1. Selecting Herbicide Original by Brent Niemeyer Modified by Georgia Agricultural Education Curriculum Office July, 2002

2.  Effective weed control depends on selecting the right herbicide.

3.  Herbicides are classified according to the way they destroy weeds.

4. Types of Herbicide  Contact Herbicide  Growth Regulators  Soil Sterilants

5. Contact Herbicide  Kills plants by exposure  Works best on Annuals  May only kill parts of the plant in contact

6. Growth Regulator  Alters growth or metabolic processes  Absorbed by the roots, stems, or leaves

7. F The movement of a herbicide inside of a weed is known as translocation

8. Soil Sterilant  Prevents the growth of plants in the soil  Most useful in greenhouse

9. Selectivity of Herbicides

10. Selective Herbicide  Kills only certain plant species and not others

11. Selective Herbicide  Possible to spray in field without injuring crop

12. Non-Selective Herbicide  Kills all plants regardless of species

13. Non-Selective Herbicide  Should not be used in growing crops

14. Using Herbicides Time of Application

15. Herbicides may be applied at three times:

16. F Pre-plant F Pre-emergence F Post-emergence

17. Using Herbicides Area of Application

18. 4 general areas of application are used:

19. Band  Treating narrow strips with herbicide  Used in cotton & corn

20. Broadcast  Treating the entire area of a field  Used with pastures  Not used in row crop

21. Directed Appl.  Treating only selected or targeted plants  Some use in row crop  Used a lot with trees

22. Spot Application  Treating only certain areas in field  Saves cost plus labor  Protects environment

23. Applying Herbicide  Knowing when and how to apply are important for effective weed control