Скачать или смотреть Apple scab- a common disease of apples and pears

(error-variety is Lord Lambourne) Sorry about this sick video, please skip if you prefer. This is a video about a nasty disease which is sadly all too common. Scab is a fungal disease which affects every part of the tree, it turns the leaves dirty brown so the tree is sapped of energy, and also causes dark spots on the apples which cause deformity. Customers can be very picky-they woudl prefer it if you did not spray, but will usually reject an apple with scab spots on it. The organic people ahve done a lot of effective propaganda, with much talk about hormone disrupters and carcinogens, but the rules for pesticide applicateion and storage are very strict and as most of the spraying is done early in the season there are effectively no residues in the apples at harvest.

Pesticide use in food production is like vaccination and contraception- they are interference with nature we'd prefer not to have to bother with, but the reality is, we wouldn't like the result if they were withdrawn. Because the wind (and our small-scale inefficiencies) meant we couldn't apply pesticide when we needed to this spring, we have a couple of outbreaks (scab and sawfly) and I estimate the crop is already down by 30%. This may not be as bad as it sounds, since I haven't done all the fruit thinning yet, but its not good.

We need new apple varieties which have natural resistance to scab and other diseases. I would welcome GM gene transfer from resistant apples if normal plant breeding isn;t effective enought. By the way, the issue of pest and disease resistance is is a reason to keep ALL old heirloom/heritage apples alive, for their genetic potential. Some of the older varieties are naturally hardier-they were developed before pesticides came into common use (in the late 19th century). We cannot afford to lose their unique genes.

In the meantime anyone planting apples trees needs to be aware of scab, and avoid planting varieties which are know to be badly affected. Ones I know to avoid are Spartan, Fiesta (Red Pippin) Cox's Orange Pippin-there are others. Adam's Pearmain and most Russet apples have some natural resistance. Sturmer Pippn gets scab very badly in our microclimate-this apple was selected in East Anglia on the English east coast where they have lower rainfall. Old local varieties often do better because the old-timers selected them because they did better.

Good orchard hygeine helps, ideally sweep up and remove fallen leaves in the autumn (scab spores from affected leaves overwinter in the soil). Open pruned trees allow light and air through which helps, but in the end you can only get complete protection by spraying fungicide. Sorry, but there is no organic solution, and its not just 'Spots on my apples' as Joni Mitchell sang, you can lose the entire crop and have stunted growth. Its worse in areas of high rainfall.