Broom (Cytisus scoparius (L.) Link) competition and management in eucalypt tree farms
C.D. Barnes and G.K. Holz, North Forest Products, PO Box 63, Ridgley, Tasmania 7321, Australia.
A trial to evaluate competitive impact of broom (Cytisus scoparius (L.) Link) on establishing Eucalyptus nitens (H.Deane & Maiden) Maiden was established in a two year old plantation with a uniform broom cover, near Waratah, north-west Tasmania. Treatments consisted of three levels of broom control (total, inter-row and none), combined with two levels of fertilizer (0 and 200 kg ha,-1 nitrogen). After one and a half years the current practice of inter-row broom control without added nitrogen had no significant impact on E. nitens stem volume. There was a significant increase in stem volume of at least 23% due to nitrogen and of 49% increase due to total broom control. This suggested that competition was likely to be for nutrients and that it would be more economic for plantation managers to apply 200 kg ha-1 nitrogen at years two to three than to perform post-plant inter-row broom control.
Mapping of broom in the north-west of Tasmania revealed 59 250 ha containing broom. Data generated during mapping was used to develop a broom management plan that includes control of isolated broom plants, isolation of large infestations and adoption of long term control strategies such as release of biological control agents.
Plant Protection Quarterly (2000) 15 (4) 163-165.