field horticulture

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What do we need to protect the trees from?

1.  Black Aphid which usually starts to appear around late October early November.  These have pupated in the ground over winter and hatched out wingless and crawl up the tree, and invest  the newest softest leaves they then pupate again hatch with wings and fly away only to appear back in March/April, invade the tree again, then pupate in the ground from where they first started and the cycle goes on.
Recommend solution is broadcast raw course sulphur around the base of the trees to break the cycle.  For protection of trees most insecticides or pirimor.
Aphids bring a host of viruses problems which severely distort growth and can cause the growth to become terminal.

2.   Cherry pear slug - Black slug-like larvae (has a repulsive odour) appears mid summer to autumn - again most insecticides - especially lime sulphur - this has a hardening effect on leaf.

3.   Leaf Roller Caterpillar can appear thru summer and like pear slug are veracious consumers of leaves and the above solution applies to these.

4.   There are other marauding insects such as Grass Grub,  Beatles, Mites, Thrips, Weevils, which can damage root systems a lot of these appear at different times and are generally hard to detect until the damage becomes apparent.  I have found that Lime sulphur applied regularly is the most effective insecticide - it is also a fungicide.

Commercial Growers 50 years ago and longer usually applied 1 Sulphur to 10 of Water for dormant fruit trees and 1 to 15 at bud movement and 1 to 120 when in leaf.  I have advised 1  to 200 when trees are in leaf but can be increased to 1  to 100  in autumn and winter and applied every 4 weeks. 
When using sprays it is also useful to use stickers or spreaders, these break the surface tension down, they can be purchased at Hort Suppliers.   One that comes to mind is calcium caseinate,  (a by product of skim milk casein).

With the management of Cherry Orchards in Tunnels, is more simplified with control of environmental conditions.  Weak diseased trees are always a target for insect infestation and wet cold conditions will compound disease problems.   So more spray programmes are required especially for pseudomonas (blast)  -  copper oxychloride - 

To Place this in some sort of spraying order would recommend the following

August     pre emergence of buds
Lime Sulphur 1 part to 30 Water
This helps to control earwigs, slaters etc from eating swelling buds.

September   Bud break or full blossom
Use Folicur     1 teaspoon per 50 Litres water
To eliminate brown rot or lurking botrytis - this goes for Tunnel house and outside growing...
This should only be applied once at this point of times then again 3 weeks prior to harvest...

October   Lime Sulphur    1 to 200
Pirimor and insecticide spray to be applied

November   Lime Sulphur 1 to 200

Lime Sulphur 1 to 200

January     Lime sulphur   1 to 200

      Lime sulphur    1 to 200

April, May, June & July
     Lime Sulphur   1 to 150
Copper Oxychloride at leaf fall and dormancy in June.

Remember healthy trees will take care of most major problems and beware of merchants trying to sell you the latest and greatest wonder cure.  Stick to tried and true solutions that have worked for the last 100 years.

                                     Copyright Fred Field/ Field Horticulture