Keep an open mind on maturity class
09 March 2009 | Mark Britton
Choosing a forage maize variety on maturity class alone could be a mistake if the British summer is a washout again.
The recent years of damp, dull summer weather have caused some maize crops to behave unexpectedly. The 2007 season was wet until a month before harvest, when maize crops benefited from some late summer sunshine. In 2008 the dreary weather returned, but this time stayed until harvest and beyond. We saw very different reactions from maize crops across these two years.
Unusual weather could affect maturity class
The most obvious change was in maturity classification, where some varieties jumped around by two or three classes. An example from National List trials was a variety being rated maturity class (MC) 9 in 2007 then changing to MC 6/7 in 2008: commercial maize crops exhibited similar behaviour.
Varieties can move from an early class 6 to a late 7 between sites, but moving two or more classes needs closer inspection. Examining the National List site data indicated that the trial result could have been an environment/variety effect, with the unusual weather causing the variety to mature earlier on high potential sites than on lower potential sites.
Changes in classification may have been exacerbated by a narrower range between maturity class dry-down rates. On one Hampshire maize trials site every variety turned very quickly in 2007, within a space of a week, significantly closing the difference between maturity classes. It was a completely unexpected reaction, never seen before.
Look for consistency in yield as well as maturity
If weather patterns remain unpredictable these variations need to be managed to maximise crop performance in field and as a feedstuff. One solution is to be a little less rigid in staying true to one maturity class and to really understand how maize performs across your farm. There could be an advantage in planting consistent, high yielding MC 6 variety like NK Bull rather than a lower-yielding MC 7.
Check out the local performance of varieties and understand how they grow across your area, looking for consistency in yield as well as maturity. Avenir’s dry matter yield has not varied by more than 2% in 11 years on the NIAB Descriptive List, despite the very different growing seasons experienced over this period. This stability has made Avenir a firm favourite throughout the UK.
