Plant Problem Diagnosis Key / Nutrient problems
Nutrient
Magnesium deficiency
Mg
Magnesium sits at the center of chlorophyll and moves to new growth when short, so older leaves yellow between their veins. High potassium feeding makes it worse.
Signs
- Yellow between the veins of older leaves while the veins stay green.
- Common during heavy fruit set.
What favors it
Acidic, sandy soils (pH below about 5.5 to 6); high potassium feeding; heavy fruit set.
Prevention
- Use dolomitic lime when liming acidic soil.
- Balance potassium feeding; heavy potassium blocks magnesium uptake.
Often confused with
NutrientIron deficiency
NutrientManganese deficiency
NutrientPotassium deficiency
DiseaseMosaic viruses
Sources
- Magnesium for crop productionUniversity of Minnesota Extension
- Scouting Guides for Problems of Vegetables: Interveinal chlorosisUniversity of Kentucky
Treatment by crop
Cultural, biological and chemical options in the order to use them, and notes written for each crop.
Identification is free. Treatment is on the Home and Pro plans.
Questions in the key that lead here
- Look the plant over, leaf undersides included. Are insects, mites, slugs, eggs, webbing or droppings on it?
No, only damage or discoloration - Where is the problem?
Leaves - What does the leaf damage look like?
Color change without distinct spots - Where did the color change start?
Older, lower leaves - What do the older leaves look like?
Yellow between the veins, veins stay green
Not a match? Start the key or describe what you see.
More photos
More from university Extension: search Extension pages on magnesium deficiency, or find a plant diagnostic lab through your state's Extension.