Decomposing yield
Total yield is the product of multiple components. Harvest index (HI) = economic yield / total biological yield — e.g., grain weight / total plant biomass. Breeding and management target HI improvement without sacrificing stress tolerance.
Yield components by crop
- Wheat — ears per area × grains per ear × grain weight.
- Maize — plants per area × ears per plant × kernels per ear × kernel weight.
- Soybean — pods per plant × seeds per pod × seed weight.
Field assessment
Sample random plants before harvest. Count and weigh components. Compare to historical field records to diagnose whether low yield came from population, fertility, or grain fill failure.
Management implications
If kernel number is low, look back to pollination conditions. If kernel weight is low, examine late-season drought or disease. Component analysis directs next season’s intervention.