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Alternative fungicides for controlling husk spot caused by Pseudocercospora macadamiae in macadamia

Akinsanmi, O.A. and Miles, A.K. and Drenth, A. (2008) Alternative fungicides for controlling husk spot caused by Pseudocercospora macadamiae in macadamia. Australasian Plant Pathology, 37 (2). pp. 141-147.

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Article Link(s): http://dx.doi.org/10.1071/AP08001

Publisher URL: http://www.publish.csiro.au/

Abstract

Husk spot, caused by Pseudocercospora macadamiae is a major fungal disease of macadamia in Australia. Chemicals to control the disease are limited and frequent failure to control the disease is a major concern to growers. The overall goal of this research was to improve the chemical control strategy of P. macadamiae through the provision of fungicides with different modes of action to carbendazim, which is the current industry standard. Husk spot incidence, premature fruit abscission, kernel quality and yield were evaluated following application of different fungicide products in replicated field experiments at three different sites. Results showed significant differences in disease incidence and premature fruit abscission between fungicide treatments, field sites and years. Generally, disease incidence and premature fruit abscission on trees treated with fungicide were significantly (P < 0.05) lower than the untreated control. Pyraclostrobin conferred significantly better protection than trifloxystrobin, reducing disease severity by 70% compared with a 50% reduction by trifloxystrobin. The pyraclostrobin treatment had a similar efficacy to the current industry standard (70% reduction cf. 73% reduction by tank-mixed carbendazim and copper). Higher amounts of immature kernels occurred in the untreated control, followed by difenoconazole and trifloxystrobin. Diseased fruit accounted for 78% of premature fruit abscission, which indicates that husk spot enhances fruit abscission in macadamia. Our results suggest that pyraclostrobin provided similar efficacy to the industry standard and could, therefore, play a key role in the management of husk spot.

Item Type:Article
Corporate Creators:Horticulture and Forestry Science
Additional Information:© CSIRO Publishing.
Keywords:Disease progress curve; Mycosphaerellaceae; nut; strobilurin; macadamia; Pseudocercospora.
Subjects:Plant culture > Fruit and fruit culture > Nuts
Plant pests and diseases > Individual or types of plants or trees
Plant pests and diseases > Pest control and treatment of diseases. Plant protection > Pesticides
Deposited On:13 Jan 2009 07:18
Last Modified:19 Apr 2011 21:59

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