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Why should you stop growing corn?
There is always a lot written about corn at this time of year. And rightly so, maize is the second largest crop after grass. After a cautious introduction by the 'Maiskern Beckum' in the sixties and seventies in the last century, things went fast in the decades that followed. Why should you stop growing corn?
Maize (starch) fits well next to grass (protein) in modern cattle rations. Maize can withstand drought better and, with about 350 litres, needs about half the water per kilogram of dry matter production than grass. In addition, for maize, based on the official Variety Lists, the dry matter yield per hectare is easily 6-8 tons higher. It is also a relatively simple and labour-intensive cultivation, and the nutrient requirement per kilogram of dry matter production is lower, making the footprint much more favorable. Due to a timely harvest of the modern maize varieties, the success rate of the catch crop, such as Fast Spring Rye, is much greater. Residual nitrogen is effectively captured. So no, there is no reason to stop growing corn!
Breeding plays a major role at KWS
Thanks to intensive breeding, maize varieties are getting better and earlier. Formerly in the sense that by selection for precociousness of the grain in particular, the certainty of harvesting a ripe crop is increasing even more. And better because compared to maize varieties that came on the market 15 years ago, the new varieties achieve 10-15% higher yields. The countries of the Benelux have the great advantage that they are centrally located in North-West Europe, a region with a large area of maize. It is therefore worthwhile to invest in genetic progress through breeding.
Starch Digestion
To say more about starch digestion - or rather the ratio of resistant/unresistant starch and thus differences in fermentation speed - we have to go back to the basics of maize breeding. In maize breeding we speak of Flint and Dent types or their crosses. Virtually all maize varieties in the Benelux and North-Western Europe are crosses between Flint and Dent. The reason for this lies in the synergy of Flint's better cold tolerance with Dent's higher yield potential. In other words, the aim is to get a maize variety ripe with certainty (cold tolerance, ripening, cob maturity, resistance), and that with the highest possible starch yield. In the current CGW evaluation systems (for recommendation on the Official Variety Lists in the Netherlands and Belgium), the two properties 'earlyness' and 'yield' are therefore determined and weighted according to their agricultural importance.
All Flint x Dent varieties contain 50% Flint, 50% Dent. The composition of the Flint and Dent pool differs per plant breeding company. However, the genetic variation for starch resistance within this Flint x Dent variety pool is limited. The property is also not evaluated in the low countries. There is therefore no comparative research into racial differences for the questioned trait. Statements in this regard cannot therefore be substantiated. There is, however, ongoing research within KWS into the evolution of starch and protein resistance based on the earliness of the tested variety, the time of harvest (ripening) and the silage time. The preliminary result of that research is that resistance is strongly determined by the cob maturity during silage harvest and the number of days after ensilage. In other words: with these 2 simple indicators it is possible to predict fairly accurately the evolution in resistance in a maize silage. In fact, this 'forecast' is already shown on the silage analysis forms of Eurofins Agro.
In the market, permanence is often equated with precocity. In principle, a late-ripening variety that can ripen well in the cob under favorable growth conditions can provide a similar starch resistance as a very early variety that was harvested at an earlier time at a comparable physiological ripening stage. In short, for the available genetics in our region, more can be achieved with the ripening/harvest time and silage time than with a choice of variety based on an undescribed and unproven varietal characteristic.
Future for Dent Hybrids
Flint x Dent varieties still give the highest achievable grain/starch yields in the agro-climatic region of the Benelux. That is, Flint x Dent strains are to this day more performing than the pure Dent x Dent hybrids. The annual results of the CGW and European maize surveys confirm this time and again. Diligent work is underway on Dent x Dent material, as Dent x Dent material is attributed an inherently higher yield potential. This effort has now been rewarded in the first Dent x Dent variety to be recommended on the Dutch CSAR Recommended Variety List 2021 (KWS Gustavius). This variety combines the positive qualities of 100% Dent maize, also known as horse tooth maize, with a better cold tolerance. Climate change provides even greater potential for these genetics. KWS continues to put in energy and invest heavily in 100% Dent breeding, resulting in varieties with an even higher yield potential, good drought tolerance and very good agricultural properties. Here, in addition to the permanent focus on Flint x Dent breeding for the northern part, lies the future for the rest of the Benelux!
Prevent rumen acidosis
Unresistant starch is 'unlocked' in the rumen, so that more energy from starch is available more quickly for rumen fermentation. But in the same way, the resistance of the resistant part of maize starch deteriorates with increasing silage time. And so the initial resistance depends on the ripening at harvest (both the ds content or the ripeness of the grain and the ds content of the residual plant). In other words: maize varieties that are known to ripen less early on the cob contain a relatively large amount of unstable and therefore relatively fast starch. Moisture in the silage allows the starch to be further digested and makes the silage even faster over time. An initially fast silage (just like unripe maize crops harvested, so with maize varieties with cobs maturing late) quickly becomes too fast. The silage therefore becomes increasingly unstable as the silage duration progresses. Less and less is being digested in the gut, and more and more in the rumen. With a greater starch breakdown in the rumen, there is an increased risk of lactic acid formation and thus rumen acidification. The negative consequences for a cow with rumen acidosis are significant and often permanent.
Choose maize with early maturing cobs
Precisely for the reasons described above, but also to strive for the highest possible balance, it is very important to choose maize with cobs that ripen on time in combination with the highest possible grain yield. Maize that ripens on time can really be harvested on time. This maize is often surprisingly early, which in practice sometimes leads to a delayed harvest and therefore high dry matter percentages. It is important to get there early.
What also needs attention is sufficient bruising of the grain. Whole grains are still too often found in the manure, which must of course be prevented as much as possible by allowing the grain conditioner of the chopper to do its job properly.
Maize varieties that have proven themselves in trials and in practice include PRIXDOR, PAPAGENO, MEGUSTO, GENIALIS AND CORAZON. Newcomer JOHANIIO also scores high. Compared to many other maize varieties, these quickly achieve a 200-250 euro extra yield per hectare. Stories that these varieties are only suitable as grain maize can be relegated to the realm of fables. Their prominent position on the various silage maize varieties lists in terms of nutritional value (VEM/kg ds and starch) show just the opposite. For example, a maize crop such as GENIALIS with the aim of threshing it for the grain is the same GENIALIS that is harvested on another plot as silage maize. There are those who lead you to believe otherwise, but it is so obvious!
When harvested at the right time, the grain yield is dominant in the silo maize trials, which is reflected in high dry matter and feed value yields. In addition, the level of the VEM and the starch index is also a good indicator of the quality of the variety in question.
Learn more
Would you like more information about KWS, the cultivation of maize and about the maize varieties of KWS, please contact contact on with your regional KWS advisor. They are happy to talk to you.
