Diagnosing manganese deficiency in field peas

Manganese (Mn) deficiency has been diagnosed in highly alkaline Esperance mallee soils that are also susceptible to Mn deficiency in cereals.

Young leaf interveinal chlorosis and puckering on dun type variety
Young leaf interveinal chlorosis on a white seed variety
Young leaf rolled inwards (right) on white seed variety
Necrotic young leaves and necrotic twisted tendrils on white seed variety

What to look for

    Paddock

  • Early symptoms are pale new leaves with interveinal chlorosis that varies with variety.

    Plant

  • In dun type varieties, new leaves become puckered and narrowly cupped with necrotic tipping on leaves and tendrils.
  • In white seed varieties, affected leaves curl downwards along the length of the leaf . Interveinal leaf chlorosis turns into necrotic light brown spotting. Tendrils on new leaves have pale and excessively curled ends.

What else could it be

Condition Similarities Differences
Diagnosing iron deficiency in field peas Chlorotic young growth. Uniformly pale to white new leaves without distortion or necrosis.
Diagnosing sulphur deficiency in field peas Chlorotic young growth. Uniformly pale leaves without distortion or necrosis.
Diagnosing glyphosate damage in field peas Young leaf interveinal chlorosis Plants rapidly wilt and die.
Diagnosing group B herbicide damage in field peas Chlorotic young growth. The growing point and new leaves become necrotic.
Diagnosing virus damage in field peas Young leaf interveinal chlorosis Stunted plants; not soil type associated.

Management strategies

Spraying foliar
Spraying foliar
  • A foliar spray will correct the deficiency.
  • Mn fertiliser is effective but expensive as high rates and several applications are required to generate residual value.
  • Seed Mn coating treatments have little effect in correcting deficiency

How can it be monitored?

  • Whole plant tests, are not reliable enough to determine deficiency.
  • Concentrations of Mn less than 15 mg/kg in youngest mature leaves indicate marginal to deficient levels
  • Soil tests are not reliable enough to detect deficient soil prior to sowing.

Further information

Where to go for expert help

Page last updated: Wednesday, 13 May 2015 - 2:13pm