Effect of soil and climate conditions on soluble solids evolution during maturation of kiwifruit

Abstract

Abstract The increase in soluble solids concentration (SSC) during maturation of kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson ‘Hayward') in 16 orchards of the eastern coastal plain of Corsica was analysed in relation to soil characteristics and climate data for 2 years (1987 and 1988). Even if time was expressed in degree days, a year‐to‐year difference in SSC evolution with time was observed. A smooth decrease in SSC in early October 1987 was noticed and may be the result of the high rainfall which occurred during that period. Using the 1988 data set, SSC increase was estimated as a function of time (under a quadratic form), total soil sand level, and the inverse of soil crude silt level, meaning that soil retention capacity probably influenced SSC increase. The derivative with respect to time of this function was also an acceptable estimate of observed rate of increase in SSC (RI). Observed RI, as well as calculated daily RI, increased as mean air temperature decreased, as repor...