The main mechanic behind the plot rotation based on grow time and upgrades is using seed IDs and chains of delay nodes.
For starters to match each seed to a specific yield and grow time we can make an ID based representation as follow (similar to a 2d array)
Once the diagram starts its execution a seed type (id) is selected randomly and placed on an available plot on our field. To check if the plot is available we must check if a plant is not already placed there and the upgrade level permits it, this aspect can be checked on the "Is busy?" flag where 1=true.
Finally based on the seed ID we will reference its grow time and yield amount using a delay node to simulate wait intervals and converters to simulate production efficiency.
Currently the provided template the diagram convers 5 seed types and 4 maximum available plots. These parameters can be easily adjusted by adding several new nodes.