Figure 4. Tree induced by decision tree algorithm with information gain ratio (L: less than 500 maize grain yield g m⁻², M: 501–1000 maize grain yield g m⁻², H: 1001–1500 maize grain yield g m⁻², VH: more than 1500 maize grain yield g m⁻², C: Clay, sandy clay).

The tree shows that there is 2 pathways (routes) for reaching high yield according to this model (1) When “Duration of the grain filling period”>1127.5 and “Soil type” is Sandy clay, and (2) When “Duration of the grain filling period”>1127.5 and “stem dry weight”>117.675.