Influencing & evaluating maize crop performance

The single biggest factor influencing the success of the maize crop is the weather. Rainfall, temperature and
hours of sunlight can all have a significant impact on crop maturity, DM yield and feed value. Of course, the
weather is completely out of our control, but there are many other factors which we are able to influence
and we should give these careful consideration!

Choosing the correct site has a surprisingly large impact on the performance of the crop. Maize does not
like wet feet so ideally choose lighter, free draining land, which is less likely to have compaction issues.
A south-facing aspect is preferred to maximise sunlight hours and heat units for cob development. An
exposed site not only suffers from the cooling effects of wind chill, but crops/varieties with weak stems or
poor anchorage are also at greater risk from lodging/brackling.

Rapid establishment is important for a good crop, this can be achieved if there is adequate moisture,
a good seed bed, sufficient temperature and adequate nutrition. Maize has the potential to produce a
huge yield of forage over a very short period of growth, and to do this the plant must be fed properly, any
shortage will restrict early growth and final yield.

Using a robust and tailored crop protection plan will ensure your maize crop is reaching its full potential.
From establishment, to weed and disease control, a full agronomic package will help to achieve high yields
and a better quality forage.

Choosing the right variety will maximise the value of your maize crop. Look at selecting early varieties which
combine a high DM yield and a high starch yield with exceptional plant digestibility to produce the highest
ME yield (MJ/ha).

Until recently the highest DM yields were associated with the later maturing varieties. However, advances
in breeding have produced early maturing varieties which display equivalent or better DM yields than much
later maturing lines. It becomes a much easier decision to grow early and very early varieties knowing there
will be no reduction in yield.

The later the maize crop is harvested, the more likely it is that the weather will cause problems. Also, if the
intention is to establish a following crop after harvest, the earlier this can be achieved the better the results
will be. Given the extremely high performance of some very early varieties such as Gema, they become an
obvious choice.

For many years increasing starch content was high on the list of plant breeders’ priorities, and for many
livestock producers this is the main reason forage maize is grown and included in the ration. Plant breeding
has moved forwards, and now in addition to selecting for high yields of highly digestible starch, it is
recognised that feed value can be significantly enhanced by breeding varieties with improved cell wall
digestibility, which in turn, improves total plant digestibility.

Metabolisable energy is displayed on the BSPB/NIAB descriptive list as MJ/kg of forage and also as MJ/
ha. The total yield of ME/ha is a function of the DM yield, the starch yield and the cell wall digestibility; as
such it provides a very useful indication of the value of a variety to a livestock enterprise. High yields of high
feed value forage when fed correctly can reduce the costs of production of meat and milk. A variety with
high ME yield per hectare, which is also early maturing, occupies a very favourable position on the BSPB/
NIAB list.