This is classic nutrient lock out. Caused by too much fert in the root zone or the PH being way off. Here are some symptoms causing it. 

• Elevated fertilizer levels can cause extreme leaf and shoot development, leading to fewer flowers and poor yields come harvest.
• Excessive fertilizer can lead to stunted growth in some plants. 
• Pale green and yellowing lower leaves are a sign that nitrogen levels are too high. 
• Symptoms of magnesium toxicity may appear as bronzing on older leaves.