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----- Original Message -----
From: Michael Roboz
To: michael roboz
Sent: Saturday, February 23, 2002 10:25 AM
Subject: Fw: Companions for apples in NZ/inc. parasitoids of
leafroller/Canadian. apple biocontrol ----- Original Message -----
From: Michael Roboz
Sent: Saturday, February 23, 2002 10:15 AM
Subject: Companions for apples in NZ/inc. parasitoids of
leafroller/Canadian. apple biocontrol UNDERPLANTING COMPANION PLANTS WITH APPLES AND VINYARDS IN
NZ; INCREASING LEAFROLLER PARASITOIDS
Buckwheat (fagopyrum sp.) was selected
for interplanting in apple and vinyards because it is an annual that germinates
in 3 days, has flowers in 6-7 weeks and has lots of easily accessible nectar for
parasitoids (beneficial parasitic wasps). Fava bean (Vicia faba) was
selected for its early spring extra-floral nectaries. Other fava (Phacelia
sp.) was selected in part because its unique pollen morphology allows easy
tracking of insect movement ( eg. Syrphid fly gut analysis).
Buckwheat underplanted with apple trees
increased leafroller parasitoid numbers by 1000%. Fecundity
(reproducibility) of the parasitoids increased by 300% and longevity by 600%;
all in comparison with other underplantings such as clover and rye.
Dr. Stephen Wratten, Lincold U, Canterbury,
NZ)
Beneficial and pest populations in apple orchards
were monitored over a 3 yr. period with underplantingfs of yarrow, tansy and
Alaska white chrysanthemum. Change is slower with planting as cover crops
in existing orchards as opposed to spraying pesticides at the beginning of the
trial, which "changes the entomological zoo overnight". Companion planting
redu;ced damage from apples pests such as tarnished plant bug (Lygus sp.), apple
sawfly and plum curculio (Conotrachelus neuphar from 64% to 2%). Parasitic
wasp and fly populations increased 400-500%.
About 20-25% of the area was set aside fro
companion plants, which were planted about 6 meters from the orchard
trees.
Noubar Bostanian, Apric. & Agri-Food Canada, St.
Jean-sur-Richelieu, QC, Canada)
IPM Practitioner, V. XXIV, $1, Jan.
2002 |
