Discovery apple, which has some natural resistance to scab and mildew
It has been my practice to control mildews and pear and apple scab with fortnightly sprays of dithane 945 and it has always been successful. I read of commercial growers success with Aston’s, garlic/seaweed/citrus, Tree Wash, in the ‘East of England Apples and Orchards Spring Newsletter’ and decided to test it for myself and ceased to used dithane for trace elements and fungus protection.
My regime for apple, pears, cold house and outdoor vines was a fortnightly wash with Tree Wash diluted 1;100 and sprayed to run off. I noticed an improvement in leaf colour and sheen and the spray appears to have maintained a good grip, despite the wet summer. I discovered the beginnings of powdery mildew on outdoor Müller Thurgau, Septimer and Perle on 7 August and so I terminated the trial for all outdoor grapes until after winter training, when I will begin the 2009/2010 programme with a winter spray at 1:250 dilution.
There is, as yet, no sign of mildew under glass where the vines look glossy and well. All apples and pears are similarly well with the exception of one very scabby Williams’ pear.
I read of the efficacy of neem oil in a letter written to the ‘National Auricula and Primula Yearbook’ by Heidi Dixon. The gist of her letter is as follows: neem oil is extracted from Azadirachta indica, native to India and known there as ‘village pharmacy’ because it acts as an insect repellent. It has been subject to much grower and university research and has been shown to be effective against aphids, thrips, white fly, mealy bug, weevils, fruit fly, slugs, snails and other plant pests. The active ingredient azaridachtin and other bitter compounds repel insects. The writer reports that it dealt speedily with red spider mite infestation with lasting effect and that it can prevent powdery mildew.
I cannot test the efficacy of neem oil for myself as I have an ongoing trial using Ashton Tree Wash but others may wish to test it.
Alan Rowe
