°BRIX (symbol °Bx) is the sugar content of an aqueous solution. We can measure a plant’s °BRIX by squeezing any part of its sap onto a refractometer and looking at the sample’s refractive index.

The higher the refractive index °BRIX, the healthier and stronger the plant. And because high °BRIX tissue will produce more alcohol from fermented sugars, higher °BRIX plants are more resistant to the predatory insects that are unable to process them.

In crops, higher°BRIX means sweeter-tasting, more mineral nutritious food. And harvested fruits and vegetables with high °Brix have shown better resistance to post harvest disease and lower water loss in storage.

Crops with higher sugar content will also have a lower freezing point and therefore be less prone to frost damage.

An early indicator of success.

A plant functioning at its genetic potential will have high °BRIX. You can often can predict potential problems by measuring °BRIX before they develop into yield losses or drag.

In general, plants with °BRIX readings of 3-5 (higher than average) have improved resistance to most plant sap sucking insects, such as aphids, spider mites, leafhoppers, whiteflies, leaf miners, cucumber beetles, squash bugs, potato beetles and others.

Healthy ranges of °BRIX measurement varies between crops. See the chart at left or download for recommended levels.