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GRAANGIDS
2017
GRAIN GUIDE
Estimating yield in a nutshell
Dryland:
Irrigation:
Ears or stalks per m
2
x seeds per ear
3 500
= t/ha
Ears or stalks per m
2
x seeds per ear
3 000
= t/ha
Research on the methods for determining accurate hail damage is conducted and refined
continuously by financial institutions. New fields are continuously studied and existing procedures
are tested and amended to keep pace with inter alia new cultivars and changing farming
techniques. This research is never regarded as completed.
One area that is studied in depth is the determination of crop yields or crop estimates.
Certain formulae are developed and adjusted, but a thorough knowledge of, among other
things, the farming branch and region remains important in determining a crop yield.
The following information should be used only as guidelines. However, it can be useful when
producers want to estimate the potential crop yield. Keep in mind that there are many variables
that can affect the accuracy of a crop or yield estimate. The closer you come to harvest time,
the more accurate are the determinations that can be made, because the chance is smaller of
major variables occurring. One of the most critical factors is the kernel mass. It not only varies
considerably from one season to the next, but also within one season. Even after the crop is
ready for harvest, factors like ear rot and other pathogens can affect the kernel mass.
The guidelines are as follows:
Wheat
With wheat a good average seed count is approximately:
Dryland:
3 500 seeds/100 g.
Irrigation:
3 000 seeds/100 g.
Two general practices, sowing and planting, are described separately to determine yields.
1.1 Sowing or planting wheat in very narrow rows
1.1.1 Firstly, the number of ears or stalks per square metre (m²) is determined.
1.1.2 The average number of seeds per ear is determined by counting the seeds in a sample
of wheat ears, including small and big ears in proportion. If the seeds cannot yet be
counted, a good average count for the cultivar concerned can be used.
1.1.3 The following formula can be used to calculate the yield where wheat was sown:
1.2 Wheat planted in distinguishable rows
1.2.1
Determine the row width as follows: The distance over ten row spaces is measured, in
other words from row one to row eleven, and the distance thus obtained is divided by
ten to determine the row width.
EXAMPLE
Distance over ten row spaces = 3,5 m
Row width is 3,5 m
10
= 0,35 m
Continued on p. 26
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