Ruud Kleinpaste: Taphrina deformans or peach leaf curl

I’m trying a different tack on Newstalk ZB.    It’s something I use with teachers and kids at school: the meaning of scientific names of living organisms helps to remind us how certain creatures operate or how they can be identified.   Once you get that in your gardening vocabulary it becomes a lot easier to prevent or control the problem that’s causing you regular troubles.   Taphrina is the name of a parasitic fungi (belonging to the family Taphrinaceae) that produce asci in a superficial hymenium having an indeterminate margin and cause leaf curling and malformations like blisters on various vascular plants.   It literally tells us it’s a name of Rotter-Fungus that causes curling, malformation, and blisters.   The second name (deformans) repeats the symptoms: it causes deformations. That tells us it is a real bummer to have on your plants (especially on stonefruit: peaches, nectarines, plums, peachcotts, peacherines, apricots, etc).  Ladies and gentlemen: we’re talking about leaf curl on peaches (and Bladder Plum/Plum Pocket on plums).   Spring and summer are the main months of queries on our Gardening programs: how to deal with Taphrina deformans and, while we're at it, Taphrina pruni.   Short answer: in spring and summer you’re too late. Yes, the disease starts in spring, but you can’t spray copious amounts of copper on the new and tender leaves – young leaves will burn!   Right now, in the middle of Autumn you can avoid the infection.  Around mid to late April, when the leaves are falling off the deciduous stone fruit trees, the new buds for the next season are formed. Taphrina deformans will then be invading those new buds and overwinter on those buds to infect the trees again in spring.  First thing to do is to remove all fallen leaves from under the trees. That reduces infection chances.   Next thing is to spray a double dose of copper spray (copper oxychloride, liquid copper, or copper-sulphur mixtures, available form garden centres) on the remaining leaves and on the branches/twigs of the tree. Use a “sticker” if you can to increase coverage and stickability.  Do this again a few weeks or a month later and ensure good coverage of all parts of the tree.   Some people use Lime sulphur. That’s okay too as a winter clean-up – seeing as the trees are getting to dormancy, Lime Sulphur won’t harm the leaves, but I think that lime may not be a great material for apricots as it has the ability to raise the pH levels.   A last smack of Copper spray before budburst should “mop up” the last surviving spores before the flowering and fruiting season begins again.   LISTEN ABOVE See omnystudio.com/listener for privacy information.