Chemical Sprays to Protect Fruit Trees
Unlike the treatment of other plants, where there are several alternatives, that of, bushes etc. involves almost entirely the use of sprays. This makes life a lot easier in centre or shop when choosing what to buy because all you need concern yourself with are the concentrated liquids and wettable powders, both of which are added to water before application. Forget the puffer packs, the aerosols and the smokes where fruit is concerned.
The basic kinds of spray are fungicides, for killing fungus diseases, and insecticides, for killing insect pests. These two are divided into either ‘contact’ or ‘systemic’.
A contact chemical is one that has to come into direct contact with the pest or disease to kill it. It can do this either by the spray landing on the pest or the diseased surface or by the pest or fungus spores landing on a treated leaf or fruit.
A systemic chemical works differently. It usually has some contact effect, but its main mode of action is to enter the plant that it lands on and, in most cases, pass into the sap stream. In this way, it can permeate throughout the plant and, at the same time, it will be weatherproof. For as long as the chemical remains active, any susceptible pest or disease landing on a treated plant will perish if it tries to eat or penetrate that plant.
Once it has been decided that spraying is needed to beat whatever it is, the ‘nasty’ must be identified reasonably accurately so that the correct spray can be bought. It is obviously a waste of time and money to spray ‘blind’ and hope for the best.
The first point of enquiry is the staff at your garden centre or shop. Several produce excellent ‘rogues gallery’ charts with the control measures given alongside the problem. Fortunately, however; many sprays today will kill several pests or diseases so it is not always necessary to pinpoint the problem. The more you can narrow it down, though, the better it is because you may find that you can use one of the increasing number of sprays that are only lethal to a small number of pests, or even just one. Clearly, it is these materials that are going to have the least damaging effect on harmless and beneficial creatures.
Having chosen the right spray for the job, read and understand the instructions before you go any further Take note of precautions, including any fruits that should not be treated, and understand the dilution rates.
When you come to spray, make sure that you do it thoroughly so that every part of the plant is treated; most sprays work on the basis of forming a toxic layer on the leaves and fruit. If this is incomplete, so will the control be.
Avoid spraying in windy weather because this will carry the spray to where it is not wanted; such as next door In addition, be sure that any vegetables in the vicinity of the fruit are either not yet mature, that they are covered during the spraying or that they will actually benefit from a dose.
In summer, always spray in the evening when the majority ofand other ‘goodies’ have retired for the night. Never use an insecticide during the blossom period; all, with the rare exception of one or two, are lethal to bees. Even some fungicides are harmful so it is much better not to spray at all until the flowers have fallen.
When you have finished spraying, dispose of any surplus safely. The best way is to offer it to a neighbour; you then also know that the particular pest or disease is unlikely to attack you again from his direction. Failing that, pour the surplus either onto a piece of empty ground or down the lavatory. Either way it will be so diluted as to be completely harmless.
Any concentrates that you want to dispose of can be flushed down the lavatory; powders may also be wrapped and put in the dustbin, along with empty containers.
Most of these precautions are a matter of common sense and really, can apply to the whole subject of pest and. Do all that you reasonably can to keep trouble at arm’s length, but, if this fails (as it often will), use chemicals sensibly They are a boon to gardeners for doing the right job in the right place and at the right time.