This spring, growers in Northern California are dealing with soggy soils that are cooler than normal, and they are starting to see some nutrient imbalances in their fields. Soil pH, soil temperatures, growth stage, and soil and tissue samples help growers determine the best application methods for essential micronutrients like Manganese and Iron.

Manganese – Mn

  • Essential in photosynthesis
  • Activates many other enzyme reactions:
    • nitrogen metabolism: regulates nitrite
    • respiration of sugars
  • Assists Iron(Fe) in building the Chlorophyll molecule = healthy, dark green leaves
  • Involved in other plant amino acid production


  • Slow growth
  • Poor wax formation on leaves &fruit
  • Poor pollen germination & growth of pollen tube
  • Leaf symptoms: Sharp, fine, light-green to yellow areas between the veins on younger leaves


  • Suppresses Mg & Fe levels
  • Black specks on leaves, stems, & fruit. Leaves also can have brown spots on tips, margins, and near or on main veins
  • Mn should be approx. 70% of Fe ppm

Iron – Fe

  • Essential in oxidation-reduction reactions
  • Component in many enzyme systems
  • Required for the production of the chlorophyll
  • Helps with nitrate & sulfate reduction


  • Slow growth & sometimes root & shoot dieback due to loss of energy, low enzyme levels, and lack of photosynthetic pigments
  • Amino acids & nitrates accumulate
  • Soft, yellow to white areas between the veins starting on the younger leaves


  • Suppresses Al, Mn, Mg easily, also will lower other metals
  • Leaf: Bronzing, followed by small brown spots
  • Many plants can take 400ppm without symptoms
  • Fe should be approx. 1.5-2 times greater than Mn

Growers who are looking to boost iron and manganese levels this time of year have better luck with foliar applications.  Our growers have relied on TECH-FLO Mn15, TECH-FLO Phi, TECH-SPRAY Mn and TECH-SPRAY IZP to improve their Iron/Manganese balance during this time of year.

Adding targeted nutrition products to a spray program is an economical way to ensure the best quality yield at harvest time.  Our products are designed to be spray-tank compatible with most crop-protection materials.

You can download our mobile app for instant help in the field, or contact our expert sales managers to customize a nutrition program for you today.

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