GM Risks and Benefits

Question 1

Who receives the most benefits from GM crops?

Answer 1

Farmers receive 76% of benefits from GM crops
Seed companies receive only 3%

Question 2

What are the barriers to plant biotech?

Answer 2

Bureaucracy and cost:
- 10 years to develop
- $135-200 million to develop a GM crop
- Uncertainty of approval
Markey fragmentation:
- Different regions prefer different varieties
- Food preferences
- Growing conditions
A GM trial costs $30 million
- e.g. Rothamstead research- took 10 years for approval, field trials were unsuccessful

Question 3

How do farmers benefit from GM?

Answer 3

• 22% increased yields
• 37% reduced pesticides
• 68% increase in profits

Question 4

What are the environmental costs and benefits to GM?

Answer 4

‘Will HT crops become superweeds?’
- Unlikely, they need management and are selected for
- There are 100s of other herbicides that can be used
‘What if HT gene is transferred to weeds?’
- Whether HT is transferred to other plants depends on the proximity of related weed relatives
- No benefit from HT if weeds are not regularly exposed to herbicide, so unlikely to persist
Reduced biodiversity and seed for over winter birds
Glyphosate resistant weeds:
- Marestail in wheat
- Pigweed in cotton
- But this is not due to GM crops, no transgene found in them
- They can be found in UK and there is no GM here

Question 5

How can superweeds be reduced?

Answer 5

• By stacking traits (e.g. multiple herbicide resistant genes)
• Selectively applying herbicide (however, costly technology, not accessible to all)

Question 6

How can transgene contamination be reduced?

Answer 6

• Chloroplast transformation (no transgene in the pollen)
• Exclusion zones
• Antibiotic gene removal
• Transient expression
• Contained growth (good for tomatoes but not viable for maize, wheat, cotton etc.)

Question 7

What did nutritional analysis find for GM crops?

Answer 7

No significant differences in protein, oil, ash, fibre, carbohydrate and amino acid content between several generations of RR and parental strains
Also no difference after glyphosate was applied

Question 8

What was found about livestock that was fed on GM?

Answer 8

Growth rate not affected for chickens, catfish and dairy cows that were fed conventional or RR soybeans
Eaten in the US since 1995 with no reported problems

Question 9

What was found about the allergenicity of GM crops?

Answer 9

RR ESPS amino acid sequence has no similarity to any known allergens
Degrades in 15 secs in a simulated gastric environment, whereas all allergens are usually more stable in the gut

Question 10

What was used as weed control pre-GM?

Answer 10

Tillage, cultivation practices
1960s - herbicide became main method, but risks of crop damage, persistence in soil and development of herbicide resistant weeds