The rediscovery of grey leaf spot (caused by Stemphylium spp.) in narrow-leafed lupins (Lupinus angustifolius L.) in Western Australia in 2007 and identification of susceptible cultivars raised concern about potential impact of this disease in crop production. This study assessed potential yield loss in narrow-leafed lupins and the importance of inoculum source in the development of the disease. In two field experiments, no disease was observed in the resistant cultivar Mandelup, but disease progress was rapid in susceptible genotypes Unicrop and WALAN2333 and resulted in up to 64% yield loss. Disease progress and yield loss were greater in plots inoculated with infested trash than in those with spray-only inoculum. Release of Stemphylium spores from infested trash was monitored during the lupin-growing period by using spore traps and seedling trap plants. Conidia were released continuously throughout the growing period and significant (P < 0.01) correlation was found between the number of conidia captured and the frequency of rain, and between disease severity on trap plants and aerial concentration of conidia. The results confirm that grey leaf spot can severely reduce yield of susceptible narrow-leafed lupin cultivars and that removal or avoidance of previous season trash will be important in preventing spread of the disease.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 67 • No. 1