RUSSET NORKOTAH Texas Selections 102,112,223,278,296

Russet Norkotah TX 102 Russet Norkotah TX 112 Russet Norkotah TX 223
Russet Norkotah TX 278 Russet Norkotah TX 296 Russet Norkotah Standard

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 at Texas A & M in the early 1990's. Five selections survived grower trials. Texas selections were made in a field with heavy verticilium and early dying pressure.

Advantages over Standard Norkotahs: Higher yields, early dying resistance, bigger vines, lower fertilizer needs, better weed competition, better heat stress resistance, bigger tuber size.

Advantages over Colorado Lines: Better tuber appearance, Less cullage in packing, higher tuber sets.

Advantages of Selections:

Norkotah TX 102 Norkotah TX 112 Norkotah TX 223 Norkotah TX 278 Norkotah TX 296
Tuber appearance, Low input needs, earlier maturity, good vine size Tuber appearance, Low input needs, earlier maturity High Yields, Tuber appearance, bigger vine size High Yields, Good vine size, later maturity, good heat resistance High yields, Good vine size, later maturity

Plant/roots Plants are fast emerging with a medium, slightly upright vine and white flowers; it has a determinate growth habit. All the Texas selections have a slightly bigger vine than the standard. The selections root system is more developed and extensive than the standard Norkotah. They are susceptible to hail damage, 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.

GROWING SEASON MANAGEMENT

These selections are generally the same as standard Norkotahs with some notable exceptions. 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 102, 112

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.Over applying nitrogen to these selections can hurt production.
Selection 278

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.
Selection 223

Apply total fertilizer in the following range: N(180-200#), 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 40 to 90# range at a rate of 15# per application.

Irrigation interval at the maximum ET is 2.5 days. Drought tolerance is poor to moderate; 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 All selections compete fair against weeds especially compared to standard Norkotah. They are 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 not required. 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.
STORAGE MANAGEMENT

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.
DISEASE REACTION

Norkotah Texas selections have some of the same disease reactions as standard Norkotahs, but these selections have better verticilium and early dying resisitance. All selections are susceptible to PVY, PLRV and late blight, but selections have a slightly more resistance to early blight.


Note: This information should only be used as a guide. Adjustments for local conditions must always be made.