Introduction
Pests - Recognition & Control

In compiling this report, I have tried where possible to identify the most serious of pests and diseases in plants of the landscape, those that kill, and cause severe contemptuous disablement of plants, and which often may occur in plague proportions, and not those that merely cause inconsequential damage. I have had to do this as there are so many different types of pests and diseases, and in an amenity situation it is not always practical to spray against EVERY pest that comes along, and often the damage is very minimal, seldom kills or spreads, and does not have an immediate effect on the vista. Most are immediately identifiable, however, some of the viruses and smaller insects can be mistaken for pollution, chemical sprays, and some fungi may live in a tree for decades before any signs of them becomes apparent, as the plants often have natural defences to the pests and disease. Those that do succumb are often sick plants.

In compilation I have learnt that there are a limited number, or similar chemicals that can be used against each disease or pest, and these must be used only in the most severe cases, or where time is limited. This is because pests and plants can become resistant, and often the area may be highly populated. Most can be contained through good hygiene and management.

The first rule is to check the stock as it comes in, and reject anything that is less than healthy. Second is to maintain good hygiene in the area the plants are contained. e.g. remove all debris, and water logging, repair all damage, use correct spacing, maintain aeration, wash pots, tools. Third is to use sterile soil wherever possible. Fourthly it is always a must that infected plants are burnt.

If a particular plant is causing trouble or is a harbour for pests then it is best to replace the plant with a resistant variety, such as in the case of Elm Disease, where varieties have been bred in sterile conditions in Holland. Hawthorn is a harbour for all sorts of pests, and can be replaced with Berberis and Holly. There are also advancing techniques for the control of pests naturally using bacterium such as Bacillius thuriginensis which kills the insects from the inside. In the field of genetics, these bacteria are also being inserted into plants, making them resistant, but there is still controversy over these methods. A proven and tested method is in the propagation of plants using the apical meristem, this allows the plant to grow, free of viruses and fungi contained in the mother plants, producing sterile plants that have a greater success in survival and propagation.

So as the ongoing war against nature is never-ending, Pest control will become an important industry, but we should always be willing to try out new methods of control and management, or use nature to aid us in some cases, but it is a very complex area, and needs more experts in the field. It is always advisable to use chemical sprays in the most die situations or where stock is of considerable value.