1. Danish Institute of Agricultural Sciences
Overview of developments in precision weed management, issues of interest and future directions being considered in Europe
Svend Christensen, Torben Heisel and
Anne Mette Walter
Danish Institute of Agricultural Sciences

2. DAPS - Decision Algorithm for Patch Spraying
Input data
Output data
Point or zone
model
Competition
PC-Plant
Protection
Decision

9. MathCad dokument

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

11. Grid weed mapping (A) 1
0.6
0.2
0.6
0.2 1

12. Tripleurospermum inidorum
Weed Maps
Plants prer m2 4 8 12 16 20 24 28 32 36 40
Plants prer m2
Brassica napus
Stellaria media
Plants prer m2
Plants prer m2
This is an example of 4 weed species being mapped in a 40 ha field at Giesegård, Sealand. Every weed species in a 0.25 circle were counted in a 20 m by 20 m grid. As you can see the weed density - the intensity of the green colour - varies significantly. Even the Capsella density varies significantly.
Grass spp.
Tripleurospermum inidorum

13. Treatment maps for injection spraying
Ioxynil + Bromoxynil
200 g a.i./l
Tribenuron-methyl
500 g a.i./kg
A decision algorithm for patch spraying two herbicides simultaneously with a injection spraying was used to make the treatment maps – based on the weed data. On the right side you see spatial variation in applying the economic optimal herbicide dose of Tribenuron - including the effect of ioxynil + bromooxynil. On the right side you see the economic optimal dose of ioxynil + bromooxynil including the effect of Tribenuron.
Dose: Tablet /ha
Mean dose: 1.1 Tablet /ha
Dose: l/ha
Mean dose: 0.2 l/ha

14. Patch Spraying Hardi sprayer with a Raven injection system
The software packages Surfer (from Golden Software), AgroSat (from Datalogisk) and PatchworkPro (from Raven Industries) were used. A injection system was mounted on a Hardi sprayer.
Hardi sprayer with a Raven injection system