1. ALTERNATIVE WEED CONTROL IN ARABLE CROPS France
Integrated weed management (IWM) is a broad term covering many methods that can be combined and
applied in various ways to the crop to constitute an IWM strategy.
This persentation shows the example of the french network Desherb’sol and the techniques in five crops: winter wheat, winter oil-seed rape, sunflower, maize and sugar-beet.
MODULE C19

2. Aims of weed mechanical or mixt control : Sustainable use of herbicides
Background: reduction of pesticides in France → Grenelle Environment → Basin supply catchment
Reducing the cost of herbicides use → 15-25% of operating expenses
Sustainable herbicide The technical "plus"
→ Effect on soil warming   
→ Interest in the positioning of fertilizers
→ Enable mineralization
INTRODUCTION
the advantages of these techniques are into the 3 pillar of sustainable agriculture:
environmental and social: political background in France (Ecophyto, Grenelle) and surface water pollution with herbicides
economic: cost of herbicides use
But this slide open the door on the technical advantages as well:
 quality of soil and fertilization

3. Weed control into the rotation:
Agronomic Principles
Diversifying crops
Take advantage of intercropping to reduce the seed bank
Use tillage wisely
Stagger planting dates
Using the factor “crop competition”
By combining these principles the maximum weed control will be facilitated, optimized the use of herbicides and the risk of emergence of resistance limited
AGRONOMIC PRINCIPLES
Weed control must be reasoned into the rotation :
to use all the techniques to minimize the growth of population of some species;
to allow the development of the crops without the influence of weeds. 3

4. Comparison of two weed management
Region Burgundy (France)
Wheat
Weeds: Alopecurus, Bromus, Veronica, Viola, Galium
Sowing 3L
Tillering
Beginning of
Stem elongation
Ear at 1cm
1 Node T2
Mesosulfuron
Iodosulfuron +
Propoxycarbazone
+ florasulame T1
Isoproturon + dff + ioxynil + bromoxynil
From 1st of october
CHEMICAL
2 to 3 stale seedbed
No possibility of mechanical control with winter weather conditions
CASE STUDIES
Presentation of 5 cases of different crops: wheat, winter rape, maize, sunflower and sugar beet.
In each case, the problem weeds in the region are named and routes of conventional chemical weeding and mixed weeding are compared. The examples are for two French regions in the north-east: Burgundy, Champagne:
with the mixt weed control, you must to shift the sowing date because you use the stale seed bed technique
you can show how less use herbicides (number of treatments, rates,…)
WEED MANAGEMENT IN WHEAT
Density +10%
2 tillages
Shifting the sowing date from the 20th of october T2
Propoxycarbazone
+ florasulam
MIXT

5. Comparison of two weed management
Region Burgundy (France)
Oil-seed rape
Weeds :Alopecurus, Bromus, Matricaria, Stellaria,Galium, (Geranium)
Sowing
Cotyledon 1L 4L
Rosette T1
Napropamid
Clomazone
Dimetachlor
+ quinmerac
métazachlor T2
Propyzamid
From mid-august
CHEMICAL
1 stale seed-bed
WEED MANAGEMENT IN OIL-SEED RAPE T1
Napropamid
Clomazone
Dimetachlor
On 1/3 of the soil
From early september T2
Propyzamid
MIXT
Hoeing

6. Comparison of two weed management
Region Burgundy (France)
Maize
Weeds : Summer grasses, Chenopodium, Amaranthus, Solanum nigrum
Semis
Emergence
2 L
4 L
5-6 L
8 L
Cover-cropping
And
Tillage T1
Acetochlore + dichlormid
CHEMICAL
WEED MANAGEMENT IN MAIZE T1
Mesotrione + s-métolachlor
On the sowing row
MIXT
Hoeing

7. Exemples d’itinéraire technique
Region Burgundy (France)
Sunflower
Weeds : Summer grasses, Chenopodium, Amaranthus, Solanum nigrum
Sowing
Emergence
4 L
Cover-cropping and Tillage T2
Flurochloridone T1
S-métolachlor
CHEMICAL
WEED MANAGEMENT IN SUNFLOWER T1
Flurochloridone on the sowing row
MIXT
Hoeing

8. Comparison of two weed management
Region Burgundy (France)
Sugar-beet
Weeds : Chenopodium, Apiaceae, Sonchus, Cirsium, Mercurialis, CRape volunteers, Matricairia, Amaranthus …
Sowing
Cotyledon 1L 4L
T1 + T2 + T3 + T4
Phenmedipham desmedipham
Ethofumesat
Metamitron
Lenacil T5
Grass killer herbicide (if needed)
40% rate
CHEMICAL
To control all the weeds emergences
WEED MANAGEMENT IN SUGAR-BEET
T1 + T2
Phenmedipham desmedipham
Ethofumesat
Metamitron
Lenacil T3
Grass killer herbicide (if needed)
40% rate
MIXT
Hoeing
2 passages
To control only the earlier weeds emergencues
Total or localised spray

9. Pesticides use reduction
Treatment Frequency Index
2,17
2,77
Herbicide
- 51%
1,77
Herbicide
- 45%
1,67
TFI Herbicide
Herbicide
- 80%
1,33
1,27
Herbicide
- 73%
0,96
TFI
This slide show the exactly amount of herbicides in the two compared management.
You can demonstrate that the reduction is from 45% to 80% by crop.
0,33
0,33
Chemical
Mixt
Chemical
Mixt
Chemical
Mixt
Chemical
Mixt
Wheat
Oil-seed rape
Maize
Sunflower
TFI = Treatment Frequency Index = number of registrared rates sprayed in a field

10. Agricultural feasibility
Rotative hoe
Weed harrow
Hoeing machine
Loamy
Clayey
SOIL
Capped
Stony
Stage EM 2L 4L 6L EM 2L 4L 6L EM 2L 4L 6L
WEEDS
Grasses
Broadleaves
AGRICULTURAL FEASABILITY
This slide gives information when you can use mechanical equipment with the type of soil, the stages of weeds and crops.
EM = emergence
L = leaves
Stage EM
<2L 4L 6L EM
<2L 4L 6L EM
<2L 4L 6L
CROP
Selectiviy
Well adapted
Adapted
Dangerous No

11. (Total – Operating expenses) (Gross margin – Mechanization expenses)
Economical viability
Comparison of operating expenses
In chemical or mixt management 50
100
150
200
250
300
350
400
450
Chemical
Mixt
Operating expenses (€/ha)
Regulators
Insecticides
Herbicides
Fongicides
Fertilization
Seeds
Intercropping
- 43 €
- 37 €
WHEAT
MAIZE
Mechanization expenses
In chemical or mixt management
180
+ 8 €
160
+ 26 €
140
120
100
Spraying and fertilization
Chemical weed control
Mechanization expenses (€/ha) 80
Mechanical weed control
Sowing 60
Intercropping 40 20
Chemical
Mixt
Chemical
Mixt
WHEAT
MAIZE
WHEAT
MAIZE
Chemical
Mixt
Gross margin (€/ha)
(Total – Operating expenses)
558
601
717
754
Net margin (€/ha)
(Gross margin – Mechanization expenses)
428
445
564
593
ECONOMIC FEASABILITY
It is very important to show the economical results with gross and net margins taking into account the mechanization expenses of the different systems in the different crops.
Costs (Burgundy chamber of agriculture / 2007):
Sprayer 24m, 1500 liters (15.000€ Taxes non included)  600 ha/year + 10 ha/h = 6,2 € /ha
Localised sprayer kit (3600 € TNI) = 8,6 € / ha
Weed harrow 12m (7000 € TNI)  140 ha/year + 9,6 ha/h = 9,8 € / ha
Rotative hoe 4,7m (9700 € TNI)  200 ha/year + 5 ha/h = 11,8 € / ha
Hoeing machine; 6 rows (7000 € TNI)  60 ha/year + 1,8 ha/h = 31,1 €/ha

12. Other inovative techniques Experimental
Direct Drilling
Live Mulch
Geraniums in early winter (weeds/m²) 20 40 60 80
100
120
140
Deep
cultivating
Deep + sup
Direct drilling
NEW SOLUTIONS
You can show new experimental solutions to be tested :
- direct drilling
- drilling under live mulch
- drilling with other crops
Mixt crops

13. Conclusion: Response to general principles of IPM
Environment: Reduced quantities of herbicides (Part 5)
Agronomy Resistance management (part 7) Use of alternative methods (part 4) Combination with preventive methods (part 1)
Terms of Success: technical knowledge
Economy Margins comparable between chemical and mixt management More advantages if mechanization investment (equipement with large width, gps, ...) More manpower is sometimes needed
CONCLUSION
You have to show the different IPM principles this technique follows:
less herbicides and less resistance
use of non-chemical methods
but also the odds and sods about economical aspects:
mechanization investment is needed
sometimes manpower as well