Every year more and more chemicals are being banned or are not getting re-registered. We will all have to ‘go organic’. Even chemicals approved by the Soil Association are under threat. Although I agree with the ban of some chemicals such as DDT and Paraquat, with other chemicals it seems a bit silly. For example, we are now no longer allowed use sulphur to control Black Spot on roses. Sulphur is still available, but only for use to reduce the Ph. level of the soil.
In days gone by, when we used to burn coal more, sulphur used to go into the atmosphere and when it rained it came down and coated the leaves and consequently there was very little Black Spot at that time. When the clean air act came in there was no sulphur in the atmosphere so we now have the problem today. So why are we unable to use it to control Black Spot now? (Sulphur was originally used to control storage rot on bulbs.)
In the UK all chemicals used to kill pests and diseases have to be approved and the cost of getting these data together runs into hundreds of thousands of pounds and has to be repeated for each formulation as well as for the EU. A formulation is typically a concentrate that has to be diluted and ready to use. For chemicals like sulphur that are very cheap to produce, the manufacturers would not be able to recoup the costs for this process unless they charged prohibitively high prices – and of course one would buy it.
We used to have a product called Armillatox that was for controlling White Rot on onion, Vine Weevil and Honey Fungus on trees and shrubs. It is estimated that it would cost £3 million to get registration and for a small company this cost is prohibitive. Armillatox is still available on line but only as a garden disinfectant. Consequently there is now no control for White Spot or Honey Fungus. This is repeated for many of our tried and tested controls that we have used for many years. Bordeaux, a copper based chemical used to control blight on potatoes and tomatoes, is another classic that is now banned – so what will we do if there is an outbreak of potato blight?
It may surprise you that at present there is no chemical for the control of diseases on fruit and vegetables. You can however make your own spray with the following recipe:
10 cloves of garlic chopped up
1tsp washing up liquid
1 litre water.
Method: Place all the ingredients except the washing up liquid in a jar and allow to stand for a day. Then strain the lumps out and add the washing up liquid and put in a sprayer. Shake well before use and spray plants regularly. This will help control some pests and diseases and act as a growth stimulant. Garlic is high in sulphur. Always spray in the evening and I would not use this on my favourite plants before I have tested it on a couple of other ones that you don’t mind losing just in case it kills them.