New ranking on whole plant DM is misleading

3 October 1997

New ranking on whole plant DM is misleading

One maize seed supplier has

withdrawn its varieties from

NIABs new descriptive

lists which it believes are

misleading. The supplier is

now proposing an alternative

method of publishing

performance data.

Jonathan Riley reports

NIABs new protocol of ranking maize varieties on a whole plant dry matter basis could cause growers to overlook other important agronomy factors when buying seed.

Thats the opinion of Karl Sauter, international marketing manager for maize breeders KWS. Speaking at a KWS-organised maize demonstration day at Cobham, Surrey, he pointed out that 90% of modern maize varieties are capable of exceeding the target of 30% DM.

"Ranking varieties on this criterion alone is, therefore, largely meaningless," says Mr Sauter.

"However, growers using the new NIAB list could be influenced by the ranking system and they may only look at the varieties at the top of the list."

Using the KWS variety Loft as an example, Mr Sauter explains that with a DM of 34.8% this variety would be ranked at number 23 on NIABs new list.

"With a ranking this far down the order, growers will be reluctant to accept that Lofts yield, cob ripeness and standing power all exceed the variety positioned at number three on the list.

"Publicising this varietys performance advantage will cost us a considerable amount of time and money, despite the fact that yield, cob ripeness and standing power are factors of great value to UK maize growers," explains Mr Sauter.

Nigel Jones of Glos-based Huntseeds, which markets KWS varieties, believes the new ranking could be so damaging that hehad refused to allow NIAB topublish data on the companysvarieties.

Mr Jones believes that all stay green varieties – which he says are beneficial because of the high green yield relative to cob maturity – will also be penalised by the listing because of their lower whole plant dry matter percentage.

As an alternative, he proposes that maize varieties could be listed on a table under six columns – DM yield, harvest DM%, cob ripeness, standing power, early vigour and digestibility.

He explains that the variety Nancis would still be top of the harvest DM% and cob ripeness columns.

"But rather than publishing its other performance characteristics alongside, growers would have to look down the other columns to find its position.

"This would help the grower appreciate an individual maize varietys characteristics relative to other varieties available."

Mr Jones said that NIAB should publish data on starch content. "This is important because starch indicates the maturity of the cob, cob size, the proportion of the cob compared with the whole plant, and the likely feed value of the plant."

He suspects that the influence of regional climate on starch is the reason why NIAB cannot publish starch data in a single list.

"Perhaps the list could, therefore, be divided into regions – as is the practice in Germany – to give growers more accurate information on likely starch content," suggests Mr Jones.

After considering Mr Joness proposals, NIABs head of fodder and forage Jim McVittie, agrees that a maize performance table could be a valuable tool for maize growers.

"Our intention is to publish information in the most accurate and useful form for growers. And although I think the table method is more complicated than a list, it does present information in a useful way," says Dr McVittie.

"We will, therefore, present information in this format to Maize Growers Association members for feedback on its ease of use."

Publication of starch

In addition, Dr McVittie says that publication of starch contents will be a feature of future maize data, once information from regional trials becomes available. But he says that rather than publishing on a regional basis, NIAB is planning to divide information into two groups for marginal and the main growing areas.

"This is because growing conditions vary more by site than they do by region," adds Dr McVittie.


&#8226 Published in tables.

&#8226 Contain starch content figures.

&#8226 Divided into regions.

Nigel Jones of Huntseeds explains to growers at a Surrey open day why his company has withdrawn varieties from NIABs new descriptive list. Inset: Cob ripeness, yield and standing power are of great value to UK growers, says Karl Sauter.

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