RANGER RUSSET: MANAGEMENT PROFILE
Characteristics | Tables | Management Profile | Seed Spacing/Nitrogen Trials
SEED
Because of their short dormancy, Ranger Russet seed tubers will physiologically age quicker than long season russets such as Russet Burbank. Cut or whole seed-pieces are acceptable but they should weigh at least 2 ounces. Eyes are uniformly distributed so blind pieces should not exist unless the pieces are too small. Spacing for seed production is 6 to 7 inches. This variety tends to oversize; therefore, for fresh or process markets, seed-pieces are placed 8 to 10 inches or 9 to 12 inches. Although Ranger Russet is highly resistant to hollow heart, at spacings at or greater than 12 inches, hollow heart may become a problem, over 20% of US1A tubers.
FERTILIZATION
In general recommendations for Russet Burbank fertilization for phosphorus and potassium can be followed. Phosphorus should be about 160 lb P2O5/acre (= 70 lb P/acre) and potassium should range between 0 to 75 lb K2O/acre (= 60 lb K/acre) depending on soil test results. Sulfur (200-400 lb ammonium sulfate/acre) is recommended for common scab control. There is little need to add micro-nutrients in most cases but check actual soil levels.
Nitrogen -- The requirement for Ranger Russet is different from that of Russet Burbank. Nitrogen can be applied all pre-plant, or half pre-plant and the rest during rapid vine growth or based on petiole nitrate analysis. Applying excess nitrogen should be avoided especially after mid-bulking. Late-season nitrogen application may cause problems with vine desiccation and its ability to be stored.
When applied all pre-plant, nitrogen application in Idaho is optimal at about 130-150 lb/acre up to 210 lb/acre depending on soil test results. With seasonal application of Nitrogen based on petiole nitrate-N concentration, starter should be 60 to 105 lb N/acre. In Wisconsin, when nitrogen was applied half pre-plant and half at emergence, optimal total N was 160 lb/acre. When application of nitrogen (ammonium nitrate) is split one-quarter before planting and the rest applied equally (one-eighth) every two weeks, the optimal total N was 125 lb/acre in Aberdeen, ID.
PETIOLE NITRATE-NITROGEN
Under sprinkler irrigation, supplemental nitrogen may be added from emergence to mid-bulking following recommendations based on nitrate-nitrogen concentrations in petioles. Ranger Russet has a relatively high petiole nitrate-N need to correspond with optimal nitrogen fertilization and yield; needs are 2,000 to 4,000 ppm nitrate-N higher than those for Russet Burbank. At Parma, ID, in 1993, the "sufficiency nutrient range" (SNR) for Ranger Russet when nitrogen was added all pre-plant (see Figure) was from 18,000 to 21,000 ppm at 55 days after planting and drops to 6,000 to 9,000 ppm at tuber maturation. When nitrogen was split applied equally as a starter plus two or three later applications, the SNR 16,000 to 20,000 ppm at 55 days after planting and decreased to 8,000 to 11,000 ppm. With the split nitrogen application, excess levels were readily obtained resulting in lower yields and quality.
[Note: SNR is the minimum to maximum nitrate concentration that should be present in petioles at different stages of the crop's growth. Petiole nitrate levels outside this range indicate a potential loss of tuber quality such as shape defects and sugar ends.]
In a three-year (1986-1988) study at Aberdeen, ID, nitrogen was split applied one-quarter as starter and the rest equally every two weeks thereafter. Optimal yield was reached with 125 lb total N/acre. The petiole nitrate-N concentration went from 21,000 ppm at 67 days after planting to 14,000 ppm at 109 days after planting (end of tuber bulking) (see Figure). Increasing total nitrogen increased the concentration of nitrate-N in petioles but did not promote yield.
IRRIGATION
Ranger Russet has good drought tolerance but is susceptible to common scab when there is low soil moisture during early tuber bulking. Due to its rapid early vine growth, more water is needed earlier in the season than required for Russet Burbank. Early season shortage of water may result in misshapen tubers. Being an indeterminate variety, irrigation should be maintained to vine kill which will also lessen tuber dehydration and internal blackspot, to both of which Ranger Russet is susceptible. Pre-harvest irrigation is acceptable to lower tuber injury during harvest.
VINE DESICCATION
Ranger Russet has a tendency to oversize. Therefore, vine kill is required. Being an indeterminate variety, it can be difficult to vine kill. Under good conditions, Ranger Russet is ready for desiccation at 110 to 120 days after planting or 90 to 100 days after emergence. Because of its susceptibility to blackspot bruising, care is needed during harvest to minimize injury-causing areas such as drops.
STORAGE
Ranger Russet has a relatively short dormancy, about 3 months. For longer storage at 40 F or above, the application of a sprout inhibitor is needed during the third month. If immature or injured tubers are stored, Fusarium dry rot may be a problem. Reducing sugar content is lower than in Russet Burbank and dry matter content is higher. It fries lighter than Russet Burbank out of 45 and 40 F storage. Unlike Russet Burbank, Ranger Russet is moderately resistant to sugar ends.
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Key Management Points for Ranger Russet |
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vine maturity |
120 days after planting |
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vine growth |
rapid during early season |
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diseases |
early blight, common scab |
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defects |
blackspot injury |
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herbicide |
tolerant to all |
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tubers |
short dormancy, oversizes |
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seed |
many, evenly distributed |
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planting |
8-12 inch spacing |
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nitrogen |
all preplant or distributed to mid-bulking, optimal total usually 150 to 180 lb/acre |
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petiole-N |
16-21, 000 ppm, 70 days post-plant |
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irrigation |
more early watering for tuber shape |
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desiccation |
difficult when green |
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storage |
excellent sugars, little sugar ends
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Literature:
Curwen, D. 1995. 1994 Cultural Profile Trials. Wisconsin's Annual Potato Meeting, Proc. pp.113-116. |
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