Black Sigatoka Infection Model
The Sigatoka Infection Model on FieldClimate.Com consists from a Model for:
- Ascospore Formation
- Ascospore Discharge
- Ascospore Infection
The Model for Conidia Formation uses relative humidity and air temperature. Conidia formation happens if the relative humidity is equal or higher than 70%. The speed of conidia formation is depending on temperature. The optimum temperature for conidia formation is 27°C to 30°C. At this temperaure maximum condia will be formed if we have 70% relative humdidity for more than 24 hours. If it is cooler or warmer maximum conidia formation will take 32 hours.
The Model for Ascospore Formation uses temperature and relative humidity too. Ascospore formation takes place if relative humidity is equal or higher than 70%. Optimum temperature again is 27 °C to 30 °C. At this temperature the maximum ascocpores is reached after 48 hours. At lower temperature it will take 2 days to form the maximum amount of ascospores.
Ascospore discharge takes place during rain. The main amount of ascospores is released at the begin of the rain. Therefore the spores will be released at the begin of the infection. The amount of released ascospores is limited to the amount of formed ascospores.
The Infection takes place during periods of leaf wetness or relative humidity higher than 90%. Under optimum temperature infection will be finsihed after 12 hours of moist conditions. If temperature is not that high it will need 15 to 24 hours.
For more Information about the Sigatoka Risk model click here. For more Information about the Black Sigatoka Spray Evaluation model click here. For more Information about the Black Sigatoka Biology click here.