Relationship between laboratory and field assessments of common bean (Phaseolus vulgaris L.) seed quality indicators

Abstract

The objective of this study was to extend the measure of seed quality beyond seed germination using three common bean (Phaseolus vulgaris. L) cultivars. Under laboratory conditions, total seed germination was included in calculation of other seed performance measures, mean germination rate and germination vigour index. These parameters were used to produce a new parameter, total potential value for germination. The laboratory measures were duplicated under field conditions over two seasons to produce comparable data for seedling emergence, mean emergence rate and emergence vigour index. Consequently, total potential value for emergence was derived. The crop was grown under field conditions at three seeding rates (177 000 plants ha-1, 150 000 plants ha-1 and 115 000 plants ha-1). Prediction of seed performance under field conditions was extended by measuring plant size from the first trifoliate to initiation of reproductive stage. During this period, new measures comparable to those of laboratory seed vigour and emergence vigour were derived on the basis of vegetative growth vigour, resulting in total potential value of plant growth. The study revealed that germination and plant growth can be correlated using vigour indices.

Keywords

• emergence
• germination
• growth index
• seed vigour