Fluoride accumulation and toxicity in grapevines Vitis vinifera L. in New South Wales

The accumulation of fluoride by fully expanded basal leaves of grapevines was measured through two seasons in ten vineyards 9–25 km downwind of an aluminium smelter near Cessnock. Accumulation was linear with time until mid-summer then declined somewhat as leaves aged. Heavy rainfall and lowered emissions reduced accumulation. The impact of fluoride on the vines each season could be readily assessed from the leaf fluoride concentration in January, just prior to harvest.

Fluoride accumulation by grapevines was assessed in four districts each January from 1981 to 1983. At Griffith and Mudgee, two districts which lacked an industrial source of fluoride, vine leaves did not accumulate fluoride (<2 μgFg⁻¹). At Muswellbrook, vines growing 15–37 km downwind of a power station generally had slightly elevated leaf fluoride concentrations (1–10 μgFg⁻¹), but certain higher values were recorded (18–27 μgFg⁻¹) in vineyards under the direct influence of the plume. These higher values did not produce leaf necrosis. At Cessnock, 9–23 km downwind of the aluminium smelter, elevated leaf fluoride concentrations (4–42 μgFg⁻¹) were also recorded, with highest levels 9–11 km from the smelter. These levels did not produce leaf necrosis in well managed vineyards. In certain non-irragated vineyards, flouride accumulation was retarded by water-deficit stress when experienced throughout the growing season. In contrast, where severe water-deficit stress was not experienced until mid-summer, certain leaves which had accumulated 26–36 μgFg⁻¹ developed marginal necrotic lesions which reduced effective leaf photosynthetic area by 5–10%.