1. Herbicide Resistance and GMO’s
Plant Science 280
Mr. Gomes

2. Definitions Resistance Tolerance
Ability to withstand exposure to a potentially harmful agent without being injured
Tolerance
Ability to continue normal growth or function when exposed to a potentially harmful agent

3. Factors affecting resistance potential
The herbicide has a high degree of control
The weed’s seed has a short life in the soil seed bank
The herbicide has long soil persistence
Used frequently
Annual rotation is not practiced
Single site of action
Use rate is high
Only one is used in a crop

4. The Advent of GM Crops 1970?? 1984 Tomatoes
1988 is the beginning of GT Soybeans
Three physiological mechanisms for natural or induced tolerance
Reduced sensitivity at a molecular site of action
Increased metabolic degradation
Avoidance of uptake or sequestration after hiding

5. GM Facts and Info 60% of the GM Crops grown in the World are in the US
In 2010, 158 million acres
Others include Argentina, Brazil, India, and China
RR has turned into “stacked genes” in corn, soybeans, cotton, and soon to be alfalfa!!
What is the future of GM Crops?

6. Concerns and Criticisms
Public Health
Complex mixtures of thousands of different chemical substances
GM Crops may contain foreign proteins, which could increase food allergies
Increasing the possibility of antibiotic resistant genes
Increases or decreases in food quality
Genetic manipulation within the human DNA strand

7. Concerns Cont... Environmental Gene Flow to sexually compatible plants
Teosinte and corn
Sorghum to sudan to Johnson grass
Canola to mustard
Sugar beets in Europe

8. Concerns Cont… Herbicide Use
Increase uses creating more unsustainability
Ability to grow crops in new areas, reducing safe zones
Increases in super weeds
Increases in invasive species
Ownership of the technology?

9. Concerns Cont… Soil Conservation
Increased soil tillage due to higher resistance
Can increase erosion, water quality, soil quality, etc.
Increases in older ways of weed management
Increases in older chemistry’s

10. Concerns Cont… Social Reduction in small farms
Severe decreases in public awareness
Lack of science
Farming age shifts which can affect social impact
Distance farm to plate