Potato Variety Response to Phosphorus Fertilizer

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Potato Variety Response to Phosphorus Fertilizer

• Mike Thornton, Deron Beck, Jeff Stark and Bryan
  Hopkins

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Petiole P status and yield are related
Y 237 7.24X 0.026 X 2
R 2 0.76
Source Westermann and Kleinkopf, 1983
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Daily uptake rate of P during three years at
Aberdeen, ID
Source Stark, Westermann and Hopkins, 2004
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Cultivar use in 2007
Washington
Oregon
Idaho
Shepody
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6LS
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Do potato varieties differ in their response to P
fertilizer?

• Differences in yield response
• Differences in P uptake or petiole levels
• Differences in P removal by tubers
• Varieties with poor root systems or
  susceptibility to early die might need more P

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Methods

• Split plot design with 4 rates of P2O5 (0,100,
  200, 300 lbs per acre) broadcast as 11-52-0 and
  incorporated prior to planting. Urea used to
  balance N rates.
• Four cultivars (Burbank, Ranger, Shepody, 6LS)
  planted as subplots

Soil test values (0 to 12)
UI recommendation
Year pH Lime Soil P (ppm) Broadcast(P2O5/ac) Starter (P2O5/ac)
2005 8.2 1 15 130 lbs 40 to 80 lbs
2006 7.7 2 8 210 lbs 40 to 80 lbs
2007 8.2 1 5 290 lbs 40 to 80 lbs
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Influence of fertilizer rate on marketable yield
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Influence of fertilizer rate on tuber size
profile
Russet Burbank
6 LS
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Vine Growth
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Vine Growth
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Influence of fertilizer rate on plant growth
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Influence of fertilizer rate on petiole P
concentration
Deficient
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Influence of fertilizer rate on plant P uptake on
Aug 15
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Influence of fertilizer rate on P removal in
tubers
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SUMMARY

• Plant development was delayed and senescence
  increased at low P rates, especially in Shepody
• Petiole P levels were highest in Ranger, lowest
  in Russet Burbank and 6LS
• Ranger and 6LS had the strongest yield response
  to fertilizer P, and removed up to 33 lbs/acre P
  in tubers at harvest

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For information about potatoes, visit Idaho
Center for Potato Research and Education
http//www.ag.uidaho.edu/potato