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ARS Home » Southeast Area » Oxford, Mississippi » Natural Products Utilization Research » Research » Publications at this Location » Publication #290474
Title: Effect of harvest timing on leaf production and yield of diterpene glycosides in Stevia rebaudiana Bert: a specialty perennial crop for Mississippi

Author
item MORAES, RITA - University Of Mississippi
item DONEGA, MATEUS - Universidad De Sao Paulo
item Cantrell, Charles
item MELLO, SIMONE - Universidad De Sao Paulo
item MCCHESNEY, JAMES - Ironstone Separations, Inc

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/8/2013
Publication Date: 11/1/2013
Citation: Moraes, R.M., Donega, M.A., Cantrell, C.L., Mello, S.C., Mcchesney, J.D. 2013. Effect of harvest timing on leaf production and yield of diterpene glycosides in Stevia rebaudiana Bert: a specialty perennial crop for Mississippi. Industrial Crops and Products. 51:385-389.

Interpretive Summary: Stevia rebaundiana (Bertoni), a perennial shrub of the Asteraceae, is one of the most important sources of non-caloric natural sweeteners. Stevia’s plant extracts and glycosides have been used for several years in Paraguay and Brazil. Several studies suggest that Stevia and its glycosides exert beneficial effects on human health, including anti-hyperglycemic and antihypertensive, properties. The objectives of this study were to evaluate Stevia’s cold hardness in Mississippi and determine the effects of different harvest timing on leaf production and yield of stevioside and rebaudioside A. S. rebaudiana plants grew well in the Northern part of Mississippi, producing quality biomass containing stevioside and rebaudioside A. The rebaudioside content was greatly affected by the number of cuts per growing season. Higher levels were found in plants harvested once at flowering stage. Further studies are necessary including plant density, influence of different types of fertilizer on growth and yield and selection trials of varieties that perform well in Mississippi and have the best quality for consumer satisfaction. Most importantly are economic analyses to evaluate the cost and benefits for the farmers.

Technical Abstract: Stevia rebaundiana (Bertoni), a perennial shrub of the Asteraceae, is one of the most important sources of non-caloric natural sweeteners. Stevia’s plant extracts and glycosides have been used for several years in Paraguay and Brazil. Several studies suggest that Stevia and its glycosides exert beneficial effects on human health, including anti-hyperglycemic and antihypertensive, properties [1]. The objectives of this study were to evaluate Stevia’s cold hardness in Mississippi and determine the effects of different harvest timing on leaf production and yield of diterpene glycosides. Plants purchased from Ritchers Herbs were the source of nodal explants for in vitro clonal propagation. Rooted plantlets adapted in trays were later transplanted in the field of the University of Mississippi Biological Field Station. Plant spacing was 30 cm between plants in a row and 60 cm between rows. Drip irrigation supplied water to the field at rate of ¼ to ½ inches per week during summer. To protect plants during the winter of 2010 a plastic in a field low tunnel was used, while in 2011 plants remained uncovered during the winter. Leaf biomass production and yield of diterpene glycosides were evaluated based on three different harvest timing: 1) Three harvests in 60 days interval, two leaf harvests in a 90-days interval and single harvest after 180 days of cultivation. Results revealed that leaf production harvested once a year yielded more than the yield of multiple harvests (2 and 3 harvests per growing season). A total of 13896.37 kg per hectare of stem and leaves were harvested in a single harvest, and the glycosides productivity obtained from a single harvest (rebaudioside A (398.80 kg ha-1) and stevioside (512.21 kg ha-1) was also greater than the yields of multiple harvests (2 and 3 harvests).