Investigations into the use of stevia as a rotation crop in tobacco production systems

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1 Investigations into the use of stevia as a rotation crop in tobacco production systems lyssa M. Koehler and H. David Shew

2 Stevia rebaundia Herbaceous perennial of family steraceae Native to South merica, first documented in Paraguay 300 times sweeter than sucrose

3 Stevia Glycosides Sweetness comes from diterpene glycosides 13 glycosides have been identified stevioside: highest proportion rebaudioside (Reb-): most desirable flavor profile Other minor rebaudiosides are under investigation Glycosides are found in the leaves These compounds are non caloric and have no nutritional value because they are not digested or absorbed by the body

4 Stevia World Usage First used in South merica, Japan, and other sian countries Currently available in 75 countries around the world pproved by the USD as a non-nutritive sweetener in 2008 Stevia global market value of $336 million in 2014, estimated to reach $578 million by 2017 Stevia Sales Volume Shares in % 25% 11% 30% 33%

5 Stevia in the Southeast The climate and soil conditions of NC and G are well suited for stevia production Existing Infrastructure Tobacco float trays Transplanters Field equipment Tobacco barns/peanut trailers

6 Stevia Production Pelletized Seed De-bearded Seed Raw seed

7 Transplanting Stevia 28,000-35,000 plants per acre Perennial crop managed for 3-5 years

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10 Stevia Harvesting Harvested with a combine or available equipment 1 harvest in first year crop 2 harvests in 2 nd and 3 rd year crops July and September Harvest prior to flowering

11 Post Harvest Dried bales are shipped to China for extraction

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14 Stevia Production in NC First planting in one field in Bertie County

15 Stevia Production in NC creage expanded ~ 500 acres currently in production Contract with Sweet Green Fields

16 Organic Tobacco Production Best management practices recommend following a rotation Corn, beans, etc. Until products are labeled, all stevia must be organically produced

17 dvantages of Stevia as a Tobacco Rotation Stevia is a perennial crop Stevia production has a strong infrastructure overlap with tobacco production Seedling production Transplant equipment Drying

18 Challenges for Establishing a New Crop Transplant production Germination rate Seedling production Fertility Weed Management Glyphosate registered for use on dormant plants Disease Management No products labeled

19 Screening Tobacco Diseases No Symptoms on stevia Granville Wilt (Ralstonia solanacearum) Black Shank (Phytophthora nicotianae) Fusarium (Fusarium oxysporum) TMV Stevia growing in Black Shank disease nursery

20 Disease Scouting in NC 2012: 1 st major pathogen Sclerotium rolfsii 2013: 2 nd major pathogen Sclerotinia sclerotiorum

21 Sclerotium rolfsii Wide host range Indigenous to NC Kills with oxalic acid Infection hyphae from sclerotia Infection occurs all season; growth between stems Disease in NC Sclerotinia sclerotiorum Wide host range Indigenous to NC Kills with oxalic acid Infection by ascospores early in the season Only early season infection; no secondary spread

22 Mean % Disease Treatment Effects of Fungicide and Biocontrol Products on Percent Disease Caused by S. rolfsii on Stevia in 2014 B B B B BC C Treatments

23 Yield (kg/ha) Stevia Yield (kg/ha) from 2014 S. rolfsii Fungicide and Biocontrol Trial B B B Treatments

24 Mean % Disease Treatment Effects of Fungicide and Biocontrol Products on Percent Disease Caused by S. rolfsii on Stevia in Treatments

25 Yield (kg/ha) Stevia Yield (kg/ha) from 2015 S. rolfsii Fungicide and Biocontrol Trial B BC C C CD D D D Treatments

26 Septoria leaf spot Disease in 2015 TSWV

27 Septoria Present in greenhouse production system and planted into fields in 2015, also present on 2 nd year plants in Kinston and other locations Species and sources of inoculum need identified Fungicide trials will be added for 2016 season May represent the greatest threat to yields among diseases observed so far

28 TSWV Seen in the greenhouse, no known field sightings Unknown as to potential for losses under field conditions

29 Conclusions Stevia is not affected by pathogens that cause Granville Wilt, Black Shank, or Fusarium wilt of tobacco Important pathogens of stevia are not of major concern in tobacco production Stevia is an exciting new crop with potential for use as a rotation crop in organic and traditional production systems including tobacco

30 Committee Dr. David Shew Dr. Marc Cubeta Dr. Lina Quesada Shew Lab Kestrel McCorkle rlene Mendoza-Moran Cody Baker ustin Kinley cknowledgements Field Staff at Caswell Research Station Field Staff at Upper Coastal Plain Research Station Sarah Seehaver Chris Reberg-Horton Funding Sources NC Tobacco Foundation, Inc. NC Tobacco Trust Fund Commission RJ Reynolds Tobacco Company - Fund of Excellence Sweet Green Fields germplasm

31 Production and Disease Management Field Day June 2014 Planting demonstration Introducing growers to stevia production

32 Stevia Production Field Day ugust 2014 Growers and agents from conventional and organic backgrounds Fungicide and biocontrol trials for S. rolfsii