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New
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PM Tool
F
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frui
TG
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• JAN
u
A
r
Y2017
UK trials atWisbechContract Farming
Trials over several seasons at
w
isbechContract
f
arming in
Norfolk have produced impressive results.
Amodern progressive fruit farm, the highly uniformGPS-
planted orchards employmodern post-and-wire hedgerow
systems.
w
orking closelywithPaul Bennett of Agrovista,
JohnPortass of
w
isbechContract
f
arming has trialled
r
AK
3+4 for the past three years on a total of 8ha – about 9% of
the orchard area.
The
r
AK3+4 ampouleswere distributed from a picking
platform at the same time asworkers carriedout other
operations, and took approximately 12man-hours/ha. “
i
n the
first year of trialswe selected an orchardwith lowmoth
pressure,” explained John. “The results gave us the
confidence to extend the trial in the second year to a higher
pest-pressure orchard.
w
ith nomoths recovered in the traps
we didn’t need to spray at all.
w
e had extremely low level
damage in fruit of just 1 or 2per 1000 and as the season
went on themoth population reduced”.
i
n comparison, in
untreated areas 60-70 codling-affected apples per 1000 fruit
were recorded.
Summarising the results at the endof the third year of
trials, CodlingMoth numbers hadbeen reducedby 95%,
Summer
f
ruit Tortrix by over 89% and
f
ruit Tree Tortrix by
over 99%. The economic thresholdswere never exceeded
and no caterpillar sprayswere needed. Putting it in context,
Paul Bennett said, “
u
sing conventional pesticides the
overwinteringpopulation tends to stay the same.
u
sing the
r
AK3+4 system the backgroundpopulation is reducing year-
on-year.”
i
mpressedwith the results, JohnPortass envisages rolling
out the
r
AK 3+4 strategy to 60-70% of his 90ha in 2017.
“
w
ewill be using it in high value varieties, such as the scab
resistant
o
pal, but at this stage not the lower value
Bramleys,” he says.
Commercial use inEurope
Matingdisruption systems are already in commercial use
in top fruit inBelgium, theNetherlands, Germany and
f
rance.
i
t is estimated that 47% of top fruit inBelgium
(7,000ha) currently usesmatingdisruption, with the
r
AK
3+4 system accounting for 20% and
r
AK 3 for a further
20%.
w
hile orchards receive a supplementary insecticide
when required, or just around the outside rows, monitoring
of 34 orchards in
w
allonia showed 19 had used no
additional insecticide.
According toSimon Townsend, pest pheromone
disruption systems have been shown toworkwell in central
e
urope, withstanding extremes of temperature, and are
alreadywidespread inGermany in various crops, including
vines. Trials inBelgium have shown that, compared to a
reference orchard,
r
AK 3+4delivers amajor decrease in the
number of males caught in traps and a significant decrease
in infected fruit. Thematingdisruption system also showed a
useful effect onmany other species of TortrixMoth including
f
ruit Tree Tortrix,
r
ose Tortrix andMarbled
o
rchard Tortrix.
Simon Townsend is keen topoint out that
r
AK3+4only
controls specificmoth species - Codling andTortrix.
i
t is
therefore important that growersmonitor for the occurrence
of these pests during the season, particularly at orchard
borders.
i
f thresholds are exceeded, BAS
f
recommends
that growers use awell-timed insecticide spray in addition to
r
AK 3+4.
u
nder high pest pressure the level of control from
r
AK 3+4 can be reduced, making careful monitoring
essential. “Growers shouldbemindful that usingmating
disruption does not rely on using any broad-spectrum
insecticides, so new or past pest speciesmay become a
problem andwill need tobe controlledwith appropriate
i
PM
measures,” says Simon. “
i
n some
u
K trials, there has been a
resurgence of moth pests that have not previously been a
problem (for example, Blastobasis sp).
o
thermoth species
not controlled that are potential pests in top-fruit include
Spilonota sp and
e
piphyas sp.”
◆
20
WisbechContract Farming
An innovative and expandingNorfolk top fruit grower
producing high yields of apples andpears,
w
isbech
Contract
f
armingproduces around 3000 tonnes of fruit
annually. A family business started in the 1990s on 25ha of
rented land, thePortass family currently crop90hawith a
further 25ha of derelict apple orchard under development for
Conference pears.
w
ith 50% owned and 50% contract
farmed, the land has all been replanted since 2004.
12 years agoBramley accounted for 80%of total
production, but today 50% of the land is devoted toGala
together with
o
pal, Braeburn,
e
velina andBramley, and
Conference pears. A fresh yellowgold apple, oftenwith an
attractive delicate blush,
o
pal is a new varietywith a crisp
and juicy texture.
