Summary. A study of the petiole nutrient status
of cvv. Shiraz, Cabernet Sauvignon and Rhine
Riesling (Vitis vinifera) was carried out in 19
vineyards of each in the Barossa Valley, South
Australia, during 1979 to 1982. The sampling unit
chosen was the petiole of leaves opposite
bunches, collected at flowering time.
Nitrogen status (assessed as nitrate
concentration) varied widely among vineyards
and high concentrations of nitrate could be associated
with use of organic materials (chicken
litter, winery marc) in the vineyards. Phosphorus
status was almost invariably higher than
necessary. Potassium, magnesium and chloride
status were usually high by Californian standards.
Of the trace elements, boron was low in 1979 to
1980 in some vineyards, but sufficient in other
years. Zinc and manganese were usually present
in sufficient quantities. Daily sampling of petioles
showed that nutrient levels during the flowering
period changed less dramatically in this region
than in California. Pre-bloom foliar sprays ofurea
with zinc had non-significant effects on petiole
nitrate concentration. Differences in nutrient
concentrations between the three cultivars were
detected in some years.
The standards used to interpret petiole analysis
data in California, while useful in the survey area,
required some modification for local use, and
working standards are proposed.