Comparison of Four Methods Calculating the Seasonal Pattern of Plant Growth Efficiency of a Kiwifruit Berry

Four methods of determining the substrate requirements for synthesisof a kiwifruit Actinidia deliciosa (A. Chev.) C. F. Liang etA. R. Ferguson var. deliciosa cv. Hayward] berry were comparedusing data derived from common kiwifruit berry samples collectedfrom anthesis to fruit maturity. The four methods were basedon fruit proximal analysis, elemental analysis, heats of combustion,or tissue carbon content. All methods gave similar patternsof seasonal costs and values of final cost to the plant (mean1.21 g glucose g^–1 season^–1) but there was lessagreement for growth respiration (mean 0.147 g glucose g^–1season^–1). This is the first time that a continuous recordof growth cost over the course of development has been presented,and the trends in seasonal cost reflect the uptake into andsynthesis of the different biochemical constituents in the fruit.The differences between the results of each method reflect theunderlying assumptions used in their development. It appearsfrom this work that the method of McDermitt and Loomis (1981),utilizing elemental analyses, is most preferred. Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson var deliciosa cv Haywood, kiwifruit, true growth yield, plant growth efficiency, production value, glucose value, bioenergetic cost