Hartrot (fatal wilt) and Marchitez Sorpresiva (sudden wilt, lethal wilt))
Phytomonas spp.: Kingdom Protozoa, Phylum Euglenozoa
Cocos nucifera (hartrot/fatal wilt), Elaeis guineensis (Marchitez Sorpresiva/sudden wilt)
Brazil, Colombia, Costa Rica, Ecuador, French Guiana, Grenada, Guyana, Honduras, Nicaragua, Peru, Surinam, Trinidad & Tobago, Venezuela
Initial symptoms are observed on the oldest leaves in the canopy, with two or three leaves discoloring at the same time. The leaf tips of these leaves become chlorotic and then necrotic (Fig. 1), and this discoloration then progresses to the leaf base. This leaf discoloration continues up through the canopy. While the leaves remain attached to the trunk, they often break and form a skirt of leaves around the trunk (Fig. 2). Fruits either drop or rot prematurely. Inflorescences rot, and the palm ceases to flower. First order root tips begin to rot as the leaves discolor. When most of the leaves are brown, the spear leaf and apical meristem (bud) rot, but this is probably due to secondary microbial infections.
Lethal yellowing of Cocos nucifera and red ring of Cocos nucifera and Elaeis guineensis also cause similar symptoms, but the progression of symptoms and leaf discoloration pattern is usually different. Phytomonas pathogens that cause hartrot and Marchitez Sorpresiva can be observed with the aid of a light microscope by examining sap from inflorescences.
This disease is not normally observed until Cocos nucifera is 3 to 4 years old or Elaeis guineensis is 2 years old.
The protozoan is vectored by insects in the order Hemiptera.