What are Vegetative Indices?

NDVI (Normalized Difference Vegetation Index) and NDRE (Normalized Difference Red Edge) are both tools that help you "see" plant health from above, but they look at different aspects of your vines' condition—like checking both the color of leaves and their thickness to assess vine health.

NDVI - The Broad Health Indicator

Think of NDVI as your general vigour assessment tool. It measures the difference between red and near-infrared light reflected by your vines.

• What it tells you: Overall canopy density and biomass. Green, healthy vines with lots of chlorophyll absorb red light strongly and reflect near-infrared light, giving high NDVI values.

• When it's most useful: Early to mid-season when you want to map overall vine vigour, identify weak areas, or assess general canopy development

• The limitation: Once your canopy gets dense (which is common in healthy vineyards), NDVI tends to "saturate"—everything looks equally green even when there are important differences in actual plant health

NDRE - The Fine-Tuned Health Monitor

NDRE is your precision health detector, especially valuable for mature vines. It uses the "red edge" band—a narrow range of light wavelengths where vegetation reflection changes rapidly.

• What it tells you: Chlorophyll content and nitrogen status more accurately, even in dense canopies

• When it's most useful: Mid to late season when canopies are full, or when you need to detect subtle stress that NDVI might miss—like early nutrient deficiencies, water stress, or disease pressure

• The advantage: It doesn't saturate like NDVI, so it can distinguish between "healthy" and "very healthy" vines, or detect problems earlier

Practical Vineyard Applications

Use NDVI when you want to:

• Create management zones based on overall vigor patterns

• Identify problem areas early in the season

• Guide variable-rate fertilizer applications in spring

• Assess vine establishment in young blocks

Use NDRE when you need to:

• Fine-tune nitrogen management in mature blocks

• Detect water stress before it becomes visible

• Monitor vine health through veraison and into harvest

• Identify disease or pest pressure in its early stages

• Make precision decisions about selective harvesting

The Analogy

If NDVI is like checking if your vines are green and growing, NDRE is like checking if they're truly thriving and have the nutritional status to produce quality fruit. You wouldn't replace one with the other—they complement each other throughout the season, just like you wouldn't judge vine health by trunk diameter alone without also looking at leaf colour and fruit set.

Most modern vineyard managers use both: NDVI for the big picture and early season planning, NDRE for precision management when it really counts toward harvest quality.

NDVI

NDRE