Bio-Control In Organic Farming Systems

• Mohammad Yousri Hashem
• Dept. of Economic Entomology and Pesticides, Faculty of Agriculture, Cairo University, Egypt.

Abstract

Organic farming follows the laws of nature. Within the organic movement there are farmers who focus on natural farming, while others take it as purely commercial approach. The challenge is to follow the principles of nature to achieve a high productivity and maintain sustainability. The latter must be seen in a holistic sense, which includes ecological, economical and social aspects. Only if the three dimensions are fulfilled, an agricultural system can be called sustainable. Pest and disease management consists of a range of activities that support each other. Most management practices are long-term activities aim to prevent pests and diseases from affecting a crop. Management focuses on keeping existing pest populations and diseases as low as possible. Control on the other hand is a short-term activity and focuses on killing pest and disease. The general approach in organic agriculture is to deal with the causes of a problem rather than treating the symptoms. Therefore, management is of a much higher priority than control. Organic farmers try to keep pests and diseases at a level which does not cause economical damage. The main focus is on supporting the health and resistance of the crop. Beneficial insects are promoted by offering them a habitat and food. If pests reach critical levels, natural enemies and herbal preparations are used. Active populations of natural enemies can effectively control pest and disease organisms and thus prevent their mass multiplication. Therefore, the organic farmer should try to conserve natural enemies already present in the crop environment and enhance their impact. This can be achieved with the following methods:

• Minimize the application of natural pesticides (chemical pesticides anyway are not permitted in organic farming)
• Allow some pests to live in the field which will serve as food or host for natural enemies
• establish a diverse cropping system (e.g. mixed cropping)
• include host plants providing food or shelter for natural enemies (e.g. flowers from which adults of beneficial insects get food)