Potato, Nemah

Andean potato information and growing instructions

Potato products and sizes

This is an OSSI open source variety. Click for more information about open source seeds.

Phytosanitary information

Tubers of this variety are offered alternately, in odd years, barring crop failure.

Nemah is a Cultivariable original variety, selected in 2016.  It is a round diploid with yellow skin and flesh.  It was selected out of a group cross between low dormancy Colombian and high dormancy Peruvian diploid potatoes.  Germplasm supplied by the USDA Potato Introduction Station was used in breeding this variety.  The name Nemah was chosen as part of a theme of place names in Western Washingon.

Culinary Traits

Nemah is a yellow flesh potato that has a flavor similar to the classic papa amarilla.  It has dense flesh that makes it suitable for both wet and dry cooking.  You can roast them in the oven or boil and cool for a salad.  Tubers are small, mostly in the 2 to 3 inch range, and it has thin, smooth skin, so cleaning is easy and there is no need to peel it or even cut it for most uses.

Agronomic Traits

Nemah is a facultative short day variety and performs a bit differently when grown in summer vs. fall.  In summer, the plants remain relatively small, perhaps 16 inches tall, the stolons can be as long as 18 inches, and the size distribution favors smaller tubers.  Plants can reach maturity in as little as 90 days in warmer weather, but usually closer to 120 days here.  In fall, the plants grow much larger, the stolons are usually 12 inches or less, and the tubers can grow larger, occasionally reaching four inches in diameter.  Although many people prefer potatoes with shorter stolons, Nemah is about the perfect length to reduce vole damage without being so long that you can’t find the tubers.  Tuber dormancy is adequate, but this is not a variety that will stay dormant at warmer temperatures.  If you can give it storage conditions of 50 F or less, it will keep five months.  Nemah appears to have moderate late blight resistance, showing low numbers of lesions per plant and slow progression even when bordered by heavily infected varieties.  I can’t say for sure if Nemah is scab resistant, but I have never seen any scab on it.  This variety tolerates our depleted soil with little complaint and appears to have some resistance to early and late blight.  It also appears to be moderately drought resistant.  The foliage is naturally yellow and this is particularly evident when the plants are emerging; this is not a problem and fertilization will not correct it.  I still haven’t done a carefully controlled test, but Nemah seems to be capable of self pollination, which is unusual for diploids.

Fertility:  MF8, FF10

True Seed (TPS)

In 2019 and 2020, I pollinated Nemah with diverse pollen from high and low dormancy diploids.  I have been really impressed with the results.  Seedlings have mostly yellow skin and yellow flesh.  Many have high yield and high tuber count in combination (lots of smaller tubers).  I have kept more seedlings from this line than any other in 2020.  Lots of great flavor and wide ranging textures from very waxy to very starchy.  This is a great variety to search for papa amarilla types with day neutral tuberization and good dormancy.

1 gram packets contain approximately 1,100 seeds.