In vitro and in vivo synthetic fungicides control of Rigidoporus microporus on Para rubber in Nigeria

Rigidoporus microporus is a major threat to Hevea brasiliensis in the rubber growing regions of the world. In vitro synthetic fungicide sensitivity assays of Tridemorph, Benomyl and Bayfidan at seven different concentrations, and in vivo effectiveness of the three fungicides on R. microporus inoculated on rubber seedlings were evaluated. The three chemical fungicides used in this study were effective on R. microporus, with Tridemorph being the most effective. The minimum inhibitory concentration value for Bayfidan was between fungicide concentrations of 0.001µg/ml and 0.005µg/ml. Percentage of plant death and presence of rhizomorph recorded at two months after inoculation were higher than that recorded at the termination of five months experimental period after inoculation. Tridemorph treatment had the highest plant health both at two months and at five months after inoculation. Decline in plant death from the third months onward suggested a reduction in fungal activity of R. microporus. Tridemorph was most effective among the three fungicides tested as it exhibited higher mycelial percentage inhibition in the management of R. microporus in vitro and higher plant health of rubber seedlings in vivo.