Overwintering grapevine debris as an important source of Botrytis cinerea inoculum. (2nd May 2012)

• Record Type: Journal Article
• Authors: Jaspers, M. V.; Seyb, A. M.; Trought, M. C. T.; Balasubramaniam, R.
• Is Part Of: Plant pathology. Volume 62:Number 1(2013:Feb.)
• Page Start: 130
• Page End: 138
• Publication Date: 2012-05-02
• Subjects: Agricultural pests -- Periodicals; Plant diseases -- Periodicals; 632
• DOI: 10.1111/j.1365-3059.2012.02631.x
• Languages: English
• ISSNs: 0032-0862

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Production of <italic>Botrytis cinerea</italic> conidia from infected grapevine debris (trash) left on the ground and in the canopy in the season following harvest was studied in vineyards in Marlborough, New Zealand. When subsamples were incubated under high relative humidity in the laboratory, rachides had the greatest sporulation potential (<italic>P</italic> < 0·05), followed by tendrils, cane lengths and petioles. Trash remaining on the ground under the canopy had higher rates of sporulation (<italic>P</italic> < 0·05) than that in the inter‐row. The sporulation potential of rachides at different times during the growing season was assessed by placing them in vine canopies or on the inter‐row soil in three vineyards in late spring. Subsamples were removed on five occasions between flowering (capfall) and harvest, and incubated under high relative humidity in the laboratory. Mean numbers of conidia produced from the canopy rachides diminished from 3·5 × 10<sup>5</sup> per rachis at capfall to 2·6 × 10<sup>4</sup> at harvest, and from 3·9 × 10<sup>5</sup> to 2·7 × 10<sup>3</sup>, respectively, from the ground rachides. The greater loss in sporulation capacity of ground rachides was considered to be associated with their earlier spontaneous sporulation and greater degradation in the moist inter‐row sward, where they lost 29% of their weight (<italic>P</italic> < 0·001) and 23% of their pedicels (<italic>P</italic> < 0·001), compared to the canopy rachides which lost 0% of their weight and 3% of their pedicels from capfall to harvest. This study has shown that necrotic, overwintering grapevine debris can produce <italic>B. cinerea</italic> conidia throughout the following growing season, so may contribute to the subsequent risk of bunch rot.</p> </abstract>