What is EVI for Vineyards?
Our Calibrated Vine Vigour data products are created using the Enhanced Vegetation Index, a ratio of how much sunlight is reflected off the plants in different colour bands, including infra-red.
Did you Know?
NDVI has been the standard multi-spectral image used to measure vigor in the wine industry, but unfortunately, NDVI has a number of inherent shortcomings. One of the most important shortcomings is that the data is highly dependent on the time of day at which the image is taken. This is because of the change in solar angle. This means that using NDVI has the potential provide inaccurate information and can show different data at different times of the day. NDVI results also vary based on other factors, like shadowing or soil variations. In order to correct for these inaccuracies, our scientists have adopted a new, improved version of NDVI, called the Enhanced Vegetation Index. Using additional wavelengths of light, we are able to correct the errors associated with NDVI.
Take a look at the examples below.
NDVI: Results are different with only 2 hours later
EVI: one extra wavelength of light captured to address shadows and provide more consistency
Did you know?
Using EVI, Vine Canopy and Cover Crop can be analyzed individually as in the images below to provide increased accuracy and superior analytics. With NDVI, the Vine Canopy and Cover Crop are analyzed at the same time, this means a healthy cover crop could hide a section of struggling vines to be missed in the diagnostics.
This as well means by using EVI technology you can evaluate the vigour of both Cover Crop and Vine Canopy for improved vineyard health.
EVI technology in combination with our proprietary viticulture algorithms, allows vine vigour to be displayed on a Vine by Vine basis. This is called Vine Analytics. By collecting an absolute EVI value on each vine, this data can be recorded over multiple growing seasons and used as a historic reference against corrective actions to determine a positive or negative effect on growth.