Micronutrients...Importance for plant nutrition

micro nutrition an important tool for increasing crop yield particularly area were it is more deficient such as alkali soils and some acidic soil ( eg Mo, B )...

1. “ MICRONUTRIENTS – IMPORTANCE IN CROP NUTRITION" UTTAM KUMAR Master of Science in Agriculture (Soil Science and Agricultural Chemistry ) 28 SEP. 2015

2. Micronutrients- An introduction The world ‘micronutrients’ represents some essential nutrients that are required very small quantities for the growth of plants and micro-organisms. There are 17 essential elements for plant growth, out of these elements 8 elements are considered as micronutrients. They are – iron (Fe), manganese( Mn ), copper(Cu), zinc(Zn), boron(B) molybdenum(Mo), nickel(Ni) and chlorine( Cl ). Out of these micronutrients iron (Fe), manganese( Mn ), copper(Cu), zinc(Zn), behave like cations, and boron(B) molybdenum(Mo), and chlorine( Cl ) behave like as anion.

3. So that the chemistry of micro- nutrients cations are different from micro- nutrients anions. Among these 8 micro- nutrients, the content of iron (Fe) in soil as well as in plants is the highest and sometimes higher than even P and S content. Micronutrients are also called trace elements, oligo elements or spurn elements.

4. Major sources of micro-nutrients S.no . Micro- nutrients Minerals 1. Fe Hor nblende , Hametite , Goethite , Pyrite , Magnetite , Olivine . 2. Mn Pyrolusite , Maganite , Rhodonite . 3. Cu Chalcopyrite, Covelite , Cuprite , Malachite . 4. zn Sphalarite , Smithsonite , 5. B Tourmaline, Colemanite , Borex,Kernite . 6. Cl Apatite, Murate of potash, Sodium chloride. 7 Mo Molybdenite , Wulfenite , Ferrimolybdenite . 8. Ni Serpentine, Olivine

5. Form of micro-nutrients absorbed by plants S.No . Micro-nutrients Ionic forms 1 . Fe Fe 2+ , Fe 3+ 2 . Mn Mn 2+ , Mn 4+ 3 . Cu Cu 2+ 4 . Zn Zn 2+ 5 . B H 2 BO 3 ­- , HBO 3 ­2- , BO 3 3­- , B 4 O 7 2- 6 . Cl Cl - 7 Mo MoO 4 2- 8 . Ni Ni 2+

6. Micro-nutrients Essentiality Discoverer S.No . Micro-nutrients Discoverer 1. Fe Griss – 1843 2. Mn McHargue -- 1922 3. Cu A.L.Sommer and C.P. Lipman -- 1931 4. Zn A.L.Sommer and C.P. Lipman -- 1926 5. B Warington – 1923 6. Cl T.C. Broyer --1954 7 . Mo Arnon and Stout – 1939 8. Ni Brown , Welch, and cary -- 1987

7. Micro –nutrients amount In soil Micro –nutrients Rang Average Fe 0.5 – 50% 3 – 4% Mn 20 – 3,000 ppm 600 ppm Cu 2 – 100 ppm 9 ppm Zn 10 – 300 ppm 50 ppm B 2 – 200 ppm 50 ppm Cl 1-100ppm 5 0ppm Mo 0.2 – 5.0 ppm 1.2 ppm Ni 2 – 750 ppm 50 ppm

8. Micro –nutrients amount In plants Micro –nutrients Amount In Plants( ppm ) Fe 100 Mn 50 Cu 6 Zn 20 B 20 Cl 100 Mo 0.1 Ni 2

9. iron – major function Important constituent of two group of protien - 1.Heme- protein 2. Fe-S protein Iron is involved in the production of chlorophyll. Oxygen carrier. Nucleic acid metabolism. Chlorophyll synthesis. Protein synthesis. Act as catalyst in N 2 Reeducates. Structural component of phorphyrin molecules. Required for nitrogen fixation.

10. iron – deficiency symptoms younger leaves exhibit interveinal chlorosis. Without dead spot this is the only symptom - Iron Plant having ≤ 50 ppm (30ppm) Fe, than Fe deficiency will occur. Whole plants turning – necrotic. Due to deficiency of Fe- 1. White eye in paddy 2. yellow blotch in citrus. 3.green rating in potato.

11. Fe- deficiency in Maize

12. Soybean

13. manganese – major function Manganese is necessary in photosynthesis, nitrogen metabolism and to form other compounds required for plant metabolism. Important constituent of Suproxide – dimutase ( Mn -SOD). It take part in electron transport in photosysytem -2. Mn act as enzyme activation, and this enzyme produce amino acid. Deficiency symptoms:- In addition to interveinal chlorosis on young leaves, grey or tan necrotic spots develop in chlorotic areas. Plant containing less than 25 ppm Mn then deficiency symptoms will occur .

14. Common micro deficiency for soybean and small grains Susceptible soils: High pH (alkaline) soils (>6.8) High organic matter soils (>6%) Due to Mn deficiency :- 1.gray spack in Oat 2.pahala blight in sugercane . 3.marshy spot in pea. 4.spekeld yellow in beetrot

15. Grey Speck in Oat

16. Soybean- compelete intervinal chlorosis.

17. copper – major function Copper is necessary for carbohydrate and nitrogen metabolism. Eletron carrier in oxidation –reduction reaction. Utilization of iron in chlorophyll synthesis. Enhance the fertility of mala flower. Enhance disease resistance in plants Deficiency symptoms:- While younger leaves have interveinal chlorosis, the tips and lobes of leaves remain green followed by veinal chlorosis and rapid, extensive necrosis of leaf blade Due to Deficiency of copper- 1.Dai back in citrus. 2.Reclamation of rice

18. zinc– major function Zinc is an essential component of three enzymes- 1. carbonic anhydrase . 2.Alcoholic dehydrogenase . 3.Suproxide dismutase. for energy production, protein synthesis, and growth regulation. Important in the synthesis of IAA. Essential for water uptake. Play important role in stablization of protein. Deficiency symptoms:- Plant containing less than 15 ppm Zn than deficiency symptoms will occur. Intervinal chlorosis first appear in younger leaves. Reduse the size of the leaves- little leaf. Mainly occur in calcareous soils.

19. Due to Zn deficiency fallowing deficiency symptoms will occur. 1. khaira disease in rice. 2. white bud in maize. 3. little leaf in cotton , chilli , brinjal . Citrus mango. Etc. 4.bronzing in Guava.

20. Tomato

21. Boron– major function A primary function of boron is related to cell wall formation. Important for pollination and pollen germination. Help in k translocation as well as stomatal opening. Calcium metabolism. Act as regulator of k/Ca ratio. Essential for translocation of sugar. Deficiency symptoms:- Terminal buds die giving rise to a witch's broom. Young leaves become very thick and leathery and chlorotic. Rust- coloured cracks and corking occur on young stems, petioles and flower stalks. Young leaves crinkled.

22. Common deficiency for alfalfa and other forages Susceptible soils: Sands and low OM soils, Dry soils. Due to B deficiency fallowing deficiency symptoms will occur. Brown or black heart in beet rot Hallow stem in cauliflower. Browning or heart rot in sugarcane. Internal cork in apple. Necrosis in Aonla Top sickness in tobacco.

23. Rice

24. Rape

25. Molybdenum-major function Mo is important constituent of nitrogenase enzyme , which help in N 2 fixation in legumes crops. Mo is essential component of NO 3 - reductase enzymes. this enzyme concerted in chloroplast which catalzes the conversion of NO 3 - to NO 2 - protein synthesis and sulfur metabolism are also affected by molybdenum. Molybdenum has a significant effect on pollen formation. Also reported to have an essential role in iron absorption and translocation in plants.

26. Mo - Deficiency symptoms The deficiency symptoms of Mo is first appear In Older leaves , interveinal chlorosis with some dead spots. Due to Mo deficiency fallowing deficiency symptoms will occur. 1. whip tail in cauliflower. 2. yellow spot in citrus. 3. scald in beans.

27. Chlorine - Functions Essential for stomatal opening. Cl is related to electrical charge balance in physiological functions in plants.   It indirectly affects plant growth by stomatal regulation of water loss. Deficiency symptoms highly branched root systems are the main chloride-deficiency symptoms, which are found mainly in cereal crops. chloride deficiencies have been reported on sandy soils,humid region with high rainfall area. willting and twisting in wheat due to Cl deficiency.

28. t Hank you