Ricerche circa gli effetti nutrizionali e sanitari su vite di irrorazioni fogliari a base di fosfati e fosfiti di potassio e magnesio.

Abstract: In order to verify the effect on vine health and yield performances of canopy treatments applied with potassium and magnesium phosphite or phosphate solution, an experiment was conduced from 2007 to 2008 in the Oltrepò Pavese D.O.C. zone (north- west of Italy). These treatments were tested in comparison with a control and with other leaves treatment based on cover and penetrating fungicides commonly used. The vines treated with the phosphate compounds (2007) has shown an increase of potassium and phosphorous leaves content, without an effect against the downy mildew (Plasmopara viticola) disease. Potassium and magnesium phospite treatments (2007 and 2008) have increase: K and P leaves nutrition, photosynthesis (SPAD measures) and productivity (yield/vine and quantity of sugar/vine) and also have decrease the downy mildew attack with nothing significant differences from the fungicides commonly used in the farm. The leaves test of K and P phosphate has showed only a curative effect on the Plasmopara viticola development. The phosphite wine residues after 8-10 vine treatments during the season were under the law limit (from 30 to 40 mg/L).