Indicators of water stress degree.

T: mean temperature recorded inside the greenhouses every month; (2) RH: air relative humidity recorded inside the greenhouses every month.Soil relative water content (SRWC), leaf relative water content (LRWC) and midday water potential (ψmid) under control, mild and severe water stress (C, MS and SS) all over the growing season. Climatic conditions under the greenhouse are also shown. Variability of these parameters due to water stress, month and their interaction are tested using two-way ANOVA (F) followed by Tukey test. Lower case letters (a>b) represent differences between treatments month by month. Capital letters (A>B) represent differences between treatments all months averaged (Annual mean column). Values are mean ± SE of n = 5; N.S.: not significant. Lower case or capital letters under brackets denote Tukey test differences at 90% confidence level; df: degrees of freedom.Indicators of water stress degree.