Characteristics | Management Profile | Tables
Due to its popularity, there is a lot of literature about the cultivar Atlantic. It is also used in a lot of research studies on cultural practices and pest control in different areas.
Seed
Because eyes are not plentiful but well distributed, seed piece size is suggested to be at least two ounces (110 grams). Seed piece treatment is highly recommended due to Atlantic’s susceptibility to dry rot (Fusarium) and stem canker (Rhizoctonia). Cut and whole seed seem to be equally vigorous.
Planting to Emergence
Due to Atlantic’s tendency to oversize for chips and develop hollow heart in large tubers, planting should use close spacing, between 8 and 11 inches. This also improves its yield and specific gravity. Sprouts emerge rapidly, in 21 days in 55-60F soil, and uniformly. Planting may be shallow to medium, 2 to 6 inches, and hills may be flat to peaked. Atlantic grows well in both acid and alkaline soils. Avoid scabby ground. Avoid using metribuzin (Lexone or Sencor); if used, apply pre-emergence safely before ground cracking.
Irrigation Management
Atlantic is moderately drought tolerant. Late season drought stress with high temperatures may induce internal heat necrosis. In some areas, heat necrosis may be minimized with the application of calcium. Late season excess moisture may induce hollow heart, lower specific gravity and increase internal brown spot bruise susceptibility. Schedule irrigation carefully; during tuber bulking, irrigate in 2 to 2.5 day intervals at maximum evapotranspiration (ET).
Nitrogen Fertlilizer
Atlantic requires moderate fertilization. It does not need to season-long spoon-fed nitrogen. Common requirements are about 150 lb N/acre applied a third to a half pre-plant, quarter to half near emergence and the rest during vine growth. Fertigation recommendations during growth are about 20 lb N/a at each application up to full bloom. Phophorus is sufficient at 40 to 80 P/acre (100-180 P2O5/a) and is added primarily to prevent nitrogen-caused reduction in specific gravity. Potassium may reduce specific gravity. Potassium is usually not needed and too much may reduce specific gravity; recommendations usually are 0 to 50 lb K/acre (0-60 lb K2O/a). Application of ammonium sulfate at planting may be suggested in conjunction with careful irrigation scheduling to lower common scab incidence.
Petiole nitrate-nitrogen levels have not been published in the USA and there is little information. Some information is available from Nova Scotia and Prince Edward Island. When half of 150-160 lb N/a is applied pre-plant then petiole nitrate-nitrogen should be 12,000 to 15,000 ppm at tuber initiation, about 50 days after planting, and 4,000 to 5,000 ppm at mid tuber bulking, about 85 days after planting. This is low compared to other varieties. Most chip growers use petiole sampling for tuber quality purposes and not in regard to yield.
Disease Note
Atlantic is susceptible to seed decay (complex) and black leg (Erwinia) when planted in wet fields. Monitoring late blight conditions and treating accordingly is very important. Care also needs to be taken at harvest and with storage due to its susceptibility to soft rot (Erwinia), leak (Pythium) and pink rot (Phytophthora erythroseptica).
Tuber Quality Note
Because of tuber oversizing, Atlantic tubers may green and, therefore, post-plant hilling may be recommended. Internal necrosis due to heat and drought is possible in severe conditions.
Vine Desiccation
Vine desiccation is required because tubers will oversize and cultivar tends to be indeterminate. However, Atlantic does desiccated relatively easy. Desiccant are usually applied 75 to 90 days after emergence (95 to 125 days after planting). Adequate skin set takes three weeks and is required due to the tubers tendency to shatter bruise and internal brown spot (IBS) bruise during harvest and handling. Extra care should be taken of mechanical desiccation is used. Shatter and IBS are both considered chip defects and loads tubers with these defects could be rejected.
Storage
Due to Atlantic’s tendency to develop leak and pink rot, it is recommended to treat fields whose tubers go into storage with metalaxyl applied mid-season. Long storage, six months, should be avoided due to increased sugar (glucose) content. Reconditioning will be needed the longer tubers are stored. Sugar in the tubers will readily increase if storage temperatures drop below 50F. The best chips from Atlantic come when they are processed from the field or within three to four months of storage. Dormancy is three to four months and storage for a longer period will require the application of a sprout inhibitor such as CIPC.