Potassium
maintain anion-cation balance and opening and closing of stomata
Calcium
formation of mitotic spindle
Magnesium
constituent of ring structure of chlorophyll and helps maintain ribosome structure
Iron
activates catalase enzyme
Manganese
splitting of water to liberate oxygen during photosynthesis
Zinc
activates carboxylases, synthesis of auxin
Boron
pollen germination
Molybdenum
component of nitrogenase and nitrate reductase
Chlorine
anion-cation balance and water splitting reaction in photosynthesis