Karyn Froud

Thesis Title
Kiwifruit bacterial canker in ‘Hayward’ kiwifruit: The application of observational study design and epidemiological techniques to the study of disease outbreaks affecting plant health

Read article at Massey Research Online:

Kiwifruit bacterial canker, caused by Pseudomonas syringae pv. actinidiae (Psa) biovar 3, was first recorded in New Zealand in November 2010. Ms Froud investigated aspects of Psa in commercial 'Hayward' orchards using observational studies. She found that productivity was reduced after one year of infection with Psa and disease prevalence was evident in 84 percent of orchard blocks. Probability of initial development of disease increased with immediate use of post-pruning protectant sprays and artificial pollination and reduced with summer girdling (ring-barking) and presence of older male vines. The likelihood of severe disease increased with time infected, frost damage, specific shelter belts present and artificial pollination, and was lowered with spring girdling. Ms Froud's research demonstrated the utility of observational studies for plant disease research and showed that study designs typically applied in veterinary and medical research were highly applicable to investigating factors that cause disease in plants.

Supervisors
Professor Naomi Cogger
Dr Rob Beresford
Professor Tim Carpenter

Froud, K., Cogger, N., In Press, Use of observational study designs and multivariable analysis in plant protection, In:  Beresford, R., Froud, K., Worner, S.P., Kean, J. (Eds.) The plant protection data toolbox: On beyond t, F and X Caxton, Christchurch.

Froud, K., Cogger, N., In Press, Kiwifruit Bacterial Canker Disease (Psa-V (Pseudomonas syringae pv. actinidiae)) impact on ‘Hayward’ Kiwifruit Productivity Acta Horticultrae: 1st International Symposium on Bacterial Canker of Kiwifruit (Psa), In Press.

Froud, K., Cogger, N., Beresford, R., 2014, The Relationship between Kiwifruit Bacterial Canker Disease (Psa-V (Pseudomonas syringae pv. actinidiae)) and Kiwifruit Productivity New Zealand Plant Protection 67, 34-40.

Froud, K., Cogger, N., Beresford, R., Clark, G., In Press, Orchardist-observed prevalence of symptoms of kiwifruit bacterial canker disease in ‘Hayward’ kiwifruit blocks in New Zealand. Acta Horticultrae: 1st International Symposium on Bacterial Canker of Kiwifruit (Psa), In Press.