New Study on Transgenic Sugar Beet: Reveals work of Research Scientists is mani

[Guest guest]

New Study on Transgenic Sugar Beet

reveals How the work of Research Scientists is Manipulated through

the Media by the Biotechnology Industry

( the address of this page is:

www.btinternet.com/~nlpwessex/Documents/sugar-beet-paper-

commentary.htm )

 

 

Whilst there are many brilliant and dedicated minds in the

scientific world there are increasing concerns that their work is

becoming easy prey for less than honest exploitation by commercial

interests - particularly when it comes to presenting industrial

agendas through the media.

 

However, journalists are now gradually becoming alert to the ways in

which science can be deliberately distorted and repackaged to suit

particular commercial objectives at the expense of full disclosure

of the facts. A number of recent articles in the mainstream UK press

have shown an increasing awareness of this type of phenomenon.

(see:

http://www.guardianunlimited.co.uk/gmdebate/Story/0,2763,194211,00.ht

ml

http://www.telegraph.co.uk/et?

ac=002175959134572 & rtmo=fasVo3ls & atmo=99999999 & pg=/et/00/2/14/nsci14.

html

http://www.the-

times.co.uk/news/pages/tim/1999/10/01/timnwsnws01005.html?999 ).

 

Although not yet picked up by the popular media, full details of the

extent to which the work of scientists can become subject to blatant

presentational manipulation by industry have recently come to light

in a case in the biotechnology sector. This follows the publication

of a study on transgenic sugar beet in the journal 'Pest Management

Science'.

 

Although this paper was only officially released in April 2000,

Monsanto had been using parts of this work prior to its peer-review

and formal publication to make misleading statements about the

environmental 'benefits' of its transgenic sugar beet since 1998.

Further details of Monsanto's manipulation of the findings of this

work, subsequently unearthed by New Scientist, are given at

http://www.btinternet.com/~nlpwessex/Documents/monsanto_sustainabilty

..htm : " The biotech industry is developing two very different sales

pitches for its products - one for farmers and one for the rest of

us, " NEW SCIENTIST, Oct 1998.

 

A few months earlier large sections of the farming and general media

had been taken in by this deception: " Genetically engineered crops

can save farmers money, reduce chemical spraying and create a better

habitat for birds and insects, scientists claimed yesterday " ,

reported an excited LONDON TIMES 25 August 1998 under the

title " Modified crops 'help man and wildlife' " - even though we now

know that the 'findings' concerned had been neither completed nor

published at that date.

 

Now, however, full details of the work used to make these claims

are - nearly two years after the first press reports - at last in

the public domain. They show that the delayed herbicide application

approaches (which were high-profiled by Monsanto at the time as

providing valuable environmental 'benefits' related to insect

populations), using glyphosate on the transgenic sugar beet

concerned, produced heavy yield losses for farmers. These approaches

are therefore most unlikely to be used in practice. In fact when

such approaches were used even the claimed environmental benefits

themselves were not conclusively demonstrated in the study, with the

authors acknowledging that: " Further studies using more rigorous

ecological sampling methods " are required to monitor the full impact

on insect populations.

 

This newly published study in 'Pest Management Science' on

Monsanto's GM sugar beet was carried out by the Institute of Arable

Crops Research (IACR) whose largest funder is the UK government (via

the Biotechnology and Biological Sciences Research Council and MAFF)

followed by finance from industry.

 

IACR has formed partnerships with a variety of biotechnology

companies - including AgrEvo , DuPont , Novartis, Rhône-Poulenc and

Zeneca - as " partnerships become increasingly multifaceted and

intellectual property management receives greater attention " (AgrEvo

and Rhône-Poulenc have recently merged to form Aventis, the company

chiefly involved in the UK's GM field scale trials in respect of

which IACR is one of the scientific contractors).

 

In addition IACR has research links with more than 40 countries

throughout the world.

 

For an analysis of the social implications of the way this latest

paper from IACR on Monsanto's transgenic sugar beet has been

presented to the pubic via the media, please see para 4) of

the " concluding observations " at the end of the commentary below

(which begins with a more technical examination of the paper).

 

The degree to which the scientific world has become dominated by

commercial interests is further illustrated in this case by the fact

that no sanction has been taken against Monsanto for its pre-

publication propaganda exploitation in August 1998 of the scientific

data emerging from the study.

 

By contrast, the internationally respected nutrition scientist, Dr

Arpad Pusztai, was immediately suspended from his job at the Rowett

Research Institute in the same month for releasing preliminary data

on the food safety of transgenic potatoes (work subsequently

published in the Lancet). This was data which Dr Pusztai considered

to be of urgent and vital public importance necessitating its early

release (something which could not be said in relation to the

claimed 'benefits' of Monsanto's trangenic sugar beet). The urgency

was acute given the large range of superficially tested GM products

whose launch onto global food markets was immanent at that time.

 

Meanwhile the pressures that modern scientists are now subject to

from political and commercial quarters have been recently examined

in a paper published in 'Research in Social Problems and Public

Policy', Volume 7, (Stamford, CT: JAI Press, 1999), pp. 105-135

entitled 'Suppression of dissent in science' (Martin, B). Reviewing

the political and industrial sociology of modern day science the

study concludes: " Studying suppression has the potential to reveal

much about the dynamics of expertise, power, and legitimacy in

contemporary society, but this type of investigation is bound to

remain controversial itself both because of definitional and

methodological challenges and because it draws attention to an

exercise of power that those exercising it would rather pass

unnoticed. "

 

How much of modern day science is therefore really about 'science'

(knowledge), and how much of science is really about 'interests'

(power)?

 

The story of this Monsanto 'funded-and-spun' transgenic sugar beet

study is just one example which may give us a clue as to how the

direction of modern 'science' is really determined.

 

Natural Law Party Wessex

16 May 2000

 

 

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" All policymakers must be vigilant to the possibility of research

data being manipulated by corporate bodies and of scientific

colleagues being seduced by the material charms of industry. Trust

is no defence against an aggressively deceptive corporate sector, "

THE LANCET, April 2000

http://www.netlink.de/gen/Zeitung/2000/000409.html

 

 

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Commentary by Mark Griffiths BSc FRICS FAAV

on the paper

" Delayed control of weeds in glyphosate-tolerant sugar beet and the

consequences on aphid infestation and yield "

authored by

Alan M Dewar, Lisa A Haylock, Kathy M Bean, Mike J May IACR-Broom's

Barn, Higham, Bury St Edmunds, Suffolk IP28 6NP, UK

and published in

Pest Management Science, Vol 56, Issue 4, 2000. p 345-350 (April

2000)

(abstract at http://www3.interscience.wiley.com/cgi-

bin/abstract/71000396/START )

 

 

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Preamble

 

This commentary provides initial observations on the above paper.

The observations are provided neither by a qualified sugar beet

agronomist nor by a qualified entomologist. They should therefore be

seen as a basis for exploratory on-going discussion with the paper's

authors, and not necessarily as definitive statements about the

significance of this study.

 

General points

 

1) The study looks at five weed management (including " no

treatment " ) scenarios for a cultivar of Monsanto's genetically

modified Roundup Ready (glyphosate resistant) sugar beet.

 

2) The study looks at such scenarios for the beet grown on a

relatively rare soil-type prone to heavy weed infestation.

 

3) The study does not involve any other sugar beet varieties - i.e.

there are no non-GM controls and therefore the study does not

provide a comparison between GM and non-GM crop performance. It

purely looks at the relative merit of different weed management

strategies for the husbandry of this particular GM cultivar of sugar

beet on a particular soil type.

 

4) Whilst of general interest, the study of itself does not provide

explicit information as to whether it is economically beneficial for

farmers to grow such a variety in these conditions because:

 

there is no comparison of yields with non-GM varieties (genetic

modification can influence other aspects of a plant's metabolism

other than those controlling the target trait, sometimes with

adverse effects on yield potential).

there is no data on seed, chemical and other costs associated with

the various regimes, in particular a comparison of the relative

costs of GM and non-GM beet seed.

there is no analysis of ongoing risk of trangenic gene flow into

weed beet [1] (providing unwanted glyphosate resistance [2,3] in

this important weed in sugar beet) and the knock on cost

implications for its subsequent control.

there is no analysis of the risk of build up of herbicide resistance

in other weed species as a result of the continual use of a single

herbicide (glyphosate), particularly if other glyphosate resistant

GM crops are used in the same rotation. Where actualised such risk

may also have cost implications. (According to MAFF [4]: " The number

of reported cases of herbicide resistant weeds in the UK is

increasing. The variety of herbicides used in sugar beet rotations

normally mean that resistance is unlikely to occur, but this risk

should still be remembered when choosing herbicides for the beet

crop, especially for control of grass weeds such as black-grass or

wild-oats. If these weeds have been controlled by a single group of

active ingredients in previous seasons, then take the opportunity to

make a change in the beet crop " . This statement has clear

implications for the likely ubiquitous use of glyphosate in 'Roundup

Ready' crops which are not restricted to sugar beet. For more

information on weed management regimes in sugar beet see

http://www.britishsugar.co.uk/bsweb/growers/weedcont.htm ).

5) In addition to looking at other effects such as crop yields the

study attempts to examine the impact of the various weed management

regimes on populations of a variety of insects, chiefly aphids. In-

depth interpretation of the ecological significance of these impacts

does, however, seem to be beyond the scope of the study and clearly

requires further investigation.

 

6) It appears that no aphicides were applied during the course of

the study. In practice there are likely to be many farmers who do

not wish to adopt such a non-interventionist approach, particularly

where in-crop colonisation levels exceed those for chemical control

measures recommended by MAFF. In such circumstances the influence of

the different weed management regimes (including the use of

glyphosate resistant sugar beet) on aphid numbers will be largely

irrelevant. (Separate informal discussions with 'LEAF' [5] would

seem to suggest that uptake of natural methods of aphid control

using integrated crop management techniques is not widespread

amongst sugar beet growers.)

 

7) The agronomic significance of crop aphids is that in addition to

feeding on crops they may also transmit plant viruses which can have

a significant effect on crop performance.

 

8) This paper makes it clear that at least two applications of

glyphosate are required with the use of such GM crops - some of the

study data, however, would seem to imply that in practice three

applications may be required for profit-maximising farmers (although

no trials were conducted on this basis, such a three-applications

scenario had been previously acknowledged as a possibility by

another IACR-Broom's Barn sugar beet research scientist in an

article published in Farmers Weekly 20 February 1998).

 

9) Although carried out by scientists at the Institute of Arable

Crops Research (IACR) the study was funded by Monsanto plc.

 

10) Below are more detailed observations on the various titled

sections of the paper. In addition to 'no-treatment'

and 'conventional treatment' scenarios the study examines the impact

on crop yield and insect populations of three different glyphosate

spray treatment regimes. All glyphosate regimes comprised two

application of glyphosate as follows:

 

Regime Description

Beet growth stage

 

first application second application

Glyphosate 1 2-4 leaves 12-14 leaves

Glyphosate 2 8-10 leaves 12-14 leaves

Glyphosate 3 12-14 leaves 16-20 leaves

 

 

 

 

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'Introduction'

 

'The advent of herbicide-tolerant sugar beet....... offers the

potential to reduce the damage caused by pests on young plants.'

 

It is not clear exactly what this statement means or how it is

supported by the study data. The only glyphosate scenario which

achieved comparable yields to the conventional herbicide management

practice appears to have produced considerably higher aphid

colonisation on sugar beet plants (whilst this might be welcomed by

ecologists it would not necessarily be welcomed by farmers who might

then be prompted to use an aphicide in response).

 

In all glyphosate usage scenarios higher weed ground cover arose

(again this might be welcomed by ecologists, but not necessarily by

farmers who in practice might feel prompted to apply a third

application of glyphosate in response when growing the crop

commercially. The later scenario was not explored in the study).

 

'Treatments'

 

The soils in which the trial beet were grown can be particularly

prone to weed infestation. They do, however, only have relevance to

9% of the UK sugar beet crop.

 

The control 'conventional' weed programme used in the study involves

five herbicide applications (table 1), whereas the study indicates

that on more normal soils only three applications would be likely to

be needed.

 

In this study it is stated that (as measured by active

ingredient) " the total herbicide burden applied in the glyphosate

programmes was 45% less than in the conventional " scenario. However,

if the later is adjusted to the norm of only three herbicide

applications (taking out the initial application of diquat/paraquat

and one of the two duplicated multi-component applications) the

total amount of active ingredient under the conventional regime

would fall to 8% below the level of the regimes utilising two

glyphosate applications, or to 39% below the level of a three

glyphosate application regime (not tested here).

 

However, such measurement does not take into account the relative

environmental toxicity of the chemicals used. The use of glyphosate

may provide an advantage here, although its ubiquitous use may also

accelerate the development of weeds resistant to it and ultimately

limit its usefulness as a herbicide.

 

The treatment regime for the conventional programme does not appear

(although this is not clear) to include a residual soil acting

herbicide which would provide long acting weed control. This may be

because such herbicides are less suited to use on this type of high

organic-matter fen soil. Nonetheless this type of herbicide may be

used in other sugar beet growing situations on mineral soils.

 

From the farmer's point of view, however, it is nonetheless clear

that the conventional regime gave the best weed control (in terms of

reduced weed ground cover - table 2), especially in the early days

after crop emergence. This is the time when competition between

crops and weeds can be most critical and farmers may not be entirely

happy with reduced weed control at this point, even when they are

using the early application glyphosate 1 scenario (leaving 29.2%

weed ground cover compared to 8.3% with the conventional regime).

This is a factor which may encourage a third glyphosate application

at an additional earlier date if and when the crop is grown

commercially.

 

'Aphid numbers on sugar beet' (measured in nos per plant)

 

The level of aphid numbers on beet appears to be considerably higher

under the glyphosate 1 regime than under the conventional regime

(table 3). The glyphosate 1 regime is the one most likely to be used

by farmers because of its improved yield effects (table 5) compared

to other glyphosate regimes. It is possible that this high level of

aphid colonisation may encourage farmers to apply an aphicide.

 

There is no data relating to numbers of aphid predators on the sugar

beet (unlike the later weed data), so it is not apparent what effect

the different herbicide regimes have on this aspect.

 

'Aphid numbers on weeds' (measured in nos per m2)

 

If increased aphid numbers (together with predators and parasites)

on weeds equates with reduced aphid numbers on beet then that may be

an advantage as far as the farmer is concerned. However, the

implications of this data are difficult to interpret because of the

statistical methods used. Nonetheless, from an agronomic perspective

it is in any case difficult to see the usefulness of this data as it

is the number of aphids on the beet which are critical to the

farmer. In the case of glyphosate 1 treatments aphid numbers on beet

appear to be higher (table 3) than when using a conventional

herbicide programme.

 

At the same time the superior (again from the farmer's point of

view) weed control obtained from the conventional regime is

indicated by the fact that it is the only case where " no samples

[were] taken due to lack of weeds " (table 4).

 

No data concerning aphid numbers on weeds relating to glyphosate

regime 3 is provided.

 

'Predators and parasites'

 

The use of glyphosate regimes does not seem to have produced an

increase in aphid predators on weeds compared with the control

regime where weeds had no herbicide treatment at all - rather they

seem to have resulted in a reduction in most cases. Most of the data

seems to indicate zero or close to zero presence of predators on

glyphosate treated weeds.

 

It would be interesting to see how this would compare with a regime

which deployed integrated pest management techniques in sugar beet.

 

It is noted that predator eggs rather than predators themselves were

recorded. Is it possible that any of the herbicide regimes could

negatively affect egg hatch success rates?

 

The study concludes that: " No significant differences could be

detected in predator or parasite numbers between the sampled plots

on either date, although of course there would have been few, if

any, in the conventional plots due to lack of weeds. " Unfortunately,

however, no data is given in relation to aphid predators or aphid

parasites on the actual beet themselves.

 

Some figures for predator and parasite levels on weeds are given in

table 4. This data, however, appears to be devalued by a statement

at the end of the study which adds that " the sampling procedures

used here were not designed to estimate populations of these latter

insects quantitatively " .

 

The general conclusions as to the influence of the glyphosate weed

management regimes on these potentially beneficial insects is

accordingly vague: " It was our impression ... Further studies using

more rigorous ecological sampling methods are required to confirm

this. "

 

There is no data in table 4 concerning predators and parasites

relating to glyphosate regime 3.

 

And to reiterate, there is no data relating to numbers of aphid

predators and parasites on the sugar beet itself for any of the

regimes (table 3).

 

'Virus Yellows'

 

'Virus Yellows' were not a significant problem in any of the trials.

Elsewhere in the study it is acknowledged that the incidence of

infection in the trial year (1998) was relatively low.

 

Nonetheless aphids can be important vectors for viral infection in

disease active years. The raised aphid levels on beet in the

glyphosate 1 treatments may therefore encourage the use of aphicides

by farmers. Aphicides can have particularly damaging effects on food

supplies for other animals in the ecosystem.

 

According to MAFF [4] : " Virus yellows, introduced and spread mainly

by green aphids, is the most important disease of beet. Early

infection can decrease yield by 40-50%. The disease is caused by

beet yellows virus (BYV) and/or beet mild yellowing virus (BMYV). " (

http://www.britishsugar.co.uk/bsweb/growers/pests.htm )

 

In late spring and early summer, British Sugar advisers inspect

crops daily and advise when and if to spray in their area. When

plants have less than 12 leaves, one or more wingless green aphids

per four plants justifies a spray; this can occur as early as the

two true-leaf stage following a mild winter and early dispersal of

aphids. Plants with more than 12 leaves do not need spraying until

they have more than an average of one wingless aphid per plant.

 

Interestingly it would appear in these trials that the only weed

treatment scenario to produce aphid levels on the beet above these

thresholds is the glyphospate 1 regime - i.e. the herbicide tolerant

regime most likely to be used by farmers planting this particular

genetically modified cultivar. This would appear to indicate that

the introduction of glyphosate tolerant beet varieties may lead to

an increase in the use of aphicides.

 

Spray regimes against green and black aphids recommended by MAFF [4]

include the following chemicals: Gaucho, Aztec, Evidence, Patriot,

Decisquick, Dovetail and Aphox (chemical names available at

http://www.britishsugar.co.uk/bsweb/growers/glossary.htm ).

 

'Effects on yield'

 

Glyphosate regimes 2 and 3 reduced yields very substantially - by

24% and 31% respectively compared to beet grown under a conventional

spray regime (table 5). No farmer, therefore, is likely to use such

a regime. Any 'environmental benefits' to be derived from such

programmes (which do not appear to be clearly specified or explained

in this paper) are therefore likely to be largely irrelevant.

 

Users of such genetically modified sugar beet (assuming that they

are willing to do so because they believe it out performs normal

sugar beet - an issue also not addressed in this paper) will

inevitably opt for the glyphosate 1 regime because of its

considerably higher crop yield outcome (table 5) compared to other

glyphosate regimes. It is even possible that they will go for yet

another glyphosate programme using three applications - an option

also not explored in this paper.

 

'Discussion'

 

It should be recognised that the conventional spray regime in the

study also required some hand-hoeing to achieve acceptable levels of

weed control.

 

Nonetheless the general levels of weed control (as measured by %

weed ground cover in table 2) prior to the date of first hand-hoeing

(given in table 1) were superior in the conventional regime compared

to the dual application glyphosate regimes.

 

" ... the number of aphids colonising beet was reduced where weeds

provided some cover to young seedlings " . It is not clear how 'young

seedlings' is defined and what data supports this statement (the

only data on beet aphid numbers given in the study is in table 3).

In fact the opposite appears to be true as far as beet aphid numbers

were concerned on 19th and 29th of June (the only dates for which

data is provided) in the very glyphosate regime most likely to be

used by farmers in practice because of its crop yield implications

(glyphosate 1).

 

" The effect of weeds in this study was substantial - they reduced it

by 71% compared to conventional plots. " It is worth pointing out

that it was only the trial receiving no weed treatment at all which

produced this overwhelming level of yield reduction. Nonetheless

glyphosate regimes 2 and 3 produced yield reductions of 24% and 31%

respectively compared to beet managed under the conventional

herbicide programme. However, for some reason the authors refer to

the 24% reduction as 'substantial' but 'not significant'.

 

 

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Concluding observations in this commentary

 

1) Most, if not all, of the glyphosate scenarios explored in this

study are unlikely to reflect the actual use of such herbicide

tolerant sugar beet in practice once farmers have gained a few

seasons experience with it. The reasons why this is likely to be the

case are as follows:

 

The soil type used in the study has special husbandry

characteristics and only a small minority of beet crops are grown on

such soils.

Conventional herbicide applications on more typical soils are much

less than used in this study (the paper itself points out that the

UK average for sugar beet is three herbicide applications, albeit it

using herbicide mixtures).

Profit maximising farmers may chose to add a third application of

glyphosate in practice (not a scenario explored in this study).

If under certain scenarios the use of glyphosate increases the

number of aphids on sugar beet plants (as appears to be the case

with the most likely glyphosate scenario in this study) farmers may

be encouraged to use an aphicide spray where they might not have

otherwise - particularly if there is a significant risk of viral

infection from aphid colonisation.

2) It is difficult to reconcile the study data with parts of the

study's concluding sentence which includes the statement that: " The

use of glyphosate ... offers the possibilities of manipulating the

habitat to the benefit of the environment ..... without loss of

yield. "

 

If it is taken that the suggested environmental benefit arising out

of habitat manipulation in this study is the use of glyphosate to

increase non-beet aphid numbers on weeds (thereby, so it appears to

be implied, increasing by attraction aphid predators and parasites

generally in the field) then the results appear to be non-

definitive, and in the case of the glyphosate 2 and 3 regimes they

are clearly associated with heavy decreases in yield. (It is these

two latter regimes which were particularly paraded in the press

prior to peer review of the study - see 4 below).

 

3) A number of matters in this paper are difficult to interpret.

Further clarification through discussion with the authors should be

encouraged.

 

4) Nonetheless, whatever the real implications of this study turn

out to be there must be concern that widespread press reports

relating to this work appeared in the farming, scientific and

general press prior to the completion of its data collection, let

alone prior to the submission of the paper to a scientific journal

for peer review. In this case the concern is especially acute

because:

 

the prior press coverage was clearly orchestrated by the commercial

sponsor of the trial who also holds the intellectual property rights

to the transgenic beet used in the trial.

 

the research was presented prematurely to reporters in a way which

did not reveal that the principal weed management scenarios paraded

as providing environmental benefits are most unlikely to be used by

farmers (when 'New Scientist' subsequently discovered this situation

it commented: " The biotech industry is developing two very different

sales pitches for its products - one for farmers and one for the

rest of us. " )

 

this situation appears to have left many professional commentators

believing that the deployment of this technology will provide

environmental benefits which are in fact not supported by the data

in the study, particularly when it comes to considering how the

technology is likely to be deployed in practice.

 

a report published in March 2000 by the World Wildlife Fund (WWF)

comprised a wide-ranging review of scientific research relating to

transgenic crops. It came to the conclusion that particularly in

North America: " The technology has been misrepresented in ways that

suggest genetic improvement can take the place of management and

skill in solving pest problems. This may explain, in part, why

farmers have so readily adopted the technology to the degree they

have. "

 

the publication of this latest paper on UK transgenic sugar beet

trials (not released in time to be included in the WWF scientific

literature review) reveals once again the extent to which the

realities of transgenic crops are regularly misrepresented by

corporate interests through sections of the (hopefully innocent)

media .

 

this situation is additionally concerning given that most data

considered by regulatory authorities during the process of approving

GM crops and food is provided by the companies developing them and

not by independent scientists.

 

 

Mark Griffiths BSc FRICS FAAV

 

Environment Spokesman

Natural Law Party, UK

 

 

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Footnotes:

 

1. According to MAFF weed beet are any unwanted beet within and

between the rows of sown beet, in other crops, or on waste ground.

They grow from groundkeepers or from seed shed by bolters. The

bolters may be in sugar beet crops, may be weed beets in other crops

or come from groundkeepers. As seedlings, weed beet are

indistinguishable from sugar beet but many bolt easily and are

prolific seed producers.

 

Weed beet are:

 

present in about a fifth of all beet fields;

seldom found where rotations have more than six years between

successive beet crops;

once established, persistent as a problem for many years.

If not controlled weed beet seedlings will bolt, compete with the

crop and set still more viable seed.

 

Sugar beet bolt in long days after experiencing cold. The plants

which bolt in a root crop are the least bolting-resistant members of

the variety. These can inter-pollinate and produce much seed in the

English climate. Over many years this natural process has selected

for easy-bolting types and these readily inter-pollinate with

bolters arising either from seed contaminated by annual types or

from groundkeepers.

 

All bolters are potential sources of weed beet if they flower early

enough to produce viable seed. Although sugar-beet varieties have

always given a few bolters, long rotations and hoeing probably

controlled the problem until the mid 1960s. At about that time

seedsmen started to make hybrid monogerm varieties using tetraploid

pollinators which are less able to avoid contamination by pollen

from diploid wild annual beets. Also, farmers started to close

rotations (so getting fewer intervening crops in which weed beet

could be controlled) and began using herbicides instead of the hoe

to control weeds in their beet crops. These herbicides cannot

differentiate between crop and weed beet.

 

Over the last 25 years these factors have allowed the balance to tip

sufficiently for beet to become a sucessful weed.

 

Weed beet compete with crop beet and depress sugar yield. When the

numbers of weed beet equal the numbers of crop beet, at best, sugar

yield is halved. Even a few weed beet depress yield slightly and, if

not controlled, each can produce about 1,500 viable seeds, many of

which survive so that the problem becomes progressively worse with

each rotation. Weed beet are woody and, if delivered to the sugar

factory, create problems in slicing and sugar extraction. No single

control method is likely to be successful, but a combination should

be effective.

 

According to MAFF bolters can be controlled by only three methods

one of which is the application of Roundup (glyphosate) using a wick

applicator.

 

( Source: http://www.britishsugar.co.uk/bsweb/growers/weedbeet.htm )

 

2. Mike May of IACR-Broom's Barn (Farming News 13th March 1998):

 

" I think we have to assume that we will get herbicide-tolerant

volunteers. Their numbers are related to the amount of seed shed by

the crop. In sugar beet this is low but we do get bolters. We may

find we need to be controlling bolters to limit pollen spread rather

than seed return and this may be much more difficult to manage. "

(Mike May is one of the authors of the sugar beet study discussed in

the commentary above.)

 

3. Keith Jaggard of IACR-Broom's Barn (Farmers Weekly 20th February

1998):

 

" Roundup and Liberty are very efficient plant killers... Initially

the new chemistry will control weed beet, but eventually [weed] beet

will become tolerant to both chemicals. "

 

4. See: " Sugar Beet: A Grower's Guide " , Fifth Edition, Edited by

K.W. Jaggard IACR-Broom's Barn, M. Limb and G.H. Proctor British

Sugar plc, published by The Sugar Beet Research and Education

Committee, Ministry of Agriculture, Fisheries and Food, London.

( http://www.britishsugar.co.uk/bsweb/growers/index.htm )

 

5. LEAF (Linking Environment and Farming) encourages the uptake of

Intergrated Farm Management (IFM) through the development of

practical guidelines and the promotion of the LEAF Audit. It

promotes IFM to a broad range of groups through its national network

of Demonstration Farms (

http://www.farmeco.co.uk/directory/news/showstory.asp?

uniqueid=1028 ) .

 

 

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Political compliance V sound science - biotech debacle set to unfold

further?

Will GM crops deliver benefits to farmers? - some realities behind

biotechnology myths

For more information on gm food risks click here

 

Why genetic engineering is not science based

Dismantling the myth of genetics as the principal constraint on

responsible global agricultural production

 

 

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Fundamental scientific conceptual errors in the development of

recombinant DNA technology

 

 

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Return to NLP Wessex GM page