What are these spots on my apples ?

It is generally a pretty poor result for apple yields this year. With the unrelenting rain that occurred over late spring/summer, our insect friends were denied much opportunity to pollinate the flowers. But whilst it might not be a good year for fruit, it has been a good year for scab! Scab is an air-borne, fungal disease that affects apples and pears and is easily recognisable by the black-brown spots that appear on the leaves, fruit and bark. It is a disease that favours damp climates and wetter regions, so all that rain provided the perfect environment for scab to flourish.  Infected leaves will develop blotches early in the season that can merge and cause premature leaf fall. Scabby lesions can also develop on the bark and young shoots. Similarly on infected fruit, brown-black spots and patches form on the skin that can scab and crack as the fruit grows, allowing further infection from other diseases. However, light infection on fruit skin is purely cosmetic and will not affect the flesh – so don’t be too hasty to throw your fruits on the compost heap! 

 

Above: Scab infected leaves and fruit

Is it worth spraying ? By the time you have noticed scab, it will be too late to control. Besides few chemicals are available to the amateur, and you would have to spray the whole tree from May until July to be effective.

The two best forms of defence against scab:

1.       Natural Resistance - Planting suitable varieties of fruit tree that have some natural scab resistance. Mostly these are varieties that are happy to grow in the wetter, Western regions of the British Isles like Discovery or Lord Lambourne. Similarly older varieties and local varieties, which were grown before the modern commercial use of fungicidal treatment, tend to have good scab resistance, apples like Ashmead’s Kernal, Beauty of Bath,Pitmaston Pineapple and Tom Putt.

2.       Good house keeping – Correct pruning practises will remove infected wood and maintain good airflow inside your trees, reducing the damp microclimate beloved by scab.  Scab will also harbour in fallen leaves over winter only to infect next year’s new growth, so it’s a good idea to either rake up fallen leaves in the autumn or collect them with a mower. 

Pitmaston Pineapple 

 

Please contact us for further advice on suitable planting varieties and information on pruning services.