ABSTRACT
Seed germination and subsequent seedling growth to emergence from the soil are crucial steps in crop production. Although some field crops such as cereals can compensate for low stands by tillering, in many crop species no amount of effort and cost during plant growth can compensate for poor seedling establishment. A wide range of biotic and environmental factors interact with the potential performance of the seed lot to determine the suc cess of seedling establishment (Hegarty, 1984). This chapter will use popu lation-based threshold models to summarize current understanding of the interaction between the seedbed environment and the seed population from sowing to seedling emergence. The potential for these threshold models to predict seedling emergence in the field will then be discussed while de scribing the construction of an example simulation. In order to see the rele vance and importance of the studies reviewed, it is necessary to briefly out line the consequences of nonoptimal seedling emergence in crops.
