Essential Plant Nutrients
PLSC-250
Chapter 4
17 Essential Plant Nutrients
Carbon, Hydrogen & Oxygen
Primary Nutrients ( N, P,K)
Secondary Nutrients (S, Mg, Ca)
Micro Nutrients(B, Mn, Cu, Zn,Fe, Mo, Cl, Ni)
CHO
Carbon- Forms back bone of plants. Photosynthesis is key.
Hydrogen- Water transport
Oxygen-important is respiration.
Primary Nutrients
Nitrogen Function-growth and
green color Deficiency- stunted
growth, pale yellow older leaves
Absorbed N03-, NH4+
Primary Nutrients
Phosphorous Stimulates early growth
and root formation, promotes seed production
Deficiency-slow growth, purplish color
Absorbed H2PO4-, HPO4
2-
Primary Nutrients
Potassium Function-improves
resistance to disease & cold. Aids in CHO production
Deficiency-slow growth,scorched effect
Absorbed-K+
Secondary Nutrients
Calcium Function Aids in
movement of CHO in terminal buds
Deficiency- Terminal bud dies, blooms shed early
Absorbed-Ca2+
Secondary Nutrients
Magnesium Function-ingredient of
chlorophyll aids in translocation formation of oils and fats
Deficiency-yellowing of lower leaves curl up
Absorbed-Mg 2 +
Secondary Nutrients
Sulfur Function-aids in the
formation of oils and certain proteins.
Deficiency-lower leaves yellow-green, stems and roots small.
Absorbed SO42-
Micronutrients
Zinc ( zinc ion Zn++) It controls the synthesis of indoleacetic acid,
an important growth regulator. Deficiency – Terminal growth areas are
affected first. Citrus & other tree crops. Symptoms – decrease in stem length &
rosetting of terminal leaves, Reduced fruit buds, Mottled young leaves, Dieback of twigs after first year, Striping or banding on corn leaves.
Micronutrients
Iron ( Fe++) An activator for respiration, photosynthesis,
and symbiotic nitrogen fixation. Symptoms – Interveinal chlorosis of young
leaves. Veins remain green except in severe cases., Twig dieback, In severe cases, death of entire limbs or plants.
Micronutrients
Manganese (ion Mn++) An activator for enzymes in plant growth. Symptoms – Interveinal chlorosis of young
leaves. Gradation of pale-green leaf coloration, with darker color next to veins., There is no sharp color distinction between veins & interveinal brown spots or streaks (barley) or necrotic spots (potatoes)
Micronutrients
Copper (ions Cu+ & Cu++) An activator of several plant enzymes & may
play a role in Vitamin A production. Symptoms – Stunted growth., Dieback of
terminal shoots in trees., Poor pigmentation., Wilting & eventual death of leaf tips., Formation of gum pockets around central pith in citrus.
Micronutrients
Boron (boric acid H3BO3)
Functions in plants in the differentiation of meristematic tissue.
Symptoms – Reduced flower or improper pollination., Death of terminal growth, causing lateral buds to develop, producing a “witch’s broom” effect., Thickened,, curled, wilted, & chlorotic leaves., Soft or necrotic spot in fruit or tubers
Micronutrients
Molybdenum (molybdate ion MoO4=)
Need by plants to utilize nitrogen Symptoms –Stunting & lack of vigor. This is
similar to nitrogen deficiency, because of the key role molybdenum in nitrogen utilization., Marginal scorching & cupping or rolling of leaves., “Whiptail” of cauliflower., Yellow spotting of citrus.
Micronutrients
Chlorine (ion Cl-) Required for photosynthetic reaction in plants
& regulating cell turgor potential. Symptoms – Spotting of leaves of small
grains, first on older leaves & more severe toward the tip half of the leaf blade., Delayed maturity.
Micronutrients
Nickel (divalent cation Ni++) Used in the conversion of urea to ammonia in
plant tissue – overall nitrogen metabolism. Symptoms – Chlorosis of young leaves.,
Death of meristem.
