Slow wilt: Another form of Marchitez in oil palm associated with trypanosomatids in Peru

Another form of Marchitez manifestation affecting oil palm (Elaeis guineensis) has been observed since 2002 in the Alto Huallaga area from Peru. Externally, the disease appears as chlorosis, drying and breaking of the lower leaves, rot in fruit bunches, accumulation and rot of spears. Internally, the meristem presents brown lesions with a yellowish halo around its base. A high proportion (94%) of affected plants showed trypanosomatids in their roots. After follow up asymptomatic plants for 22 months, 85% develop symptoms of slow wilt. After the appearing of the symptoms the affected plants die between 5 and 8 months. Lincus spurcus population present in affected plants was evaluated and 44% were positive for trypanosomatids. In addition, trypanosomatids were observed in wild plants such as Acalypha cuneata, Urera caracasana, Trema micrantha, Cecropia spp., present in areas with incidence of the disease. The chlorosis, the long period of incubation and the time evolution of the disease are different in comparison with sudden wilt, suggesting a new disease manifestation affecting oil palms. The presence of Lincus positive to trypanosomatids leads us to propose an association of these parasites with slow wilt as reported for sudden wilt.