15 August 1997

All change in NIABforage

maize lists…

By John Burns

FORAGE maize growers are promised more information on varieties than before with the publication of the new NIAB list on Sept 1.

NIABs recommended list for maize has been abandoned in favour of a descriptive list, but varieties will still be listed in descending order of whole plant dry matter content.

Explaining the changes, Co Durham farmer Gordon Tweddle, a Maize Growers Association representative on the NIAB maize trials committee, said the MGA – which contributed to the cost of variety trials – wanted more trials covering more areas of the UK.

"We wanted to improve the geographical spread and cover the marginal areas as well as high potential yield areas," he said. The only way to achieve that with the money available was to set up extra trial sites as well as the five run by NIAB.

Three new sites would be operated by a designated breeder who would be monitored by NIAB, and inspected regularly by the NIAB maize committee – made up of NIAB, MGA and BSPB members. The inclusion of trials operated by breeders on behalf of the maize committee forced the change to a descriptive list. NIABs constitution did not allow breeder trial results to be used in preparing recommended lists. But the extra trial sites would mean more representative testing, he said.

MGA members had access to results from individual sites and could judge varieties grown under their local conditions. More sites meant more members got local information.

"We feel we are now getting it right in terms of physical testing. The next step is to look at ways to improve presentation of data," said Mr Tweddle. Further changes to the way results were presented were being considered. "These will probably include information on starch potential. Now the difficulty is finding a reliable way of testing for starch across all samples."

Jim McVittie, head of forage variety testing at NIAB, said the new list would comprise two sections: Early varieties and medium/early varieties. And in each section there will be first choice and second choice varieties, ranked according to dry matter content.

Dr McVittie was convinced that for the time being, whole plant dry matter % was the correct criterion on which to list maize varieties. He could not list them on starch content because there was not yet enough information, and testing methods varied. His advice to farmers was to choose the latest maturing variety which would reach the desired whole-plant dry matter content under the individual farms conditions. He felt many maize growers were using varieties which were unnecessarily early.

Because he suspected the correct choice of variety might vary according to what percentage of the cows diet was to be provided as maize silage, he was currently seeking advice on this aspect from the Maize Growers Association.

MAIZE LIST CHANGES

&#8226 Descriptive not recommended.

&#8226 Includes extra three sites.

&#8226 Ranks on whole plant DM%.

Glos-based Huntseeds runs its own maize variety trials near Chepstow. It will publish results from these and the NIABtrials itself – but refuses to have the varieties included in NIABs descriptive lists. Sales manager Nigel Jones (inset) objects to listing varieties in order of whole plant DMcontent.