1. Role and Deficiency Symptoms of Potassium in Tomato

2. Introduction  Potassium is used in carbohydrate metabolism and increases water-use efficiency  It is essential for protein synthesis and activates enzymes and controls their reaction rates  It promotes flower and fruit production and is vital for maintaining growth and helping plants resist diseases  K management should be considered part of long-term soil fertility management because K is not easily lost from or added to the root zone Role and Deficiency Symptoms of Potassium in Tomato

3. Role of Potassium in Plants  Involved in osmoregulation and enzyme activation  Regulates transpiration by stomata and transport of assimilates  Increases leaf area and chlorophyll content  Delays leaf senescence and thus contributes to greater canopy photosynthesis and crop growth  Improves the plant’s tolerance of adverse climatic conditions, lodging, insect pests, and diseases. Role and Deficiency Symptoms of Potassium in Tomato

4. Chemical fertilizers  Potassium chloride (Muriate of potash) (50% K)  Potassium nitrate (37% K, 13% N )  Potassium sulfate (40–43% K, 18% S) Sources of potassium Role and Deficiency Symptoms of Potassium in Tomato

5. K deficiency symptoms Woody stems and slow growth. Stems become weak and fall down Leaves are blue-green in color and the interveinal area often fade to a pale grey color Leaves may also have a bronzed appearance and yellow and orange patches may develop on some of the leaflets Fruits often ripen unevenly and sometimes have green patches near the stalks Older leaves may look scorched around the edges and/or wilted. Symptoms first appear on older leaves Role and Deficiency Symptoms of Potassium in Tomato

6. Deficiency symptoms of K in leaves Source: http://5e.plantphys.net/article.php?ch=t&id=289 Role and Deficiency Symptoms of Potassium in Tomato

7. Potassium deficient tomato fruit Source:http://extension.umass.edu/vegetable/diseases/tomato-blotchy-ripening Role and Deficiency Symptoms of Potassium in Tomato

8.  Lower K-supplying capacity of soil  Low recovery efficiency of applied K fertilizers because of high K-fixation capacity of soil or leaching losses  Complete removal of previous crop straw/ residues  Wide Na:K, Mg:K, or Ca:K ratios in soil and sodic/saline conditions.  Presence of excessive amounts of reduced substances in poorly drained soils (e.g., H 2 S, organic acids, Fe 2+ ) causing retarded root growth and hence K uptake.  Imbalanced fertilization especially excessive use of N or N and P fertilizers with insufficient K application. Causes of K deficiency Role and Deficiency Symptoms of Potassium in Tomato

9.  Potassium is used in starch and sugar synthesis so is more important in vegetables and fruits  Potassium is naturally found in wood ash  Prevention and cure can be achieved in short term by adding potassium-specific fertilizer called potash  Adequate moisture is necessary for effective potassium uptake; low soil water reduces K uptake by plant roots  Limiting acidic soils also increase K retention in the soil by reducing leaching Let us sum up Role and Deficiency Symptoms of Potassium in Tomato