- EVAPO-TRANSPIRATION (ET)
- ETo is Evapo-Transpiration calculated for a "well-watered pasture" (i.e. reference crop, "o") if it were to exist at the weather station. This is the baseline ET from which other values can be derived.
- ET values are calculated using the ASCE Penman-Monteith or FAO-PM (Penman-Monteith) mathematical equation using other weather parameters as input values & ET as the output. Units are mm.
- "ETo (current)" values are incremental reference-crop Evapo-Transpiration calculations over a period of 1 hour
- To apply ETo (current, daily, weekly) to a particular crop (ETc) at a particular point of time in the growing season, you must first determine your crop's Crop Factor (Kc). To do this, establish your crop's Kc values via the below link (or elsewhere). To calculate ETc (mm), simply multiply the ETo value by your Kc value.
- CROP SPRAYING - PREFERRED CONDITIONS
- "Delta T" can help deciding if conditions are favourable for spraying. You can use the temperature & (relative) humidity values from the weather stations, along with the graph & information provided in the following links, to assist in determining whether now is a suitable spray time.
- Note that conditions at weather stations may not be representative of those at your spray site. Delta T values are indicative of preferred conditions only & can change quickly. Please confirm conditions locally before spraying.