Stage identification

Hello, I am doing a project where irrigation is performed with different soil moisture targets in every growing stage (i.e. irrigation method 1). Therefore, I need to see how much yield is generated in every stage? I have identified that stage 2 begins when CC is no longer CC and stage 4 begins when CC decays, but cannot find when stage 3 begins…

Hi the function aquacrop.solution.growth_stage will have your answer as that is where the growth stage is assigned. Have a look at the 03_solution notebook to see the code:

    # Update growth stage
    if tAdj <= Crop.Canopy10Pct:
        NewCond.GrowthStage = 1
    elif tAdj <= Crop.MaxCanopy:
        NewCond.GrowthStage = 2
    elif tAdj <= Crop.Senescence:
        NewCond.GrowthStage = 3
    elif tAdj > Crop.Senescence:
        NewCond.GrowthStage = 4

    # Not in growing season so growth stage is set to dummy value 
    NewCond.GrowthStage = 0

So these growth stages are essentially: emergence, canopy growth, max canopy, senesence. Just so you are aware these growth stages are only used in that irrigation strategy and so do not represent the only 4 key stages in crop growth. You can dice up the growing season in other ways so im not sure what the value is in finding out the yield growth in each stage.

Hope that helps

It seems these 4 stages are the same as the crop growth stages described in FAO-56 (page 95) - initial, crop development, mid-season, late-season. However, the stresses (e.g. water stresses) in Aquacrop correspond to phenological growth stages (Zadoks etc.).

Does anyone know a source which maps the FAO-56 growth stages to phenological growth stages? That is, is there a direct relationship between the FAO-56 and phenological growth stages? I am looking for spring wheat.

Thanks in advance!

PS: The major phenological growth stages, defined by Zadoks (1974) are: Germination, Seedling development, tillering, Stem elongation, Boot, Head emergence, Flowering, Milk development in kernel, Dough development in kernel, Kernel ripening