Phosphorus tables

PHOSPORUS TABLES

Table 1. Phosphorus efffects on yield and process quality.

 
 

P Rate
lb/acre

Effect on US #1 Yield

Effect on % Dry Matter

Effect on Sugar Levels

0-50

Increase

Slight increase

Decrease

above 50

No change

No change

No change

0-100

Increases larger tuber size grades

 

 

 

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 Table 2. Phosphorus fertilizer suggestions for potatoes.

 
 

P Soil Test Level

Bray P-1
Soil Test, ppm

P2O5 to Apply
lbs/acre*

very low

0-5

100

low

6-15

80

medium

16-25

40

high

>25

0

*These amounts may be higher for table-stock and fry-stock markets.

 

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 Table 3. Influence of phosphorus status on potato plant characteristics..

 
 

Organ

Deficiency

Excess

Leaves

crinkled, cuppsed upward leaf-roll, dark green, brown margins

none

Stems

stunted, spindly

none

Roots

decreased mass

none

Stolons

shortened

none

 

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Table 4. Influence of nitrogent status on harvested tuber characteristics.

 
 

Plant or Soil Fertility Level

Deficient

Adequate

Excess

Very small tubers

Optimal-sized tubers

Optimal-sized tubers

High sugar levels

Low sugar levels

Low sugar levels

Low dry matter

High dry matter

High dry matter

Few usable

Many usable

Many usable

Over-mature tubers

Mature tubers

Mature tubers

Disease susceptible

Disease resistant

Disease resistant