Proceedings of a workshop on research methodologies Medan ...

METHODOLOGY FOR ESTABLISHING SELECTION
CRITERIA FOR FORAGE SPECIES EVALUATION
W.W. STUR
Department <strong>of</strong> Agriculture, University <strong>of</strong> Queensland, Queensland 4072, Australia
ABSTRACT
The evaluation <strong>of</strong> new forage species for integration into plantation systems is a vital step
in the quest to improve animal production. Before embarking on a species evaluation process, it
is necessary to define the aim <strong>of</strong> the evaluation and to establish criteria which will be used to
select new species. This requires an understanding <strong>of</strong> the environment, the existing animal
production system and the limitations infeed supply, the opportunities forforage improvements
in the plantation system and a detailed description <strong>of</strong> the proposed use and management <strong>of</strong> the
forages. These considerations need then to be translated into desired species characteristics.
INTRODUCTION
The raising <strong>of</strong> ruminants in association with plantation tree crops is a well
established practice, both for aniimal production and for the control <strong>of</strong> undergrowth.
Natural vegetation will always grow under plantations as trees cannot fully utilize the
incoming light, the available water and nutri,ents. While regarded by plantation
managers as weeds, a large proportion <strong>of</strong> the naturally occurring vegetation under
plantations is eaten by ruminants and can therefore b: regarded as forage rather than
weeds. Once animal production becomes an objective within plantations, the question
<strong>of</strong> improving the existing feed resources to raise the level <strong>of</strong> animal productivity
becomes an issue.
The Australian Centre for International Agricultural Research (ACIAR) has
commissioned Tne University <strong>of</strong> Queensland to conduct a collaborative research
program with the Rubber Research Institute in iialaysia, and Sam Ratulangi and
Udayana Universities in Indonesia. The project is entitled "Improvement <strong>of</strong> Forage
Productivity in Plantation Crops" and one activity <strong>of</strong> the project is the evaluation <strong>of</strong>
forage species for shaded environments. This evaluation includes not only existing
cultivars, but also a large number <strong>of</strong> accessions which have originally been collected
in shaded habitats.
Evaluation <strong>of</strong> new, introduced forage species for integration into plantation
systems is a vital step in the quest <strong>of</strong> improving animal production. Before embarking
on a species evaluation program, it is necessary to define the aim <strong>of</strong> the evaluation and
to establish the criteria which will be used to select new species. This paper will discuss
the various factors which need to be considered when establishing selection criteria, and
this will be discussed in relation to two contrasting plantation types, rubber (Hevea
brasiliensis) and coconut (Cocos nucifera).
The establishment <strong>of</strong> selection criteria requires an understanding <strong>of</strong> (i) the
environment, for which the forages are intended, (ii) the existing animal production
system, particularly in regard to the current feed supply and its limitations, (iii)
opportunities for forage improvement, taking into consideration constraints imposed
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