PHOSPHORUS--DEFICIENCYPlants deficient in phosphorus may have a purplish cast on the underside of the leaves (corn) or purplish/red leaves and stems (tomatoes). Flowering and fruiting will be limited. Plants will be slow to form new roots and establish. Plants are slow growing. Premature fruit drop may occur.
Phosphorus may be deficient in a plant in early spring following a cold, wet spell. However, plants will generally recover.