Water relations, growth and physiological response of seven strawberry cultivars (Fragaria x ananassa Duch.) to different water availability

Strawberry production requires the input of large amounts of water and its cultivation under plastic tunnels, relies entirely on water provided by irrigation during the production cycle. In these systems, water management is not easy, since soils are very poor and with low water holding capacity (sandy soils), and growers tend to use excessively and inadequately supplied water. This is especially tough at Huelva (the most important strawberry cropping area in Europe), where water is scarce and its use for irrigation is limited. Knowledge of water requirements of the main competitive strawberry cultivars of the region and their physiological and agronomical response to possible restrictions on water supply is required to keep its environmental sustainability. In this sense, no information pertaining to water requirements, crop-water use efficiency (WUEc) and to the relative response to water shortage of the main strawberry cultivars currently growing in Huelva is available. Two experimental designs were carried out for the comparative evaluation of water requirements of seven strawberry cultivars (Fragaria x ananassa Duch.) and of their physiological and growth response to water shortage (70% ETc). Main results showed that water consumption differs substantially among cultivars and these differences were associated with differences in the biomass partitioning into the harvest product (i.e. harvest index; HI) and in the transpiration efficiency of the standing biomass (TEv) closely related to instantaneous water use efficiency (A/T). Cultivars were segregated on the basis of the relationship between both parameters, which integrate the differences among cultivars at the physiological (chlorophyll fluorescence, gas exchange, SPAD index, etc.) and at the growth response (fruit production, patterns of carbon allocation, LMA) levels in both water treatments. It is concluded that, in horticultural crops, such strawberry, greater leaf-level water use efficiency is not always an agronomical advantage in terms of water use. (C) 2015 Elsevier B.V. All rights reserved.