**4. Risk management in use of GM crops**

Risk management involves strategic techniques to reduce the adverse effect of GM crops and associated products on non-target species or environment and also to reduce the chances of development of resistance in target pest population. Several

tactics *viz*. application of alternate or mix insecticides with different modes of action or use of refuge strategy could be effectively employed to minimise the risk of development of insecticidal resistance in insects. These techniques are also helpful in avoiding the problem of resurgence in insects. In Bt crops newer techniques *viz*. use of alternate or combined Bt toxin or refuge strategy are much rewarding in management of resistance. Similarly, weeds could develop resistance in them following various mechanism *viz*. modified site of action, detoxification and compartmentalisation. By doing so they rendered the herbicides or weedicides ineffective against them in long run. Thus, to minimise or to prevent the risk of development of herbicide resistant in weeds and evolution of super weed various techniques have been utilised. Rotation of herbicides or using them in combination effectively reduces chances of development of resistance against herbicides in weeds. Crop rotation is another technique that could be used to reduce this risk [6].
