Stevia grows well on infertile, acid soils, but can also be cultivated on more neutral soils (pH6.5-7.5). Stevia will not grow in saline soils.
Land Preparation
Fields should be plowed and either disced and/or cultivated twice to prepare a fairly smooth, firm planting surface.
Transplants
Transplants from cuttings would be superior, however the cost is prohibitive. Stevia must be propagated from seed in plug trays placed in a greenhouse for a period of 7 to 8 weeks.
Planting
In early to mid-May the stevia plug plants are planted into the field on either 53 cm or 61 cm row spacing with a total plant density in the order of 100,000 plants/ha.
Fertilization
The plant appears to have low nutrient requirements, however a soil test should be conducted. For the year 1995, test plots were fertilized with 100 kg/ha of 6-24-24 prior to planting and a split application of urea at 140 kg/ha
Irrigation
Normally, the stevia plant requires frequent, shallow irrigation. Generally, irrigation is required when the stem tips begin drooping.
Weed Control
Repeated mechanical row-cultivating can be used to control weeds. The crop may also require hand hoeing and weeding. Contact your local OMAFRA specialist to determine if any chemical control options are available.
Pests
Insect pest pressures other than cutworm are minimal. Septoria disease caused considerable damage to the over-mature 1995 crop. Contact your local OMAFRA specialist to determine if any chemical control options are available. Browsing by deer, who seem to like the sweet taste of stevia, may also be a problem.
Harvesting
Time of harvesting depends on variety and growing season. Generally harvesting occurs in mid to late September when plants are 40-60 cm in height. Shorter days induce flowering. Optimum yield (biomass), and stevioside quality and quantity are best just prior to flowering. The plant will tolerate temperatures to -6°C. Specialized harvesters may need to be fabricated to mechanize the harvesting process.
