White lupine (Lupinus albus L.), also referred to as lupin or sweet lupine, grows as a grain and winter cover crop in the United States and southern Canada. The cool-season legume produces seeds high in protein that work perfectly for feeding livestock and for use as a specialty food item.
Lupine cultivation likely started in Egypt and the Mediterranean region more than 2,000 years ago. Because the seeds contain high levels of alkaloids, they went through a time-consuming soaking process to remove the bitter tasting alkaloids. In the 1920's, German plant breeders produced the first crops of sweet lupine. Sweet lupine requires no processing to make it palatable for livestock or humans, and it quickly became a foraging and grain crop in the USSR, Poland, Germany and the Mediterranean. Australia grows and exports the crop to European markets.
Lupine grows up to more than 3 feet in height with five to seven leaflets on each stem. The annual plant produces blue, white or pink flowers. Numerous seedpods form along the main stem, with each pod containing three to seven white seeds that reach about 1/2 inch in length. Most lupine planted in April is ready for harvest in August.
Lupine grows in slightly acidic, well-drained soil. The plants do not grow in soils with high clay content. They also experience more diseases when planted in poorly drained soil. Seeds should be planted in mid-April once freezing temperatures begin moderating. Plant the seeds from 3/4 inch to 1 3/4 inches deep; planting seeds any deeper often results in destructive seedling diseases.
Weeds often mingle with lupine, making it necessary to put an effective weed control program into effect. Early planting gives lupine a jump-start on weeds, but once the weeds start growing, it's time to apply herbicides. In smaller plots, weeds may be removed by hand.
The high protein and low oil content in sweet white lupine makes it good livestock feed for turkeys, calves, lambs, pigs and dairy cattle. In the United States, lupine is used for specialty flours and pastas as well as an additive to breads and cereals. Dietary fiber is made from the hulls of lupine. Snacks made of lupine seeds preserved in brine are sold in stores in Portugal and Egypt.
Pests and Diseases
A variety of pests attack lupine, including the corn seed maggot, potato leaf hopper and tarnished plant bug. All of these pests reduce the lupine yield. Fields attacked by the leaf hopper and tarnished plant bug often result in the plants not producing any seedpods. Chemical insecticides may help eliminate these problems. Several diseases such as root rot caused by several fungi also cause reduced yields. Unfortunately, the only way to fight these diseases requires not planting in areas with excessive soil moisture.