18 January 2002

Know your varieties to make the most of promising lupins

By Marianne Curtis

AS Lupins become more popular with producers seeking an alternative protein source to soya, becoming aware of differences between varieties can help make the most of this promising crop.

Last year, trials were conducted around the UK by seed company Cebeco to gain more information about lupins, says its product development manager, Ray Starling.

"There is a lot of information around on lupins, but not all is relevant to livestock producers. Protein values of the crop, which producers need to know, are frequently left out."

Protein levels can vary considerably between and even within the same variety, says Mr Starling. "Three main species dominate in Europe – L albus, L angustifolius and L luteus. In L angustifolius varieties, protein averages 33%." Protein average for L luteus species is 42%, winter-sown L albus, 40% and spring-sown L albus, 37%."

In trials of Wodjil, at sites ranging from Cornwall in the south to Cleveland in the north, proteins ranged from 38.3% to 43.9%. "Low values can be due to inoculant being applied incorrectly at sowing, weeds or soil types."

Lupins do not grow well in strong, heavy clay soils and it is important to take soil type and variety into account when deciding upon seed rates, says Mr Starling. He is concerned there may have been insufficient UK trials to establish suitable agronomic practices for different varieties.

"Lupin varieties can be either non-branching or bush-like. Non-branching lupins require a higher seed rate than bush-like varieties to reduce competition."

Wodjil is non-branching and last years commercial trials showed an average yield of 2.53t/ha (1t/acre) with moistures ranging between 14% and 18%. Average protein content was 42% and oil, 7.5%, says Mr Starling. One livestock producers costings show harvested grain from a Wodjil crop at 42% protein worked out at 31p/kg protein, compared 36p/kg protein for soya (see table).

Using lupins for grain production rather than whole-crop is advisable, as phomopsis – a lupin stem fungus – can be toxic to sheep, warns Mr Starling. "Such toxicity has occurred in Australian flocks. Although there are signs that newer lupin varieties are more resistant to phomopsis than older ones, be cautious about using lupins for whole-crop until more is known."

With arable area aid being granted for lupins in Scotland, producers here should be particularly careful, he says. "Aid will provide a greater incentive for producers to grow lupins. But late senescence of crops in the north, combined with damp conditions, could make lupins more susceptible to phomopsis." &#42

More trials are needed to establish suitable agronomic practices for different lupin varieties, says Ray Starling.

&#8226 Protein content varies.

&#8226 Stem fungus dangers.

&#8226 Agronomy needs refinement.

£/ha

Arable area payments -247

Straw -31.13

Seed 100.43

Fertiliser 24

Spray 28.69

Crop establishement 97.5

Harvest and baling 91

Milling 10

Rent 247

Total cost 320.49

Yield 2.44t/ha, cost/t £131.34