New Zealand Plant Protection 67 (2014): 13-17
Herbaceous indicator bioassays are used to screen for unwanted plant viruses on imported plant material. To optimise virus detection, the effect of plant nutrition was investigated to determine whether this plays a role in virus symptom expression and severity. Apple stem grooving virus and Tobacco ringspot virus were inoculated onto a range of herbaceous indicator species grown in potting mix supplemented with differing rates of slow-release fertiliser. Higher rates of fertiliser resulted in better plant nutrition and a greater incidence of virus expression and more severe expression of disease in the seven indicator plant species. Overall, disease assessments indicated that plant nutrition affects plant growth, virus infection rate, and virus symptom expression. As virus infection affects plant growth and leaf colour, good plant nutrition is important to avoid masking virus symptoms and to optimise the detection of viruses in post-entry quarantine facilities.
Keywords: Apple stem grooving virus, Tobacco ringspot virus, fertilizer, infection rate, symptom expression.
Copyright © 2014 New Zealand Plant Protection Society (Inc.).