organically certified solution for a range of fungal problems. Ecocarb PLUS is a new dual action fungicide combining the curative powers of potassium bicarbonate with the protective and systemic barrier properties of potassium silicate.

Powdery mildew outbreaks are most likely to occur in spring and early summer and again in autumn if new growth occurs. Rust is favoured by warm weather with periods of rain and heavy dews.