Seed quality of sweet white lupin (Lupinus albus) and management practice in eastern Canada

White lupin (Lupinus albus) has shown considerable yield potential as a spr ing-sown grain legume in eastern Canada and the northern USA. However, the effects of agronomic factors on seed protein and oil of white lupin cultiva rs have not been quantified under such short growing season conditions. The objective of this research was to determine appropriate management practic es for production of better quality sweet white lupin. A 2-year study was c onducted in eastern Canada to determine the responses of seed protein and o il in two large-seeded white lupin cultivars (Primorski and Ultra) to manag ement factors. The two lupin cultivars were factorially combined on two soi l types, with two planting dates and two row spacings. Of the 2 years, 1991 was more or less typical for the region, while 1992 was unusually cool and rainy. Both lupin protein and oil concentrations were not affected by the tested management factors over three of the 4 location years, except that t he early planting date deer-eased the protein concentration of seeds in pod s formed on the stem. The protein yield of seeds in pods formed on the bran ches was more sensitive to management factors in both sites in 1991. Total protein and oil yields of Ultra were higher than those of Primorski in the typical year (1991), but not in the atypically cool year (1992). On average , protein and oil yields were 59 and 93% higher, respectively, under the co oler climate conditions of 1992 than in 1991. The seed protein:lipid ratio in white lupin seeds was approximate to 4:1 and 3:1 in 1991 and 1992, respe ctively. In general, early planting in narrow rows resulted in the highest yields of both protein and oil. (C) 2000 Elsevier Science B.V. All rights r eserved.