Post on 16-Dec-2015
IAEAInternational Atomic Energy Agency
Application of Radiation Sources in Agriculture
Day 6 – Lecture 6
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To learn about the use of ionization radiation in Agriculture to improve the quality and yield of crops and fruits and their preservation
Objective
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Contents
Crop Improvement by Mutation Insect Control Food Preservation Fertilizers Water Resources Animal Production and Health
.
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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.
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Crop improvement by mutation techniques
• 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.
Genetic Variability
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Crop improvement by mutation techniques (Cont.)
• 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.
Technical basis
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- Higher yielding- Disease-resistance- Well-adapted- Better nutrition
Mutant cultivars
Crop improvement by mutation techniques (Cont.)
no mutation
negative mutation
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- Improving crop cultivars
- Enhancing biodiversity
- Increasing farmer’s income
Crop improvement by mutation techniques (Cont.)
IAEAInternational Atomic Energy Agency
VND99-3High quality for exportShort duration (100 days)
3 rice harvests per year in the Mekong Delta
8 new high quality rice mutant varieties have been developed and adopted by farmers in Vietnam, where rice export is one of their main revenues.
VND95-20High qualityTolerance to salinity Key rice variety for export
“National Prize of Science and Technology of Viet Nam 2005” for its “significant socio-economic contribution”
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• 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.
Insect Pest Control by Sterile Insect Techniques (SIT)
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• 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.
Insect Pest Control by Sterile Insect Techniques (Cont.)
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• 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 suppression, containment, or even eradication.
Insect Pest Control by Sterile Insect Techniques (Cont.)
Technical basis
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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 screw-worm 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.
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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.
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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.
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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)
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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)
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Food and Irradiation (Cont.)
• Food irradiation is the treatment of food by ionizing radiation
• Radiation at appropriate doses can kill harmful pests, bacteria, or parasites, and extend shelf-life of foods
Technical basis
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Several energy sources can be used to irradiate
food
• Gamma Rays
• Electron Beams
• X-rays
Food and Irradiation (Cont.)
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Food and Irradiation (Cont.)
• 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.
Choice
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Effects of various doses on food
Dosage level
• Low dose(1kGy)
• Medium dose(1-10kGy)
• High dose(10-50kGy)
Effects
• Sprout inhibition• Delay ripening• Insect disinfestations• Reduction of pathogenic
microorganisms• Reduction of spoilage
microorganisms• Delay ripening• Sterilization• Functional modification
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Food Irradiation
Codex General Standard for Irradiated Foods
ENSURE FOOD HYGIENE
OVERCOME QUARANTINE BARRIERS
FOOD SAFETY TRADE
MEAT SHRIMP
CHICKEN
GRAPES
MANGOS
ORANGES CUT FLOWERSSPICES
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'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.
Fertilizers
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31P
14N
32P
15N31P
14N
13CO2
12CO2
13C12C
18O 16O
31P
32P
13CO2
12CO2
16O
18O
Fertilizers (Cont.)
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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.
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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.
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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
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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.
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Animal Production And Health (Cont.)
• Coordinated research programmes on the study of non-protein 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
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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.