ABSTRACT
The appearance of a plant has been used by scientists and by laymen, by gardeners and by farmers as an indication of the health of the plant. Scientists have determined that several elements are necessary for plant growth. Some of these come from the air, some from water, and others from the soil or from fertilizers and lime. Since some of the plant nutrients do not move very far in the soil, the extent of the root system will determine whether the plant gets enough of a nutrient. Indeed, if conditions are such that root growth is rather shallow, a plant may show a deficiency symptom when the soil actually contains a rather good supply of that nutrient. The necessity for study and experience has been stressed in learning to detect symptoms due to plant nutrient deficiencies.
