taken from ses vanderhave's growing beet magazine

18

SESVANDERHAVE’S GROWING BEET – Spring 2014 edition

Spring cropping especially with a non-

cereal crop, is considered one of the ‘ten

key factors’ to consider when planning to

control this difficult weed.

Planting a non-cereal crop allows

alternative herbicides, with different

modes of action to those approved for

cereals, to be used. The aim should be

to minimise the number of viable black-

grass seeds produced during spring

through both cultural and chemical

techniques. While non chemical methods

are extremely important this article

focuses on herbicide matters when

growing Sugar Beet.

Post-emergence graminicides There is a very high incidence of both

ACCase target site and enhanced

metabolism resistance in UK black-

grass populations. Table 1 lists ACCase

inhibitors (fops and dims) with approval

for post-emergence use in Sugar Beet.

Varying degrees of black-grass control

can be expected from these products.

Centurion Max (clethodim), recently

approved for use in Sugar Beet is unusual.

Currently, it is less affected by target site

resistance than other ACCase inhibiting

herbicides, but using clethodim in

sequences with other relevant herbicides

with differing modes of grass-weed

activity will be important to prolong its

effectiveness.

Tank-mixing graminicides with annual broad-leaved weed herbicides Tank-mixing has huge benefits in

minimising spraying time as well as

reducing fuel and labour costs. Whilst

manufacturers’ advice on tank-mixing

graminicides with annual broad-leaved

weed herbicides is generally no, should

you be tempted?

During 2013 United Phosphorus Ltd

(UPL) looked at black-grass control

in Sugar Beet at sites in Lincolnshire

and Norfolk. One objective was to

Pam ChambersTechnical Support Manager UK & Ireland

BLACK-GRASS control in Sugar Beet – not straight forward!

With adequate soil moisture,

80% of black-grass germination

occurs between September

and November.

Black-grass

19


Group Mode of Action

Chemical family Active Example Product

A Inhibition of acetyl CoA carboxylase (ACCase)

aryloxyphenoxy propionates (fops) cyclohexanediones(dims)

eg. fluazifop-P-butyl eg. cycloxydim tepraloxydim clethodim

Fusilade Max LaserAramoCenturion Max

Table 1. ACCase inhibitors (fops and dims) approved for use in sugar beet

6.2plants/m2

40.4heads/m2

4000potentialseeds/m2

16.9plants/m2

68.9heads/m2


13.1plants/m2

140.7heads/m2


22.4plants/m2

117.8heads/m2


Lincolnshire – Aramo Lincolnshire – Aramo + Oblix MT

Norfolk– Aramo Norfolk – Aramo + Oblix MT

6.2plants/m2

40.4heads/m2


16.9plants/m2

68.9heads/m2


13.1plants/m2

140.7heads/m2


22.4plants/m2

117.8heads/m2


Lincolnshire – Aramo Lincolnshire – Aramo + Oblix MT

Norfolk– Aramo Norfolk – Aramo + Oblix MT

evaluate tank-mixing the graminicide

Aramo (tepraloxydim) with Oblix MT

(metamitron + ethofumesate) at T3

timing. Assessments on 3 July 2013

(Fig 1) show the tank-mix resulted in much

higher plant and head counts which could

potentially lead to high seed returns.

Pre and post-emergence annual broad-leaved weed herbicides with activity on black-grass

A few annual broad-leaved weed

herbicides approved for Sugar Beet

will have some effect on resistant

‘ACCase’ black-grass populations

(Table 2). Currently only triallate has a

recommendation for use in cereals.

Using information in Tables 1 and 2,

a programme can be devised using

herbicides with different modes of

action. Herbicide sequences and mixes

can improve black-grass control, but will

not prevent resistance developing.

Fig. 1. Results from black-grass trials assessing tank-mixing efficacy. (July 3rd 2013)

Triallate pre-emergence activity on black-grass Triallate, as Avadex 15 G, was included

in the UPL 2013 and BBRO 2012 black-

grass herbicide trials with inconclusive

results, but its use should continue to be

investigated.

Ethofumesate e.g. Ethofol 500SC – pre and post-emergence activity on black-grass

A ‘container screen’ assessing

the efficacy of Ethofol 500SC

(ethofumesate) on a selection of black-

grass populations was carried out for

UPL by AgHerba Consultants in 2013.

Ethofumesate applied pre-emergence

at 250 g ai/ha gave excellent control

of black-grass populations with a range

of herbicide resistance mechanisms.

See Photo 1.

There are strong indications that applying

Ethofol 500SC pre-emergence will give

better results than post-emergence

timings. However, caution is needed as

results from screens will show higher

efficacy than field results. Also note

that only 1000 kg of ai ethofumesate/

ha can be used per field in any three year

period. This is important when planning

herbicide programmes as ethofumesate

is in many formulated products applied

post emergence for the control of annual

broad-leaved weeds.

Black-grass

20


Group Mode of Action Chemical family Active Example Product

B Inhibition of acetolactate synthase ALS

Sulfonylureas triflusulfuron-methyl Debut

C1 Inhibition of photosynthesis at photosystem II

Triazinones metamitron Bettix FloDefiant SCGoltix Flowable

N Inhibition of lipid synthesis

Thiocarbamates

Benzofurans

triallate

ethofumesate

Avadex Excel 15G

Ethofol 500SCEthosat 500

Table 2. Sugar beet herbicides with activity against resistant ‘ACCase’ black-grass

Photo 1. Response of five UK black-grass populations to 250 g and 125 g ai ha-1 ethofumesate on 13th February 2013. Populations from front: Rothamsted, Peldon 07, Notts 05, Long C 11 and ISL-PTCH08.

Metamitron e.g. Bettix Flo – pre and post-emergence activity on black-grassIn UPL 2013 trials and BBRO 2012 trials

metamitron was included in black-

grass control programmes at both

pre and post-emergence timings and

a combination of both. Results were

inconclusive, but there is evidence that

metamitron shows activity against

black-grass. Thus it is advisable to

continue to use metamitron eg. Bettix

Flo, in a black-grass control programme.

Triflusulfuron methyl eg Debut – post emergence activity on black-grassDebut is a sulfonylurea herbicide

and agronomists and farmers have

commented on its activity on black-grass.

A leaflet produced by Dr Stephen Moss ‘Black-grass (Alopecurus myosuroides)

Everything you really wanted to know about black-grass but didn’t know who

to ask’ revised in 2013 is recommended reading.

Black-grass

21


Timing of crop

Active Programme Example Product Rate/ha Comments

Pre-em metamitronethofumesate

Bettix Flo Ethofol 500SC

1 to 2.0 l/ha1.0 l/ha

Do not use more than 1.0Kg ethofumesate per ha in any three year period.

T1 desmediphamphenmediphamethofumesatetriflusulfuron methyl

metamitron

Beetup Compact SC Ethofol 500SCDebut

Bettix Flo

1.5 l/ha

0.4 l/ha20 g/ha

0.5 l/ha

Apply at 2 to 3 leaves of black-grass. Adjust rates according to crop size. Include oil if conditions and crop size allow.Use of a pre-em should permit a delayed T1 timing.

clethodim Centurion Max 1.0 l/ha Consult label for optimum timings, do not tank mix with any other herbicides. Do not apply products containing an ACCase inhibitor herbicide more than twice to any crop. Centurion Max can only be applied once before row closure.

T2 desmediphamphenmediphamethofumesatemetamitrontriflusulfuron methyl

Betasana Trio

Bettix FloDebutOil

2 to 2.5 l/ha

1.0 l/ha20 g/ha0.5 to 1.0 l/ha

Apply according to growth stage, emergence of fresh black-grass and other weed species present. Adjust rate of oil according to weather conditions.

Black-grass

Table 3. 2014 option for black-grass control in sugar beet

Black-grass heads/m2 July 3 2013

60

50

40

30

20

10

0Untreated

40.2

25.3

B.Trio B.Trio + Debut Broadacre

18.9

49.3

Note: Broadacre is the UPL version of the Dupont Broadacre programme which contains Beet-up Compact SC, Ethofol 500SC, Debut, Bettix Flo, Venzar + oil.

Trials (BBRO 2012 and UPL 2013)

show evidence to substantiate this.

Although not statistically different, at

the UPL Norfolk site there were strong

indications that Debut with Betasana Trio

reduced the final number of black-grass

heads/m2 (Graph 1 and Photos 2 and 3).

Resistance testing

If black-grass resistance is suspected

then a test is advisable to help plan

control options.

The resistance status of the black-grass

population within a field is likely to affect

efficacy.

2014 recommendations for black-grass control in Sugar Beet Several herbicide products can be used

in a black-grass control programme, but

it is important to include key actives, see

Table 3 for one suggestion. Adjustments

for crop growth stage, other weeds

present and weather conditions.

Information in this update does not constitute a recommendation, it is for guidance only. Up to date information can be found on our website www.upleurope.com.Some brand names used in this document are trademarks of other manufacturers, in which proprietary rights may exist. Use plant protection products safely. Always read the label and product information before use.

Graph 1. Norfolk trials site – Debut and Betasano Trio

Photo 2. Betasana Trio programme Photo 3. Betasana Trio + Debut programme

taken from ses vanderhave's growing beet magazine

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