New Zealand Journal of Crop and Horticultural Science abstracts
Viruses and phytoplasma in European pear trees in New Zealand
and the role of these pathogens in the compatibility
of pear with quince rootstocks
G. A. WOOD
The Horticulture and Food Research
Institute of New Zealand Ltd
Mt Albert Research Centre
Private Bag 92 169
Auckland, New Zealand
Abstract The history of European pear (Pyrus communis
L.) cultivars, and pear and quince (Cydonia oblonga Mill.) rootstocks
used in New Zealand during the present century was investigated in relation to
their virus and phytoplasma disease status. Early attempts to control tree size
and vigour using quince clonal rootstocks or seedlings of Oriental pear
(P.pyrifolia Burm. Nak.) were unsuccessful, in part because of
the presence of these diseases, and pear trees were grown for most of this
century on European pear seedling rootstocks. Testing of 12 older pear
cultivars commonly grown in commercial orchards at the present time showed that
most were infected with several viruses, and also with the phytoplasma disease
apple rubbery wood. All of the 12 cultivars were imported before, or at the
beginning of this century, and were likely to have been infected in their
country of origin before being introduced to New Zealand. When freed from
infection by heat therapy, some were successfully grown on the virus-free East
Malling rootstocks `Quince A' and `C', and on the French rootstock `Quince BA
29' without incompatibility problems, but others required an intermediate such
as `Beurre Hardy' to overcome non-pathogen induced incompatibilities.
Keywords Pyrus; pear cultivars; pear rootstocks;
Cydonia; quince rootstocks; virus disease; phytoplasma disease; disease
testing
New Zealand Journal of Crop and Horticultural Science, 1997, Vol. 25:
333-340
0114-0671/97/2504-0333 $7.00/0 (c) The Royal Society of New Zealand
1997
PDF file of entire paper: medium quality (673K); (scanned from paper original: notes about this process)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
