NZPPS   ·  Journal home   ·   Past issues  ·  This volume   ·   Previous abstract   ·   Next abstract

New Zealand Plant Protection 69 (2016): 99-110

The influence of nutrition, maturity and canopy density on the incidence of apple bitter rot

K.R. Everett, O.E. Timudo-Torrevilla, R.W.A. Scheper, P.W. Shaw, P.N. Wood, D.C. Mundy and D.R. Wallis


'Royal Gala' apple fruit were inoculated with Colletotrichum acutatum (the cause of apple bitter rot) conidia at monthly intervals throughout the season in three growing regions in New Zealand. The resultant lesion size was measured on harvested fruit after 9 weeks of coolstorage to generate a disease curve. Nutrient composition, Brix, and mean weight of uninoculated fruit were measured at monthly intervals. The canopy density of the trees at harvest was also determined. These results were compared with the area under the disease curve (AUDC lesion-size days). Starch pattern index and fruit weight at harvest were positively correlated with AUDC, suggesting that fruit towards the end of the season was more susceptible to infection by C. acutatum. Nitrogen was also positively correlated with AUDC. Canopy density, potassium and boron were negatively correlated, although the relationship with potassium needs confirmation. There was no relationship of apple bitter rot with calcium.

Keywords: potassium, boron, nitrogen, starch pattern index, fruit weight, canopy density, field trials, Colletotrichum acutatum.

Related articles
pdfEvaluation of fungicides for control of bitter and sprinkler rots on apple fruit
K.R. Everett, I.P.S. Pushparajah, J.T. Taylor, O.E. Timudo-Torrevilla, T.M. Spiers, A. Ah Chee, P.W. Shaw and D.R. Wallis (2015)
New Zealand Plant Protection 68: 264-274
pdfFungicide timing for control of summer rots of apples
K.R. Everett, O.E. Timudo-Torrevilla, J.T. Taylor and J. Yu (2007)
New Zealand Plant Protection 60: 15-20
pdfTaxonomy of fruit-rotting fungal pathogens: what's really out there?
P.R. Johnston, S.R. Pennycook and M.A. Manning (2005)
New Zealand Plant Protection 58: 42-46

Copyright © 2016 New Zealand Plant Protection Society (Inc.).

Please refer to the terms of use.