GTZ's work focuses on raising awareness and transferring know-how concerning feasible alternatives to MB in developing countries that are dependent on the industrialised nations for their technological developments. In consequence, they grow and disinfest their produce for export with MB to gain a small economic advantage.
The GTZ services concerning the assistance in phasing out MB are based on:
GTZ activities to phase out MB are coordinated by the Environmental Protection and Conservation of Natural Resources Section (PROKLIMA project) and the Plant Protection and Post-harvest Section. As substituting MB is primarily a part of integrated crop production and integrated pest management, a series of agricultural and quarantine projects are working on alternatives for specific applications.
GTZ has commissioned the elaboration of a compendium of feasible or promising MB alternatives (cf. chapter 3). The compendium is intended to assist decision makers and practitioners to adopt alternative solutions. This process promises to become difficult for several reasons, such as:
GTZ wants to contribute to overcome these obstacles by disseminating alternatives that are tested in several countries and by providing information on the costs that facilitate the choice of suitable alternatives. The compendium is the first step in GTZ's awareness and training programme. Details on further activities within this programme are given in chapter 7.
GTZ has established a worldwide network of offices and projects which engage in target-group and problem-oriented work. Several bilateral and regional projects are actively involved in developing and testing MB alternatives under field conditions. Current and future priority areas are soil disinfestation, treatment of durabledurables durables commodities, the development of economic instruments and the disposal of obsolete stocks of MB.
As far as soil fumigation is concerned, GTZ opts for non-chemical alternatives, as many of the chemicals that could substitute MB are themselves potentially hazardous to human beings and the environment. In Germany, the registration of chemical alternatives has become difficult for these reasons. Suitable crop rotation schemes, cultural practices such as deep ploughing and water management, integrated pest management, biological control and solarisation are considered to be feasible alternatives (also from the economic point of view), even though some aspects of their practical application have yet to be further studied with regard to the specific situation of developing countries.
GTZ is successfully assisting activities in the field of MB substitution for soil treatment in projects in Egypt, Jordan and Morocco. The relevant project activities are briefly presented below:
Integrated Pest Management, Egypt (PN 90.2195.7)
In Egypt, the use of MB to fumigate soil in vegetable production has been banned for several years. IPM project measures to combat soil nematodes include testing the planting of Tagetes in summer, the grafting of cucurbits on resistant stocks and an algae-based product that is to be registered in the near future. The project also recommends enriching the soil with organic material, crop rotation and solarising the soil.
Sustainable Pest Management Systems, Jordan (PN 94.2085.2)
In Jordan, MB is still widely used in greenhouses. The GTZ-assisted project recommends the following alternatives:
The GTZ-assisted project pays particular attention to developing a technology that is adapted to the needs of small-scale farmers. Participative cooperation with a group of women farmers led to promising results for solarisation plus use of the beneficial fungus Trichoderma Compared to MB application, the average treatment cost could be reduced by almost 60 % (about 100 USD) per greenhouse (500 m²).
Phytosanitary Control, Morocco (PN 90.2195.7)
Trials started during 1996 use Tagetes which are planted after tomato es and act as trap crops in controlling nematodes.
Even in very intensive agricultural systems the use of methyl bromide in soil fumigation can already be phased out. This is proven by the Netherlands where this treatment has been banned since 1991 without adversely affecting yields. On the contrary, according to the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia, yields of strawberry and cucurbits in greenhouses have since doubled. Other countries like Germany, Denmark and certain regions in Italy are also competitive in vegetable production without or with very restricted use of MB (Prospect Consulting, 1997; Gyldenkærne & al, 1997).
There is a wide range of alternatives available for fully substituting methyl bromide in the treatment of cereals and pulses.
The overall need for fumigations of agricultural products could be considerably reduced by applying integrated pest management principles during crop production and storage. Crops are often produced and then stored under conditions conducive to pest development, due to a lack of means or knowledge, economic considerations, or simply negligence. In many cases, improvements in IPM techniques lead to reduced pest pressure on stored products and thus to a reduction in the number of times food needs to be fumigated to maintain quality.
The fact that MB acts quickly (within 24 hours) is not a justifiable argument for continuing to use it to fumigate durables. Good management, like proper planning and timing of treatment instead of last-minute actions before shipment, allows the use of other methods, even if an exposure time of one week or longer is required, as is the case with phosphine and other alternative fumigants. In most cases, pests resistant to phosphine can still be controlled with this gas. However, conditions required to use this technique (the product or storage structure must be well sealed) must be carefully adhered to.
In-transit fumigation of cereals on board bulk carriers has become a routine treatment and can be used in many cases as an alternative to MB in fulfilling quarantine requirements. It is advantageous as the transport period can be used for the fumigation process and thus no time is lost.
These techniques are part of the extension services of the following GTZ-assisted projects:
Post-harvest Project (PN 94.2153.8)
This supra-regional project has been promoting the post-harvest treatment of durables without MB for several years. Training and extension work focus on hygiene and other preventive measures and on proper application of phosphine in large-scale storage. Magnesium phosphide is recommended for quarantine purposes because it acts comparatively quickly (exposure time: 3 days) and, like other formulations releasing phosphine, does not influence the taste of produce with a high moisture content.
Training courses for participants from all over the world also recommend this technique. In collaboration with the German Foundation for International Development - Food and Agriculture Development Centre 1 (DSE-ZEL), specialists from African, American and Asian countries have been trained. Special fumigation courses, in which the MB problem has been extensively covered, have recently been carried out in Syria and Benin. South-East Asian countries use an unusually high proportion of MB for post-harvest treatment of durables that can easily be replaced by phosphine. These countries will be targeted for training measures aimed at short-term reduction of MB application.
GTZ-assisted Plant Quarantine Project, Syria (PN 90.2227.8)
This project recommends the use of phosphine for quarantine fumigation wherever this is technically feasible and sufficient time is available. Fumigation trials planned by the project include applying ozone in cereal bag stacks under gastight sheets and using controlled atmospheres with elevated carbon dioxide concentrations in fumigation chambers.
In some countries, old stocks of MB in rusty and/or leaking containers seriously endanger human beings and the environment. GTZ helps to deal with this problem in the
Pesticide Service Project (PN 96.2079.0)
This supra-regional project assists developing countries to dispose of methyl bromide in line with international environmental and safety standards and is working out guidelines and procedures in order to avoid similar problems in the future. The project submitted an offer for disposing 8.5 t of MB stored in Port Sudan and which is no longer of use to the Sudanese Government. Additionally, the project provides advisory services in the fields of pesticide use and quality control and information on the choice and application of alternative synthetic and natural products intended to substitute MB.
The phase-out of MB and the promotion of suitable alternatives require the change of the economic and institutional framework. Over- and misuse of pesticides in general are caused by continuing subsidisation (see Waibel & Fleischer, 1995). The
Pesticide Policy Project (PN 93.2183.7),
a supra-regional project assisted by GTZ and the University of Hannover, is conducting case studies in four countries on the assessment of economic and political factors in crop protection. Workshops and training activities are conducted on the use of economic instruments to reduce pesticide consumption and implement phase-out programmes.
1 Deutsche Stiftung für Internationale Entwicklung - Zentralstelle für Ernährung und Landwirtschaft
