Argentine stem weevil effects on Nui and Ruanui ryegrasses grown with two levels of nitrogen/water nutrition

Autor: W. F. Hunt, D. L. Gaynor
Rok vydání: 1982
Předmět:
Zdroj: New Zealand Journal of Agricultural Research. 25:593-599
ISSN: 1175-8775
0028-8233
DOI: 10.1080/00288233.1982.10425225
Popis: Monoculture plots of ‘Grasslands Ruanui’ and ‘Grasslands Nui’ perennial ryegrasses were established with high and low nitrogen/water treatments. Twice-weekly examinations of tagged rye grass tillers showed Ruanui with high N/water (RH) to be more severely damaged by Argentine stem weevil larvae than Ruanui with low N/water (RL) or Nui with either treatment (NL and NH). More stem weevil larvae were found in Ruanui plots, and in plots with high N/water. Peak larval densities in RH plots were 1500 larvae/m2 or one per 4.8 tillers. Although RH plots sustained higher rates of stem weevil damage, no similar cultivar × nutrition interaction was detected for larval density. Net growth rates for RH plots were reduced because of high rates of herbage and tiller death during January and February when stem weevil damage was greatest. High rates of tillering in RH plots during April were associated with a recovery of both tiller density and growth rate. It is suggested that studies concerning stem weevil susc...
Databáze: OpenAIRE