The CIVC run an experimental vineyard called Plumecoq. We were taken round by one of their viticultural researchers, and were impressed at the range and depth of work being undertaken. Perhaps most obviously impressive was the “precision viticuture” which took the form of a small tracked vehicle with GPS, computer and optical sensors. These sensors monitor canopy density and colour, hence indicating vigour and nutrient levels. Plumecoq monitors all vines once a week and has a few years of data already.
It was interesting to hear comments made about vine density. Champagne planting can be around 10,000 vines per hectare, about 3 times a typical recent planting in England. But the researchers at Plumecoq have trialled many different vine spacings and reckon the 2m row width makes sense. Going from 1m to 2m (with associated increases in canopy height) showed only a 20% reduction of yield. I was interested, though, that they said they saw a slight increases acidity in the grapes. But when taking into account the extra labour and machine costs of the higher density spacing, the view shared was that wider spacing probably made sense (especially in an era in which Champagne grape acidities are creeping down for climatic reasons).
Perhaps the other most notable point I heard was regarding botrytis, and the result that a grass cover-crop reduces the incidence of this fungal disease. I had previously heard the opposite that grass makes the atmosphere humid and hence encourages botrytis. However, the researcher said that empirically the a grass sward reduced incidence of botrytis, and gave 2 reasons: that grass dries out the ground in general, and that the competition with the vines triggers a vine response which makes them less susceptible to botrytis. The second reason in particular sounds curious to me, though others in the group thought it matched with other things they had heard.
Lastly of interest was an observation that there is more chlorosis in the region than in most years, despite the dry weather. We were told that the conventional wisdom is that chlorosis comes when conditions are wet, which causes increased dissolved calcium (from the chalk-rich soil) to antagonistically effect the vines’ ability to uptake iron. However, the increased chlorosis this year might be caused either by the high yield last year (hence decreased reserves within the vine) or the fact that vines are drawing water from lower down in the ground, an area with a higher concentration of calcium. Interesting stuff.