Effect of population density on agronomic performance and chemical yields in pokeweed, Phytolacca americana

Abstract

Pokeweed ( Phytolacca americana L.) has been identified as a promising species for development as a whole-plant source of polyphenols and oil and as a high protein feed. Plants were established in the field in the spring of 1982 at Beltsville, Maryland (MD) and Experiment, Georgia (GA) and harvested in the fall of 1982 and 1983. In 1982, maximum dry matter (DM) yields (leaves, stems, and berries) in GA and MD were 7·5 and 3·1 Mg ha −1 respectively, maximum acetone extract (EX) yield in GA was 0·53 Mg ha −1 (leaves and stems only). In 1983 in GA and MD, maximum DM yields were 13·6 and 4·1 Mg ha −1 respectively, amd maximum EX yields were 0·59 and 0·32 Mg ha −1, respectively. Population densities of 12 000, 18 000 and 36 000 plants ha −1 had no significant effect on yields in GA, but in MD, DM yields were highest at 36 000 plants ha −1 in 1982 and at 18 000 plants ha −1 in 1983. Genetic variation for DM and EX yield was noted.