Effects of nutrient spray applications on malic and tartaric acid levels in grapevine berry

The levels of tartaric and malic acids in grape berries sprayed with either CaCl2, KCl, KNO3, NH4Cl, or Ca(NO3)2 in order to increase potassium (K), calcium (Ca), ammonium (NH4), or nitrate (NO3) availability during the fruit set-veraison period did not show a direct effect on the synthesis of malic and tartaric acids in the berries during the pre-veraison period; however at veraison, a relationship was established between K and malic acid, a relationship that did not last until the ripening of the berry.