Apple replant disease

Replant disease is a widespread problem in areas that grow tree fruit and nuts, greatly impacting intensive apple production. It is characterized by reduced productivity in fields repeatedly planted to the same or closely related tree fruit or nut crops. It can also occur in tree fruit and nut nurseries. In apple orchards, the disease reduces productivity costing growers $70,000 to $150,000 an acre during the first four years of orchard production. It is also called by multiple names, such as soil sickness, soil exhaustion, replant disorder, and replant problem. Research suggests that harmful soil microorganisms are the main cause of replant disease; however, abiotic factors, including low soil fertility, residual herbicide activity, and degraded soil structure have also been linked to replant problems. In this factsheet we will describe replant symptoms, disease causing organisms, and management recommendations