Phosphorus deficiency (P)
Shades of red or purple at the base of cereals together with thin leaves and stunted plants are classic signs of P deficiency. Symptoms tend to show very early on and plants with poor root structure are affected most severely.
Treatment: P deficiency is difficult to treat curatively and emphasis should be ensuring adequate soil P is available. Foliar application of Potassium phosphite may help to alleviate temporary demand.