Submitted to: International Wheat Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/20/1997
Publication Date: N/A
Interpretive Summary: Agronomists can be more effective in understanding crop growth and production if they pay close attention to the different stages of plant development when they evaluate practices or design experiments. This article addresses the use of plant staging in the study of cereal crops and reviews several important shifts of physiology that are important to understand in breeding and crop management. The use of heat units instead of calendar time is also discussed and recommended so that crops in different years and locations can be better compared. The information is of especial importance to scientists who are modelling crop growth and development and must specify life-cycle markers in order to shift distribution patterns of growth and deposition of dry matter.
Technical Abstract: Recent efforts to model winter wheat (Triticum aestivum L.) crop growth and yield have required scientists to define processes involved in wheat physiology and to link knowledge of physiology with detailed descriptions of phenology. The use of precise visual plant staging to express different phenological phases of the wheat life cycle has allowed modellers to define such features as the specific organs available for growth; resource allocations to tiller, root, and leaf growth; above versus below ground distribution of dry matter; and timing of phenological events in the crop. Use of cumulative heat units (growing degree days) to drive cereal development has simplified expression of some of these relationships. This paper will present phenological aspects of wheat development that have been used over the past 15 years for modelling and will discuss how this information might be of use to breeders and crop managers concerned with selection and management of plant materials. Cultivar properties such as stress avoidance, timing of critical stages, and harvest ratios as well as management factors including spray schedules, fertilization timing and amounts, and planting geometry can all be examined for their impacts on production by use of models and are the types of properties that breeders typically use to improve yields.