Apple Scab Control

The Control of Apple and Pear scab by Sulphur Sprays

My James Grieve has for the past 3 years suffered some scab on the leaves. This wouldn’t be a problem, except for the fact that it can severely mark the fruit in due course and in wet seasons. By resorting to a regular spray of sulphur, I have managed to prevent it reaching and marking the fruit. Sulphur is a basic chemical, so relatively harmless to the environment. The weather conditions earlier this year in the east were very favourable for scab spores, but luckily this last week’s dryer conditions has improved the situation tremendously. In the west of Scotland it is a problem most years. Powdery mildew has also been prevalent on many apples this year also and sulphur will reduce this also. It attacks the new young leaves and slows down the growth of trees for many months.

I use 5.6 mls in 10 litres of litres water and spray the leaves every 10 to 14 days if I can. I start at the ‘pink bud’ stage and continue until the end of extension growth, around about mid- July. It is essential to achieve good coverage of all parts of the tree, especially the growing points – they will have the appearance of a smattering of snow after spraying!

Certain varieties of fruit trees and bushes may be damaged by sulphur sprays. In the old books they called this ‘sulphur shyness’. The following are reportedly susceptible to leaf damage: Beauty of Bath, Belle de Boskoop, Cox’s Orange Pippin, Lane’s Prince Albert, Lord Derby, Newton Wonder, Rival, Stirling Castle, and Doyenne du Comice.

My Hawthornden seems a touch damaged, and possibly my George Cave, but since the first few applications, I have restricted my sprays to Worcester Pearmain and James Grieve only, the only two in my garden showing any significant scab symptoms.The Boskoop seems to be ok in my garden, and none of the pears show any damage.

I have seen scab on Scrumptious this week, and many new so-called resistant varieties usually succomb after a few years in the field unfortunately. Knowing when spores are in the air is how the professional’s are able to time their spraying; we may rely on regular pruning and good open sunny sites as the best prevention!

 

Spindlebush Apple Trees

The Spindlebush Method of Growing Apple Trees

Some of the small apple and plum trees i left in the field after i moved my nursery two years ago ( I move to a new patch every year), started to fruit this year in earnest. At the moment they have central leaders and i have the option of letting them branch out with 5 or 6 framework branches, and later cut out the leader to form open centred trees. This is an easy method of formative shaping to understand for amateurs and semi-professionals.

However, with the advent of dwarfing rootstocks, in the early 1940’s in Germany, and later in Holland, the growing of high density spindlebushes was becoming of great interest to growers. We in the uk were still growing very large trees on M7 rootstocks at a very wide spacing, and it was only post – war visits to Germany which opened our eyes to developments there.

So here are a few jottings on the subject:

So what are spindlebushes?

Its similar to my cordon grown trees, in that it is all about having fruiting wood in abundance and basically nothing else! Those of you who have attended my workshops will be familiar with the need to identify fruiting wood.

 

Its advantages are as follows:

Very high rates of production per hectare.

Small trees, enabling pruning, spraying and harvesting from the ground.

Very efficient use of land and available sunshine.

 

They are normally grown on very good land, and M9 rootstocks, a very dwarfing one. Basically, there is a central stem and lots of wee laterals to carry the fruiting buds. A tall thin pyramid is required. Thicker pencil sized laterals are cut back to 4 buds, anything thinner to 2 or 3 buds. Cut to downward facing buds always. So horizontal wood is the aim, use spacers if necessary. Unlike some methods I teach, this one requires very severe pruning. The leader is pruned – that is the new growth to 4 or 2 buds on a weak tree.

The common mistakes are to not cutting back the leader hard enough and allowing too much fruit early on leading to stunting of shoots. The aim is to have lateral branches with lots of fruiting spurs and no gaps along the branches.

Red George Cave

Fruit from my 2 year spindlebush tree

In late July, the new growth from the stubs are tied down to form horizontal fruit wood. Be careful not to droop the ends below horizontal if possible. Prune back all sub-laterals in summer

(‘Lorette pruning’), or next winter if you forget! You can allow your laterals to branch to fill the space a little, such as if theres a gap in your tree you want to fill. Tie a higher one down to fill a space if necessary. Keep the pyramidal shape by pruning harder if necessary your top laterals. Each tree should yield 10 lbs of fruit by the 4th year. The original spacing recommended was 10 feet ( 3m) and 435 trees per acre. In you have an acre, you could be producing 4.3 tonnes of fruit by your 4th year! Using an m26 rootstock in most areas of Scotland, and tieing to stakes or wires in North-South lines is probably ideal. A modification is the Tall Spindle, which is allowed to grow to 3m and planted 1m x 3m spacings. It must have up to 10 short feathers ( branches) already from the nursery. Visit your nurseryman and select your trees personally!

If you want to know more about pruning workshops, please see our google calendar on the website http://www.plantsandapples.co.uk.

 

References:

Wertheim, S.J., The Training of the Slender Spindle of Four Apple Varieties. Nov. 1970

Golschmidt and Delap, The Spindle Bush Method of Growing Apple and Pear Trees, The RHS Fruit Yearbook, 1950, pages 54-66.

The RHS Encyclopaedia of Gardening , ed C. Brickell, page 380.,1992.

http://fruitgrowersnews.com/index.php/magazine/article/The-Tall-Spindle-System-Apple-Orchard-Design-For-The-Future