Herbage yields and persistence of lucerne (medicago sativa L.) cultivars and the incidence of crown and root diseases

Abstract

Herbage yields and persistence of lucerne cultivars were measured over 4 years on a ‘winter-dry’ site and a ‘winter-wet’ site in northern Canterbury. Assessments of lucerne crown and root rotting diseases were made. Bacterial wilt, crown rot, verticillium wilt, and stagonospora root rot were present at both sites. Also, physoderma crown wart and lucerne stem nematode occurred at the ‘winterwet’ site. Crown rot was the most significant disease. No single cultivar was superior at both sites though ‘Wairau’ and ‘Saranac’ rariked moderately well at each. At the ‘winter-dry’ site where all cultivars persisted well, ‘Saranac’, ‘ATRA 55’, ‘Iroquois’, ‘Wairau’, ‘Vernal’, and ‘520’ were the most productive. At the ‘winter-wet’ site, ‘Washoe’ and ‘Lahontan’ were the most persistent cultivars and, in the final years, the highest yielding. Herbage yields of associated volunteer species were found to be inversely proportional to lucerne herbage yields and persistence. © 1982 Taylor & Francis Group, LLC.