Predictors of yield of Lupinus angustifolius (cv. Gungurru) seedlots from different sources in Western Australia

Abstract

The growth and yield of 97 seedlots of Gungurm narrow-leafed lupins (Lupinus angustifolius L.) from Western Australia were assessed to identify geographical source or nutritional and physical parameters in the seed that can be used to predict the yield potential of a seedlot. Seedlots were obtained from the 1990 harvest on farms in the south-western cropping region of Western Australia, with up to 7 seedlots from each of 14 crop variety recommendation areas. Each seed lot was assessed for seed size (mean 144 mg), germination percentage (mean 87%), cucumber mosaic virus seed infection (mean 0.11%), and several seed nutrients. Seedlots were sown at 100 kg/ha (without adjusting for germination or seed size) at 4 sites in Western Australia in 1991. Plant density, shoot dry weight (at 6 weeks), and grain yield varied significantly among seedlots, with average grain yield ranging from 951 to 1478 kg/ha (l.s.d. = 240 kg/ha at P = 0.05). Seed size influenced (P<0.001) stand density (r = -0.33) and shoot dry weight (r = 0.58) but not grain yield (r = 0.09, n.s.). No seed nutrient was more than weakly associated with grain yield, nor was there an association of seedlot yield with geographical source of seed. High germination percentage and low cucumber mosaic virus infection were the main predictors of high grain yield in this experiment, but accounted for only 40% of the yield variance among seedlots.