Glen Creasy presented 2 papers for colleagues. Both were about rootstocks. He quoted a 1926 paper on how the root architecture affects performance (does someone have a link for this, or the author?), shallow vs deep rooted. An interesting point, when comparing rootstocks to own roots, the own rooted vines need to be grafted on to themselves, to remove any effects of the graft union, clever. I don't think I have ever heard of that being done. In Chardonnay, rootstock had no effect on numbers of flowers, but did on fruitset and numbers of small berries.
Rob Agnew proposed that the average Dec temperature was an indicator of bunch number for the following season. If last years Av Dec temp is less than the long term average, then you get less bunches. How simple, we will use this at Pressing Matters.
Larry Bettiga has investigated the effects of using an under vine cover crop. Barley was sown and was herbicided at 20cm tall. They found that it:
- lowers soil moisture in spring
- raises soil moisture in summer
- increases OM in the 3rd year
- reduces available soil Nitrogen
- Roundup timing needs to be early enough to avoid competition
Mark Krasnow found that if you remove all the leaves before flowering you can reduce the incidence of botrytis. This could be due the reduction in compactness, reduces berries/bunch and bunch weight. It could also have something to do on the increase in UV. He may need to try some shade cloth ground truthing.
Robert Beresford spoke about the development of the Botrytis Decision Support website, predicting bunch rot in grape vines. It looks great, but is only for NZ. Sad face. How about an OZ mirror?
Dion Mundy is trialing the use of mechanical harvesters to thin fruit at pea size in NZ. It is reduces bunch weights and opens up bunches. There is a reduction in Botrytis, but this could be due to the reduction in bunch trash. He may need to trial removing some of the trash with air on a couple of panels.
And then lastly, Dean Metcalf spoke about his Trichoderma flying circus (I imagine the Trichoderma doing mini circus tricks like a flea flying circus). Sounds like he has some good organic products.
Done and dusted. A great seminar. Time to go put these things into use at the vineyard.
Glen Creasy here - thanks for the write-ups! The diagram of roots was from Perold, A. I. A treatise on viticulture. MacMillan and Co. Ltd, London (1927).
ReplyDeleteCheers!
-g