KWS Maize - early and ultra early varieties

October 2016

Growers are increasingly seeking early varieties for forage maize production, but breeders may be close to reaching the end of their quest to satisfy this demand, due to the limitations of our climate, according to KWS product manager, John Burgess.

Maize breeders have responded to market demands and have developed a range of early-harvesting varieties which allow time to prepare land for autumn cropping and reduce the risk of soil structure damage, says Mr Burgess. While their initial search uncovered varieties which lacked the quality potential of more standard types, rapid genetic progress has produced new hybrids which can match, and in some cases out-perform, their later counterparts on quality.

“We already have ultra-earlies and earlies with high starch levels and MEs; Augustus KWS would be one example. It is an ultra-early with an FAO of 160 that can deliver 33.8% starch and average ME of 11.32 MJ/kg. Another feature of the new ultra-earlies is reliability; I can almost guarantee that certain varieties will mature, whatever the weather throws at us.

“However the UK climate prevents us from pursuing the early route much further. We simply do not have enough heat units over the season for plants to mature at a faster rate. Another point, and one that dairy cattle breeders will fully appreciate, is that selecting for one trait may come at the expense of another.

“At present, ultra-earlies will not yield as much dry matter tonnage as the later varieties, so if you are looking for bulk only, then they may not be for you. Despite Augustus being one of the best examples we have to offer, it is listed on the NIAB Forage Maize Descriptive List as having a 95% yield on all marginal sites. But depending on the farm situation, their advantages can more than make up for the small sacrifice in yield.”

Plant breeders are working hard to develop new ultra-earlies which retain the benefits achieved to date and push yields higher, he says. About 300 varieties arrive at the KWS maize testing site each year, with only a handful selected for further investigation. One of the reasons behind the advancement of genetic progress is the development of new technology.

“Our mobile laboratory, called the Kroq, is a small trailer which literally takes in plant samples as they are cut and can process the results within about 24 hours. The testing system closely mimics the standard NIAB method, so we have a very good idea of how the forthcoming List is likely to look, before it is even published.

“These technological advances may change our approach to the way that varieties are brought to market. Historically, farmers have waited for the List to come out to make their selection. This creates a time lag of about three or four years, between the point at which we identify a variety with good commercial potential, to its arrival on farm.

“In the not too distant future, it could become commonplace for farmers to be sowing varieties before they have made the official List, although it would obviously unwise to plant the entire acreage with a variety of this type.”

Ultra-earlies can achieve rapid grain-fill and this feature can catch growers unaware, says Mr Burgess.

“Varieties which fall into this category can move from the milk dough stage to hard ripe in a very short time frame; sometimes within as little as three or four days. This means crops should perhaps be inspected more frequently.

“They also tend to dry down more rapidly than varieties in other classes and this can lead to a shorter harvest window, in some seasons. This trait has been particularly relevant this year, when we have had a late spring and an early finish, which is very unusual. Crops over the previous few seasons have been very slow to reach the point of harvest. ”

Ultra-earlies have mainly found favour in the north and west of the country, but large-scale growers in the South are also finding them useful for spreading harvest dates and some are incorporating 10-15% into their portfolio, he adds. They can be cut, clamped and fed out between four to six weeks before the main crop is ready to break open, depending on the season.

This year’s maize silage should provide an ideal complement for the grass silage, which has seen variable results. Quality will have been greatly enhanced, if contractors have used the corn cracker on its highest settings.

“The combination of an ultra-early or early variety with high starch and a good growing season will a long way towards fulfilling the requirements for winter rations. But the grain must be fully broken down after cutting, to release its nutritional properties. Otherwise, there is a high risk that it will pass through the cow undigested.

“Contractors are under pressure and effective grain cracking will slow down the work rate, to some extent. But having waited a full year to harvest your ‘rocket fuel,’ paying attention to detail at this stage should prove well worthwhile.”

Maize Acreage Update

The UK maize acreage has consolidated into the hands of fewer growers, whose average acreage has increased, although the total number of producers growing the crop dipped slightly in 2016, compared with the previous year.