This paper reviews current knowledge concerning the occurrence, losses caused, epidemiology, and management of virus diseases of annual pasture legumes. The viruses commonly present are spread by contact, or aphid vectors either non-persistently or persistently. Whether they are seed-borne and their means of transmission are critical factors determining their incidences within pastures in climatic zones with dry summers or substantial summer rainfall. Large-scale national or state surveys of subterranean clover pastures revealed that some viruses reach high infection incidences. Contamination with seed-borne viruses was widespread in plots belonging to annual pasture legume improvement programs and seed stocks of subterranean clover, annual medics, and alternative annual pasture legumes, and in commercial annual medic seed stocks. Yield loss studies with grazed swards were completed for three common viruses: two in subterranean clover and one in annual medics. These studies demonstrated considerable virus-induced losses in herbage and seed yields, and established that virus infection causes deteriorated pastures with high weed contents even when foliar symptoms are mild. Comprehensive integrated disease management tactics involving phytosanitary, cultural, chemical, or host resistance measures were devised for these three viruses in infected pastures, and for seed-borne viruses in annual pasture legume improvement programs. Several other viruses are potentially important, but, with these, quantification of losses caused in grazed swards is lacking and information on incidences in pastures is currently insufficient. Critical research and development gaps that need addressing are identified.
How to translate text using browser tools
13 August 2012
Virus diseases of annual pasture legumes: incidences, losses, epidemiology, and management
Roger A. C. Jones
ACCESS THE FULL ARTICLE
Crop and Pasture Science
Vol. 63 • No. 5
August 2012
Vol. 63 • No. 5
August 2012
contact and seed transmission
control
ecology
economic importance
field experiments
forage legumes
improvement programs