Agriculture Reference
In-Depth Information
9.7.5 Take-all
Forecasting the risk from take-all (caused by Gaeumannomyces graminis ) is
dependent on an understanding of cropping, soil type and drilling conditions. The
take-all decline phenomenon (see also Chapter 14), makes it possible to predict
those crops in cereal successions which are likely to be at risk and to take action by
altering the rotation to avoid them. It is a classic example of a disease that integrates
inoculum as judged by symptoms in the previous crop and agronomic factors, thus
avoiding the need to use weather data. However, Clarkson and Polley (1981)
suggested that there were general weather factors that do influence take-all but these
are essentially short-term when, to be effective, information concerning any
increased risk is needed at the time of drilling.
Unfortunately, plants are subjected to more than one disease. For this reason, a
system of integrated disease control is required to take account of the development
of, for example, rust, mildew and septoria that can attack cereals simultaneously.
EPIPRE (Zadoks, 1981) was one such system developed in Holland with the
specific aim of providing information specific to an individual crop. It was a
centrally devised system that depended on farmers, or their consultants, returning
disease observations. A central computerised system calculated the projected disease
development and possible loss and generated a reply form - treat, no treatment
necessary, and wait (Fig. 9.2).
Figure 9.2. Block diagram of EPIPRE (redrawn from Zadoks, 1981).
In 1984, in England and Wales a system called 'Managed disease control' was
introduced by ADAS (Anon., 1984a and b, 1985). This was a decision support system
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