02553nam a2200409 a 450000100080000000500110000800800410001910000240006024500880008426000410017230000100021350000170022352015360024065000160177665000110179265000130180365000110181665000220182765000210184965000320187065000160190265000130191865000130193165000160194465000130196065000150197365000160198865000260200465300110203065300150204165300110205665300150206765300250208265300120210765300120211965300120213115565901996-12-17       1988    bl uuuu  m   00u1 u    #d1 aCASTRO, A. M. G. de  aA systems approach to determining priorities for natural rubber research in Brasil.  aReading: University of Readingc1988  a290p.  aPhD. Thesis.  aA systems approach was demonstrated to determine priorities and resource allocation for agricultural research in Brazil with the objective being to alleviate the subjectivity of the process which often has led to internal conflict and loss of efficiency in the traditional approach. The research program in natural rubber, an important commodity in Brazil, was chosen to represent the single commodity research in that country. A review of the Brazilian rubber farmers and problems faced by them, was given together with a description of the natural rubber research organization. Performance was assessed at the two primary rubber producing centers of Brazil, Manaus and S. Paulo. A preliminary crop growth model was built in order to simulate rubber growth and produc-tion. The model consists of a carbon & water flow can simulate the modrubber growth and yield on daily basis. Two submodels were developed to determine the nutrient uptake and yield losses resulting from foliar diseases. The model was constructed using data from Brazil but data from other producing countries was also included when information was not available. Only a qualitative model evaluation was attempted at this stage of the model contruction. The output of the biological model was fed into a specially built budgetary model, which was used to assess the relative importance of alternative research, measured by its impact on rubber yield and profitability. Alternative research was simulated through sensitivity analysis and by grouping parameters...  aagriculture  aBrazil  aplanning  arubber  asimulation models  asystems analysis  aAdministração de Pesquisa  aAgricultura  aAnálise  aBorracha  aCrescimento  aPesquisa  aProdução  aSimulação  aSistema de Produção  aBrasil  aManagement  aModelo  aProduction  aResource allocations  aRsearch  aSistema  aSystems