The mathematical separation of plant and weather effects in field growth studies

Abstract

The only serious limitations of field growth studies are due to the erratic nature of the curves caused by short-term weather variations and the less apparent deviations caused by secular changes. The method of constant-fitting is applied, via a suitable mathematical model and experimental design, to separate growth and weather effects. A detailed account of the analysis is given, using a trial conducted as a test of the technique as an example, and the future possibilities of the technique in field growth studies are discussed.

Pasture irrigation in the Mackenzie Basin

“…A phase cutting technique similar to that of Glenday (1955) and Brougham & Glenday (1969) was used so that plots of each treatment were sampled fortnightly throughout the growing period September-May.…”

Methods of Crop Response Studies (Emphasis on Thermal Effects)1

“…When a series of such single-element-sorters is applied one at a time to crop yield, the mixed zone would eventually disappear. This is true if the available environmental elements are: (I) the only determining factor of yield, (2)' large enough to cover all possible environmental effects, ( 3} correctly chosen and ( 4) reliable and representative of an over all microenvironment. Choosing the right element for the sorter is very important.…”

The contributions of Dr Raymond Wilkie Brougham to grassland science and management

“…The technique Brougham used in his pasture growth studies was developed in collaboration with Glenday (1955Glenday ( , 1959 and involved layouts that provided replication in time as well as space to allow separation of temporary weather variations on growth. This enabled derivation of pasture growth curves with the influence of shortterm weather fluctuations removed.…”