Leaves are becoming yellow and developed brown spots. You will see first signs of a manganese deficiency in the stem of each leaf, yellowing between the veins and then moving toward leaf tips. As the deficiency progress’s you will also see stunted growth as well as leaves cracking and shredding apart and falling off.
Because of manganese role in photosynthesis and nitrogen assimilation it very much an important part of a healthy plants diet.
More often than not this micronutrient is plentiful and should be readily available for uptake by your plant. Common reason why a grower might see a manganese deficiency are media Ph issues and/or nutrient competition from iron.
To correct a manganese deficiency, first as per usual we identify the source. Make sure your nutrition’s has at least a small amount of manganese you don’t need much. Do a pH test of your media run-off and make sure it is between 5.5 and 6.5 pH. Also measure the pH of your solution.
If your media or solution is out of pH range it to 6.0 and then feed normally. If your media is out of range, flush and then recharge with a medium-heavy nutrient solution mix. This should effectively set your pH in your media and provide a good source of fresh nutrients for your plants.