2 June 1995

A WELCOME TO THE GROWER-FRIENDLY LUPIN

Ex-lupin growers may never want to see or hear of the crop again. Think twice, says one expert – new types are a very different prospect. Robert Harris reports

COMBINING a soggy crop in the middle of November is nobodys idea of fun. But that was often the fate awaiting early UK lupin pioneers.

Not surprisingly, going to that amount of trouble to salvage all-too-common low yields soon saw growers dropping the crop from their plans.

But researchers have not been idle in the meantime. Now a different lupin, suited to UK conditions, has been developed. And further improvements are imminent, says George Milford, project leader at IACR-Rothamsted.

So confident is he of the crops future that he predicts at least 100,000ha (240,000 acres) will be grown in the UK by 2000. "Dont be put off by previous bad experience or what you once heard. Were dealing with a totally new crop, with a very different structure and performance."

Branches and flowers

The problem with the old type of lupin was that it kept producing branches and flowers as long as growing conditions remained favourable, says Mr Milford. That indeterminate growth habit is no problem in hot climates where drought and heat limit growth. But it is much more pronounced in cooler, wetter areas like the UK, and allows growth to continue into late autumn.

That starves and shades pods struggling to set seed, delaying ripening and cutting yield. "These types do well in southern Europe, often yielding 5t/ha. Here they struggle to make 1-2t and are very late to harvest, often November or December," explains Mr Milford.

The first breakthrough was the advent of autumn-sown lupins, he says. These were bred in the late 1980s to boost yields in the milder regions of France. "We hoped that by sowing these in the autumn we could get them to flower and ripen earlier here – but it didnt happen. They still grew indeterminately."

Plant structure key

Mr Milford suspected that rather than sowing date, plant structure was the key. He tested this by pruning trial plots back to the main stem and the first set of branches. Better pod set, quicker ripening and much higher yields resulted. He put this to the breeder, Christian Huyghe of the Institute Nationale du Recherche Agronomique, who managed to breed determinate genes into the plants, producing a plant like the pruned ones.

These are in their fifth year of tests at Rothamsted. "We want to be really sure this time round that the plants will behave as we expect them to. So far, theyve done everything we predicted – they grow fast, ripen early and yield well."

Harvest date has been brought forward to early September, and yields are much improved at 3.3-5t/ha (1.3-2t/acre). French experience backs these findings, he adds. "They have been better able to maintain yields in the cooler northern climates, and have brought forward the harvest date considerably."

Crop tested

Last year the crop was tested on 11 sites throughout the UK. Yields ranged from 3.5t/ha (1.4t/acre) at the Scottish Crop research Institute at Invergowrie, to 5t/ha at ADAS Bridgets, Hants. Further trials to test soil and climate suitability are being carried out this year, including Aberdeen and Belfast. "If we can get them to ripen there, theyll ripen anywhere."

Another 20 farm trials, each about 3ha (7.5 acres), are being run by Dalgety, which has acquired the rights to the two most promising varieties. These are sited in the midlands and the south.

Further improvements can be expected, says Mr Milford. Dwarf types will reduce lodging risk and allow a wider sowing window in the autumn. These will be sown in French national trials this autumn, and should be commercially available within two to three years here, he says.

Alkaline-tolerant types are also expected by the end of the decade. "At the moment lupins need acid soil – between pH 4.6 and 7. higher pH types could see the area double in a short time," predicts Mr Milford.

&#8226 Visitors to Cereals 95 will be able to compare new lupins with older types. Plots will demonstrate quicker growth – Mr Milford expects new types to be in flowerby the time of the event while the others are still vegetative. Pot-grown plants in pod will also demonstrate the structure of the new type.