Hort 1 – Objective 24.01 Nutrients

B. Functions of nutrients & symptoms of deficiencies1.Primary nutrients

a. Nitrogen1.Functions:

a)Promotes growth of leaves & stems

b) Gives dark green color & improves quality of foliage

c) Necessary to develop cell proteins & chlorophyll2) Deficiency symptoms:

a) sick, yellow-green colorb) Short stems, small

leaves, pale colored leaves & flowersc) Slow & dwarfed plant growth

b. Phosphorus1) functions: a) Stimulates early formation & growth of rootsb) Provides for fast & vigorous growth & speeds maturityc) Stimulates flowering & seed developmentd) Necessary for the enzyme action of many plant processes

2) Deficiency symptoms:a)Decrease in

growth

b) slow maturity

c) older leaves are purplish color

c. Potassium1)functions:

a) used to form carbohydrates & proteinsb) Formation & transfer of starches, sugars, & oilsc) Increases disease resistance, vigor, & hardiness

2) Deficiency symptomsa) mottled, spotted,

streaked or curled leavesb) scorched, burned, dead leaf tips & margins

2. Secondary nutrientsa. Calcium

1)functions:

a) improves vigor

b) Influences intake & synthesis of other plant nutrientsc) Important part of cell walls

2) Deficiency symptoms

a) Small developing leaves, wrinkled older leavesb) Dead stem tips

b. Magnesium1) functions:

a) Influence the intake of other essential nutrientsb) Helps make fats

c) Assists in translocation of phosphorus & fats

2) Deficiency symptomsa) Interveinal chlorosis – yellowing of leaves between green veins

b) Leaf tips curl or cup upward

c) slender, weak stems

c. Sulfur1)functions:

a) Promotes root growth & vigorous vegetative growth

b) Essential to protein formation

2) Deficiency symptomsa) Young leaves are light green with lighter color veinsb) Yellow leaves and stunted growth

3. Micro nutrientsa. Iron

1) functions

a) Essential for chlorophyll productionb) Helps carry electrons to mix oxygen with other elements

2. Deficiency symptomsa) Mottled & interveinal chlorosis in young leaves

b) Stunted growth & slender, short stems

b. Copper1) Functions

a) helps in the use of iron

b) helps regulate respiration

2) Deficiency symptomsa) Young leaves are

small & permanently wiltb) Multiple buds at stem tips

c. Zinc1)Functions

a) plant metabolismb) Helps form growth hormonesc) reproduction

2) Deficiency symptomsa) Retarded growth between nodes (rosetted)b) New leaves are thick & smallc) Spotted between veins, discolored veins

d. Boron1) functions

a) Affects water absorption by rootsb) Translocation of sugars

2) Deficiency symptomsa) short, thick stem

tipsb) Young leaves of terminal buds are light green at base

c) Leaves become twisted & die

e. Manganese1)Functions

a) plant metabolism

b) nitrogen transformation

2) Deficiency symptoms

a) Interveinal chlorosis

b) young leaves die

f. Molybdenum1)Functions

a) plant development

b) reproduction2) Deficiency symptoms a) stunted growth

b) yellow leaves, upward curling leaves, leaf margins burn

g. Chlorine1)Functions

a) essential to some plant processes b) acts in enzyme system2) Deficiency symptoms

a) Usually more problems with too much chlorine or toxicity than with deficiency