Planting date and seeding rate effects on white lupin yield in Alabama and Virginia

White lupin (Lupinus albus L.) has high potential as a winter grain (33 bu/acre), silage (15 tons/acre), wildlife, and cover crop in the southeastern USA. Management recommendations have to be developed for producers. We examined planting date and seeding rate effects on grain and biomass yield in winter-type white lupin. From 1991 to 1993, seeds were sown in north Alabama on a Wynnville fine sandy loam (fine-loamy, siliceous, thermic, Glossic Fragiudult), in central Alabama on a Norfolk sandy loam (fine-loamy, kaolinitic, thermic, Typic Kandiudult), and in south Alabama on a Lucedale fine sandy loam (fine-loamy, siliceous, thermic, Rhodic Paleudult). In 1994 and 1995, a study was sown in north Virginia on a Davidson silty clay (clayey, kaolintic, thermic, Rhodic Kandiudult). Treatments were three planting dates, three seeding rates (35 000, 70 000, and 105 000 seeds/acre) and two to five cultivars in Alabama. In Virginia, one or two cultivars were sown on three planting dates at 70 000 seeds/acre. Grain yield in 1995 in north Virginia averaged 60 bu/acre while the Alabama locations were less than 30 bu/acre. These differences are due to the more moderate, maritime climate in north Virginia. The second planting date and middle seeding rate produced acceptable grain yield across environments; we advise higher seeding rates for delayed planting. The highest biomass yields were achieved at earlier planting dates and the highest seeding rate. Based on these recommendations, producers should obtain acceptable grain, silage, wildlife, and cover crop yields.