Physiological and Nutritional Responses of Ungrafted Merlot and Cabernet Sauvignon Vines or Grafted to 101-14 Mgt and 1103P Rootstocks Exposed to an Excess of Boron

The aim of this study is to analyze the effect excess boron (B) on nutrient uptake, growth, and physiological performance grapevines. Merlot Cabernet Franc grapevines, either own-rooted or grafted onto 1103P 101-14 Mgt rootstocks, were exposed in a hydroponic pot experiment 0.5 mM for sixty days. Twenty-five days following beginning B treatment, first symptoms toxicity appeared, including leaf edge margin yellowing, subsequent necrosis, cupping blades. At harvest, after start experiment, concentration treated vines increased all parts vine order: Leaves > Roots Trunks Shoots. Leaf Boron ranged from 980.67 1064.37 mg kg−1 d.w. significantly reduced concentrations macro micronutrients studied experiment. total chlorophyll (Chl) decreased 35.46 44.45%, thirty days, respectively, treatments. In addition, an amount resulted dramatic decrease net CO2 assimilation rate, stem water potential, PSII maximum quantum yield, irrespective type (own-rooted grafted). end experimental period, phenolic content by 71.73% 71.16% due stress. tressed showed shoot root dry weights, content, rates, Fv/Fm ratio compared Mgt. It was found that rootstocks play important role toxicity. results accumulation delayed greater extent rootstock Mgt, resulting earlier appearance 1103P.