Virus Diseases of Taro (Colocasia esculenta) and Xanthosoma sp. in Papua New Guinea

An account is given of the early reports and distribution of possibly virus induced symptoms on taro in Papua New Guinea. Also given are records of large and small bacilliform virus particles and a flexuous rod-shaped particle, as determined by electron microscopy of plant sap. The large bacilliform particle occurred in 62.3% of the samples, whereas the small bacilliform particle was confirmed in only 18.9%; bacilliform particles occurred only ir, Colocasia esculenta. Flexuous rods, presumably of dasheen mosaic virus, were recorded in 10.2% of the determinations from C. esculenta and in 14.3% of those from Xanthosoma sp .. Names suggested for the bacilliform viruses are taro large bacilliform virus (TLBV) (*/*:*/*:U/*:5/Au, rhabdovirus group) and taro small bacilliform virus (TSBV) (*/*: */*:U/*:5/ c(Au)). The names of the diseases, host identity and chromosome numbers, occurence of vectors and control measures are discussed.