Manganese (Mn) Micronutrient and Immobile Element
Manganese Helps enzymes break down for chlorophyll and photosynthesis production, as well as it works with plant enzymes to reduce nitrates before producing proteins.
Having plants that are deficient in manganese can turn the young leaves into spotted (mottled) yellow and or brown areas on young leaves. Dead (Necrotic) yellow spots form on top leaves, while the lower older leaves will or may have gray specks and or spots. Symptoms can include yellowing of leaves while the leaf veins can stay green. Can also produce a chequered effect. As the plant gets newer growths the plant will seem to grow away from the problem, that’s why the younger leaves may be unaffected. On the top of the leaves, brown spots can appear. While the severe areas of the leaves turn brown and wither. Parts Affected by a Manganese deficiency are: Young leaves.
Too much Manganese in the soil will cause an iron deficiency. The blotchy leaf tissue is caused by not enough chlorophyll synthesis. Your plants will seem to have very weak vigor caused by the excessive amount of manganese.
Problems with Manganese being locked out by PH troubles
Soil ph of over 6.5, High iron soils, Low nitrogen Soils, Dry weather
and compacted soil.
Soil
Manganese gets locked out of soil growing at ph levels of 2.0-5.0
Manganese is absorbed best in soil at a ph level of 5.5-6.5 (Wouldn’t recommend having a soil ph of over 7.0 in soil) anything out of the ranges listed will contribute to a Manganese Deficiency.
Hydro and Soil less Mediums
Manganese gets locked out of Hydro and Soil less Mediums at ph levels of 2.0-4.5
Manganese is absorbed best in Hydro and Soil less Mediums at ph levels of 5.0-5.6 (Wouldn’t recommend having a ph over 6.5 in hydro and soil less mediums.) Best range for hydro and soil less mediums is 5.0 to 6.0. Anything out of the ranges listed will contribute to a manganese deficiency.
Solution to fixing a Manganese deficiency
Foliar feed with any chemical fertilizer containing Mn., or mix with water and water your plants with it. Any Chemical/Organic nutrients that have Manganese in them will fix a Manganese deficiency. (Only mixing at ½ strength when using chemical nutrients or it will cause nutrient burn!) Other nutrients that have Manganese in them are: Manganese chelate, Manganese carbonate, Manganese chloride, Manganese dioxide, Manganese oxide, Manganese sulfate, which are all fast absorption. Garden Manure, Greenssand are both good sources of manganese and are medium/ slow absorption.
Now if you added to much chemical nutrients and or organics,( which is hard to burn your plants when using organics) You need to Flush the soil with plain water. You need to use 2 times as much water as the size of the pot, for example: If you have a 5 gallon pot and need to flush it, you need to use 10 gallons of water to rinse out the soil good enough to get rid of excessive nutrients.
Picture 1 shows a manganese deficiency in flowering.
