Plant Disease Epidemiology

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Plant Disease Epidemiology

• 04--Disease progress in time

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1.????

• ?????????(temporal dynamic of epidemic
  )?????????????????????????????????????????????????
  ????????????
• ???????????????????????

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2. ???????????????
? ? ???? ???? ????? ????
?????? ????? ? ??,?????? ??????,????
?????? ?????? ? ????????? ?????,???????
?????? ???? ?? ?????? ???????,????
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2.1 ??????

• ??????,??????????(????)?????,????????????,???????
  ???????????????????????????????????????,??????????
  ??????????????????????????????????????????????????
  ????????????,??????????,??????????????????????,???
  ?????,?????????????????????????

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2.2 ??????

• ??????????????????????????????????????,?????????,?
  ?????????????????????????????????????????,???????,
  ??????????????????,???????????????????????????????
  ???????,??????????????????????

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2.3 ??????

• ????????????????,????????????????????,????????????
  ???????????????????????????,??????????????????????
  ??????,??????????????????????,????????

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2.4 ?????????

• ????????????(t)????,????(x)??????,??????????????,?
  ????????????(x)???(t)?????(?x/?t)?
• ?????????????????,????????????????????????????????
  ?????????????????????????????????????

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3. ??????

• ???????????(polycyclic disease)
• ???????????(monocyclic disease)
• ?????,??????????,?????????????

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3.1 ???????????(polycyclic disease)

• ?????????????????,??????,?????????????????????????
  ????,?????????????????????????(polycyclic
  disease)
• ?????(Vanderplank, 1963)???????(compound interest
  disease,??CID)????????,??????????????????????????,
  ??????????????????????????????????????????????????
  ????????????????

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?????????

• ??????????
• ????????????
• ????????
• ?????????
• ???????,???????

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Late blight of potato
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3.2 ???????????(monocyclic disease)

• ????????????????,???????????????????????????????
  ???????????????????(monocyclic disease)
• ?????(Van der plank, 1963)???????(simple interest
  disease,??SID)??????????,?????????????????????????
  ??,????????(?)?,??????????????????????????????????
  ??????????????????

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?????????

• ????,???????????
• ??????????,?????????????
• ???????????
• ???????????????,????
• ??????????,?????????

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• In general, there are three types of plant
  diseases that tend to produce only one infection
  cycle per host cycle (1) postharvest diseases,
  (2) diseases caused by soil-borne plant
  pathogens, and (3) rusts without a urediniospore
  stage.

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postharvest diseaseBrown rot of peach
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soil-borne diseaseFusarium root rot of bean
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Demicyclic rustsCedar-apple rust
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Demicyclic rustCedar-apple rust
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4 ????????

• ????????,??????????,??(?????????)????????(???),???
  ????(???????)????????,????????????,?????????????,?
  ??????????????????????????

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Bean Rust
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Grey leafspot of maize
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4.1 ??????????

• (1) S??????????????????S???,???????,????????,?????
  ,???????????????????????????????????????,?????????
  ????????????????????,????????????????,????????S
  ?,????S???????,???J??

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Black stem rust on ryegrass
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4.1 ??????????

• (2) ??????????????????????,?????????????????,?????
  ?,??????????,?????????,??????,?????????????

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?????
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4.1 ??????????

• (3) ???????????????????????????????????????????,??
  ??????????????????????,??????????????????????????
  ????????????,?????????????????????????????????????
  ???????????????????,??????????,??????????????????
  ?

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Apple powdery mildew
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4.2 ?????????

• (1) ???,???????(exponential phase)???????????????,
  ???????0.05????????????????????,?????????????,????
  ????????,?????????????,?????????????????????,?????
  ????????,???????????????????????????????(0.0001)
  ,??????5(0.05),????????500????,?????????????,????
  ???????????????????

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4.2 ?????????

• (2) ???,?????????(logistic phase)?????0.05???0.95
  ???????????????????,????????,???????,????????19?
  ??????????????,???????????????,??????,???????????,
  ???????????

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r???????,??????
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4.2 ?????????

• (3) ???,???????????????,?????????????,????????,???
  ???????

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5 ???????????
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5.1 ??????

• ????(exponen-tial growth model)???????????????????
  ????????????????,?????????????,???????????????????
  ?????x0??t0??????,x???t??????,r??????,e???????(e
  2.71828)??????x?????,?t??????,??????J???

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re??????
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• ????????????,??????????,????????????????,?????????
  ?????????????????????????????,???????????
  ????????????,?????,??????????,?????????????
  ????????,???????,?????,??????????????
  ????????,???????????
• ???,??????????????,?????????,???????????????,?????
  ???????????,????????????????,???????????(????lt0.05
  ),???????????????,??????????????,????????,????????
  ???

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5.2 ????????

• ????????(Logistic growth model)???????????????????
  ??,??????????

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r???????,??????
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5.3 ???????????

• ?????(gompertz model)
• ?????(richards model)
• ?????(Weibull model)
• ???????????p44-46

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6 ??????
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6.1 ???????????

• ????????????
• ??????????,???????????????????????????????????????
  ???????,???????,????,???????????????,??????,??????
  ???????????????,?????????,?????????,??????????????
  ???????,???????????????????????????????????,??????
  ??????????????????????????,???????????????????????
  ?,?????????????????????????,??????????,???????????
  ??????

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• ??????????????????

Dutch elm disease
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Dutch elm disease
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6.2 ??????????

• ??????????????????,?????????????,?????????????????
  ????,??????????????????????????????,???????????,??
  ???????????

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???

• ??????????0.001,20????????3.8,???30??????86.4,?
  ???????????????20???30????????,???????????????????
  ????????????,?????????????????????