CLONAL SELECTIONS AND STUDY
BREELAND CLONAL RESEARCH TRIALS
“Information is the currency of our age.” says CEO Petrus Bosman, “Reliable data gives us the power to make good decisions. The research we are putting out now makes it possible for all South African producers to become more efficient with resources such as land use, water and crop protection, but also more profitable and sustainable in the long-term.”
The Bosman Adama vine nursery produces more than 30% of the grafted cuttings for the South African wine industry. The research we produce affects the clones we graft, which dictates planting choices made by our wine farmer customers.
Situation: The Cape Wine industry is faced with challenges around climate change, scarcity of resources, competition from other agricultural products and from international wine markets.
A farmer should replace 5% of his vineyard every year to produce optimally. So, every 20 years the entire farm should be planted with new clones of desirable varietals, hence a significant and continued capital outlay. To be able to make well-informed, environmentally friendly planting decisions affects the sustainability not only of the farm but of the entire industry.
Aim: To provide the South African wine industry with accurate data on grape clones that perform best in terms of yield, colour, bunch size, berry size, bunch compactness, growth potential and chemical analysis.
These categories for evaluation were selected to assess plant vitality, disease resistance, fruit quality and crop yield to enable the farmer to produce maximum tonnage of good quality grapes with the smallest carbon footprint.
GRAPHIC EXPLANATION
Increased yield + disease resistance = smaller area under cultivation = less chemical sprays + less diesel + less erosion from tractors = smaller carbon footprint
Project: Gieliam Botma, plant manager at Bosman Adama Vine Nursery, has been driving this project. In 2017 the nursery established a vine garden over an area of 7ha on the farm Breeland in the Breede River Valley.
The project entailed the trialing of 170 clones of 70 wine grape varietals grafted onto the same rootstock and planted in the same soil. Evaluation began in 2020 when the vines started producing viable grapes. Each year since then, these grapes were picked at optimum ripeness (21˚Balling for white grapes and 24˚Balling for red grapes) and evaluated.
This homogenous approach means that the results are reliable, and now that we have 4 years of data, we can make confident recommendations to farmers.
What does this mean for Bosman Family Vineyards wines?
Having generated the research, we can propagate and plant these vines and produce wine, providing assurance to our consumers of the quality and sustainability of our wines as well as their provenance.
What does this mean for the wider supply chain?
Wine farmers will now be able to reduce their own carbon footprint by planting these more sustainable grape cultivars, reducing the carbon footprint of the Cape wine industry as a whole.
Examples of high performing wine grape clones:
The Chenin blanc clone 258: Vigorous growth and big bunches contribute to an above average yield. The berries in the bunches are not compact so less likely to become diseased.
Shiraz clone 198: Vigorous growth and big bunches contribute to an above average yield. The clone has a naturally dark skin colour that transfers during skin contact towards a good colour in the resultant red wine.
Colombar clone 254: Moderate to high vigorous growth and average bunch size positively impact the yield, but this clone also has big berries and so produces an above average yield. The bunches are also loose so less likely to become diseased, especially when rain occurs during ripening.
