svend christensen, torben heisel and anne mette walter danish institute of agricultural sciences

Overview of developments in precision weed management, issues of interest and future directions being considered

in EuropeSvend Christensen, Torben Heisel and

Anne Mette WalterDanish Institute of Agricultural Sciences

Input data Output data

Point or zone model

Competition model

PC-Plant Protection

Decision model

DAPS - Decision Algorithm for Patch Spraying

Input dataField namePositionWeed speciesWeed density (leaf area and plant density)Sowing dateSeed rateRow distanceVarietyCrop leaf areaGrowth stageHistorical data (weed species and yield data)Soil typeExpected pricesWeedEye measurementsSampling

Point or zone modelHerbicide choiceEconomic optimal treatmentCrop managementRelative weed leaf area

Competition modelWeed speciesPlant densityWeed leaf areaSowing dateSeed rateRow distanceVarietyCrop leaf areaCompetition parametersEstimated yield loss

PC-Plant ProtectionWeed speciesPlant densityGrowth stageHerbicide parametersFind useable herbicides

Decision modelEstimated yield lossSowing dateSeed rateRow distanceVarietyPhysical weed control methodsHerbicide parametersCostPotential crop yieldEstimate yield gainEstimate efficacy

Output dataTreatment maps (chemical or physical)Yield gain mapEfficacy mapOptimal row distance mapWeed map(s) before and after treatmentOptimal seed rate mapGeostatisticKrigingGIS

MathCad dokument

1/3 N 1/1 N1/10 N1.5 1 0.5 00

20

40

60

80

100

alpha=-2, beta=-4alpha=-1.5, beta=-4alpha=-1, beta=-4alpha=-0.5, beta=-4alpha=-2, beta=-1alpha=-1.5, beta=-1alpha=-1, beta=-1alpha=-0.5, beta=-1

Log 10 dose

% b

iom

ass r

espo

nse

redu

ctio

n

1/10 N 1/3 N 1/1 N

Grid weed mapping (A)

. . . .

. . . . . . . .

10.6

0.20.6

0.2

1

Weed MapsWeed Maps

55.422

55.424

55.426

0

1

2

3

4

Plan

ts p

rer m

2

11.906 11.910 11.91455.422

55.424

55.426

0102030405060708090100

Plan

ts p

rer m

2

11.906 11.910 11.91407142128354249566370

Plan

ts p

rer m

2

0481216202428323640

Plan

ts p

rer m

2

Stell

aria

media

Brass

ica na

pus

Tripl

euro

sper

mu

m inido

rum

Grass

spp.

Tribenuron-methyl 500 g a.i./kg

Ioxynil + Bromoxynil 200 g a.i./l

Dose: 0.1 - 1.7 Tablet /haMean dose: 1.1 Tablet /ha

Dose: 0 - 1 l/haMean dose: 0.2 l/ha

Treatment maps for injection Treatment maps for injection sprayingspraying

Hardi sprayer with a Raven injection system

Patch SprayingPatch Spraying