Weeds and their Control



Based on NZQA 21555

This is a unit standard for people handling agrichemicals in land based industries. People credited with this unit standard are able to: identify weeds, and the ways they survive and spread; and describe methods of weed prevention and control, and the relationship between weed control and plant life cycles.


 * Learning activities
 * Library of resources

This unit is used in the following courses

 * Horticulture

Identify weeds, and the ways they survive and spread
Range: evidence is required for at least 15 weeds. Range: plant type, plant reproduction, physical and chemical defences, plant vigour, root systems. Range: life cycles – annual, biennial, ephemeral; perennial – herbaceous, woody.
 * Weeds are defined, and their detrimental effects are identified and described, in relation to a specified land based industry.
 * Weeds from a specified region and land based industry, are identified by sight.
 * Weed survival is described in terms of plant adaptation and dispersal.
 * Plant life cycles are described.

Describe methods of weed prevention and control, and the relationship between weed control and plant life cycles
Range: methods – biological, chemical, cultural, physical, legal. Range: life cycles – annual, biennial, ephemeral; perennial – herbaceous, woody.
 * Weed prevention and control is described in terms of the methods used.
 * The implications of weed prevention and control are described in relation to each stage of the plant life cycle.

Definitions

 * agrichemical – any substance, whether inorganic or organic, man-made or naturally occurring, modified or in its original state, that is used in any agriculture, horticulture or related activity, to eradicate, modify or control flora and fauna. It includes agricultural compounds, fertilisers, vertebrate pest control products and oral nutrition products (this definition differs to that given in NZS 8409:2004, where agrichemicals exclude fertilisers, vertebrate pest control products and oral nutrition products);
 * weed – a plant that interferes with the management objectives of a land based industry at a particular location. It is a plant growing where it is not wanted, however under certain situations, the plant may not be totally undesirable;
 * legal – a weed prevention and control method carried out in response to legislative requirements which includes but is not limited to the Biosecurity Act 1993.