1.
Plants and Agriculture – a history
Bernie Jones

2.
3
1
4
14
1
What do you know about farming?
1. I am a farmer
2. I grew up and/or have lived in a farming community
3. I am a city person, but members of my family farm
4. I have no experience of farming
5. What’s a farm?

3.
5%
5%
9%
27%
55%
When did people start to farm?
1. People have always farmed
2. Around 10,000 years ago
3. Around 5,000 years ago
4. Around 2,000 years ago
5. Around 500 years ago

4.
How did it start?

5.
Early Farming

6.
Domestication

7.
When? Why? How?
9000BC Wheat/barley, Fertile Crescent
8000BC Potatoes, South America
7500BC Goats/sheep, Middle East
7000BC Rye, Europe
6000BC Chickens, South Asia
3500BC Horse, West Asia
3000BC Cotton, South America
2700BC Corn, North America

8.
Diversity & Traits
Living things are variable
(This is genetics!)

9.
Selection

10.
Selection
• Early farmers discovered they could select better traits in
their crops
• This becomes a continuous process

11.
Crops already “genetically
engineered” over 1000’s of
years…
Selection

12.
Change: mutation & crossing
• Natural mutations and crosses
• Selection for desirable traits
• Deliberate crossing/hybridisation

13.
Deliberate plant breeding
• Realisation that attributes of plants could be
deliberately influenced
• Launched plant breeding as necessity
(disease) and “pastime”
• Gradual realisation that there must be
principles underlying this process
• Constant searches to find new plant material
for cross-breeding

14.
Breakthrough of “genetics”
• Could observe some underlying principles…
• Led to gradual understanding and discovery of
genetics and inheritance. More of this in next
session
• But allowed breeding, and breeding process,
to become much more focussed and
productive

15.
Where are we today
• All our crops are “modified” in some way
• Plant breeding and selection have been basic
way of life for farmers for millennia
• Techniques have developed over time
• Current technological options just part of this
continuum
• Risks from traditional breeding?

16.
Agricultural systems
• Crop rotation
• Sustainable agriculture
• Sustainable intensification
• Organic
But these are all potentially complementary
techniques, not alternatives

17.
Colonisation, migration and
agriculture
• Centres of origin vs most productive zones now
• Why are Africa’s staple crops what they are?

18.
8
2
3
1
12
Which of these are “African” crops?
1. Cassava
2. Maize
3. Sorghum
4. Cocoa
5. Oil palm

19.
12%
4%
12%
20%
52%
Which of these are “African” crops?
1. Pearl Millet
2. Mango
3. Rice
4. Sugarcane
5. Cotton

20.
Modern-day crops/foods
• Are often not indigenous
• Have (in the main) been significantly altered
by humans over 1000s of years
• And are therefore “genetically modified”
(but are NOT GMO’s)

21.
Genetics/Breeding recap
• Natural (genetic) variety/diversity in crops
• Selection (natural, accidental, deliberate)
• Mutation (environmental, genetic)
• Crossing & hybridisation (natural, deliberate)
GENETICS!

22.
Recap
• Agric practices and environments complex
• Planting material/crops complex
– “natural breeding”
– deliberate and accidental breeding
– constant process
• No silver bullets