Jump to content

Manganese deficiency


Recommended Posts

Manganese is an essential trace element for all plants. Manganese acts as an activator for different enzyme reactions in the plant, for example in water-splitting during photosynthesis, the synthesis of amino acids and proteins and the build up of plant cell membranes and chloroplasts.

Manganese is generally taken up via the roots. Once inside the plant it is difficult to transport but not as difficult as calcium or iron for example. Silicon and molybdenum improve the transport possibilities for manganese in the plant.

About manganese in short

What is it and what does it do?
The metal manganese is an essential trace nutrient and acts as an activator for different enzyme reactions in the plant.
What can you see?
Yellow stripes appear between the leaf’s side veins.
What can you do?
Using products that contain trace elements (Tracemix).

Manganese deficiency guide

Symptoms of a deficiency

A manganese deficiency causes different physiological changes in the plant due to a decrease in protein production. Amongst others, this causes less nitrate to be fixed in the plant, which can lead to dangerously high levels of nitrate. Additionally, a lot of chemical reactions in plant cells slow down which may result in a build up of organic acids.

Development of a deficiency

The progression in chronological order:

Yellow stripes appear between the leaf’s side veins on the larger leaves at the top of the plant.

The yellowing between the side veins spreads further over the leaf and small, yellow/brown necrotic spots can form.

The final result is a small plant (-10%) with minimum fruit/flower production.

Manganese deficiency guide







Reasons for a deficiency

In practice, the most common reason is that the pH in the substrate is too high. Like iron, manganese is easily dissolved at a low pH value in the substrate. If the pH is too low, a risk of excess manganese may occur. At high pH values manganese precipitates into manganese oxide (MnO2) which cannot be taken up by the plant which can cause deficiency.

Solutions to resolve a deficiency

Check the medium’s pH when the first symptoms are noticed. High pH values mean that there is less manganese available for the plant. By lowering the pH of the nutrition (pH minus (down)) the medium’s pH can be lowered to 5.0 - 5.5.

Low substrate temperature can be the cause of reduced manganese absorption. If a deficiency is noticed, check that the substrate temperature is sufficiently high (68 - 77 oC) during the day.

Using products that contain trace elements may also help. A manganese deficiency is usually not a problem on its own. To facilitate manganese transportation in the plant, molybdenum is needed. Thus, the problem may well be a molybdenum deficiency. High levels of phosphorus may also result in a reduced availability of trace elements like zinc, copper and (of course) manganese. CANNA advises to use a mix of all needed trace elements. Trace elements can be given to the plant both in the feeding and by spraying the leaves. Spray the plant at the end of the day and spray daily with water after spraying to prevent burning.

Excess Manganese!

When there are high concentrations, manganese precipitates into manganese oxide (MnO2 or black manganese) which causes yellow-brown spots on the leaves. Initially, small spots will appear along the main and side veins of the leaf, following this, the spots will spread out from the veins. Excess manganese can be a result of a low pH in the substrate.

  • Like 4
  • Thanks 2

I'm just a billiard ball that's chipped and scratched and soaked in smoke and wine.

Yeah, I'm a little too stoned to keep up with the times

Link to comment
  • 1 year later...



Image result for cannabis Manganese deficiency

Type: micronutrient
Involved in enzyme activity for photosynthesis, respiration, and nitrogen metabolism. 
Deficiency symptoms: lnterveinal chlorosis of new leaves with some green next to veins and later with grey or tan necrotic spots in chlorotic areas. 
Alkaline soils, poorly drained soils, and soils high in available Fe can induce Mn deficiency. High available Mn can cause Fe deficiency. 
Manganese toxicity is a relatively common problem compared to other micronutrient toxicity. It normally is associated with soils of pH 5.5 or lower, but can occur whenever the soil pH is below 6.0. Symptoms include chlorosis and necrotic lesions on old leaves, dark-brown or red necrotic spots, accumulation of small particles of MnO2 in epidermal cells of leaves or stems, often referred to as "measles", drying leaf tips, and stunted roots

Edited by shaggyballs
  • Nice Job 1
Link to comment

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now
  • Create New...

Important Information

By using this site, you agree to our Terms of Use Guidelines Privacy Policy and We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue..