Skip to main content

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


	Back to Phosphorus page


	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.


	Back to Phosphorus page


	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


		Back to Phosphorus page



	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