There are generally several options available for controlling any given weed situation. Long term control of weeds in pastures is achieved by utilising a range of these control options as part of the farm management system. It is useless to control weeds in the short term unless the primary cause for the weed invasion is identified and management steps are taken to avoid future situations conducive to reinvasion. The Vanuatu Pasture Improvement Project (VPIP) encourages farmers to take a long term, whole farm approach to weed control using appropriate management of weed populations.

Weeds are frequently introduced to otherwise clean properties in contaminated pasture seed (e.g. Achyranthes aspera - chaff flower), by grazing animals (Cuphea carthagenensis tar weed) or in soil on uncleaned machinery (Parthenium hysterophorus dispersal along the roads of Efate and Tanna). Introduced weeds tend to radiate from farm roads, bolding paddocks and stockyards. Care should be taken in using only certified seed, quarantining new stock in specific holding paddocks and thoroughly washing machinery from contaminated areas.

Common weeds are troublesome because they have biological characteristics which enable them to persist and spread in a particular environment. Their various mechanisms for dispersal allow them to spread rapidly from farm to farm 50 that control of common weeds must be dealt with as part of everyday operations. Good farmers control weed outbreaks before they seed and thereby reduce future problems. It is important to realise that single plants of pico (Solanum torvum) and pistache (Cassia tora), if left to mature, can produce hundreds of seeds which will germinate over a period of several years.

'file four main methods are (1) pasture management, (2) cultural practices of weed control, (3) use of herbicides, and (4) biological control through use of natural pests or pathogens. A combination of these control methods is usually required for economical, long term control of weeds.