Role and deficiency/toxicity symptom of micronutrient in rice

1. Role and deficiency/toxicity symptom of micronutrient in rice Next

2. Role and deficiency/toxicity symptom of micronutrient in rice Introduction Micronutrients are those nutrients which are required for the growth and development of plant. These nutrients are mostly iron, manganese, zinc, copper, boron, molybdenum and chlorine. Out of these, chlorine deficiency and toxicity is not generally observed in plants as this micronutrient is supplied indirectly from various sources. Though these micronutrients are required in trace/small quantity, but their absence in the plant affect the plant. Because, these nutrients are required to complete the life cycle of the plant . The vegetative and reproductive growth of the plant are also checked in absence of these nutrients. Contd…. End Next

3. Role and deficiency/toxicity symptom of micronutrient in rice Introduction These micronutrients are generally present in organic sources of nutrients. These organic sources like FYM, Compost, vermicompost etc may contain less quantity of these nutrients but presence of these help the plant in their growth and development. Soils supply these nutrients to the plants. When the soil cannot supply the required quantity of nutrient to the plant, it starts showing deficiency symptom. On the contrary when soil supplies more quantity of nutrient than the plant’s requirement ,plant shows toxicity symptom . both deficiency and toxicity are bad phenomenon for plant. Contd…. Previous End Next

4. Role and deficiency/toxicity symptom of micronutrient in rice Micronutrient Deficiency/ Toxicity in rice Plants show various symptom of deficiency in absence of these but these symptoms sometimes intermingle with symptom of plant diseases which confuse the farmers. Therefore it is very essential to know the symptom of deficiency and toxicity of these nutrients so that the farmers may take appropriate decision for management of the problem. Here, the role of micronutrient in plant and their deficiency /toxicity symptom in rice plant is described in brief. Previous End Next

5. Role and deficiency/toxicity symptom of micronutrient in rice Role of Iron • Chlorophyll development and function. • It plays a role in energy transfer within the plant. • It is a constituent of certain enzymes and proteins. • Iron functions in plant respiration, and plant metabolism. • It is involved in nitrogen fixation Previous End Next

6. Role and deficiency/toxicity symptom of micronutrient in rice Deficiency Symptoms of Iron The most easily observed symptom of iron deficiency in plants is extensive chlorosis in the leaves. Generally the younger leaves are most affected, the most mature leaves sometimes showing no chlorosis at all. This is because of the relative immobility of iron in the plant. First of all, interveinal chlorosis on surface of the leaf showing a fine reticulate network of green setting off chlorotic areas. Under severe deficiency conditions total chlorosis of theyounger or emerging leaves results. Previous End Next

7. Role and deficiency/toxicity symptom of micronutrient in rice Toxicity Symptoms of Iron Tiny brown spots on lower leaves starting from tip and spread towards the leaf base or whole leaf coloured orange-yellow to brown. Spots combine on leaf inter-veins and leaves turn orange-brown and die Leaves narrow but often remain green In some varieties, leaf tips become orange-yellow and dry up Iron toxicity in rice Leaves appear purple-brown if Fe toxicity is severe Stunted growth, extremely limited tillering. Coarse, sparse, damaged root system with a dark brown to black coating on the root surface and many dead roots Freshly uprooted rice hills often have poor root systems with many black roots Previous End Next

8. Role and deficiency/toxicity symptom of micronutrient in rice Role of Manganese Important for normal functioning of many enzymes, nitrogen metabolism and carbon dioxide assimilation. The assimilation of carbon dioxide in photosynthesis. It aids in the synthesis of chlorophyll and in nitrate assimilation. Manganese activates fat forming enzymes. It functions in the formation of riboflavin, ascorbic acid, and carotene. It functions in electron transport during photosynthesis. It is involved in the Hill Reaction where water is split during photosynthesis. Previous End Next

9. Role and deficiency/toxicity symptom of micronutrient in rice Deficiency Symptoms Chlorotic patches between veins are first noticed on younger leaves. Stunted plants with normal tiller numbers Toxicity Symptoms Stunted Plants and limited tillering . Brown spots on the veins of the leaf blade and the leaf sheath in lower leaves.. Manganese deficiency in rice Previous End Next

10. Role and deficiency/toxicity symptom of micronutrient in rice Role of Zinc Production of Auxins, an essential growth hormone. It activates enzymes in protein synthesis and is involved in the regulation and consumption of sugars It is necessary for starch formation and proper root development. Zinc influences the rate of seed and stalk maturation. It is necessary for the formation of chlorophyll and carbohydrates. The presence of adequate amounts in the tissue enables the plant to withstand lower air temperatures. Previous End Next

11. Role and deficiency/toxicity symptom of micronutrient in rice Deficiency Symptoms of Zn The midrib of the younger leaves, especially the base , become chlorotic Brown patches and streakes in lower leaves appear Appearance of rusty-brown spots and discoloration of older leaves beginning 2-3 weeks after transplanting is noticed. Under acute conditions, leaf margins of older leaves dry up. Zinc deficiency symptoms in rice • New leaves are smaller in size. • Crop maturity is non-uniform and delayed. • Khaira disease of rice Previous End Next

12. Role and deficiency/toxicity symptom of micronutrient in rice Role of Copper It functions as a catalyst in photosynthesis and respiration. It is a constituent of several enzyme systems involved in building and converting amino acids to proteins. Copper is important in carbohydrate and protein metabolism. Copper also affects the flavor, the storage ability, and the sugar content of fruits. It is important to the formation of lignin in plant cell walls which contributes to the structural strength of the cells, and the plant. Previous End Next

13. Role and deficiency/toxicity symptom of micronutrient in rice Deficiency Symptoms Bluish- green leaves , which become chlorotic near the tips. Development of chlorosis downward along both sides of the midrib,followed by dark brown necrosis of the tips.. New leaves fail to unroll and maintain a need like appearance of the entire leaf. Copper deficiency symptoms in rice Previous End Next

14. Role and deficiency/toxicity symptom of micronutrient in rice Role of Boron Maintains a balance between sugar and starch and translocation of sugar and carbohydrates. It is necessary for normal cell division, nitrogen metabolism, and protein formation. It is important in pollination and seed reproduction. It is essential for proper cell wall formation. It plays an important role in the proper function of cell membranes and the transport of K to guard cells for the proper control of internal water balance. Previous End Next

15. Role and deficiency/toxicity symptom of micronutrient in rice Role of Molybdenum It functions in converting nitrates (NO3 ) into amino acids within the plant. It is essential to the symbiotic nitrogen fixing bacteria in legumes. It is essential to the conversion of inorganic P into organic forms in the plant. Previous End

16. Role and deficiency/toxicity symptom of micronutrient in rice Deficiency Symptoms of Boron Chlorosis at the tips of the older leaves , especially along the margins , followed by the appearance of large, dark brown elliptical spots in the affected parts, which ultimately turn brown and dry up. Previous End Next