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Uittreksel
Die groeifunksies benodig vir die simulasie van produksie van ‘n Themeda triandra‐grasveld met behulp van die PUTU 11 simulasiemodel is ontwikkel. Vir die ontwikkeling van die model is die veldproduksiedata van die 1980/81 groeiseisoen gebruik waarna dit suksesvol, vir drie groeiseisoene met uiteenlopende klimaatstoestande, getoets is. In die model is koolhidraatverdeling tussen verskillende plantdele gesimuleer deur van verskillende funksies vir elke groeistadium gebruik te maak. Die hipotese is gestel dat die verskillende plantdele na ‘ n gewenste massaverhouding tot die totale plantmassa streef deur die translokasie van koolhidrate. ‘n Beperkte maksimum tempo van translokasie in en uit plantdele is gestel. Die werklike translokasietempo verander sigmoidaal met die relatiewe massaverhoudingafwyking.
Abstract
The growth functions required for the simulation of production in Themeda triandra grassland were developedfor the PUTU 11 growth model. The model was developed using veld production data collected during the 1980/81 growing season. The theory successfully simulated production in three subsequent years, each with widely differing climatic conditions. Carbohydrate translocation within plants, in each growth stage, is driven by the ratio of the existing mass of given plant parts to the total plant mass. The mass in each plant organ strives to attain an optimal proportion of the total plant mass by means of the translocation of carbohydrate. In each growth stage a maximum translocation rate is possible into and out of each plant organ. The actual translocation rate varies sigmoidally with the relative mass ratio deviation from the desired proportion.
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Uittreksel uit M Sc Agric verhandeling deur senior outeur aan die Universiteit van die Oranje‐Vrystaat.