First report of Meloidogyne hapla and M. javanica coinfection on Parthenium hysterophorus in Kenya.
Parthenium hysterophorus (Asteraceae) is an annual or short-lived perennial herbaceous noxious weed native to North and South America. Parthenium has spread in Kenya and has become a menace to agriculture. Stunted and wilted Parthenium plants with globular galled roots marked with profuse roots were observed in a field in Tigoni, Kiambu County (average, 15.3°C; Koeppen-Geiger Climate Classification Cfb). Nematodes were extracted from root zone soil using the Baermann tray, and population densities of infective second-stage juveniles ranged from 300 to 980 individuals per 100 cm3 of soil. Mature females and their corresponding egg masses were handpicked from a single infected plant root. The posterior part of 20 adult Meloidogyne females was used for morphological analysis and the respective anterior part stored in ethanol for molecular analysis. The results revealed the presence of two Meloidogyne species, namely M. hapla and M. javanica. This is thought to be the first report of coinfection by M. hapla and M. javanica on Parthenium. M. hapla can infect Parthenium and facilitates infection by M. javanica.