Walnut orchard with many ulcers on the trunks of trees

Walnut orchard with many ulcers on the trunks of trees at various distances from the ground. It is assumed that these ulcers were caused by infestation of the fungus Fusarium sp. after frost which caused raptures on the bark of young tree trunks. Plant’s effort to react by creating healing tissue around the wounds is evident. The exact cause needs further investigation and diagnosis during the vegetative period.