Korean Highland Potato Variety Guide — Matching Sumi, Daejima, Dubaek, and Atlantic to Market Channel, Altitude, and Stone Clearing Standard

Yes — and this is the common approach for Korean highland farms supplying Atlantic to crisp manufacturers on contracted delivery schedules. Manufacturers typically specify October–December delivery, which matches the harvest period well without requiring extended cold storage. The risk of ambient barn storage for Atlantic is that if delivery is delayed (crop exceeds contracted volume, manufacturer scheduling changes), the Atlantic stored beyond December in an uncontrolled barn will experience temperature swings that accelerate sugar accumulation — particularly during cold November and December nights at highland altitudes. Ambient storage for Atlantic requires close temperature monitoring (ideally between 8–12°C consistently) and a confirmed manufacturer delivery schedule before harvest begins. Do not plant Atlantic without a confirmed processing supply contract — the variety has limited alternative market channels if the processing contract falls through, because its high dry matter makes it unsuitable for fresh market eating compared to Sumi or Daejima.

Yes — two setup differences. First, forward speed: Atlantic should be harvested at 1.5–2.0 km/h (slower end of the range) because Atlantic tubers are more bruise-sensitive than Sumi at equivalent harvest speed — the bruising produces the Maillard browning in the finished crisp product that fails manufacturer colour specification. Second, skin set confirmation: Atlantic skin set must be thoroughly confirmed (3-week vine destruction minimum before harvest, firm skin at thumb-rub test) before deploying the EP-AWB-1600 on Atlantic lots — immature Atlantic skin is particularly susceptible to harvest mechanical damage because the high dry matter content makes the tuber less resilient to impact compared to lower dry matter varieties. Other EP-AWB-1600 setup parameters (share depth, vibrating web amplitude) are the same across varieties for given soil conditions.

Yes — Dubaek at 500 m is commercially viable if planted at the earliest possible date for that altitude (typically April 10–20 at 500 m) and if vine destruction is performed 3 weeks before the planned early harvest date to force skin set before maturity is fully complete. This early vine destruction approach sacrifices some yield (the tubers are not at maximum size when vine is killed) but produces a harvestable Dubaek crop that fits within the growing season at this altitude. The trade-off is approximately 15–20% lower yield versus Dubaek grown to full maturity at 600 m or above. For farms at 500 m where market positioning for the December–February premium is the strategic objective, this yield sacrifice may be worthwhile — confirm the economics against the price premium available in the target market window before committing to Dubaek at 500 m altitude.

Mixing varieties on the same field creates harvest timing conflicts that are difficult to manage — Sumi (80-day maturity) and Dubaek (100-day maturity) planted on the same day will not be ready for harvest simultaneously, requiring either early harvest of the Dubaek (reducing yield) or late harvest of the Sumi (increasing frost risk at highland altitudes). The more manageable approach for farms wanting variety diversification is to plant different varieties on different field sections — with each section assigned to a specific variety matched to that section’s altitude, harvest timing, and market channel. The THOR 2.4 stone clearing and EP-AWB-1600 harvesting can serve multiple variety sections sequentially within the same farm operation, starting with the earliest-maturing variety at the lowest-altitude section and progressing to later-maturing varieties at higher altitudes as the harvest window advances.

Yes — within-row spacing selection on the EP-PAI-2100 (which offers 16 adjustable gear spacings between 25–40 cm) should be adjusted based on the target tuber size for each variety and market. Atlantic for processing supply benefits from tighter spacing (25–30 cm) that limits individual tuber size to the 50–80 mm diameter range preferred by Korean crisp manufacturers — oversized Atlantic tubers (above 90 mm diameter) have reduced specific gravity and higher reducing sugar risk. Sumi for fresh market premium can use wider spacing (30–35 cm) that produces fewer but larger tubers per unit area — appropriate for markets that pay premium for large-size Grade 1. Dubaek for premium fresh market uses the widest spacing (35–40 cm) to produce the large, well-formed tubers that command the highest per-kilogram price in the December–February market window. Confirm the target size specification with your cooperative or buyer before selecting the gear ratio on the EP-PAI-2100 for the season.