Nutrients

N Nitrogen
P Phosphorus
K Potassium
Mg Magnesium
Ca Calcium
S Sulfur
B Boron
Cu Copper
Fe Iron
Mn Manganese
Mo Molybdenum
Zn Zinc

Lettuce - Growth retardation

Symptoms
Growth of the plants is stunted with delayed heading or no heading at all. The leaves are darker green than normal, but no clear symptoms can be found. If the variety contains anthocyanine, the leaves may have a purple flush.

Reasons
Phosphorus Deficiency Symptomes may be confused with excessive nitrogen supply. Excess nitrogen leads also to dark green lettuce plants, but in this case the underside of the leaves does not turn purple. Low temperatures may inhibit the uptake of P.

Lettuce - Growth retardation

Symptoms
Due to strongly restricted growth and delayed heading, or no heading at all (rosetting), phosphorus deficiency causes high yield losses. The leaves become dark green and can look fallow. Sometimes reddish discoloration appears. Older leaves show paper-like necrotic areas and finally die off. With phosphorus deficiency plants develop less secondary roots than normal. Often roots show reddish discoloration .

Reasons
Phosphorus deficiency on leaves and roots Symptoms may be confused with excessive nitrogen supply. Excess nitrogen leads also to dark green lettuce plants, but in this case the underside of the leaves does not turn purple. Low temperatures may inhibit the uptake of P.

Lettuce - Growth retardation

Symptoms
Due to strongly restricted growth, and delayed heading, or no heading at all (rosetting), phosphorus deficiency causes high yield losses. The leaves become dark green and can look crinkled. Sometimes reddish discoloration appears. Older leaves show paper-like necrotic areas and finally die off.

Reasons
Phosphorus deficiency (right) compared to optimum supply Symptoms may be confused with excessive nitrogen supply. Excess nitrogen leads also to dark green lettuce plants, but in this case the underside of the leaves does not turn purple. Low temperatures may inhibit the uptake of P.

Phosphorus deficiency made worse by

  • Acidic or very alkaline (calcareaus) soils
  • Low organic matter
  • Cold or wet conditions
  • Crops with a poorly developed root system
  • Soils with low P reserves
  • Soils with a high phosphate capacity
  • Iron rich soils

Phosphorus is important for

  • Proper growth and head formation
  • Healthy green leaves

Yara recommended fertilizers for Phosphorus

YaraMila® 15-15-15

YaraMila® 15-15-15

Lettuce (field grown): Apply 400-1000 lbs YaraMila® 15-15-15/acre in split applications according to yield potential and soil test. Apply no more than 25% of product at planting. Apply the remainder in 2-3 side dress applications. Utilizing YaraMila® 15-15-15 provides a balanced nitrogen approach by supplying both nitrate and ammoniacal nitrogen along with fully available Phosphate, soluble Potassium and Sulfur in a homogenous prill. Consult with your agronomist for local recommendations. Consult with your agronomist for local recommendations.

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YaraMila® 21-7-14

YaraMila® 21-7-14

Lettuce (field grown): Apply 275-750 lbs YaraMila® 21-7-14 /acre in split applications according to yield potential and soil test.. Apply the remainder in 2-3 side dress applications. YaraMila® 21-7-14 provides fully available Phosphate along with Nitrogen, Potassium and Sulfur, in a homogenous prill. Consult with your agronomist for local recommendations.

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YaraVita® MAGPHOS™

YaraVita® MAGPHOS™

Lettuce (field grown): 1-2 quarts/acre. Apply 10 to 14 days after transplanting or emergence. One or two repeat applications may be made at 10 to 14 day intervals. Water rate: 50 gallons/acre.

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YaraVita® SENIPHOS™

YaraVita® SENIPHOS™

Lettuce (field grown): 2 to 4 quarts per acre 2 weeks after transplanting or for direct sown crops at the 4 to 6 leaf stage. Repeat as necessary at 7 to 14 day intervals. Water rate: 20 to 50 gallons/acre

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NUTRA-PHOS CALZINC

NUTRA-PHOS CALZINC

Lettuce (field grown): 2 to 10 lb. per acre per application. Make several applications at intervals of 2 to 3 weeks starting at thinning period. Apply aerial applications in at least 5 gallons/acre and ground applications in at least 10 gallons/acre; however, when total application gallonage is 25 gallons per acre or less, DO NOT mix more than 1 lb. of this product per gallon of water.

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NUTRA-PHOS Zn-K PLUS

NUTRA-PHOS Zn-K PLUS

Lettuce (field grown): 2 to 10 lb. per acre per application. Make several applications at intervals of 2 to 3 weeks starting at thinning period. Apply aerial applications in at least 5 gallons/acre and ground applications in at least 10 gallons/acre; however, when total application gallonage is 25 gallons per acre or less, DO NOT mix more than 1 lb. of this product per gallon of water.

Read more about NUTRA-PHOS Zn-K PLUS