Cool orchard temperatures or growing trees in containers can inhibit leaf gas exchange of avocado and mango.
Whiley A. W., Searle C., Schaffer B., Wolstenholme B. N.
Author Affiliation: Maroochy Research Station, Queensland Horticulture Institute, P.O. Box 5083 S.C.M.C., Nambour 4560, Australia.
Journal of the American Society for Horticultural Science 124 : 46-51
Abstract : Leaf gas exchange of avocado cv. Hass and mango cv. Kensington trees in containers and in an orchard (field-grown trees) was measured over a range of photosynthetic photon fluxes and ambient CO2 concentrations in Queensland, Australia. Net CO2 assimilation (A) and intercellular partial pressure of CO2 were determined for all trees in early autumn (non-cold-stressed leaves) when minimum daily temperatures were ?14°C, and for field-grown trees in winter (cold-stressed leaves) when minimum daily temperatures were ?10°C. Cold-stressed trees of both species had lower maximum CO2 assimilation rates, light saturation points, CO2 saturation points and quantum yields than leaves of non-cold-stressed, field-grown trees. The ratio of variable to maximum fluorescence (Fv/Fm) was ~50% lower for leaves of cold-stressed, field-grown trees than for leaves of non-stressed, field-grown trees, indicating chill-induced photoinhibition of leaves had occurred in winter. The data indicated that chill-induced photoinhibition of A and/or sink limitations caused by root restriction in container-grown trees can limit carbon assimilation in avocados and mangoes.