Case studies on Integrated Weed Management

Weed Management for Developing Countries: Addendum 1

This volume is a supplement to the previous publication Weed Management for Developing Countries, and its aim is to provide up-to-date information on new developments and progress made in weed management. Many people involved in agriculture consider applying herbicides the only approach to weed management, but in reality there are a number of weed problems that need to be controlled by the use of various strategies. This material once again emphasizes the importance of weed ecology in understanding weed problems, the need to evaluate seed banks in the soil, the importance of evaluating weed competition and the ability of crops to compete with weeds.

Management of herbicide-resistant weed populations: 100 questions on resistance

Although herbicide-resistant weeds are a known problem, farmers in many countries detect the problem of herbicide inefficacy when the resistance is already in the field. This document is an contribution and guidance for agricultural extension workers on herbicide resistance prevention. The material carefully describes the activities to be carried out by personnel working with farmers and the strategies to implement for preventing and managing resistance. The application of these lessons learned by specialists on this issue may help towards a better use of herbicides in general and the avoidance of its resistance.

Progress on farmer training in parasitic weed management

The damage caused by the parasites Orobanche on field and vegetable crops in Northern Africa and the Near East, and Striga on cereals in several countries of Africa South of the Sahara is significant. No single method has so far been found to successfully control these root parasitic weeds. An integrated control approach is required that should be feasible for small-scale farmers to implement. The present material is a compilation of various country reports generated within the framework of the project. It clearly shows the progress made by farmers in the process which empowered them to implement improved management strategies against Orobanche and Striga parasitic weeds.

The need for improved weed management in rice

Weed control in overpopulated areas of Asia has mainly been carried out through a combination of water management and hand-weeding, but the latter is becoming less common in areas with an increasing labour shortage problem; furthermore, this method affects transplanting. Improved weed control can be applied within the context of integrated pest management (IPM). This is an important prerequisite for achieving the expected yield growth in rice production and obtaining the necessary reduction in weed stand, including weed seed bank. This paper aims to give an idea of the work entailed in the implementation of improved weed management practices.

Expert Consultation on Weed Ecology and Management

There is an evident need to provide weed management technology to farmers in the developing world, but this should be based on an Integrated Pest Management approach. Such technology should include various elements, such as weed monitoring and sound criteria for the adoption of various control methods, including chemical control where required. Twelve papers were presented by various weed scientists and an IPM specialist covering various issues related to improved weed management. Topics also spanned externalities providing constraints and opportunities for weed management, and current development in weed ecology to improve tools for farmer decision making.

Management of problematic aquatic weeds in Africa

The control of aquatic weeds in Africa is difficult and all sound options should be considered. When necessary, a combination of control measures may be used, depending on the nature of the local problem. Among the ways to control exotic weeds, environmentally friendly and sustainable methods should be adopted. A sound option is the so-called classical biological control, which is the use of beneficial organisms - the natural enemies that effectively limit the populations of the host plant in its area of origin - to reduce the growth and population density of the weed in the area of introduction. The organisms used are host-specific and do not harm other desirable plants.

Recommendations for improved weed management

Improved weed management in the agriculture of developing countries is needed for the development of Integrated Crop Management (ICM). Plant protection services, research and agricultural extension must deal with the problem of weed control through the necessary farmer education, and publishing leaflets and bulletins on the subject. Based on the importance of weed control for sustainable agriculture, FAO has decided to prepare and publish the present practical guidelines as a modest contribution to the efforts of developing countries to secure food for their population.