beds is the most economical way to grow Stevia. The raised bed should be of
15 cm in height and 60 cm in width. The
distance between each plant 23 cm. This would give a plant population of
around 30,000 per acre.
Stevia can be
planted in many ways. The types of agronomic practices generally depend on
type of soil and climate conditions.
Generally it is advisable to plant minimum of 40,000 plants per acre. Since
the economical part is the leaves it is very important
to achieve highest vegetative growth.
basically two options for multiplication. The first is the tissue culture
and second the stem cutting. Tissue culture is the best
option but many farmers are tempted to try the stem cutting method for
multiplication. As per practical experience,
stem cutting is sometimes more expensive to produce than the tissue culture
since the success rat e of the stem cuttings
establishment is very low, it takes minimum of 25 weeks for the stem cutting
to develop in proper feeding roots for transplantation
(younger stem cuttings transplants have shown more than 50% mortality in
first few weeks of transplants in main field). It
is also noticed that Stevioside content of the stem cutting plants is lower
by at least 2%
points in tropical conditions.
There are about
90 varieties of stevia rebaudiana developed all around the world. Basically
all these varieties have been developed for
different climate requirements, many times these varieties perform strangely
in different climate conditions. At the end of
the day, just like sugarcane, it is the stevioside and rebaudioside content
in the Stevia leaves that determine the price and
marketability of Stevia leaves. In many causes in south India it was
observes that stevioside content was as low as 3.5%, which was
below the minimum market requirement of 9%. Hence it becomes imperative that
the grower selects proper
varieties with adequate guarantees from the planting material suppliers
about minimum assured stevioside and rebaudioside
ample supply of good water all year around. As the plant cannot tolerate
drought, frequent irrigation is required Micro
sprinklers are the best method of irrigation would not supply the required
amount of water at the right time.
micro sprinklers, the water can be sprinklers, the water can be sprinkled
once in a day in winter and two to four times in a day
in summer depending upon the heat and relative humidity in the air. Watering
frequency should be scheduled so that the
plants do no wilt for want of water.