A comparison of symptom-development by different isolates of Phellinus noxius: the causal agent of brown root disease of rubber

Brown root disease caused by the pathogen Phellinus noxius is an emerging condition in Sri Lankan rubber industry. The possibility of development variant isolates with more pathogenic forms can be considered as one factors influencing increased frequency its occurrence country during recent past especially certain parts country. study was conducted to evaluate variability symptom ability 24 noxius. A pot trial carried out artificially inoculating three months-old seedlings inoculated mixture rice bran and saw dust. Forty were each isolate, another forty kept controls without inoculation. Starting after two weeks inoculation, ten destructive samplings at intervals observe pathogenicity levels different isolates. Based on below-ground signs symptoms, a score given uprooted plant. Then those ranks subjected Kruskal–Wallis analysis subsequently Wilcoxon rank-sum test. variation observed among As all showed stabilized value half months cluster performed for mean values rank developed dendrogram that test separated into main clusters similarity level 0.8. It denotes studied population consists these results applied management strategies.