Miroslav Jursík Jiří Andr Veronika Venclová Josef Soukup E-mail: [email protected]

Miroslav JursíkJiří Andr

Veronika VenclováJosef Soukup

E-mail: [email protected]

Efficacy and selectivityEfficacy and selectivityof pre-emergence herbicidesof pre-emergence herbicides

in sunflower as influencedin sunflower as influencedby soil water conditionsby soil water conditions

Typical sunflower weeds in Typical sunflower weeds in the the Czech Czech RepublicRepublic

Chenopodium album

Echinochloa crus-galli

Polygonum lapathifolium

Amaranthus retroflexus

Locally occurring sunflower weedsLocally occurring sunflower weeds in in the the Czech RepublicCzech Republic

Mercurialis annua

Abutilon TheophrastiSolanum nigrum

Datura stramonium

Weed control in sunflower in Weed control in sunflower in Czech RepublicCzech Republic

90 % of sunflower 90 % of sunflower area area is is treated btreated by pre-emergence y pre-emergence

soil herbicidesoil herbicidess sunflower is very sensitivsunflower is very sensitive e to m to many hany herbicideerbicidess – –

metabolicmetabolic type of type of selectivity selectivity iis usually low s usually low intensive precipitation after herbicide application intensive precipitation after herbicide application

(especially on sandy soil) may cause vertical (especially on sandy soil) may cause vertical

movemovementment of herbicide into of herbicide into the the zone zone with with

germinatgerminating ing seeds of sunflower and damage them seeds of sunflower and damage them

(phytotoxicity) (phytotoxicity)

widely used widely used tank-mixtank-mix combination combinationssof herbicidesof herbicides

linuronprosulfocarboxyfluorfen pendimethalin flurochloridonebifenox

acetochlor alachlor dimethenamidmetolachlor

+

dicot weeds

grass weeds

Pre-emergence weed control in Pre-emergence weed control in sunflower in sunflower in the the Czech Czech

RepublicRepublic

Material and methodMaterial and methodssTrial layoutTrial layout

tested herbicides:tested herbicides: HerbcideActive ingredience Herb. rate

(l.ha-1)

Goal 2 E oxyfluorfen 1,00

Afalon 45 SC linuron 1,50

Racer 25 EC flurochloridone 3,00

Stomp 400 SC pendimethalin 4,00

Boxer prosulfocarb 5,00

Trophy acetochlor 2,50

Half of each plot was irrigatedHalf of each plot was irrigatedby by simulation of 3simulation of 30 mm0 mm precipitationprecipitationss

(2-3 weeks after herbicide application)(2-3 weeks after herbicide application)

Material and methodMaterial and methodss

experimental yearexperimental yearss:: 2008 and 2009 2008 and 2009 soil characteristic:soil characteristic: chernozem, clay content 46 %, soil pH (KCl) 7.5, sorption chernozem, clay content 46 %, soil pH (KCl) 7.5, sorption

capacity of soil: 209 mmolcapacity of soil: 209 mmol(+)(+), 87 ppm P, 203 ppm K, 197 ppm Mg, 8073 ppm Ca, 87 ppm P, 203 ppm K, 197 ppm Mg, 8073 ppm Ca occurring woccurring weeds:eeds: Echinochloa crus-galliEchinochloa crus-galli, , Amaranthus retroflexus, Chenopodium Amaranthus retroflexus, Chenopodium

albumalbum and and Mercurialis annua Mercurialis annua

Materials and methoMaterials and methodsds

Soil moisture conditionSoil moisture conditionss::

dry condition – dry condition – natural precipitation – natural precipitation – 25 mm 25 mm within within 4 WAT4 WAT

wet condition – wet condition – intensiveintensive natural natural precipitation (65 mm precipitation (65 mm within within 4 WAT)4 WAT)

simulated simulated rainfall – rainfall – ((natural natural precipitation precipitation 25 mm 25 mm within within 4 WAT4 WAT + + 30 mm 30 mm irrigationirrigation))

Efficacy of tested herbicides on Efficacy of tested herbicides on Amaranthus retroflexusAmaranthus retroflexus

under different rainfall conditionsunder different rainfall conditions

0 10 20 30 40 50 60 70 80 90 100

oxyfluorfen

linuron

fluorochloridone

pendimethalin

prosulfocarb

acetochlor

efficacy (%)

dry condition simulated rainfall wet condition

low efficacy in dry condition

low efficacy in dry condition

Efficacy of tested herbicides on Efficacy of tested herbicides on Chenopodium albumChenopodium album

under under different different rainfall rainfall conditionconditionss

0 10 20 30 40 50 60 70 80 90 100

oxyfluorfen

linuron

fluorochloridone

pendimethalin

prosulfocarb

acetochlor

efficacy (%)


efficacy was not influenced by rainfall

Efficacy of tested herbicides on Efficacy of tested herbicides on Echinochloa crus-galliEchinochloa crus-galli

under under different different rainfall rainfall conditionconditionss

0 10 20 30 40 50 60 70 80 90 100

oxyfluorfen

linuron

fluorochloridone

pendimethalin

prosulfocarb

acetochlor

efficacy (%)




Efficacy of tested herbicides on Efficacy of tested herbicides on Mercurialis annuaMercurialis annua

in difin diffferent dry conditionerent dry condition

0 10 20 30 40 50 60 70 80 90 100

oxyfluorfen

linuron

fluorochloridone

pendimethalin

prosulfocarb

acetochlor

efficacy (%)


efficacy was not influenced by soil moisture

Selectivity of tested herbicides to Selectivity of tested herbicides to sunflower in different dry conditionsunflower in different dry condition

4 week after application4 week after application

0 5 10 15 20 25 30 35 40 45 50

oxyfluorfen

linuron

fluorochloridone

pendimethalin

prosulfocarb

acetochlor

efficacy (%)


no phytotoxicity in all tested rainfall conditions

phytotoxicity influenced by size of rain drops

ConclusionConclusionss

excellent and lonexcellent and longg-term residual -term residual efficacy efficacy onon E. crus-galli E. crus-galli and and A. A. retroflexusretroflexus

efficacy efficacy waswas not not aaffected by ffected by rainfallrainfall

acetochloracetochlor



wet conditions dry conditions

Chenopodium album Mercurialis annua


excellent and lonexcellent and longg-term residual -term residual efficacy to efficacy to E. crus-galli E. crus-galli and and A. A. retroflexusretroflexus

efficacy efficacy waswas not not aaffected by soil ffected by soil moisture moisture

slslow ow metabolism bymetabolism by sunflower - sunflower - risk risk if usedif used on sandy soil on sandy soil

sunflower injursunflower injuryy is often hidden is often hidden and and cause a cause a growgrow retardation retardation


excellent efficacy excellent efficacy on on A. retroflexusA. retroflexus and very good efficacy and very good efficacy onon M. annua – M. annua – notnot very very influenced by influenced by rainfallrainfall

oxyfluorfenoxyfluorfen





Chenopodium albumE. crus-galli

only in

excellent efficacy excellent efficacy onon A. retroflexusA. retroflexus and very good efficacy and very good efficacy onon M. annua – M. annua – not not very very influenced by influenced by rainfallrainfall conditionconditionss

short residual short residual activityactivity

slow metabolism by slow metabolism by sunflower – sunflower – phytotoxicity phytotoxicity waswas caused by rain caused by rain drops which reflected from soil drops which reflected from soil surfacesurface – – necrosis and deformation necrosis and deformation of leavesof leaves



good efficacy good efficacy onon all tested weeds, all tested weeds, but only in wet conditionbut only in wet conditionss

very low efficacyvery low efficacy in dry conditionsin dry conditions

linuronlinuron


linuronlinuron

ConclusionConclusion

wet condition dry condition

good efficacy good efficacy onon all tested weeds, all tested weeds, but only in wet conditionbut only in wet conditionss

low efficacylow efficacy in dry conditionsin dry conditions relative short residual relative short residual activity activity (up to (up to

2 month2 monthss after application after application)) – – fast fast development of sunflower leaf development of sunflower leaf coverage is necessarycoverage is necessary

high selectivity to sunflowerhigh selectivity to sunflower – – posposssibility of use ibility of use onon sandy soil sandy soilss

linuronlinuron


Lower selectivity to sunflower – Lower selectivity to sunflower – risk irisk if f useusedd on sandy soil on sandy soilss

phytotoxicity symptom on sunphytotoxicity symptom on sunflowerflower is is bleaching bleaching

excellent efficacy excellent efficacy onon all tested weed all tested weedss, , but only in wet conditionbut only in wet conditionss

reduced efficacy mainly reduced efficacy mainly onon E. crus-galliE. crus-galli and and M. annuaM. annua in dry condition in dry conditionss

llongong-term-term residual residual activityactivity

flurochloridoneflurochloridone


flurochloridoneflurochloridone



excellent efficacy excellent efficacy onon all tested weeds, all tested weeds, but only in wet conditionbut only in wet conditionss

in dry soil conditionin dry soil conditions,s, good efficacy good efficacy was found was found only only onon A. retroflexusA. retroflexus

prosulfocarbprosulfocarb




wet condition dry condition

excellent efficacy excellent efficacy onon all tested weeds, all tested weeds, but only in but only in wet wet conditionconditionss

in dry conditionin dry conditionss good efficacy only good efficacy only onon A. retroflexusA. retroflexus was foundwas found

relative short residual relative short residual activityactivity high selectivity to sunflowerhigh selectivity to sunflower – –

possibility of use possibility of use onon sandy soil sandy soilss



excellent and long-term efficacy excellent and long-term efficacy onon C. albumC. album in all tested wet condition in all tested wet conditionss

for other for other assessedassessed weeds weeds - short - short residual residual activityactivity andand efficacy is efficacy is partpartiallyially influenced by soil influenced by soil waterwater conditionconditionss

pendimethalinpendimethalin





excellent and long-term efficacy excellent and long-term efficacy onon C. albumC. album in all tested condition in all tested conditionss

for other tested weedsfor other tested weeds - short - short residual residual activityactivity andand efficacy is efficacy is partpartially ially influenced by soil winfluenced by soil watteratter conditionconditionss

bbreaking reaking and lodging of and lodging of stemsstems maymay occurr as aoccurr as a result of callus result of callus creation creation on on stem basestem base



Thank you for your attention

Documents

Miroslav Jursík Jiří Andr Veronika Venclová Josef Soukup E-mail: [email protected]