Canopy microclimate modification for the cultivar Shiraz I. Definition of canopy microclimate

Three treatments providing different canopy microclimates were applied to mature Shiraz grapevines at Gawler River 30 d before veraison. Constraining foliage into a smaller volume increased shading over control vines, and GDC training and slashing reduced it. Measurements demonstrated significant differences in terms of fruit exposure to solar radiation. Effects on microclimate due to vine vigour were also noted. A K balance made on vine shoots demonstrated that shade was associated with increased K concentrations in the leaves, petioles and stems at veraison. A visual scoring system of microclimate and growth characteristics was evaluated, and results correlated weil with microclimate measurements. A conceptual model is proposed to: explairi how soil and climatic factors and cultural decision can affect canopy microclimate