Performance of North American and Australian lucernes in the Queensland subtropics 2. Yield and plant survival in irrigated stands

Abstract

The yield and plant survival of 23 North American and 5 Australian lucerne lines were assessed at Biloela and Gatton, Queensland, under irrigation over a 40-month period. Total yields ranged from 49 to 72 t/ha at Biloela and from 14 to 47 t/ha at Gatton. The relative performances of lines were similar at each site. The highly winter non-dormant lines were the highest yielding, particularly HS Gen 3 Composite, Matador and CUF 10 1. Semi-dormant lines were generally more productive than nondormant and dormant lines, with Pioneer 581, Falkiner and DeKalb 167 the most productive. Multiple regression analyses showed lucerne yield at both sites to be highly correlated with relative winter dormancy and plant survival. At Gatton, population at establishment, winter dormancy and disease ratings for Phytophthora root rot and anthracnose all influenced survival of lucerne plants, whilst at Biloela establishment population was the only significant factor. The potential commercial impact of lines with reduced winter dormancy and improved resistance to root rot and anthracnose in irrigated stands in south-east Queensland is discussed.