Time to flowering in narrow-leafed lupin

Abstract

The relationship between flowering time and daylength and temperature is described for L. angustifolius using multiple linear regression. The main cultivar was Gungurru but cvv. Danja, Yorrel and the L. albus cv. Kiev Mutant were also studied. Regression analyses were performed on time to flowering observations for lupins grown with serial sowings at up to 12 sites over up to 5 years in Western Australia (there were 102 separate observations of time to flowering for Gungurru). Time to flowering in the L. angustifolius cultivars was best explained by a model incorporating terms for average temperature and daylength between sowing and flowering. Models of this form were not satisfactory for L. albus, probably because of vernalization requirements which the L. angustifolius cultivars do not have. Using data from the experiment with the widest range of sowings, 94.6% of the variation in time to flowering was explained by the above model and an additional 3.5% was explained by including an interaction term. The rate of progress through all stages of development to flowering, except for the period between appearance of the last leaf and flowering, was sensitive to temperature. The rate of leaf appearance responded to both temperature and daylength and the rate of progress through the period between appearance of the last leaf and flowering was sensitive only to daylength.