Summer drying injury

French disease name: Dessication estivale
Pathogen name: Siccitas aestiva Nature
Class: Température élevée

Distribution

Canada

Damage, symptoms and biology

When drought conditions affect the soil and high transpiration occurs owing to wind and heat conditions, trees undergo partial dehydration and exhibit symptoms linked to summer drought. The upper portions of the tree become dehydrated more rapidly, and this often permits the penetration of air into the sap conducting system. This results in an irreversible air bubble that stops the flow of sap in the affected vessel elements. This is referred to as a summer embolism. If the embolism is severe, the leaves will no longer be supplied with sap and they will wilt, dry out, turn brown and may drop prematurely. In some cases, young trees may succumb to the drought.