Season one reflections: crop differences & adjustments in Marlborough

By Jacqueline Maclaurin

Viticultural Technician, Wither Hills

 

The start of a new season is upon us; buds are starting to burst and slowly the temperatures are starting to rise, although frosts bring us back to the reality of what nature can deal.

Spring cultivation in the organic Pinot Noir

Rebecca, the project manager, has put some questions to us to answer for this blog:

How was the harvest for your vineyard? How did organic and conventional hold up through the varying weather conditions in the different regions?

Marlborough some could say was somewhat blessed this harvest – picking decisions were made without the unwanted pressure of rain events on our heels, causing visions of botrytis infections to interrup our dreams.

2012 for Pinot Noir was a year of hen and chicken berries – evident in the conventional Pinot Noir that had flowered slightly earlier during a cooler and wetter period, resulting in bunches with a high severity of berry shrivel at harvest. The organic Pinot Noir block was just starting flowering during this weather pattern and had a more even fruit-set and so minimal shrivel of the berries at harvest.   The conventional Pinot Noir matured earlier throughout the season – veraison and brix levels. The fruit came in clean and the winemakers were happy with the block.

The organic Pinot Noir showed signs of vine imbalance that became evident from veraison when maturity was slower. Due to the small canopy it became apparent that the vines may not be capable of ripening the crop. The decision was made in early March to reduce the crop load by bunch thinning. The crop was reduced to one bunch per shoot where the shoots were deemed healthy or all bunches removed where this was not the case. The harvest of the organic Pinot Noir was six days later than the conventional Pinot Noir. Again there was no concern for disease levels in the fruit.

A variety of factors could have contributed to the slower development of the organic Pinot Noir over the season: vine age – unformed root system, rootstock, undervine weeding disturbing the root system or competition of weeds undervine during the season. These may be some of the reasons. We would be interested to know if there other findings out there that fellow growers have found and remedied in their blocks in conversion.

The Sauvignon Blanc showed little difference between the organic and conventional blocks – both were clean of pests and disease and there were no significant differences between maturity analysis and crop levels. All Sauvignon Blanc was harvested on the same day.

What went well or was easy in the first year of conversion? Considering those challenges, what (if anything) are you considering changing in your management in the coming season and why?

As the organic Pinot Noir had started conversion to organics a year earlier, I will focus on the Sauvignon Blanc for this question. On a well-established vineyard the first year of conversion has been relatively simple. In our location, on an old river terrace, rocks have become a challenge – both damaging and becoming a hazard for machinery. Inter-row and undervine cultivation both disturb rocks that may have been lodged in the ground since the establishment of the vineyard. Every time a pass is made with the undervine weeder the rocks are tossed out into the row, waiting in the path of a mower. In an aim to return the rocks to their place under the vine an A-frame implement is attached to the 3-point linkage to push them out to the edge of the row. This has helped, but there has also been the necessary task of picking up rocks with the aim of reducing the number to be thrown out into the row with the next pass of the weeder.

There are a few changes we are making this coming season and things that we have become more aware of and will manage going forward:

–        We will plan our bud rubbing rounds with the weeding rounds in mind, so that we are able to remove the most buds possible without covering them up with the weeder.

–        Watching our crop levels in the organic Pinot Noir so that we get better shoot growth for pruning the following year.

–        Monitor the number of weeding rounds and the depth of the disk and blades that may be cutting the feeder roots of the vines, especially in the organic Pinot Noir.

–        Develop a cover crop plan for the Organic Sauvignon Blanc to work around frost season with the aim of planting something that will help increase organic matter and structure in the soil.

–        Increase the microbial life in the soil by spraying a soil drench undervine and inter-row each time a weeding round is done

In the past month we have begun our Spring mounding. By using the mounding disk on our undervine weeder we are trying to create a mound we will then ‘cut down’ throughout the season using the blades. The benefit we see with the mounding disk is the speed at which the driver is able to go – about 6km/hr. We see better results achieved with this piece of equipment when a higher ground speed is achieved. In the organic Pinot Noir the blades have also been used to try to disturb the Californian Thistles while they are still small as there are high numbers present in this block. Fertiliser is being spread on all blocks currently – a mixture of RPR and boron in response to soil tests taken post-harvest.

Also coming up is the ground work in preparation for the sowing of buckwheat and Phacelia that will flower in December.

In the coming months we are also looking to spread compost on the organic Pinot Noir by banding it undervine to help increase the soil life and the organic matter levels in the soil. This compost was made in December 2011 by the viticulture team and was a combination of ingredients bought onto or sourced from our own property. Hay, cow manure and wood chips were sourced from outside our property, and we used shredded paper, green waste and grape marc from our own property. The compost has a high carbon content and so some of the matter has taken time to break down. As we become more confident with making compost I feel we will master the art of making a product that will bring more life to our soil.

Below is a photo of the compost currently.