1. After successful completion of this Unit, you should be able to answer: 1.Why phosphorus deficiency symptoms are observed only in the very early stages sorghum crop? 2.Under what conditions phosphorus deficiency results in sorghum? 3.Describe the leaf symptoms due to phosphorus deficiency in sorghum? 4.How the sorghum plants look in phosphorus deficient field? Virtual Academy for the Semi Arid Tropics Lesson 2. Deficiency Symptoms of Primary Nutrients Course on Sorghum Production Practices Module VI: Plant Nutrient Deficiency Symptoms Unit 2: Phosphorus Deficiency Symptoms

2. Virtual Academy for the Semi Arid Tropics Lesson 2. Deficiency Symptoms of Primary Nutrients Course on Sorghum Production Practices Module VI: Plant Nutrient Deficiency Symptoms Unit 2: Phosphorus Deficiency Symptoms There will be greater demand for phosphorus during the very early stages of crop growth. Hence, phosphorus deficiency symptoms are more pronounced in young plants. Therefore, the plants should be examined for phosphorus deficiency during the early stages of crop growth. Note stunted growth of plants

3. Virtual Academy for the Semi Arid Tropics Lesson 2. Deficiency Symptoms of Primary Nutrients Course on Sorghum Production Practices Module VI: Plant Nutrient Deficiency Symptoms Unit 2: Phosphorus Deficiency Symptoms Severe deficiency of phosphorus is usually characterized by stunted growth of plants and dark red or purple coloration developed on the sheaths and blades of older leaves. Note the stunted plant with the purple leaves.

4. Virtual Academy for the Semi Arid Tropics Lesson 2. Deficiency Symptoms of Primary Nutrients Course on Sorghum Production Practices Module VI: Plant Nutrient Deficiency Symptoms Unit 2: Phosphorus Deficiency Symptoms The degree of red or purple pigmentation varies from cultivar to cultivar. Some cultivars develop very little red or purple pigmentation. Note the thinner stems and the purple sheaths of the deficient plants (center and right) compared the healthy one (left)

5. Virtual Academy for the Semi Arid Tropics Lesson 2. Deficiency Symptoms of Primary Nutrients Course on Sorghum Production Practices Module VI: Plant Nutrient Deficiency Symptoms Unit 2: Phosphorus Deficiency Symptoms Some cultivars develop an additional symptom on their young mature leaves; a pale yellow, interveinal chlorosis develops on one or both sides of the mid-vein about halfway along the leaf blade. Note the pale yellow interveinal chlorosis on the deficient leaf (right).

6. With this, the Unit 2 on Phosphorus Deficiency Symptoms in this Lesson concludes. The last Unit in this Lesson is about potassium deficiency symptoms in sorghum. In Lesson 3, you will learn about deficiency symptoms of secondary nutrients. Select Unit 3 of Lesson 2 from Module VI contents Virtual Academy for the Semi Arid Tropics Lesson 2. Deficiency Symptoms of Primary Nutrients Course on Sorghum Production Practices Module VI: Plant Nutrient Deficiency Symptoms