
TY  - JOUR
A1  - McKenzie, FR 
T1  - Influence of applied nitrogen on weed invasion of <I>Lolium perenne</I> pastures in a subtropical environment
JF  - Australian Journal of Experimental Agriculture
JO  - Aust. J. Exp. Agric.
Y1  - 1996
VL  - 36
IS  - 6
SP  - 657
EP  - 660
KW  - 
UR  - https://doi.org/10.1071/EA9960657 
N2  - Lolium perenne L. (perennial ryegrass) exhibits poor persistence in subtropical environments and this is often characterised by weed invasion. The effect of applied nitrogen (N) (120-720 kg/ha.year), on weed invasion of perennial ryegrass was examined during the establishment year. Weed tiller densities ranged from 50 tillers/m2 (at 360 kg N/ha.year) during November 1993, to 2400 tillers/m2 (at 120 kg N/ha.year) during February 1994. Increasing levels of applied N up to 360 kg/ha.year reduced both weed tiller densities and relative frequencies in perennial ryegrass pastures. Seasonally, high weed tiller densities (up to 2400 tillers/m2 at 120 kg N/ha.year) and high frequencies (46-82% for 120 and 600 kg N/ha.year, respectively) were observed over midsummer (December) to autumn (May). Applying N at levels above 360 kg/ha.year (or 30 kg/ha.month) is useful in minimising weed invasion of perennial ryegrass during its establishment under subtropical conditions. 
ER  -

