FRU Mar 17 - page 30

F Comment F
www.thefruitg rowe r.co.uk ThE FrUITGrOWEr •MArCh 2017
In a ho rticultural t rademagazine 40 years ago, any a rticle
about a pest, disease or weedwould inevitably refer at some
point to the latest agrochemical control. Agronomists
produced a spray programme for their customers eac h winter,
g rowers followed these, and any pest or disease outbreak or
weed infestationwouldprompt a recommendation for an
additional sp ray application(s). The effects of broad spect rum
treatments on the natural enemies of pestswas gradually being
understood, andby the 1980s sp ray programmeswere being
adapted to reduce the negative impact on these ‘beneficials’.
Aswith somany advances, this approach was first developed
for production under glass.
Nowadays, despite somany things having t he ‘i’ prefix, we
tend not to refe r to ‘-icides’ but instead to ‘c ropprotection’,
and a rticles about this aremore likely to cover biocontrol and
physical approach es todealingwith cropprotection issues th an
to new agroc hemical products. Indeed, in the Feb ruary issue of
T he Fruit Growe r therewas one refe rence to a new fungicide for
top fruit, one to a treatment of pear budweevil with awell-
establish edpest control treatment (‘insecticide’ is so ‘last
centur y’), one about the loss of thewell-established use of
coppe r (so 19t h century), two tobiofungicides, one to th e use
of garlic extracts againstmildew on strawberry and one about
biostimulants on bluebe rries. This is a dramatic change over 40
yea rs, driven in part by consume r demand for minimum
residues and legislation ove r contamination of t he environment,
pa rticularlywater. F rom society’s point of view, andwe are all
members of society, this is a good thing.
Wherewill cropprotection go over the next 40 year s?One
pointer iswhat has been going on in th e agroc hemical sector
over the last 40 years - diversification, mer gers and
acquisitions. T here is a dwindling number of ever larger and
mo re diverse businesses dominating this sector, rather akin to
wh at is goingonwithin the info rmation, communication
technology and social media a renas. This processwill inevitably
continue, unless national and international regulators rein it in.
The current stage of a holistic app roach involving the
selection of resistant va rieties, control of the crop environment
tomitigate against pests, diseases andweeds, the use of
beneficials andbiocontrol, and the occasional use of carefully
selected ag roc hemical products, will continue for some time,
with the emp hasis gradually sh ifting away from agroc hemicals
as newdevelopments allow and legislation demands.Well, that
is one scena rio, but the sho rt-term reality couldwell be rather
diffe rent - just ask an organic grower wh o can no longer use
low levels of copper for disease control due to legislation being
implementedbefo re adequate alte rnatives have been
developed and approved. Th emulti-faceted h olistic approach
toSpottedWingDrosophila hasworked reasonablywell so far
for UK growers of soft fruit and stone fruit, but as populations
of this pest continue to
rise, it couldbecome
increasingly difficult togain
control until new approvals
are granted and novel
management techniques
are developed.
Amajor element of the
strategy adoptedby the
major cropprotection
companies has been
diversification intoplant
breeding, indeed the st rength of Monsanto in this area is one
of the compelling reasons for Bayer to embark onmerging
th ese two companies. In addition to th e her bicide glyphosate,
Monsanto iswell-known for its development of genetically
engineered varieties. The initial welcomingof this new
technology soon gaveway topublic disquiet in some parts of
th eworld, settingback development in thesema rkets.
however, it has been reported that th e global production of
geneticallymodified field and specialty crops is growing from
around108m tonnes in 2015 to a projected 122m tonnes by
2020, with a compound annual growth rate of some 2.4%. Of
course, themajo r part of that production is of ag ricultural field
crops, with speciality crops growing from0.55m tonnes in
2015 to1.0m tonnes by 2020 - a compound annual growth
rate of nearly 13%.With theUK leaving th eEU and aligning
itself with theUSA, it is possible th at theremight be g reater
political andpublic acceptance of advancedbreeding
techniques, if not full-blownGM.
A technique th at has been exciting inte rest in breeding
circles of late isCrISPr-Cas9, which, in theo ry, allowsworkers
to edit parts of the genome of a plant by removing and adding
sections of th eDNA sequence, thus introducing amutation.
Work has been done on seve ral fruit crops tomap the
genome, and in some casesmarkers fo r specific traits of
interest have been identified. Theoretically, it s hould th erefore
be possible to edit the genome of the target crop to ensure
that progeny have th e desired traits, thatmight well include
resistance tomajor pest anddisease problems, aswell as
quality attributes.With the environmental, economic and
population pressures facing us over the rest of this centu ry, it is
very likely t hat advancedbreeding tech niqueswill become
acceptable and thiswill h ave amajor effect on cropp rotection
- hence the str ategy adoptedby th emajor ag rochemical
companies.
Unlike the answer ‘Well, I wouldn’t start from here’ in
response to the question ‘howdo I get toDublin?’ we are in a
very goodplace and th ere is a clear way forward for f ruit crop
protection. ◆
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CropP rotection A comment by Andrew Tinsley, Consult 80