Module VI: Nutrient Deficiency Symptoms

1. After completing this Lesson, you will be able to • answer: • What are the reasons for plants to show abnormal growth symptoms? • Why nutrient deficiencies result in chili pepper? • What are the tools you use to diagnose plant problems of a standing crop? • What points you need to consider in preparing the checklist to diagnose plant problems in a standing crop? • What are the most likely causes for poor germination of chili pepper in a field? Module VI: Nutrient Deficiency Symptoms Lesson 1: Understanding Problems of a Standing Crop

2. At the end of this Lesson, you will be able to • answer • What are the most likely causes for irregular patterns related to soil in a chili pepper field? • What are the most likely causes for irregular patterns not related to soilin a chili pepper field? • What are the most likely causes for poor growth with no distinct leaf patternin a chili pepper field? • What are the most likely causes for a distinct leaf or stem chlorosisin a chili pepper field? • What are the most likely causes for discoloration, galls, over-growths, surface injury of roots? Module VI: Nutrient Deficiency Symptoms Lesson 1: Understanding Problems of a Standing Crop

3. From the lessons in the Module 5 you have learnt that all nutrients must be present in optimum quantities for the proper growth and development of chili pepper. When the soil does not provide the needed quantities of nutrient/s, the crop plants may reveal their hunger for the nutrient/s through certain symptoms. These symptoms differ depending on the non availability of a particular nutrient to chili pepper crop. Module VI: Nutrient Deficiency Symptoms Lesson 1: Understanding Problems of a Standing Crop

4. First you should understand that the symptoms you observe in the crop is a secondary effect and may be the result of more than one cause. Some symptoms are clear cut and others or not. So, the symptoms observed have to be carefully identified and confirmed for their cause. One has to use systematic visual inspection to find the primary cause or at least narrow down to one or two of the most likely possibilities. Module VI: Nutrient Deficiency Symptoms Lesson 1: Understanding Problems of a Standing Crop

5. The diagnosis for these plant symptoms can best be made on the individual plant in the field. Some of the most useful tools in diagnosing the plant problems are: Spade Pocket knife Hand lens (if you have one) An “Open Mind” Module VI: Nutrient Deficiency Symptoms Lesson 1: Understanding Problems of a Standing Crop

6. Step 1: Start your diagnosis by eliminating most obvious problems first. Make thorough field observations in a systematic manner. Make a check list of crop production practices adopted, and note possible unusual practices or conditions. Check for any varietal differences. Module VI: Nutrient Deficiency Symptoms Lesson 1: Understanding Problems of a Standing Crop

7. Step 2: Check the field pattern of the affected plants. Use the following “Key” as a guide Field patternMost likely causes Poor germination and Uneven depth of sowing emergence Uneven moisture availability Salinity, Soil Crusting, Soil insects Herbicide injury Damping off disease Module VI: Nutrient Deficiency Symptoms Lesson 1: Understanding Problems of a Standing Crop

8. Field patternMost likely causes Scattered individual Mechanical or animal injury plants Genetic mutations Seed or insect borne diseases Irregular patterns Nutrient deficiencies related to soil Salinity or alkalinity differences Soil compaction Moisture deficiencies or excesses Module VI: Nutrient Deficiency Symptoms Lesson 1: Understanding Problems of a Standing Crop

9. Field patternMost likely causes Irregular patterns Soil-inhabiting nematodes not related to soil Soil-inhabiting fungi differences Insects or insect borne diseases Uneven irrigation Edge or corner of Poor leveling fields Damage by animals Spray injury Soil compaction Module VI: Nutrient Deficiency Symptoms Lesson 1: Understanding Problems of a Standing Crop

10. Step 3: Check the plant pattern Move about in the field and observe gradation in symptoms from the mildest to the most severe effects. Check also for secondary or associated symptoms. For example leaf symptoms and the plant growth etc. Check the roots. Choose at least 3 plant specimen - a normal plant, one showing mild symptoms, and one showing severe symptoms. Check the following points. Module VI: Nutrient Deficiency Symptoms Lesson 1: Understanding Problems of a Standing Crop

11. Plant symptomsMost likely causes Poor growth with no Excess or low moisture distinct leaf pattern Soil compaction Salinity or alkalinity Nematodes, soil insects, diseases A distinct leaf or stem Nutrient deficiencies chlorosis Nutrient toxicities Virus or fungus diseases Insect damage Chemical injury Module VI: Nutrient Deficiency Symptoms Lesson 1: Understanding Problems of a Standing Crop

12. Plant symptomsMost likely causes Discoloration, abnormal Nematodes Texture of internal Insects tissue Diseases Excess of chemicals Discoloration, galls, Plant disease organisms over-growths, surface Nematodes injury of roots Insects Soil aeration, Mechanical, chemical or rodent injury Module VI: Nutrient Deficiency Symptoms Lesson 1: Understanding Problems of a Standing Crop

13. One need to decide the cause for the observed visual plant symptoms after ruling out other possible effects. Even mechanical damage to the leaf at the first look may resemble phosphorus deficiency symptom as shown in the picture. By closer examination like whether the symptoms are seen in the initial stage of plant growth (then it is P deficiency) or on a grown up plant clarifies whether the symptoms are that of phosphorus deficiency or not. Module VI: Nutrient Deficiency Symptoms Lesson 1: Understanding Problems of a Standing Crop

14. Also, relate one symptom with other symptoms observed on the plants. In case of nutrient deficiency symptoms, fortunately, more than one symptom appears. For example, nitrogen deficiency symptom is yellowing of leaves but these leaves are young or lower leaves of the plants. If yellowing of leaves is observed on older leaves, we can rule out nitrogen deficiency. Module VI: Nutrient Deficiency Symptoms Lesson 1: Understanding Problems of a Standing Crop