On the Phenology of Field Corn, the Vegetative Period 1

R. H. SHAW AND H. C. S. TnoM r I 'HE anticipated yield and quality of a corn crop JL may be described quite effectively at any time by two characteristics: condition and progress. The condition of a crop at any given time is mostly an indicator of final yield, while the progress of the crop is an indicator of the date of maturity, and hence of the quality. Factors which can lower quality are high moisture content, low test weight, and spoilage. Since yield has always been of primary interest, there have been many experiments conducted for measuring and improving yield, but practically no experiments have been designed to study progress or phenology. This seems to have been due to the large gains in yield that have been accomplished by breeders in comparison with the relatively small potential that phenology experiments have for variety improvement. Although well adapted varieties are available for all areas, farmers often use a longer maturing variety than that adapted for their particular area in the hopes of getting increased yield, in spite of the increased danger of frost injury. Experiments on the progress of the crop will give the grower and breeder information leading to better adaptation of varieties. There has also been some realization recently that we may be approaching the point of diminishing returns in augmenting yields, and that perhaps more effort to improve quality may be in order. It was with these thoughts in mind that