Root-knot nematode (Meloidogyne javanica) did not affect banana production in subtropical Australia

Abstract

Root-knot nematodes (Meloidogyne spp.) are thought to reduce growth and yield of banana in the subtropics and that in vitro-propagated plants are more intolerant than those established conventionally from sucker or corm pieces. This paper describes a field trial in subtropical Queensland, Australia, on a site which was naturally infested with spiral nematode (Helicotylenchus dihystera) and inoculated with M. javanica, but where there were no Radopholus similis, Pratylenchus goodeyi or P. coffeae. It compared the effects of M. javanica and H. dihystera on in vitro-propagated and conventionally-grown plants. Inoculation with M. javanica did not affect any parameter of plant growth or yield in the plant crop of either planting type or in the first ratoon of in vitro-propagated plants. However, in the first ratoon crop of plants established as suckers, inoculation with M. javanica reduced numbers of fingers and hands per bunch but did not affect bunch weight. There was no correlation between plant growth or yield and numbers of M. javanica in either planting type in either plant or first ratoon crop, with 0-43 736 M. javanica/100 g root and 0-7940/200 g soil. H. dihystera populations in roots (0-420/100 g) were negatively correlated with growth and yield of the first ratoon of plants established as suckers but positively correlated with growth and yield of plants established as in vitro-propagated plants.