AGRI 31 3rd LEARNING GUIDE

• The soil serves as a storehouse for plant nutrients and normally provides a substantial amount of the nutritional requirement of crops.
• Eighteen (18) nutrient elements have been shown to be essential for plants. These are:

  carbon (C)

  hydrogen (H)

  oxygen (O)

  nitrogen (N)

  phosphorus (P)

  potassium (K)

  calcium (Ca)

  magnesium (Mg)

  sulfur (S)

  boron (B)

  iron (Fe)

  manganese (Mn)

  zinc (Zn)

  copper (Cu)

  molybdenum (Mo)

  chlorine (Cl)

  nickel (Ni)

  cobalt (Co)
• Nutrient: Nitrogen

  Major Functions In Plants

  • Constituent of many important molecules including proteins, nucleic acids, hormones and chlorophyll

  • _ is mobilized from mature leaves and re-translocated to areas of new growth

  Visual Deficiency Symptoms

  • Growth is retarded

  • General chlorosis or yellowing then enhanced senescence of older leaves
• Nutrient: Phosphorus

  Major Functions In Plants

  • Component of nucleotides, phospholipids; ATP, ADP, NADPH

  • Plays an integral role in the energy metabolism of cells

  Visual Deficiency Symptoms

  • Reduction in leaf expansion

  • Leaves gave a darker color

  • Flower initiation is delayed

  • Seed formation is restricted
• Nutrient: Potassium

  Major Functions In Plants

  • Component of nucleotides, phospholipids; ATP, ADP, V

  Visual Deficiency Symptoms

  • Growth retardation

  • Net re-translocation of K from mature leaves and stems and under severe deficiency these organs become chlorotic and necrotic
• Nutrient: Calcium

  Major Functions In Plants

  • Required for the physical integrity and normal functioning of cell membranes

  • Regulates the activities of a number of enzymes

  Visual Deficiency Symptoms

  • Symptoms usually occur in fast- growing tissues and organs

  • Tip burn in lettuce, blackheart in celery, blossom end rot in tomato or watermelon
• Nutrient: Sulfur

  Major Functions In Plants

  • Important in the structure of proteins

  • Constituents of vitamins

  • Important in electron transfer reactions

  • Responsible for the pungent flavors of crucifers

  Visual Deficiency Symptoms

  • Closure of stomates and reduced leaf area; depressed short growth

  • General chlorosis
• Nutrient: Iron

  Major Functions In Plants

  • As part of the catalytic group for many redox enzymes involved in photosynthesis and respiration

  • Essential in the electron transport system

  Visual Deficiency Symptoms

  • Chlorosis of the younger leaves

  • Root elongation is inhibited

  • Toxicity symptoms are similar to those deficiency
• Nutrient: Manganese

  Major Functions In Plants

  • As a co-factor for a number of enzymes in respiration

  • Essential role in the photosynthetic oxygen evolution

  Visual Deficiency Symptoms

  • Dicots: interveinal chlorosis of the younger leaves

  • Cereals: greenish gray spots on the more basal leaves

  • Legume seeds: the split seed, discoloration and deformity

  • Toxicity: brown speckles on mature leaves; interveinal chlorosis and necrosis
• Nutrient: Magnesium

  Major Functions In Plants

  • Required in the chlorophyll molecule

  • Critical to reaction involving ATP; links ATP to the active site of the enzyme

  Visual Deficiency Symptoms

  • Chlorosis of the fully expanded leaves
• Nutrient: Copper

  Major Functions In Plants

  • Co-factor for oxidative enzymes e.g. plastocyanin, cytochrome oxidase and ascorbic acid oxidase

  Visual Deficiency Symptoms

  • Stunting, distortion of young leaves, necrosis of the apical meristem
• Nutrient: Zinc

  Major Functions In Plants

  • Activator of a large number of enzymes

  • Essential in auxin synthesis

  Visual Deficiency Symptoms

  • Dicots: shortening of the internodes (rosetting) and a

  drastic decrease in leaf size (little leaf)

  • Mottle leaf
• Nutrient: Molybdenum

  Major Functions In Plants

  • Necessary for nitrogen metabolism such as the reduction of nitrates to ammonium ions

  Visual Deficiency Symptoms

  • Stunted growth and chlorosis in young leaves

  • Irregularities in leaf blade formation (whiptail)

  • Local chlorosis and necrosis along the main veins of mature leaves
• Nutrient: Boron

  Major Functions In Plants

  • Forms stable esters with cell wall saccharides

  • Essential in cell division and elongation

  Visual Deficiency Symptoms

  • Discoloration at the terminal bud or youngest leaves

  • Internodes are shorter

  • Interveinal chlorosis on mature leaves

  • Stem cracking in celery or hollow stem disorder in broccoli

  • Drops of flower buds, flowers and developing fruits

  • Water-soaked areas, tipburn and brown- or blackheart in head lettuce
• Nutrient: Cobalt

  Major Functions In Plants

  • Necessary for stem growth, coleoptile elongation, essential for nitrogen fixation in legume species; found in B12 and propionate

  Visual Deficiency Symptoms

  • Small root nodules on legume species, overall pale green color of the leaves which are fairly uniform, retardation of grain or seed production

  • Excess cobalt can result to iron deficiency
• Nutrient deficiency symptoms are manifested when an essential element is insufficient or not available to meet the required amount during the growth and development of crops.
• The nutrient toxicity symptoms are shown when an element is excessively available and beyond the crop requirement.