GAS EXCHANGE CHARACTERISTICS AND WATER RELATIONS OF KIWIFRUIT VINES DURING DROUGHT CYCLES

Young, container-grown kiwifruit vines (Actinidia deliciosa cv.
Hayward) were grown outdoors, and subjected to drought cycles over two growing seasons to determine their response to soil water deficit.
When soil drying decreased predawn leaf water potential (_w) by 0.10 MPA, stomatal conductance (g₈) was reduced to 51% of that of control vines.
Soil water deficit decreased transpiration rate (E) and stem water flow of non irrigated vines to the same extent as g₈. Leaf relative water content (RWC) decreased from 99% to 95% as _w decreased diurnally from -0.3 to -1.2 MPa in irrigated vines.
A high leaf RWC (>90%) was retained even after severe stress (predawn _w of -1.06 MPa). Recovery of leaf _w was complete within 10 h from rewatering; in most cases recovery of g₈ and E occurred within 48 h.
Kiwifruit responded to soil water deficit by ready stomatal closure which drastically reduced E and stem water flow and maintained a high leaf RWC.

International Symposium on Irrigation of Horticultural Crops

R. Gucci, R. Massai, D. Piccotino, C. Xiloyannis

https://doi.org/10.17660/ActaHortic.1993.335.24