TOMCAST (FAST - Dew) model
TOMCAST is based on a model that was originally developed for leaf spot diseases in tomato. The model that is used here is tested and adapted to be used against early blight in potato in Denmark (Alternaria solani). The model calculates daily risk values (DSV: Disease Severity Values) based on temperature and leaf wetness the previous day. DSV represents the risk of attack of early blight the previous 24 hours. Daily values of DSV are accumulated until a threshold value is reached, and treatment is recommended. When a spray is performed and entered into the model, accumulation of DSV is reset and starts over at 0.
The model will be evaluated in potato and carrots in Norway in 2020, and is only available for private warnings. Based on experience from other countries, the threshold for a warning to be issued is set to 20.
When to initiate the model
Potato plants vary in susceptibility during the season, and gradually become more susceptible. This means that the requirement for protection against early blight vary accordingly. The model is started when the first symptoms are visible, and first treatment is performed (below 0,1% attack).
Interpretation of results
The model will be green (no risk) until it reaches 15. From this value the warning will be yellow (possible risk) until the threshold is reached, and the warning turns red (risk of infection).
The model will be green (no risk) until it reaches 15. From this value the warning will be yellow (possible risk) until the threshold is reached, and the warning turns red (risk of infection).
Description of required input parameters:
timeZone - What timezone the calculation is for. Necessary to calculate daily values from the provided hourly values. See this list of time zones: http://en.wikipedia.org/wiki/List_of_tz_database_time_zones (Column "TZ")
observations - list of weather data. The following parameters are required:
* TM - Average temperature (Degrees Celcius)
* BT - Leaf wetness (Minutes/hour) (IF you don't have leaf wetness, you must provide UM (relative humidity). Then we will calculate the leaf wetness.
sprayingDate - (Optional) Farmers can choose multiple spraying dates (upto four spraying dates).
This is technical info for model and web developers
{
"loginInfo": {
"username": "example",
"password": "example"
},
"modelId": "ALTERNARIA",
"configParameters": {
"timeZone": "Europe/Oslo",
"observations": [
{
"elementMeasurementTypeId": "TM",
"logIntervalId": 1,
"timeMeasured": "2018-08-11T00:00:00+02:00",
"value": 10.46
},
{
"elementMeasurementTypeId": "BT",
"logIntervalId": 1,
"timeMeasured": "2018-08-11T00:00:00+02:00",
"value": 60.0
}
],
"sprayingDates": [
"2018-07-02T22:00:00Z",
"2018-07-30T22:00:00Z",
"2018-09-04T22:00:00Z"
]
}
}