1	Sweetpotato Production in NC Bill Jester Extension Associate Horticulturist Dept of Horticulture, NCSU
2	Sweetpotato Sweetpotatoes are not yams. Yams are viney tropical monocots and sweetpotatoes are dicots. Sweetpotatoes are true roots. Sweetpotatoes are very cold sensitive, hence storage temperatures above 55 F. Ipomoea batatas Sweetpotatoes were domesticated in Central America and South America at least 5000 years ago and spread throughout the tropical Americas and the Caribbean. They were also known in pre-Columbian times in Polynesia. Member of the Convolvulaceae (morning glory family)
3	The Breakdown China has about 85% of the Sweetpotato acreage worldwide. North Carolina ranked first nationally in the production of sweetpotatoes in 2003, representing 37.0 percent of U. S. production. In 2003, 42,000 acres of sweetpotatoes were harvested in North Carolina. In 2003, 5,880,000 cwt. of sweetpotatoes were produced in North Carolina for a value of $85,260,000. Approximately 60 to 70 percent of the crop is destined for fresh market and 30 to 40 percent for processing. The best prices are received in June, July, and August, while the lowest prices are received in mid-September through November.
4	US Sweetpotato Acreage
5	Major Area of Production
6	Growing Sweetpotato in NC Harvesting and Handling Curing the Crop Storage Grading and Packaging Marketing Seed (Variety) Transplant Production Soils and Fertilizers Weed Control Insect and Disease Control
7	Good Seed Seed should be derived from greenhouse grown elite plants originating from virus-indexed nuclear stock from the NCSU Micropropagation Unit. Stay close to the elite stock. Go no further than G3 for seed stock.
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10	Varieties Beauregard Covington Japanese-minor White Delight-minor Porto Rico 198-minor
11	Beauregard
12	Beauregard
13	Covington
14	Plant Production 600 plants/bushel=2 to 3” diameter roots 1000 plants/bushel = 1 to 2” diameter roots Bed width = 24 to 28” Roots covered with no more than 3” of soil Beds covered with 1 ml plastic Bed G1 or G2 roots Use the MPU program
15	Plant Production Presprout before bedding: 2-4 weeks at 75 to 85 F prior to bedding Bed: Coastal Plains March 15 to April 15 12 sq ft/bushel for 2-3” roots 20 to 30 sq ft/bushel for 1-2” roots Remove plastic when plants emerge CUT PLANTS
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18	What’s Wrong?
19	Transplanting Avoid skips. Apply two ounces of water per plant. Set plants as deep as possible.
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21	Fertilization Soil Sample yearly Average: 50 N-60P₂O₅-180K₂O/A Varietal differences Seasonal program Preplant: 20-60-90/A Sidedress 2X: 15-0-45/A Micronutrient: .5 lb Boron/A
22	Pest Management Insects Diseases Weeds
23	Insect Management Foliage Feeders Aphids Flea beetles Tortoise beetles Lafhoppers Leafminers Corn earworms Hornworms Armyworms Cutworms Loopers Soil Borne Pests Wireworms White Grub Flea beetle Banded Cucumber Beetle White Fringe Beetle
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37	INSECTICIDE PROGRAM ADMIRE IN PLANT BED LORSBAN PREPLANT ADMIRE UP TO 45 DAYS AFTER PLANTING CAPTURE Section 18 Emergency FOLIAR SPRAYS EVERY 7-10DAYS STARTING AT APPRX.
38	FOLIAR INSECTICIDES MARLATE SEVIN THIODAN - PHASER IMIDAN CAPTURE SPINTOR BT INTREPID
39	MONITORING Soil Baits – Spring Sweep nets Trapping devices Sticky cards White buckets JB traps. Black light traps.
40	Monitoring Devices
41	SUGGESTED ACTION THRESHOLDS WFB - IN SOIL BAITS DO NOT PLANT GRUBS - 3 BEETLES IN WHITE WATER PAILS 5 BEETLES IN JAP. BEETLE TRAPS WIREWORM - LARVAE IN CORN BAITS, 5 BEETLES IN YELLOW STICKY TRAPS OR BLACKLIGHT TRAP
42	SUGGESTED ACTION THRESHOLDS SPFB - 5 BEETLES IN YELLOW STICKY TRAPS OR NET SWEEPS, 5 % DAMAGE EARLY TB - 10 BEETLES IN TRAPS OR NET SWEEPS, 10 % DAM. EARLY AND DRY CUC. BEETLES - 10 BEETLES IN TRAPS, 10 % DAMAGE
43	Diseases Fungal Leafspots- plant beds, field Viruses-plant beds, field, storage, packing house Nematodes-plant beds, field Root Rots-plant beds, field, storage, packing house Diseases affecting appearance- packing house
44	Fungal Leaf Spots White Rust Chlorotic Leaf Distortion
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47	Viruses Produce foliar and root symptoms FMV
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50	Nematodes Can produce unmarketable roots Control by fumigation.
51	Root Rots Fusarium surface rot Fusarium root and stem rot Rhizopus rot Scurf Soil Rot (Pox) Southern Blight (Circular Rot)
52	Circular Spot
53	Black Rot
54	Bacterial Stem and Root Rot
55	Fusarium Root Rot
56	Fusarium Surface Decay
57	Rhizopus Rot
58	Scurf
59	Nematode Injury
60	Sour Rot
61	Soil Rot
62	Physiological Disorders
63	Weed Control Preemergence Clomazone (Command) preemergence Dimethenamid (Outlook) preemergence EPTC (Eptam) preemergence Flumioxazin (Valor) (Beauregard only) after fields are bedded but prior to transplanting. Napropamide (Devrinol)
64	Weed Control Postemergence weed control Grasses Fluazifop (Fusilade) Sethoxydim (Poast) Clethodim (Select) Nutsedge Sandea Tall Weeds Roundup with wick bar
65	Harvesting “Sweetpotatoes should be seen and not heard!” Henry Covington NCSU Sweetpotato Specialist Careful handling during harvest to avoid bruising.
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70	Curing and Storage Curing 85F at 95%RH for 5 to 7 days At storage temperatures of 58 F at 95%RH, roots can be held for 10 months. The objective of curing is to quickly heal the wounds that occur during harvesting.
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72	Grading and Packaging Grading is done during harvest and during the packing operation. Field grading is important since it is important only to store the marketable roots.
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75	Marketing
76	Budget