By Jacqueline Maclaurin
Viticultural Technician, Wither Hills
The Marlborough summer seems to have arrived, with typical long hot days, interspersed with the odd day of rain to calm the dust.
With the windy sunny days we have not yet seen any high disease pressure incidents in the blocks, although we have been running a tight spray programme this season to mitigate any disease outbreaks: an organic programme of sulphur and protector and copper if conditions are looking favourable for downy mildew.
All blocks have been leaf plucked followed by a PBC closure spray – Switch for the conventional Sauvignon Blanc and Pinot Noir, and Serenade Max for the two organic blocks, with cover for Powdery Mildew. We have also had a closer look at our nutrient inputs this season for the organic blocks – applying nitrogen (Wuxal Amino 9.2% N), calcium (Biomin Calcium 15% Ca) and magnesium (Organic Mag Super 9.4% Mg). We will look to apply two rounds of Viafos MSK in the lead up to veraison. The conventional blocks have also had nutrients such as Stopit, Zinctrac and Bortrac. We will look to do soil tests in April and develop a nutrient input plan for the blocks for the coming season.
As part of this, with project consultant Bart Arnst we are also going to look at what to plant in the inter-row to help increase nutrient levels and nutrient availability.
The blocks are all looking healthy, and have balanced cropping levels. The organic Pinot Noir is still to have a trim as the canopy is not as vigorous as the conventional Pinot Noir. Because of the lower vigour a pass will be done to bunch thin excess crop where the vines look unbalanced. The fruit set looks good on both Pinot Noir blocks, although a little more uneven on the conventional Pinot Noir, which may have been influenced by a slightly earlier flowering than the organic block.
The Sauvignon Blanc blocks show little visual difference between organic and conventional, although there may be a slight difference in vigour: less vigour in the organic block.
Another weeding round will be done in the organic blocks, and a hand leaf pluck in the Pinot Noir blocks prior to the nets going on. We will hope to spread some compost on the organic Pinot Noir, starting on our organic blocks that are showing less vigour, and working around the blocks each year.