Ecological concepts in organic farming and their consequences for an organic crop ideotype

Currently, organic farmers largely depend on varieties supplied by conventional plant breeders and developed for farming systems in which artificial fertilizers and agro-chemicals are widely used. The organic farming system differs fundamentally in soil fertility, weed, pest and disease management, and makes higher demands on product quality and yield stability than conventional farming. Organic farming systems aim at resilience and buffering capacity in the farmecosystem by stimulating internal self-regulation through functional agrobiodiversity in and above the soil, instead of external regulation through chemical protectants. For further optimization of organic product quality and yield stability new varieties are required that are adapted to organic farming systems. The desired variety traits include adaptation to organic soil fertility management, implying low(er) and organic inputs, a better root system and ability to interact with beneficial soil micro-organisms, ability to suppress weeds, contributing to soil, crop and seed health, good product quality, high yield level and high yield stability. In the short run, organic crop ideotypes per crop and per market segment can help to select the best varieties available among existing (conventional) ones. However, until now many of the desired traits have not received enough priority in conventional breeding programmes. Traits like adaptation to organic soil fertility management require selection under organic soil conditions for optimal results. The limited area of organic agriculture will be the bottleneck for economic interest in establishing specific breeding programmes for organic farming systems. The proposed organic crop ideotypes may benefit not only organic farming systems, but in the future also conventional systems that move away from high inputs of nutrients and chemical pesticide