This is the amount of crop you are producing per area unit for example “tonnes per hectare” or “bushels per acre” in your crop marketing plan.
- Pre-harvest, is the uncertain phase for the harvest yield of a season.
► With rain-fed crops the harvest yield is very uncertain, and typically the average harvest yields of your previous ten seasons can be used. A ten-season average may seem very long, but according to research, rainfall roughly fluctuates in 10 to 20 year wet and dry cycles, and you must keep this in mind for more accurate planning, but it is your choice. 
► With irrigated crops, the harvest yield is less dependent on rainfall, and the more robust approach is to use the average harvest yields of your previous ten seasons.
► If you do not have harvest yields for ten previous seasons available you can use the lower estimate of what you think the harvest yield would be. If your estimate is higher than your final harvest yield, your pre-harvest transactions will not have the profits you aimed for, literally throwing money in the water.
► If at any time during the pre-harvest period your crop is hit by a severe drought, flooding, frost, or any other type of disaster, you can typically lower the harvest by 10% to 20%. In the spirit of robust planning, harvest yields do not have to be increased when conditions are expected to be above average, but again it is your choice.
► You can update your pre-harvest yield if you can get very reliable harvest yield estimates.
- Post-harvest, update the harvest yield to reflect the season’s final harvest, and remember to make the deliverable harvest 100% as well. From now on the harvest yield is certain and the guess work for the season is over.
1. Vines, R. G. (1980). Analysis of South African Rainfall. South African Journal of Science, September 1980, Vol. 76, pp. 404-409. Retrieved from https://journals.co.za/doi/pdf/10.10520/AJA00382353_1881
2. Malherbe, J., Landman, W. A., & Engelbrecht, F. A. (2014) The bidecadal rainfall cycle, Southern Annular Mode and tropical cyclones over Limpopo River Basin, Southern Africa. Climate Dynamics, Retrieved from https://repository.up.ac.za/bitstream/handle/2263/41920/Malherbe_Bidecadal__2014.pdf;sequence=1