Effect of the clover cyst nematode de Heterodera trifolii Goffart, on the vegetative development of two white clover cultivars

Abstract

As a means of evaluating the root nematode Heterodera trifolii G. performance on the vegetative growth of white clover (Trifolium repens L.), nine different inoculation densities, consisting of eggs and second juveniles stages, were assayed on 500 g soil pots containing clover seedlings of" Huia" and "Kopu" cultivars, under glasshouse conditions. Clover samples were uprooted for evaluation during the second and fourth month after the root nematode inoculation. Data estimating growth of white clover were taken as follow: total dry root weight and total root length, Rhizobium trifolii Dangeard nodule number. Foliage and stem yield were evaluated as total dry weight, leaf and stolons number. After statistical analysis of variance, the above estimates, under the environmental and soil conditions of the experiment, had no significant difference on the foliage yield of white clover regarding the nematode infecting treatments. Differences on the average root length and nodule number of R. trifolii were detected, associated to H. trifolii under different infective densities.