Transcript Slide 1

Midge Tolerant Wheat
Retailer Training
Module 1
Midge Tolerant Wheat Technology
Presentation Overview
• Orange Wheat Blossom Midge
– Life Cycle
– Midge Damage
• Midge Tolerant Wheat
–
–
–
–
Varieties
How it Works
Single Gene Resistance
Interspersed Refuge System
Wheat Midge Life Cycle
• The orange wheat
blossom midge has 4
stages:
1. Adult – Adult flies emerge
in late June/early July,
mate and females lay
eggs on newly emerged
wheat heads during
warm, calm evenings.
Emergence peaks midJuly.
Wheat Midge Life Cycle
3. Eggs – Eggs are laid, either singly or in
clusters of 3-4 eggs, on the wheat heads. This
stage lasts 4-7 days.
4. Larvae – Upon hatching, the larvae move into
the florets to feed on the developing kernels for
2-3 weeks. Then they crawl off the wheat head
and over-winter in the soil.
5. Pupae – Once temperature and soil conditions
end the over-wintering period, larvae move to
the soil surface to pupate. Emergence of adult
flies begins in late June/early July and can
continue for up to 6 weeks.
Midge Damage
• Crop damage occurs when midge larvae
feed on the developing wheat kernel,
causing them to shrivel, become
deformed or completely abort.
• Damaged kernels cause downgrading in
wheat samples.
• Crop yields are also reduced as 40-50%
of damaged kernels are blown out of the
combine during harvest.
Midge Tolerant Wheat
Varieties
• Several spring wheat varieties were developed
by Canadian wheat breeders at AAFC in
Winnipeg & Swift Current, and the Crop
Development Centre at the University of
Saskatchewan.
• Funding for these projects comes from
government, the WGRF check-off program and
variety distributors.
• All these new varieties contain the single gene
(Sm1) which provides midge tolerance.
• Sm1 was moved into spring wheat using
traditional plant breeding techniques.
Midge Tolerant Wheat
Varieties
Variety
Refuge
Class
AC® Unity VB
AC® Waskada CWRS
SeCan
AC® Goodeve VB
AC Intrepid
CWRS
Alliance Seed
Corporation
AC® Glencross
VB
AC® Burnside
CWES
Faurschou
Farms
AC® Fieldstar VB
AC® Waskada CWRS
SeCan
AC® Shaw VB
AC Domain
CWRS
SeCan
CDC Utmost VB
Harvest
CWRS
FP Genetics
AC® Conquer VB
5701PR
CPSR
Canterra
Seeds
AC® Vesper VB
AC® Waskada CWRS
SeCan
Spring 2013
Enchant VB
AC Crystal
FP Genetics
Spring 2014
CPSR
Distributor Available
Benefits of Midge Tolerant
Wheat
• Prevent an estimated $36 per acre* loss from
midge damage downgrading and yield
reductions.
– *Based on the economic threshold of one midge per 4 to 5
wheat at flowering = estimated 15% yield loss if not
controlled. Higher midge levels can lead to greater losses.
15% x $6/bu wheat x 40 bu/acre = $36
• Reduce reliance on insecticides, the traditional
method of midge control.
• Gain more flexibility in crop rotations and
seeding dates.
How it Works
• When the insect begins to feed on the
seed, the Sm1 gene causes the level of
phenolic compounds (naturally occuring
acids in wheat kernels) to elevate more
rapidly than in wheat kernels without the
Sm1 gene.
• The higher levels of phenolic acids cause
the midge larvae to stop feeding and
starve to death.
Single Gene Resistance
• Midge tolerance is based on a single
gene (Sm1) that can become ineffective
over a relatively short period of time as
insect populations change.
• An interspersed refuge system is
required to extend the life of midge
tolerance from as little as 10 years to 90
years or longer.
Interspersed Refuge System
• Requires planting a varietal blend (VB)
which contains 90% midge tolerant variety
and 10% midge susceptible variety.
• Ensures the refuge is evenly distributed
(inter-seeded) throughout the field.
• Objective is to prevent a build-up of
naturally occurring virulent midge – midge
that are able to attack plants with the Sm1
gene.
No refuge system
No refuge system
No refuge system
Interspersed Refuge System
Interspersed Refuge System
Interspersed Refuge System
Please proceed to
Quiz 1
Thank you