Thread blight disease of tea [Camellia sinensis (L.) O. Kuntze] caused by Marasmius pulcher (Berk & Br.) Petch in South Western Nigeria

Abstract

The causal organism(s), and percentage infection of thread blight disease observed on some tea stands established in 1985 at the Cocoa Research Institute of Nigeria (CRIN), Ibadan, experimental plot was investigated for a period of one year (12 months). For the first months, the percentage infection ranges between 41.4% and 47.9%.  Out of three fungi isolates (Botryodiplodia theobromae, Fusarium sp. and Marasmius pulcher) only M. pulcher produced the characteristic symptom observed in the field.  The fungal hyphae infect through the stomata pores that were found only on the abaxial surfaces of the leaves.  Clone 35 was found to be most susceptible followed by clones 143 and 318 while the least infection was recorded in clone 236.  Pruning as a cultural control method proved effective by reducing the percentage infection by 100% in the first 3 months.  However, re-infection of 5.4 and 5.9% were recorded in the 4^th and 5^th months respectively.