Vergara - 1976 - Physiological and morphological adaptability of ri

500 cusmrs AND RICE
3. For any given crop or area how may productivity (ratio of output to input)
be raised and sustained at the highest possible level?
Australian answers to these questions are sought by a tangled web of institutions—regional.
state. and national—each claiming responsibility for one or
more of them. This fragmentation of responsibility for separate facets ofwhat is,
in fact, a more general problem, has obscured the thread which binds them
together. Stated more simply the problem is one of prediction. lf it were possible
to predict the behavior of any crop production system at airy location under any
technology and any set of weather conditions, we could answer all three questions.
Taking this as an ultimate goal of crop research. is it really possible to
achieve it, and how‘?
The traditional techniques of statistical agronomy will not provide solutions
to this global question (nor are they logically" structured to do sol). The inadequacies
of the conventional field experiment were well documented by Collis-
George and Davy (1960). Statistical differentiation of treatment effects in
situations where site >< season interactions account for 80-90% of total variance
is not conducive to the development of general functional relationships; what
is not so well appreciated is that results from laboratories. glasshouses. and
controlled-environment facilities are commonly just as location-specific,
technology-specific, and genotype-specific as the maligned field experiment.
Whether field. laboratory, or phytotron based. the development of general
functional relationships depends on adequate definition and measurement of the
system under study. With instrumentation now available and appropriate experimental
designs and data collection techniques. field experiments need not
suffer by comparison with more controlled environments in this respect. It is the
underlying assumptions and logic. rather than the particular mode of experimentation
which are at issue.
The development of logic and method in agrobiological research through an
evolutionary’ sequence of trial and error, transfer by analogy, statistical correlation.
multivariate analysis. and the now fashionable systems analysis and
simulation techniques has been described by Nix (1968). These methods are not
mutually exclusive and all have a useful role to play, but basic systems concepts
provide a frame of reference within which all methods can be ‘viewed in perspective.
The single central concept is that the whole system must be understood in
order to evaluate changes properly in any component of the system.
Systems analysis is concerned with resolution of a complex sn-"stem into a
number of simpler components and subsequent synthesis into a symbolic representation
(diagram. flowchart) and ultimately a mathematical model of the
whole system. When a model is developed which accurately describes the behavior
of the complex system. experiments can be performed on the model
(simulatfion experiments) rather than on the real system.
Given then. that our goal is to develop models of crop production systems
such that we can predict the consequences (both ecological and economic) of
imposing any specified management strategy on any specified crop for any area,