Application of Radiation Sources in
Agriculture
IAEA
International Atomic Energy Agency
Day 6 – Lecture 6
Objective
To learn about the use of ionization radiation in
Agriculture to improve the quality and yield of
crops and fruits and their preservation
IAEA
2
Contents
.






IAEA
Crop Improvement by Mutation
Insect Control
Food Preservation
Fertilizers
Water Resources
Animal Production and Health
3
Food & Agriculture
A billion people go to bed hungry every night and tens of
thousands die daily from hunger and hunger related
causes.
Radioisotopes and radiation used in food and
agriculture are helping to reduce these tragic figures.
IAEA
4
Crop improvement by mutation
techniques
Genetic Variability
• Ionising radiation is used in plant breeding to produce
new genetic lines. Some examples have been sorghum,
garlic, wheat, bananas, beans, avocado and peppers.
The new lines are more resistant to pests and more
adaptable to harsh climatic conditions.
IAEA
5
Crop improvement by mutation
techniques (Cont.)
Technical basis
• Radiation can cause genetic changes in living organisms
and increase mutation rate up to 1×10-5 ~ 1×10-2
• Induced mutation is useful for crop improvement
Induced Mutation: mutation that is produced by treatment
with a physical or chemical agent that affects the
deoxyribonucleic acid molecules of a living organism.
• Induced mutants are not GMOs (Genetically Modified
Food), as there is no introduction of foreign hereditary
material into induced mutants.
IAEA
6
Crop improvement by mutation
techniques (Cont.)
negative
mutation
Mutant cultivars
-
Higher yielding
Disease-resistance
Well-adapted
Better nutrition
no mutation
IAEA
7
Crop improvement by
mutation techniques (Cont.)
- Improving crop cultivars
- Enhancing biodiversity
- Increasing farmer’s income
IAEA
8
VND99-3
High quality for export
Short duration (100 days)
3 rice harvests per year in the
Mekong Delta
VND95-20
High quality
Tolerance to salinity
Key rice variety for export
“National Prize of Science and
8 new high quality rice mutant
Technology of Viet Nam 2005” for
varieties have been developed
its “significant socio-economic
and adopted by farmers in
contribution”
Vietnam, where rice export is one
of their main revenues.
IAEA
International Atomic Energy Agency
Insect Pest Control by Sterile Insect
Techniques (SIT)
• While some insects are important for maintaining
the natural ecological balance, others destroy
valuable food crops. Some insects such as the
mosquito and tsetse fly are vectors of infectious
diseases. It has been estimated that, for the world
as a whole, crop losses caused by insects may
amount to as much as 10 per cent of the total
harvest, an amount equal to the total harvest of a
country such as the USA or the USSR.
IAEA
10
Insect Pest Control by Sterile Insect
Techniques (Cont.)
• The Sterile Insect Technique (SIT) consists of
irradiating laboratory-reared male insects before
hatching to sterilise them then releasing them in
large numbers in the infested areas. When they
mate with females, no offspring are produced.
With repeated releases of sterilised males, the
population of the insect pest in a given area is
drastically reduced.
IAEA
11
Insect Pest Control by Sterile Insect
Techniques (Cont.)
Technical basis
• Radiation is used to induce lethal mutations in
chromosomes of insect pests to cause sterility.
• Sterile males are released into the wild where they
compete with wild males for matings with wild females.
• SIT relies on:
•
•
•
•
mass production of the target pest
sterilization and shipment
In-undative releases mostly by air
matings result in no offspring
• SIT integrated with other pest control methods is
applied for
eradication.
IAEA
suppression,
containment,
or
even
12
Insect Pest Control by SIT
Gamma Radiation
Sterile
Sterile
Wild
No
Offspring
(BIRTH CONTROL)
Insect Pest Control by Sterile Insect
Techniques (Cont.)
Few Examples:
• The first successful SIT application was made on the
screw-worm fly, a troublesome pest that lives in the wounds
of warm-bodied animals, particularly livestock. Male screwworm flies were reared and sterilized by radiation and
released on the Caribbean island of Curacao. Within a few
breeding cycles, the pest virtually disappeared from this
island.
• Later SIT used to control the screw-worm fly in Florida,
where cattle losses due to that fly had reached a figure of
more than 25 million US dollars a year.
IAEA
14
Insect Pest Control by Sterile Insect
Techniques (Cont.)
• A great research effort was made into the
Mediterranean fruit fly, which proved to be another
success in Capri and other islands Recently, an
isolated pocket of Mediterranean fruit fly infestation
was eradicated in California by first using
insecticides followed by SIT and the method is now
being used in Central America on a large scale
with support from the Joint FAO/IAEA Division and
its Laboratory. The melon fruit fly was similarly
eradicated from the island of Rota in the South
Pacific.
IAEA
15
Food and Irradiation
• In a hungry world, it is too great a luxury to lose 25 to 30
per cent of the harvested foods to spoilage by microbes
and pests. What is even more regrettable is that these
losses are largest in developing countries. Often an
extension of shelf life of certain foods (i.e. fish and fruit) of a
few days is enough to save them from spoiling.
• More than 25 years have passed since radiation was found
to be applicable to extend the shelf life of certain foods.
Since then, great efforts have been made to test the
wholesome-ness of radiation-processed food In the 25
years of testing such foods, no harmful effects to animals or
humans have been found.
IAEA
16
Food and Irradiation (Cont.)
Food Preservation
 25-30% of food lost due to spoilage and pests
 irradiation technology can be used to preserve food
 More than 40 countries have approved food irradiation
(spices, grains, grain products, fruit, vegetables and meat)
IAEA
17
Food and Irradiation (Cont.)
Food Preservation
 astronauts eat foods preserved by irradiation
 worldwide standard adopted in 1983
 concerns about food-borne diseases and international
trade in foodstuffs
 Radiation also used to sterilise food packaging (milk
cartons)
IAEA
18
Food and Irradiation (Cont.)
Technical basis
• Food irradiation is the
treatment of food
ionizing radiation
by
• Radiation at appropriate
doses can kill harmful
pests, bacteria, or
parasites, and extend
shelf-life of foods
IAEA
19
Food and Irradiation (Cont.)
Several energy sources
can be used to irradiate
food
• Gamma Rays
• Electron Beams
• X-rays
IAEA
20
Food and Irradiation (Cont.)
Choice
• The choice of a irradiator facility and
radiation source depends on some
practical aspects of the treatment process
viz. required absorbed dose, material
thickness (bulk product), processing rate
etc.
• Capital and Operating costs and also the
availability of the technology/ back up
etc.
IAEA
21
Effects of various doses on food
Dosage level
Effects
• Low dose(1kGy)
•
•
•
• Medium dose(1-10kGy) •
•
• High dose(10-50kGy)
IAEA
•
•
•
Sprout inhibition
Delay ripening
Insect disinfestations
Reduction of pathogenic
microorganisms
Reduction of spoilage
microorganisms
Delay ripening
Sterilization
Functional modification
22
Food Irradiation
Codex General Standard for
Irradiated Foods
ENSURE FOOD
HYGIENE
OVERCOME
QUARANTINE
BARRIERS
SHRIMP
MEAT
CHICKEN
SPICES
IAEA
FOOD
SAFETY
TRADE
MANGOS
GRAPES
ORANGES CUT FLOWERS
23
Fertilizers
'labeled' with a radioactive isotope, such as 15N and
32P, provide a means of finding out how much is taken
up by the plant and how much is lost.
IAEA
24
Fertilizers (Cont.)
14N
32P
31P
31P
13CO
2
12CO
2
15N
32P
14N
16O
31P
18O
13CO
2
12CO
2
18O
16O
13C
12C
IAEA
25
Fertilizers (Cont.)
Few Examples:
In one country that took part in a research programme on
nitrogen fertilization of maize, which was organized by the
Joint FAO/IAEA Division, it was estimated that the benefit to
that country amounted to 36 million US dollars per year after
its farmers had adopted the findings of the research
programme for the most efficient placement of fertilizer.
In a similar programme involving coconut palms in Sri
Lanka, it was found that the efficient use of fertilizer not only
yielded direct savings in the cost of fertilizer but also an
estimated potential saving in production cost.
IAEA
26
Fertilizers (Cont.)
Similar programmes on crops such as rice
have yielded savings of millions of dollars in
decreased fertilizer costs. Additional savings
are also possible.
A group of experts recently estimated that
up to 50 per cent of the fertilizer used at
present in all countries could be saved by
improved fertilizer, better water management
and better cropping methods.
IAEA
27
Water Resources
 radioactive liquid tracers injected into water supply
 underground - trace and measure the extent of
underground water, provide information about origin, age
and distribution and the interconnections between
ground/surface water and renewal systems
 surface - evaluate leakage through dams, dynamics of
lakes and reservoirs, flow rates, river discharge
measurements, sedimentation rates
IAEA
28
Animal Production And Health
• In many regions of the world animal production is
limited by poor growth, reproductive performance
and milk output of livestock, which limits the
availability of animal products such as meat, milk,
eggs, fibres, leather, etc. for use by man. Reduced
animal production results from inadequate or
unbalanced nutrition, lack of adaptation to the
prevailing climatic conditions, and parasitic and
other diseases.
IAEA
29
Animal Production And Health (Cont.)
• Coordinated research programmes on the study of nonprotein nitrogen metabolism using N-15 and the utilization
of low quality roughages and agro-industrial by-products in
ruminants, together with studies on mineral imbalances, are
helping to devise alternative feeding practices in countries
where traditional feeds for ruminants are in short supply.
• A programme in which radio-immunoassay techniques are
used to measure the hormonal changes during the
reproductive cycle of cattle and buffalo is leading to
enhanced
reproductive
efficiency
through
better
management practices and more efficient use of artificial
breeding techniques
IAEA
30
Animal Production And Health (Cont.)
• A major limitation to increased production is that caused by
parasitic and other diseases. Isotope techniques are not
only providing a well-defined picture of the effect that
parasites have on hosts but are also illustrating how
management and genotypes (breeds and species) can be
modified to reduce the effect of the parasite or disease on
production. Ionizing radiation has been successfully used to
produce an attenuated vaccine against lungworm in cattle
and sheep and this technology is being transferred to those
areas of the world where control of this parasitic disease is
of economic importance, e.g. Brazil, India, Ethiopia.
IAEA
31