many years I successfully grew tomatoes and cucumbers in my greenhouse,
but for the last three my telegraph cucumbers have succumbed to
a mystery disease. Can you identify the problem? I grow the tomatoes
on the outside row in the greenhouse with the cucumbers on the inside.
samples didn't arrive in good enough condition to positively identify
the problem. However, there are a range of fungal and bacterial
diseases that affect cucumbers which could cause this type of problem.
As a basic rule, to reduce
the risk of soil-borne diseases in cucumbers you should avoid growing
them in the same soil for more than two or three years. So it sounds
as if you should stop growing them in the soil and plant them in
bags or large pots using a good quality potting mix. You'll need
to adjust your fertiliser and watering regimes to suit the new mix.
They'll probably need more regular watering, as potting mix dries
out more readily than soil. But it should reduce the disease problem,
especially if you isolate the pots from the soil with a sheet of
Alternatively, if you
want to continue growing in the soil, you could try using a product
such as Basamid, which helps control soil-borne pests and diseases.
Follow the label recommendations carefully.
Either way, bear in mind
that most cucumber diseases are worse in cool, wet conditions, so
try to avoid watering or wetting the foliage when the weather is
cool and cloudy. To further reduce the chances of infection, you
could spray with fungicides like Bravo and Champion Copper or copper
Gardener, Issue 191, 2005, Page 29
Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.