microclimate → edge-vs-centre-effects
Crop performance is rarely uniform across a block, tunnel, or glasshouse.
One of the most consistent patterns is the difference between edges and centres.
These effects are driven by microclimate, not luck.
Edge effects describe systematic differences in conditions at the boundaries of a crop compared with its interior.
Edges include: - Outer rows - End bays - Near walls or doors - Along paths or vents
Centres are areas buffered by surrounding plants.
Edges often experience: - Greater temperature fluctuation - Higher or lower airflow - Faster drying - Greater radiation exposure - Increased stress variability
Centres tend to be: - More humid - Less ventilated - More stable - Higher disease risk
Neither is universally “better”.
Disease often: - Starts in centres (humidity, poor airflow) - Accelerates at edges (stress + exposure)
This explains mixed symptom patterns that seem contradictory.
Edges are more prone to: - Heat stress - Cold damage - Water stress - Salinity fluctuation
Centres are more prone to: - Hypoxia - Disease - Latent stress accumulation
Edge effects are often worsened by: - Uniform irrigation - Uniform ventilation - Sensor placement in “easy” locations - Assuming uniformity
Uniform actions applied to non-uniform environments increase variability.
Better outcomes come from:
Edges reveal stress first; centres accumulate it.