Your plant is hungry.

it is a magnesium deficiency. You can apply Epsom Salts (Magnesium Sulfate). Use 4-Oz. per gallon of WARM water as a foliar spray. Can also be used as a root drench.

Thank you very much! I appreciate

NOTE: Although magnesium deficiencies can be cured, the damaged leaves sometimes are unable to return to full green. However, new growth will produce a complete green leaf.

Silica are you sure it is 4oz per gallon of epsom salt? That is an astounding 32000 ppm concentration. Most fertilizer recommendations max out at around 2000pm. Max I have read about epsom salt in water should be around 1 tsp per gallon and that gives value of 1300ppm which is high but still within tolerable range for plants. Max I have seen is 1 tbsp per gallon but I think that is too much (about 4000ppm).