On 19 Sep, 10:58, "Paul E. Lehmann" > wrote:
> shbailey wrote:
> > On Sep 18, 4:42 am, michael > wrote:
> >> I thought that I would try again to further my understanding of
> >> observations on my vines in England this year,based on the very useful
> >> replies and discussion.There will always be disagreement,but as
> >> someone new to growing grapevines,I hope that I can understand the
> >> issues.I apologise to doubi..for my recent comment,and hope that he
> >> can continue to help.
> >> Let me try again to summarise my recently gained knowledge:
> >> 1)Using wood chip as a mulch on the surface around the vine can
> >> greatly help in the stabilisation of upper soil moisture content,and
> >> will not affect the nitrogen of the vines-rotovating or digging in
> >> wood chip will rob the soil,and this is my gardening experience.Garden
> >> compost could be even better,as it introduces a living worm population
> >> which may help soil texture.
> >> 2)Wasps or other insects are not the source of primary damage to
> >> ripening grapes,but can spread the rot to other grapes in the bunch.A
> >> primary source of damage could be a heavy rain shower,causing
> >> splitting,followed by wasps,etc moving in.I think that this is what
> >> happens with plums after they split when nearing ripeness.My culling
> >> of the majority of the wasp population will still help,I believe.
> >> 3)I thought that darker vine leaves to be an indicator of too much
> >> nitrogen.I would like to know what the indicators are for vines
> >> needing more phosphates,or potash,so that I know what fertiliser to
> >> add to my compost.
> >> 4)One indisputable fact is that my vines and grapes are sofar much
> >> healthier this year. I believe that probably the main cause is the
> >> long very warm dry spell here in June-but I do not really know.It
> >> could be the compost keeping moisture levels stable.
> >> 5)My original post was about pruning of laterals or sideshoots for
> >> vigorous vines in a cool climate.My policy now is to remove most of
> >> them in June and July to prevent a dense canopy developing,thus
> >> encouraging powdery mildew,and then leave them alone after veraison to
> >> have maximum leaf for the ripening period.
>
> >> I hope that my understanding is improving and welcome your comments
>
> >> Michael
>
> > The following link provides pictures of grape leaves with various
> > nutrient deficiencies. *Potash (potassium) and magnesium are the most
> > common. *Magnesium can be easily supplied with a few spoonfuls of
> > Epsom salts. *I read the other day that grapes usually don't need
> > added phosphates. *http://www.honeycreek.us/leaf_chart.php
>
> > You hit the nail on the head about the benefit of mulch. *If you had a
> > long warm, dry spell and your vines remained healthy, it was due to
> > the stable moisture levels enabled by your mulch.
>
> > Stephen
>
> It was probably the long warm, dry spell that made the vines healthy. *Vines
> love and thrive in those conditions.
>
> I don't think Michael lives in a semi-arid part of the world requiring
> mulch.- Hide quoted text -
>
> - Show quoted text -
Hi Paul,
Although I do not live in a semi-arid part of the world,my
sloping dry limestone south facing soil does dry extremely quickly
during the summer.The grass on the adjoining orchard becomes a pale
straw colour for a couple of months,and the planting of fruit trees in
the orchard is almost impossible without regular watering in the first
couple of years.So it may be the case that mulching in March helped
the vines over the very warm dry June period,and stopped any powdery
mildew developing.In other years,I have some powdery mildew,even
though I spray regularly with wettable sulphur.This year I have not
detected any powdery mildew on any of my four varieties of
vines.So,maybe the jury is still out as to whether the mulching has
helped the vines in my particular situation,but I am tempted to mulch
again next year.
Best regards
Michael