Healthier plants have more sugar
Measuring the density of plant juices is measuring
the health of a plant.
Total sugars in a plant are made up of fructose, sucrose and
carbohydrates which have been manufactured by the plant during its growing
cycle. The higher the percentage of sugar the healthier the plant can be
assumed to be. The greater the density of a liquid the higher is the sugar
content.
A refractometer is a device for refracting light through a prism to
measure the density of a liquid placed on the surface of the prism. The
density of a liquid squeezed from the fruit or leaf of a plant represents
the total sugars present in that plant.
Refractometers gives a good indication of the success of the methods
used by the grower. This does not replace analysis done by more extensive
equipment. A hand-held refractometer can be used on site and is a useful
gauge to the effectiveness of growing procedures. The more accurate
refractometers have inbuilt automatic temperature compensation circuitry.
This compensates for the effect of temperature on the refractive index of
the sample.
Effects such as changes to nutrient mixes, or the onset of impending
disease, may be assessed quickly using a refractometer. It may be possible
to make early corrections, while awaiting laboratory confirmation, or else
it may show that no such changes are needed.
On hot humid days there is a substantial decrease in the percentage of
sugars in the leaf of lettuce which reduces the shelf life of the product.
Many large produce buyers use a benchtop version of the refractometer, to
ascertain the quality of their suppliers, and even use this as a means of
determining their contracts. This is one reason for picking early in the
mornings.
TPS does not supply refractometers. Please
check with your local scientific supplier, or search the web for a
supplier.
Copyright © 1996, 1997, 2001 TPS Pty Ltd
