leaf curl and die-back on fruit trees
coming up to bud season and I'm worried about leaf curl and die-back
on my fruit trees. What can I do now to prevent this?
fruit trees come into full blossom we do get problems with stone
fruit peaches and nectarines in particular. One of those
problems is the famous leaf curl.
Leaf curl is caused by
a fungus called Taphrina deformans a logical name
because it deforms the leaves. The leaves turn a pinky colour, then
fall off the tree. That's where the life cycle of the fungus continues.
To stop this cycle you
need copper and a good diary. Those fallen leaves keep on culturing
this fungus, and sooner or later the tree gets weaker because it
loses leaves. But the fungus continues on. Finally it releases its
spores in autumn back into the trees, into the new buds being formed
for next spring.
Timing, therefore, is
crucial. Your tree will need regular spraying with Copper Oxychloride
to keep the disease at bay. Spray soon after pruning in winter,
just before the tree comes into leaf in spring and again 10-14 days
Another solution is to
protect the buds at the time they get infected by the fungus in
autumn. When half your leaves have fallen in autumn, give the tree
one spray with a double dose of copper. If you time that well, you'll
get rid of it for the whole season.
Another common problem
in the North Island on peaches and nectarines is die-back of new
twigs. It's caused by oriental fruit moth, which only occurs in
the North Island.
The first generation
of caterpillars make their home in the new twigs. The twigs fight
back, gumming up the tunnel, trying to flush out the caterpillar.
But the caterpillar just keeps on feeding and kills the new growth,
giving you die-back.
The second generation
of this species of moth will go not for the twigs, but straight
into the peaches. That is similar to codling moth on apples, and
that's what damages your peaches.
Spray with Carbaryl,
or simply remove the offending twigs and burn them. By doing that,
you're removing the first generation of these moths. That way your
second generation will be lower and you've protected many of your
by Dr Dan Blanchon from Unitec's Diploma in Sustainable Horticulture and Bachelor
of Resource Management.
with permission from NZOOM Home and Garden content,
from the previous
The views expressed here are not necessarily those of the RNZIH