Implement A Pre-Application Plan

Crops attract a great variety of pests and diseases that cause external and internal damage to the crop and plant.

Although some pests and diseases in a field or orchard are controlled manually, the greater majority are controlled through the use of chemicals. The crop protection application methods covered in this unit standard refer to the chemical control of pests and diseases.

The term Crop Protection Manager is used in this learning material when referring to the person responsible for the implementation of the crop protection program. In practice, this function may be fulfilled by the farmer or the general manager of the farming operation.

Proper planning for protecting crops from pests and diseases is critically important. Poor planning could result in financial losses due to a reduced crop or a poor-quality crop, and possible damage to the health of trees. Time and money will also be lost if incorrect or unnecessary applications are made.

Planning entails two steps. Firstly, a crop protection program is compiled to control the pests and diseases commonly found in the area where the farm is located. The crop protection manager decides which chemicals to use, in what concentration to apply the chemicals and the schedule of application. This information is incorporated in a crop protection program, which is normally compiled before the start of the season and strictly adhered to as the season progresses. There may be minor changes made during the season if circumstances in the field change.

Pre-application planning is done before each stipulated application on the crop protection program and may be best accomplished by using a simple checklist. We will look at the checklist at the end of this session, after considering the various components of this planning process.

A proper plan for the application of plant protection products, a thorough understanding of the following components are required:

• Plant protection products
• Application methods
• Application equipment
• Health and safety

Plant Protection Products

The first step in the pre-application planning is to identify the product indicated in the crop protection program. Plant protection products are generally classified as insecticides, fungicides or herbicides.

Pesticide is the overall term used for all classified Crop protection products (CPPs) or agro-chemicals.

Insecticides are plant protection products (PPPs) that are used to control insects.

Fungicides are plant protection products (PPPs) that are used to control fungi.

Herbicides are plant protection products (PPPs) that are used to control weeds.

Plant Protection Product Registration

Only chemicals that have been registered with the National Department of Agriculture in accordance with Act 36 of 1947 are permitted for use in South Africa. These products are listed in the following Government publications, which are updated from time to time:

• Guide for the Control of Plant Pests
• Guide for the Control of Plant Diseases

There is a section in these publications covering citrus pests and diseases where remedies for specific problems are listed. If these books are not available, the crop protection manager may need to consult a representative of one of the agrochemical companies.

Plant Protection Product Identification

The first step in identifying a product is to consult the chemical label. All chemicals must, by law, have a label on the container when it is supplied to the end-user.

The following information appears on the product label:

Full instructions on how to use the chemical are indicated, together with detailed information on the uses for which the product is registered. The instructions must be read carefully and adhered to strictly. This will ensure that the best results are attained, that the safety of the user and others is not at risk, and that the environment is not excessively harmed. It is an offence to use a chemical in a manner for which it was not registered.

A physical description of the product is supplied, including its colour and whether it is in fluid, powder or granular form. The crop protection manager should inspect the chemical in the container to ensure that it answers to this physical description. If not, the container and its contents should be discarded in the prescribed manner.

The chemical composition of the product is indicated on the label.

The toxicity of the product is indicated, along with instructions for its safe handling.

The pre-harvest interval (PHI) of the product is indicated. The PHI, also known as the Withholding Period, refers to the period after the application of a chemical treatment during which time the fruit may not be harvested. PHIs vary considerably from chemical to chemical and need to be checked by the crop protection manager when he compiles the crop protection program. It must also be checked as part of the pre-application planning.

The product expiry date is stated, being the date on or before which the chemical should be used. Chemicals should be used before the expiry date to make sure that the chemical is still effective.

Please Note: All chemicals leave a residue on the fruit. There are very specific regulations regarding the chemical residue levels that are allowed, especially if they are exported. Minimum residue levels (MRLs) are prescribed for all plant protection products registered with the Department of Agriculture. The PHI indicates the period of time during which the chemical residue will be too high and beyond the regulatory limits. During this time the fruit must not be harvested.

Plant Protection Product Availability

The crop protection program indicates the concentration at which the product must be used and the quantity required per tree or hectare. It may also indicate the total quantity of a chemical required for the application, but if not, the crop protection manager can calculate this by using the information provided.

The crop protection manager must ensure that a sufficient quantity of the chemical is available before application commences. In this regard, he needs to consult with the person in charge of procurement (buying) and the inventory manager.