1. Preventive Weed Control

2. Weed control practices must be:  Effective, economical, practical  Safe to humans  Safe to environment  Minimal non-target effects

3. Objectives of Weed Management Prevention: Keeping a weed from being introduced into an uninfested area. Control: Suppression of a weed to the point that its economic ( or harmful) impact is minimized.

4. Objectives of Weed Management (cont.) Eradication: Elimination of all plants and plant parts of a weed from an area (seeds, vegetative propagules, rhizomes, creeping roots, tuber).

5. Methods or Strategies of Weed Control  Prevention  Physical  Mechanical  Cultural  Biological  Chemical

6. Preventive Weed Control Definition – Those measures taken to prevent or forestall the introduction and spread of weeds.

7. Preventive measures include:  Weed-free seed.  Competitive crops.  Crop rotation and diversity.

8. Preventive measures include: (cont)  Manage wind-borne seeds.  Weed cleaning equipment.  Legal measures – county, state, agency, national, quarantines.

9. Preventive measures include: (cont)  Spot eradication.  Clean equipment.  Manage feedstuffs and manure.  Weed-free waterways and drainage.

10. Prevention can be an integration of other methods Physical – burning, draining, flooding, mulching, sterilization.

11. Preventive Weed Control Definition – Those measures taken to prevent or forestall the introduction and spread of weeds. A gram of prevention is worth a kilogram of cure.

12. Preventive weed control embraces all practices that control weeds, with the objective of preventing the introduction or propagation of weeds in a specified area.

13. Methods of Weed control Four General Principles (simple concepts that underlie all control practices – keep in mind when considering method of control use)

14. Methods of Weed control (cont.) 1. Weed control practices depend on the life cycle of the specific weeds (annual, biennial, or perennial – time of germination – when seed matures (must prevent seedling)).

15. Methods of Weed control (cont.) 2. Weed control practices will depend on the habitat (where the weed is growing) of the weed (corn field – cultivate; grain field – spray; pasture – mow; wasteland – sterilization; good land vs. poor land – economics).

16. Methods of Weed control (cont.) 3.Weed control practices will depend on the size, density, and age of the infestation (small intensive patch (expensive) – large patch – extensive acreage).

17. Methods of Weed control (cont.) 4. Weed control methods depend on prevailing farm practices and available equipment (depends on the individual farmer and his past experience).