PH is a old Bad habit. Try the LaMotte method using the Morgan extracting solution soil test. Your looking for Limiting Factor, in the main 20 mineral elements for plants. Dr. Carrie Reams stated “All disease is the result of a mineral deficiency”.
Also Test your Plant’s Health in the field with refractometer which gives readings in BRIX, (a term popularized by Dr. Carey Reams) and Test Weight.