Dibotryon morbosum or Apiosporina morbosa is a plant pathogen, which is the causal agent of black knot. It affects the cherry, plum, apricot and chokecherry trees of North America. The disease produces rough, black areas that encircle and kill the infested parts, and provide habitat for insects. The most common treatments are pruning infected parts during the winter and spraying buds with a fungicide. Nearby wild plants with the disease are also destroyed.