Evaluating Stevia Production
Stevia is a perennial herb that contains glycosides up to 300 times sweeter than sugar. As such it is commonly used as a no-calorie sugar substitute. Typically, within Eastern NC, transplants are grown in a greenhouse and transplanted in June using tobacco transplanting equipment. The entire plant is harvested green in the fall and dried in tobacco barns or peanut trailers. The dried product is then baled and sold for processing.
Stevia is typically grown on well-drained soils, planted to 30″ rows with 6-7 inch spacing. As a perennial crop, it may be harvested for 3-5 years. Currently, average yields reported fall between 5,500-8,000 pounds per acre with organic production in the lower range. Price for conventional production is about $0.57 per pound and organic production is $0.75 per pound.
The uncertainty of profit and production lies within any additional equipment expense one might make as well as the high labor requirement for weed control. No herbicides are currently labeled so the crop must be weeded by hand. A few herbicide products are anticipated for registration soon that will greatly reduce reliance upon intensive hand weeding. According to the purchasing company representative, a net profit of $600-$800 is common but higher profits may be realized depending upon ownership of existing equipment.
Another consideration of production is disease control. Phytophthroa diseases are common. Since no fungicides are currently labelled, loss of 5-30% of plants is possible each year depending upon environmental circumstance, Thus, the additional labor and expense of production and transplanting of replacement plants must also be considered an annual expense. Research is being conducted by NCSU to evaluate efficacy of potential fungicides. Should the favorable products become labeled for this crop, the feasibility of production within this area would increase. Currently cost of establishing one acre of plants is about $900. If only three years of harvest are obtained from the field, then annual transplant cost is $300 per acre. If five years of harvest is obtained, then transplant cost is $180 per acre. Whether or not plants will survive for 5-year harvest will depend upon loss from disease and/or winter-kill. Currently, it appears that loss of 20% of plants from seedling disease and winterkill is common.
While this crop affords a better profit potential than many of of the common commodities grown within Craven County, the limitation discussed need to be considered. Additionally, until processing venture include efforts within the US, this may be a viable crop but with limiting number of acres of production. At the time of writing, essentially all processing of stevia is performed outside of the US (mostly in China). A lack of commercial processing in the US is likely to also limit production.
A short summary of the stevia plant, production and harvest is available HERE.