Effect of seeding practices, temperature and seed treatments on fusarium seedling blight of narrow-leaved lupin

Abstract

Chang, K. F., Hwang, S. F., Gossen, B. D., Strelkov, S. E., Turnbull, G. D. and Bing, D. J. 2011. Effect of seeding practices, temperature and seed treatments on fusarium seedling blight of narrow-leaved lupin. Can. J. Plant Sci. 91: 859–872. Narrow-leaved lupin (Lupinus angustifolius) has the potential to become an important pulse crop for the Canadian prairies because of its high protein content and adaptation to a short growing season. However, disease surveys conducted from 2003 to 2007 in Alberta revealed that the crop is vulnerable to seedling blight and root rot caused by Fusarium spp. In field trials, the incidence of seedling blight was reduced by the application of the seed treatment fungicides Apron Maxx RTA, Crown, and Vitaflo 280. Seeding in late May resulted in reduced seedling emergence compared with early or mid-May in some cases, but the results were not consistent. Yield was reduced in the late-sown crop. Seedling emergence was often higher from seed sown at a 2- to 5-cm depth compared with a 7- to 10-cm depth. Yield was lower at seeding rates of 150 seeds m−2 compared with 300 seeds m−2. Under controlled conditions, emergence was greatest in inoculated soils at 25/15°C (day/night). Optimum shoot growth occurred at this temperature and plants were stunted at both higher and lower temperatures. Root growth was greatest at 15/5°C in non-inoculated soils and declined with increasing temperature; root growth was lower, but less variable, among the temperatures in inoculated soils. Root rot severity rose and seed emergence declined with increasing concentration of Fusarium avenaceum inoculum. To successfully grow lupin crops, soils with low Fusarium concentrations must be chosen and the crop should be planted in areas where high temperatures are not common.