Virtual Academy for the Semi Arid Tropics Course on Insect Pests of Groundnut Module 5: Sorghum Plant Nutrition After completing this Lesson, you will be able to answer: 1.List the secondary plant nutrients? 2.List the plant micronutrients? 3.Why and where these plant nutrients become deficient in sorghum? 4.How do you identify the need for the application of these plant nutrients to sorghum? 5.How do you decide whether to apply zinc or not? 6.What is the recommended rate and method of application of zinc to sorghum? 7.What is the recommended rate and method of application of iron to sorghum? Lesson 3: Importance of other nutrients

Virtual Academy for the Semi Arid Tropics Course on Insect Pests of Groundnut Module 5: Sorghum Plant Nutrition Lesson 3: Importance of other nutrients Plants need certain other nutrients in addition to the nutrients which were discussed in the Lesson 2. These nutrients are secondary nutrients and micronutrients. The secondary nutrients are Calcium, Magnesium, and Sulfur. The important micronutrients are Iron, Zinc, Boron, Molybdenum, Manganese, Copper, Chlorine and Cobalt.

Virtual Academy for the Semi Arid Tropics Course on Insect Pests of Groundnut Module 5: Sorghum Plant Nutrition Lesson 3: Importance of other nutrients These nutrients are equally essential for sorghum plants for proper growth, development and disease resistance. Continued use of only common fertilizers, which do not supply these nutrients, is leading to their deficiencies resulting in reduced sorghum yields.

Virtual Academy for the Semi Arid Tropics Course on Insect Pests of Groundnut Module 5: Sorghum Plant Nutrition Lesson 3: Importance of other nutrients Testing the soil will help in identifying the need for the application of these plant nutrients. Application of organic manures like well decomposed farm yard manure (FYM) and compost, green manuring and green-leaf manuring practices provide most of these plant nutrients. Also, using choice fertilizer material containing some of these nutrients help in supplying some of these nutrients. For example, applying super phosphate will not only supply phosphorus but also provides calcium and sulfur.

Virtual Academy for the Semi Arid Tropics Course on Insect Pests of Groundnut Module 5: Sorghum Plant Nutrition Lesson 3: Importance of other nutrients Calcium and sulphur deficiencies may occur in problem soils. In acid soils, calcium application may be required. Similarly sulfur deficiency may occur in alkaline soils. However, we come across very rarely the deficiency of these secondary nutrients in many sorghum growing areas. Among the micronutrients, Zinc and Iron are the most commonly deficient in sorghum growing areas.

Virtual Academy for the Semi Arid Tropics Course on Insect Pests of Groundnut Module 5: Sorghum Plant Nutrition Lesson 3: Importance of other nutrients Zinc deficiency can be corrected by applying 15 to 25 kg/ha of Zinc sulfate to the soil before the final ploughing. Zinc application to soils last for several years. So, zinc need to be applied once in 3 to 5 years. Zinc Deficiency

Virtual Academy for the Semi Arid Tropics Course on Insect Pests of Groundnut Module 5: Sorghum Plant Nutrition Lesson 3: Importance of other nutrients Soil application of 25 kg per ha of ferrous sulfate at the final ploughing is recommended in soils low in available iron. Foliar application of % ferrous sulfate solution corrects iron deficiency if noticed in a standing crop. Soil applications of iron may be long-lasting than foliar application. Iron Deficiency