A Population Study to Aid the Selection of Improved Dried Pea (Pisum sativum) Crop Plants

Publisher Website
Google Scholar
Abstract
The effect of genotype and plant density, over the range from 100 to 277 plants m−2, on plant to plant variation in precision sown microplots has been assessed for three ‘leafless’ (afafstst) pea (Pisum sativum) lines. This range of planting densities did not significantly affect the total above ground biological yield per unit area of two of the genotypes (BS5 and BS4) whereas the biological yield of the third (BS151) declined at densities above 156 plants m−2. The differences were due to changes in seed yield. The effect of planting density on the variation between plants for biological yield within the microplots differed between the genotypes. The distribution pattern of BS4 and BS5 changed from normal to skewed with increased density, while the distribution for BS151 remained skewed at all planting densities. The differences between the three genotypes in the proportion of biological yield partitioned into seed yield (harvest index) on a unit area basis was due almost entirely to the differences in structure of the plant populations. The maximum level of partitioning by individual plants was similar for all three lines. The difference between this maximum for an individual and the crop harvest index therefore represents the area for improvement of crop harvest index through breeding. It is suggested that improvements in dried pea yields will come, therefore, by selecting plants which form more uniform populations with regard to plant size and to the proportion of plant biomass partitioned into seed (plant harvest index).