Competitive effects of wireweed (Polygonum aviculare L.) in field and glasshouse studies

摘要

Wireweed (Polygonum aviculare L.) is a widespread weed of agricultural systems in Australia. Field and glasshouse experiments investigating inter and intra specific competition were conducted between wireweed and lucerne or wheat. At the vegetative stage, branch number declined, and wireweed dry matter (DM) increased, with increasing wireweed density. Dry matter per plant generally decreased with increasing density. At flowering similar trends were observed for plot DM and plant DM. Above average rainfall in the spring may have contributed to better growth at higher densities but the result is consistent with previous density studies by Donald (1951). In the glasshouse experiment, irrespective of wheat density, there was a 19% reduction in wheat DMbetween one and three wireweed plants per pot (314 cm~(-2), and a 57% reduction in wheat DM between three and six wireweed plants per pot. Where lucerne and wireweed were grown together, lucerne DM was reduced by 52% and 81% between one and three, and between three and six wireweed plants respectively. It is recommended that wireweed densities are kept below 10 plants m~(-2) in wheat, and below five plants m~(-2) in establishing lucerne.