Bot canker on pecan

摘要

Young pecan trees are a big investment and we hate to see them get weak, decline, or up and die. I've seen a lot of young tree die-back this year. While much of this has been related to cold damage, some trees are feeling the effects of a subtle problem that often goes unnoticed until it becomes severe.Botryosphaeria canker or "Bot canker" is caused by a fungus that can infect the tree through wounds like limb breakage, pruning sites or small cracks. The term "canker" is a general one referring to a dead area on the stem or trunk of the tree. The vascular tissue under the canker is dead. Cankers are common on a wide range of trees, typically occurring on trunks, older branches, or injured plant areas on smaller twigs. Cankers develop slowly over months or years when fungi invade the plant following injury or stress. They may be initiated by injuries (hail, mowers, insect feeding, etc.), environmental stress (cold, heat, scald, etc), chemicals or pathogens.