A symposium on biophysical ecology was held at The University of Michigan Biological Station on Douglas Lake August 20-24, 1973. Biophysical ecology is an approach to ecology which uses fundamental principles of physics and chemistry along with mathematics as a tool to understand the interactions between organisms and their environment. It is fundamentally a mechanistic approach to ecology, and as such, it is amenable to theoretical modeling. A theoretical model applied to an organism and its interactions with its environ ment should include all the significant environmental factors, organism properties, and the mechanisms that connect these things together in an appropriate organism response. The purpose of a theoretical model is to use it to explain observed facts and to make predictions beyond the realm of observation which can be verified or denied by further observation. If the predictions are confirmed, the model must be reasonably complete except for second or third-order refinements. If the pre dictions are denied by further observation, one must go back to the basic ideas that entered the model and decide what has been overlooked or even what has been included that perhaps should not have been. Theoretical modeling must always have recourse to experiment in the laboratory and observation in the field. For plants, a theoretical model might be formulated to explain the manner and magnitude by which various environmental factors affect leaf temperature.

Crops and world food supply, crop evolution, and the origins of crop physiology; Maize; Sugar cane; Rice; Wheat; Soybean; Pea; Potato; Sugar beet; Cotton; The physiological basis of crop yield.

This volume contains papers on anatomy, physiology and action of stomata.

It has been ten years since the publication of the third edition of this seminal text on plant virology, during which there has been an explosion of conceptual and factual advances. The fourth edition updates and revises many details of the previous editon, while retaining the important older results that constitute the field's conceptual foundation.Key features of the fourth edition include:* Thumbnail sketches of each genera and family groups* Genome maps of all genera for which they are known* Genetic engineered resistance strategies for virus disease control* Latest understanding of virus interactions with plants, including gene silencing* Interactions between viruses and insect, fungal, and nematode vectors* New plate section containing over 50 full-color illustrations