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Estelle
Jourdan
Evaluation of new day neutral strawberries selections for
their
resistance to the tarnished plant bug
- Estelle
Jourdan is carry out a 6 months training course
during which she is charged to evaluate new day neutral strawberries
selections for their
resistance to the tarnished plant bug.
- Abstract
- The day neutral strawberry market in Québec has
strongly increase the past few years. Thats why, answering to the strawberry growers
wishes, the Horticulture Research and Development Center (HRDC) of St-Jean-sur-Richelieu
has developed a day neutral strawberry selection program, in year 1998, with the
strawberry growers association "les Fraises de lIle dOrléans".
- The day neutral strawberries have a continuous
production, allowing producers to supply the market from spring to fall. But this
characteristic allow also one of the major strawberry pest, the tarnished plant bug (Lygus
lineolaris, P. de B.) to keep on strawberries fields and to cause great damages, in so
far as chemical products are forbidden by the harvest frequency.
- Two different way of management are tested in the
HRDC, in order to reduce this pests damages : the genetic way and the integrated
pest management way.
- As a consequence, one of the objectives of the
breeding program is to create new resistant to tarnished plant bug selections. To evaluate
different genotypes, an experimental protocol has been built, in order to reveal a
resistance, early in the selection scheme. The best way to evaluate this resistance is to
calculate the deformation rate, that is to say number of misshapen strawberries compared
to the total number of marketable strawberries. Among ten evaluated selections, one
tolerant and three semi-tolerant selections has been found, but no real resistance yet.
The trials for integrated pest management are a good complement to the breeding program.
They are based on the feeding behavior of the tarnished plant bug, which moves from hosts
to hosts according to feeding resources. A comparison has been done between a control plot
without any treatment, two plots with a chemical treatment, and one plot surrounded by
white mustard as host plant. This experience has shown that the presence of host plant
reduces strongly the damages caused by the tarnished plant bug. Nevertheless, those
results are not yet as low as those of the chemically treated plots.
Thus, researches should be continued, as well in the breeding program as in the choice of
host plant, in order to eliminate the tarnished plant bug on strawberries.
- Key words : day neutral strawberry ; tarnished
plant bug ; selection ; resistance ; host plant ; feeding behavior ; misshapen
Address
:
Estelle Jourdan
LEcole Nationale des Ingénieurs des
Travaux Agricoles de Clermont-Ferrand
Site de Marmilhat
63370 LEMPDES
FRANCE
- Professeur responsable de la formation : PIQUET
Agnès
- Professeur responsable du suivi du stage : DUPARQUE
Annie
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- The
persons in charge of the training course: Shahrokh Khanizadeh &
Johanne Cousineau
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