15 September 2000

Changes welcome but dont go far enough

By Jessica Buss

CHANGES to this years NIAB Descriptive List for maize varieties 2001 have been welcomed by most breeders.

But Pioneer plans to continue testing varieties under its own scheme, saying the changes dont go far enough.

Speaking at the National Forage Maize Day at CEDAR last week, Advanta, Grainseed and Nickerson spoke in support of the move, which splits the list into three sections, providing five separate lists. Starch content for tested varieties is also included in the list for the first time.

The first list still details medium-early varieties, but the previous early variety list is now split into those for favourable dry matter potential situations and those for marginal and mainstream DM potential situations.

The list for favourable sites takes data from trials grown in the south, south-east and East Anglia, excluding some trial sites in the south-west. NIABs Jim McVittie said it would suit growers without a long enough growing season for early varieties who wanted the highest possible yield from an early harvest date. This list is further split into first and second choice varieties on relative DM yield.

Early varieties for marginal and mainstream DM potential sites are collated using data from all trial sites except those used in the favourable site list. But this list is ranked in dry matter % order at harvest. It is again split into first- and second-choice varieties.

Dr McVittie said yields increased going down the list, so he recommended growers to select as late a variety as they feel will comfortably achieve the minimum dry matter required on the field where it will be grown. He advised taking into account the altitude, attitude, exposure and soil type.

Grainseeds Neil Groom said his company was committed to sticking with the NIAB lists. Splitting data from NIABs eight trial sites into two groupings would allow growers to use data from farms in their own area.

Julie Graham from Advanta also welcomed the list improvements. "It makes the early list more complicated and means no variety is absolutely right," she said, "but producers will have more information and a better guide to make their decision. It shows some varieties will perform well on marginal sites compared with their average performance on previous lists."

Peter Schofield of Nickerson said changes to the descriptive lists were an improvement. For the past two years, his company has argued for a dry matter yield ranking rather than a maturity ranking.

"I am pleased that the importance of maximising output per hectare on the best maize sites has been recognised," he said. "The main aim of growing maize is to grow as much as you can."

However, Pioneer Hi-Breds Simon Preece said his firm would continue to run its own, alternative trial sites in local areas, as it had for the past 10 years.

On the 23-30 sites, it compares its varieties with those of other breeders under its Pioneer Accurate Crop Testing System (PACTS). This takes into account suitability for local conditions, which Mr Preece said was vital for growers.

"Its more important to consider whats happening locally than an average of all regions. NIAB has attempted to improve the list, but it has a limited number of trial sites because of cost. Other breeders are not prepared to pay money to establish those sites as maize is a small crop compared with wheat.

"We still have no plans to join the NIAB scheme. We believe there is still a significant flaw in the way it is compiled." &#42

MAIZE LISTS

&#8226 Split for early-maturing varieties.

&#8226 Dry matter ranking.

&#8226 Starch content added.

More maize means more milk. Peter Schofield of Nickerson welcomes the changes made to the Descriptive Lists for forage maize.