Methods for Evaluating Birdsfoot Trefoil for Susceptibility to Foliar and Shoot Blight Caused by Rhizoctonia Spp.

Abstract

Production of birdsfoot trefoil (Lotus corniculatus L.) is limited in humid, temperate regions by foliar and shoot blight caused by Rhizoctonia species. The objective of this study was to develop methods for quantifying blight symptoms on 14 plant introductions and three cultivars of birdsfoot trefoil. Susceptibility was evaluated in the greenhouse on the basis of shoot lesion formation and blight of leaves and apical meristems. On the basis of these symptoms, no entry of this limited collection of birdsfoot trefoil was completely resistant to infection. However, 4 d after inoculation, shoot lesion length differed significantly among entries. Additionally, lesion lengths varied between experiments in relation to environmental conditions. In contrast to shoot lesion length, foliar blight and the time to blight of apical meristems did not vary significantly among entries in either experiment. Shoot lesion development limits foliage production and survival under field conditions and should be considered an important factor in further screening of birdsfoot trefoil for disease resistance.