Littleseed canarygrass (Phalaris minor) and short-spiked canarygrass (Phalaris brachystachys) interference in wheat and barley

Field experiments were established in Greece from 1990 to 1993 to study the effect of littleseed and short-spiked canarygrass density on wheat and barley yield, as well as the influence of littleseed canarygrass removal time on wheat yield. Competitive ability of both canarygrass species in wheat was similar, though littleseed canarygrass showed faster growth rate and formed more panicles than short-spiked canarygrass. Grain yield of wheat was not significantly affected by the presence of 76 plants m(-2) of either canarygrass species, but it was reduced by 36 to 39% by the presence of 304 canarygrass plants m(-2). None of the canarygrass species at any density had any effect on grain yield of wheat when cold and dry conditions prevailed during the early stages of growth. Grain yield of barley was not affected by any density of either canarygrass species. Growth and consequently panicle number of both canarygrass species were severely reduced by the interference of barley. The littleseed canarygrass removal time study indicated that emergence of this weed was completed by the middle of February. Grain yield of wheat grown with 150 littleseed canarygrass plants m(-2) was not affected even when these plants were removed early in April. However, the presence of these canarygrass plants until harvest reduced grain yield of wheat by 23 to 28%.