2. What means of nematode management on plant? Maintaining nematode damage or loss below an economic injury level or remain nematode population below that level ( 선충의 피해나 손실을 경제적 피해수준 이하로 유지시키는 것, 또는 선충의 발생밀도를 경제적 피해수준이 이하로 유지하는 것 )

3. Historical background Andes of South America the Inca ’ s ; Law a 7 years rotation for potato (potato cyst nematode) ⇒ Inca ’ s discovered a cultural practice that gave them the best potato crop

4. Basic principles of Management 1.Sanitation 2.Crop rotation 3.Time of planting 4.Soil amendment 5.Biological control 6.Management by physical factors 7.Management by chemical factors

5. Sanitation 1.Soil, tools, farm machinery, water, and nursery stock ;nematode can be transported by wind, and human 2. Quarantine 1) restrict the movement of infected plant materials and contaminated soil into a state or country 2) prevent the movement of infected plant materials and contaminated soil out of area known to have nematodes

6. Historical background Andes of South America the Inca ’ s ; Law a 7 years rotation for potato (potato cyst nematode) ⇒ Inca ’ s discovered a cultural practice that gave them the best potato crop

7. Crop Rotation 1.Basic idea : without food, nematode population decline 2. Fallow : decrease nematode populaiton problem-erosion by wind or water 3. Nonhost : decline nematode population need to consider market value of selected crop 4. Resistant cultivar : reduce nematode population also have market value *Nematode population, market value, additional problem

8. Time of planting 1.Basic idea : avoid optimum condition or time for nematode, but plant withstand it 2. Example *early planting: soil temperature too low for nematode activity *late planting: under the same condition, result in severe losses *late autumn after rains: Even soils are at the optimum temperature for nematode activity, but wheat seedlings growth is advanced to withstand the attack by nematode after dry summer

9. Soil amendment 1.Basic idea : High organic contents of soil affects nematode population and increase yields of crops 2. Functions of soil amendment ( 계량제 ) 1) organic matter→improve soil texture→increase plant growth 2) breakdown organic matter→toxic to phytonematode 3) rhizosphere effects ex) chitin→increase nonpathogenic fungus →affect nematode activity ex) bacteria growth→bacteriovorus nematode increase →nematode trapping fungi increase→decrease phytonematode

10. Biological control 1.Basic idea : reduction of nematode population by stimulation or introduction of predators and parasites 2. Principal enemies 1) Other nematodes(large mouth or teeth) 2) Soil arthropods (mites, tardigrades, collembola) 3) Protozoa 4) Fungi and bacteria ex) trapping fungi (constriction ring) adhesive fungi Pasteruria penetrans (bacteria) →In field condition, large amounts of treatment required also there is no great increase in fungi activity

11. Fungi attacking plant parasitic nematode

12. Biological control agents for plant parasitic nematode

13. Tardigrades

14. Life cycle of the root-knot nematode and Pasteuria penetrans

15. Management by physical factors 1.Heat: hot water 2.Gamma ray, ultraviolet light Management by chemical factors 1.Addition of toxic compounds 2.The factors influence the effect of toxic formulation 1) The degree of toxicity of the compounds 2) Vapor pressure of the toxic molecules 3) Solubility in water 4) Rate of destruction of the toxicant 5) The soil condition (Temperature, moisture, size of soil particle)

16. Types of compounds 1. High volatile compounds : Methyl bromide (MBr) 2. Moderate volatile compounds : Dichloropropene (D-D) Ethylene dibromide (EDB) 3. Systematic compounds : Oxamyl (apply to leaves and distribute throughout the plant to affect nematodes ) → widely use but change soil microbial system → leave chemical residues → ecological problem → occurrence of chemical resistant or tolerant pest

17. Integrated pest management * The objective of integrated control is to keep pest populations at low levels by judicious application of the minimum effective dosages of pesticides only when needed. Other measures such as rotations and the use of resistant varieties are also part of the program. * Monitoring of nematode population is essential * Introduction biological control agent if possible * Consideration of environmental condition