Saprophitic and parasitic activities from differents solid inocula of KlamiC^®

Actividad saprofítica y parasítica de diferentes inóculos sólidos de KlamiC^®

Dear Sir: ]]> KlamiC^® is a bionematicide formulated with chlamydospores of the fungus Pochonia chlamydosporia var. catenulata (IMI SD 187), obtained by Solid State Fermentation (SEF) in Polipropilene Bags with filter. These spores are the inocula of preference for the establishment the fungus in soil, but it requires a high period of incubation, which joined to high concentrations for application, limits the economic feasibility of the product. Therefore, the saprophytic and parasitic activities of P. chlamydosporia var. catenulata (IMI SD 187) from others inoculum forms with smaller period of incubation in SEF has not been evaluated yet. Then, an experiment in greenhouse condition was carried out to compare different kinds of inocula. Colonization of the rizosphere from a five days inoculum (basically mycelium) was significantly high and from a 7 days inoculum (more biomass and conidia; less clamydospores) had no differences when compared with the standard inoculum of 21 days (principally chlamydospores). Root and soil colonization were satisfactory to 10³ CFU.g root^-1 and 10⁴ UFC.g soil ^-1, except for the inoculum of 10 days of incubation (mainly conidia) which reached the smallest colonization 10² and 10³ UFC.g^-1, respectively. For all kind of inoculums: endophytic colonization was 20-30%, egg masses were colonized in a range between 40-70% and egg parasitism was 20-40%. This result showed that other structures of the fungus (biomass and conidia), with smaller time of incubation in solid medium, have saprophytic and parasitic activities similar to the standard inocula of KlamiC^®. Furthermore, shelf-life, field survival for long time and feasibility of these inocula under production conditions should be evaluated.

L. Hidalgo-Díaz, Jersys Arévalo

Grupo Plagas Agrícolas. Protección de Plantas. Centro Nacional de Sanidad Agropecuaria (CENSA), Apartado 10, San José de las Lajas, Mayabeque, Cuba. E-mail: lhidalgo@censa.edu.cu. ]]>