Scab, avoiding the disease

Partager

0

Often called apple scab, this fungus is responsible for important damage to this fruit tree, but also to plum trees and pear trees.

As it forms brown spots on fruits and leaves of trees, scab can lead to their growth clearly slowing down.

You’ll also observe that fruits are malformed, and even start to rot.

Follow the steps listed here, and your harvest will be protected and effectively guarded against scab.

Conditions that lead to scab appearing

Like all fungal diseases, moisture is the most relevant appearance factor. When in conjunction with heat, the risk of seeing scab colonize your fruit trees is even higher.

It is often at the end of spring that this fungus appears, and it will develop during the entire fruit formation phase.

But sometimes scab appears only in fall when moisture is very present, especially since nights grow longer.

• Wounded trees are much more vulnerable to fungus attacks.

Effective treatments against scab

Preventive care is the best solution

• In fall, it is critical to pick up and burn all the leaves.
  Also mow around the tree once leaves have fallen to speed their breakdown.
  Pick fallen fruits up regularly, so that they don’t stay on the ground.
• Provide compost at the foot of the trees in fall.
• Spray fungicide based on a solution of Bordeaux mixture in fall and again at the beginning of spring.
  In fall, once leaves have fallen
  In spring, renew the treatment 2 to 3 times depending on rainfall.
  Indeed, treatment must be reapplied after a rainy span of time.

There isn’t really any curative treatment

• Removing infested leaves, and burning them while renewing the bordeaux mixture-based fungicide treatment is about the only thing to do.
• Good to know: the scab disease from one species, say apple, won’t infect trees from other species, like pear.

Note that the fungus overwinters on leaves that have fallen from the tree when diseased.

In spring, the ascospores, which are how this fungus reproduces, are ejected in the air during rainy days and reach the trees born by the wind.

That is why it is critical in fall to pick up and burn all the leaves of your apple trees, pear trees and plum trees.