|
Description | |
| Tuber Shape | Oblong to Long | |
| Eyes | Shallow evenly distributed eyes | |
| Skin | Smooth medium russet | |
| Flesh | White | |
| Plant | Medium sized upright vine with white flowers | |
For a study comparing Lines 3 & 8 click here
Russet Norkotah is a early-maturing potato released in 1987 by North Dakota State University(APJ 65:597-604, 1988). It
is primarily a fresh market potato with good boiling and baking qualities. It is widely adapted to the western U.S. and
performs especially well in the SLV. Selections were made in the San Luis Valley Colorado State University Research
center in 1991. Two selections survived grower trials.
Plant/roots Plants are fast emerging with a medium, slightly upright vine and white flowers; it has a determinate growth
habit. The Selection 3 has a much bigger vine than the standard. The selections root system is more developed and
extensive than the standard Norkotah.They are susceptible to haildamage, but better than the standards.
Tubers are white flesh, long to slightly oblong with medium to heavy russeted skin. Eyes are shallow, numerous and well
distributed; medium specific gravity (1.085). Although not considered suitable as a processing potato, it will fry directly
from the field.
Yield potential 450 to 500 cwt. range with a high percentage of No. l's.
Pre-planting considerations Tubers have a medium dormancy. Whole or cut seed is acceptable. However, cut seed often is
preferred since the increased stem number helps prevent over sizing of tubers late in the season. Closer seed spacing also
will help control tuber size. Avoid prolonged warming (usually no more than 60 F for two weeks) to minimize excessive
sprouting and physiological aging. Pre-cutting seed a month or more before planting also can add physiological aging.
Avoid planting seed in cool soils; delayed emergence can aggravate rhizoctonia stem cankering and result in poor fertilizer
uptake. Plant this cultivar 4 to 6 inches deep in a broad well shaped hill to control late season greening.
Fertility (soil test basis; lbs/acre)
Selection 3
Apply total fertilizer in the following range: N(140-150#), P(l20-200#), K(O-40#). Performance in alkali soils is
moderate. Pre-plant N applications (110- 140#) are critical for early vine growth necessary to support maximum yields;
high N rates do not delay tuberization. Sprinkler applied N should be in the 0 to 30# range at a rate of 15# per application.
Selection 8
Apply total fertilizer in the following range: N(160-180#), P(l20-200#), K(O-40#). Performance in alkali soils is
moderate. Pre-plant N applications (110- 140#) are critical for early vine growth necessary to support maximum yields;
high N rates do not delay tuberization. Sprinkler applied N should be in the 20 to 70# range at a rate of 15# per application.
Irrigation Irrigation interval at the maximum ET is 2.5 days. Drought tolerance is poor; significant yield reduction occurs
if plants are moisture stressed. Adequate irrigation applied at short intervals coupled with high early season fertility will
help this cultivar develop necessary vine growth prior to tuberization. After tuberization, vine growth often slows
dramatically. Subsequent rapid tuber bulking and early vine senescence results in minimum late season water
requirements. Growers should strive to avoid late season over watering since it creates ideal conditions for expression of
many diseases such as blackleg or leak.
Pest control
Weeds The Selection 3 competes well against weeds while the selection 8 competes fair against weeds, but is not sensitive to any major herbicides.
Insects Standard insect control measures generally are effective but time and rotate insecticides properly because of high aphid preference and virus spread.
Fungicides Three to five fungicide applications may be necessary to control foliar early blight.
Tuberization/bulking Tuber set is light to medium, high in the hill. Greening may be a problem without good hill
management. Tuber bulking occurs in a short interval during early to mid-season at an extremely rapid rate. Russet
Norkotah is moderately resistant to blackspot and resistant to growth cracks, second growth and hollow heart.
Vine Kill Average days from planting to vine kill are 95 to 110. Vine killing usually is notrequired.
However, if senescence is not complete, vines are killed easily; adequate skin set occurs in 12 to
21 days. Tubers can become large late in the season, so close monitoring is necessary after early
August.
Russet Norkotah generally has few storage problems, but leak, blackleg and silver scurf can become serious. This cultivar
is not considered a long-term storage potato. It should be marketed by mid-March because tuber dehydration can result in
pressure bruises and blackspot development.
Potato early dying caused by Verticillium dahliae is a problem in some years, but can be easilyconfused with natural vine
senescence. Soil-borne disease problems such as leak and silver scurf also can be serious. Disease reaction ratings susceptible, moderately susceptible, moderate, moderately resistant and resistant.
Bacterial Ring Rot symptom expression is erratic and difficult to see under most circumstances. Symptoms are mild and
tend to appear only after vines begin senescing (90 + days after planting). Reaction to PVY infection is mild to latent. The
selection 3 is more latent in expressing PVY than the standard. Infected plants are difficult to detect early in the growing
season, but usually express mild symptoms that become somewhat more detectable as the plants age. Infected plants tend
to die by mid-season with potentially significant yield losses when PVY incidence is high.
Toxic-seedpiece-decay syndrome is characterized by severe plant wilting just prior to tuberization,when the plants are
switching from seedpiece nutrition to their root system. Plants appearwindburned with dehydrated leaf margins in the
upper canopy. A light brown, jelly-type rottedmass is all that is left of the seedpiece and brown streaks may be visible in
the lower stem. Normally the plant recovers within a couple of weeks. This problem may be present when earlyseason wet
conditions are linked with warm weather.
Field
Storage Foliar early blight: Susceptible
Tuber early blight Moderate Verticillium wilt: Susceptible
Bacterial soft rot Susceptible Blackleg Susceptible
Fusarium dry rot Susceptible Seedpiece decay Susceptible
Leak (Pythium) Susceptible Leafroll virus Susceptible
Pink rot (Phytophthora) Susceptible Leafroll Net necrosis Susceptible
Silver scurf Susceptible PVY, PVX Susceptible, Latent Reaction
Rhizoctonia scurf Moderate Bacterial ring rot Susceptible
Common Scab Moderately Resistant