Preparing for undervine cultivation

By Grant Rolston, Vinewise Viticulture

This blog will be short and sweet as there was not a lot happening in the vineyard during September.

The School House vineyard site is not overly vigorous, like most in Central, and heavy weed competition causes problems with vigour, soil moisture and vine health.

Some here have tried undervine mowing without much success, the problem being that the weeds are still present, and they continue to grow and compete.

We will use the Braun undervine weeding system for the duration of the project. This seems to be the most popular organic way of dealing with weeds in Central Otago. We like that this system has little impact in the root zone of the vines. The process basically takes a little soil from beside the vine and mounds it up underneath the vine row. Here we can work with that soil by using a weeding blade. There is a machine available for the work on a contract basis.

In preparation for the undervine weeding we are required to lift the irrigation to a height of around 40cm. This needs to be done to allow the feeler arm of the Braun to pass unimpeded. This will result in a superior job as well as preventing any drip line damage. Further to this we have used metal stakes to stake the irrigation risers and any young plants in the block to protect them from potential undervine weeding machinery damage.

We have also disked every tenth row in readiness to plant a flowering crop of buckwheat and Phacelia around mid-October.

We had hoped to spread compost and have our first mounding pass with the weeder completed by now, but we have had problems in securing the services of a compost-spreading machine. Rather than do this by hand we have decided to wait and will do it early October.

We have carried out routine irrigation maintenance. Hydro Services have installed their soil moisture monitoring sites on both the organic and conventional blocks. We have had very little rain during the winter and it was of no surprise that we needed to apply 10 hours of water prior to budburst.

The buds are swelling by the end of the month and we expect budburst during the first week in October.