Cereals processing technology

18 Cereals processing technology
without fungicides in trials throughout the country provides further information
on their yield and quality characteristics. Recommendation depends on their
average performance exceeding the mean performance of varieties already
recommended.
2.3 Crop establishment
Traditionally the UK wheat crop has been predominantly winter sown, while
barley was largely spring sown until the mid 1970s when the winter crop
increased in popularity through the introduction of high yielding feed varieties.
Spring barley varieties remain the dominant malting types. In England and
Wales winter oats are preferred, whereas in Scotland spring oats dominate.
The optimum sowing time for both winter wheat and barley is from mid
September to early October, although with the increase in farm size and the
reduction in full-time farm labour both wheat and barley are now sown earlier in
the autumn. Early sowing is beneficial in promoting good root and shoot systems
before the onset of winter, which in turn enables the crop to intercept a greater
proportion of available radiation during spring and summer, thereby establishing
a higher yield potential. To achieve this potential growers frequently incur
additional production costs, especially through increased use of herbicides and
fungicides.
Spring cereals are normally sown as soon as soil conditions allow from
February onwards, although spring varieties of wheat may be sown during the
period from the middle of November until January after harvesting sugar beet
and potatoes on light land. The yield potential of late sown spring wheat and
barley is generally inferior to crops sown before the end of March.
Soil conditions during seedbed preparation have a significant effect on crop
performance. Seedbeds have normally been produced by ploughing, followed by
a series of secondary cultivations to produce a satisfactory tilth. Whilst effective,
this method of crop establishment is both time consuming and expensive. Direct
drilling of winter cereals became popular in the 1970s as a cost effective system
of establishment, but the introduction of the straw burning ban in England and
Wales, coupled with an increase in grass weeds has made it less effective in
recent times. Minimum cultivation systems have become a popular method of
crop establishment on suitable soils in the absence of major grass weed
problems. Recent advances in machine design, combining cultivation and
drilling machinery behind a single power unit, have significantly increased the
ability of growers to sow large areas quickly and effectively. Reducing
establishment costs is now regarded as a major factor in containing fixed costs.
An important feature of all cereal plants is their ability to produce a large
number of shoots or tillers, although by harvest many of the tillers will have
died, leaving a main stem and one to three ear bearing tillers. The number of
tillers produced is often negatively correlated with plant density, while tiller
survival is strongly influenced by environmental and agronomic factors which,