Maize! Variety Consistency Is The Key To Full Clamps and Quality Maize

But after a disappointing harvest for many, growers are being advised to grow varieties that are not just early, but which are consistent year in year out over a range of contrasting seasons.

This means checking all the available data, sticking with what works well on their own farms and not necessarily being talked into taking the latest table-topping early type.

Speaking at a maize outlook press conference, CPB-Twyford forage manager, Julie Goult said that basing decisions on just one set of trials and one season is misleading.

She pointed out that in any trial situation, some varieties are harvested too early and others when they have gone too far. As a result, NIAB maturity class measurements don’t always hold true on farm.

“This is purely a function of lack of core trials funding meaning that NIAB only has a trials matrix of 8 sites,” she points out.

“In addition, NIAB can no longer look at cob ripeness of cob:stover ratios, both of which are key characteristics when measuring maturity.

She pointed out that some very early maturing varieties, based on NIAB data alone, may simply be classed as such as a result of early senescence of the stover, while cobs may remain less mature. In contrast, other early types may have ripe cobs but a stay green nature to their leaves and stem.

While both different types of variety are lumped in the same maturity bracket, each one will behave differently in the clamp and provide different feed values in the cow. It is more important to have an indication of total plant performance.

Miss Goult highlighted the fact that certain Maturity Class 6 varieties were capable of giving similar higher DM yields to Class 8 types, but improved feed quality. This is pretty evident from visual inspection of trials, but not always borne out by the results.

“As a result, growers need to look at as many trials as possible – particularly those in their own regions – in order to get a true handle on likely performance,” she said.

In this respect she confirmed that CPB-Twyford’s policy of strip trialling its variety selections on arable farms would be expanded to maize growers this year.

“Working with regional maize specialists from distributor companies we will be establishing six farm sites to gain a better understanding of maize performance in 2007,” she said. “They will also look at the role of seed treatments and a number of other agronomic issues.”

Thomas Mallmann of KWS – which is currently number two to Advanta in terms of UK-wide maize sales – confirmed that the German breeding business would also continue to widely trial maize varieties in fully replicated trials at an additional 7 sites across the UK.

These also include detailed analysis of quality, providing a useful additional database for KWS varieties, especially when there are problems with NIAB sites.

“Whereas other companies normally invest 10% of turnover into R&D, we allocate 15% in breeding and research,” he said. “This includes one of the most comprehensive breeding programmes for NW Europe.”

Mr Mallmann pointed out that a key selection characteristic of KWS hybrids is their ability to produce early cobs on green stover. “85% of starch comes from the grain, so it is important to maximise cob fill by maintaining plant growth.

“By providing growers with yield stability through improved stress tolerance, we can improve consistency by maximising growth.

“Thus in a year like 2006, when drought in July caused some problems in other material, our varieties were generally better able to hold on and make the most of wetter, August conditions.”

Field Options managing director, Francis Dunne, supports this view. “It is important to iron out the peaks and troughs in the production cycle,” he said.

“While many will be swayed by a 2-3% yield improvement as illustrated on the NIAB Descriptive List, it is much more important that the variety can achieve a consistent performance and so maintain a good supply of forage in the clamp.”

Mr Dunne bases his variety selection on an increasingly wide range of trials data, including work in Denmark as well as Northern and Southern Ireland.

“Early grain development is particularly important in a cool wet season,” he says. “Slow leaf die-back means that the crop won’t go over the top and senesce too quickly.

“This type of plant can ensure high starches as well as impressive whole plant digestibility.” He points to the KWS variety Kaukas as one of the most consistent, stable high yielding, early varieties of this type.

While not top in the UK, it has produced the highest dry matter yields in Danish Farmers Union trials in 2005, with one of the highest starch contents.

Similarly in DARDNI trails in N Ireland last year, Kaukas produced DM yields of 121% and a starch content of 26% - well ahead of other types.

Mr Dunne points out that growers can further iron out inconsistent performances by mixing maize varieties in the field.

“By growing matched maize types in alternate drill widths, growers can combine two agronomically different varieties from the same maturity class to provide a stable performance and more uniform silage in the clamp.

“The key is to select varieties from the same earliness groups and similar physiology. Such an approach is also a good way of testing a new variety, minimising the effects of any poor performance,” he suggests.