4fcb4a28_Quick_Guide_to_Plant_Nutrition__Signs_of_Deficiency
[Primary Nutrients] Phosphorus (P) [Function in Plant] Helps to stimulate new growth and cell division; assists in protein synthesis; promotes early growth; required for transfer of energy during photosynthesis [Sources for Fertilizer] Bone meal Rock phosphate [Signs of Deficiency] 
Slow or stunted growth; unusually dark green leaves and foliage; reddening of leaves and foliage
A Quick Guide to Plant Nutrition
Signs of Deficiency