Interpreting Plant Tissue Analysis

Nitrogen is involved in the structure of all amino acids, proteins, and many enzymes. It is also present in the chlorophyll, which gives the plant its green color. However, it is generally recognized that ammonium greens a plant and nitrate grows a plant. All nitrogen forms are mobile in plants. Therefore nitrogen deficiency symptoms first appear in older leaves. Leaves are small, the foliage color is light green to yellow, and the older leaves often fall prematurely.

Phosphorus

Aids in proper root development which aids in root:shoot ratio. Also aids in enhancement of fruit production, seed production and flower production. Deficiency symptoms include a darkish green color in the older leaves. A purplish color to the leaves along with necrosis of the leaf margins will appear. Also to note is low production in fruits, seeds, and flowers

Potassium

Magnesium

Magnesium moves to the roots by mass flow. Its' principle function is in stabilizing the ribosomes for adequate configuration of protein synthesis. However, magnesium is also responsible for the chlorophyll integrity of a plant. Deficiency symptoms are characterized by an interveinal yellowing of the leaf blade. Magnesium uptake is strongly influenced by pH, its availability markedly declining when the soil pH drops below 5.5.

Calcium

The main structural role of Calcium occurs in the middle lamella between adjacent cell walls, where it binds with free carboxyl groups of pectines. Therefore, Calcium acts as a cement between adjacent cell walls. Calcium is also involved in cell elongation in the shoot and growing tips of roots. Calcium deficiency causes leaves to become chlorotic, and deformed. A shortage of calcium in fruit causes a bitter pit in apples, tip burn in tomatoes and other vegetables and in some cases blossom-end rot.

Sulfur

Is associated with the formation of proteins and chlorophyll. Sulfur is also essential for the formation of glucoside oils and volatile compounds. Sulfur promotes legume nodule formation and stimulates seed production. It also helps plants withstand low temperatures. One of the most important S-containing proteins is ferredoxin, which is involved in the carbon dioxide assimilation. It is not a highly mobile mineral in the plant therefore any deficiency symptoms will appear in the younger leaves. At first the leaves appear yellow-green in color. Later red or purple pigmentation will appear. Reported as Parts Per Million (ppm)

Iron 

An essential role of Iron is related to changes in oxidation-reduction state of a plant. In other words, aids in the carbon-dioxide assimilation needed for plant function. Other roles include aiding in chlorophyll and protein synthesis, and root-tip meristem growth. Because iron is not mobile in the plant, deficiency symptoms first occur in the younger leaves. It is described as an interveinal chlorosis, or a yellowing.

Copper

Copper is essential for carbohydrate and Nitrogen metabolism in plants. Since copper is immobile in the plant, young foliage is affected first. Effects consist of reduced or stunted growth with distortion of young leaves. In cereals the young leaves may have a white or bleached tip. Additionally, an increased incidence of lodging will occur. And flowering or fruiting may be absent.

Zinc

Enzyme activity is highly dependent on zinc levels in the plant. Zinc is also responsible for protecting certain proteins from denaturation resulting from local pH changes. In anaerobic respiration, Zinc catalyzes lactic acid dehydrogenase for the conversion of pyruvic acid to L-Lactic acid. Zinc deficiency symptoms are a chlorosis in the interveinal areas of the leaf resulting in the leaf turning yellow and in some cases white. In fruit trees leaf development is restricted, fewer buds are formed and of those buds that are formed many remained closed.

Manganese

Pollen germination and growth of the pollen tube is highly dependent on manganese. It is also important to note that manganese is involved in controlling the amount of superoxides and free radicals generated by ozone and atmospheric pollutants. In general, Manganese deficiency symptoms are a chlorosis between the veins of older leaves.

Boron

Boron is directly involved in cell differentiation, maturation, division and elongation. Boron also affects the growth of the pollen tube. It is also related to the rate of germination of seed. Boron deficiency is the most common and widespread of all micro-nutrients. Young leaves are misshapen, wrinkled, thicker and darker in color. Eventually, terminal growing points die. Fruits of boron deficient plants may be small, and of poor quality.

Molybdenum

Aids in the conversion of nitrates (NO3) into amino acids within the plant. It is essential to the symbiotic nitrogen fixing bacteria in legumes, and is essential to the conversion of inorganic P into organic forms in the plant. The most obvious Molybdenum deficiency symptom is leaf chlorosis resembling Nitrogen deficiency. This deficiency first appears in older leaves than younger leaves until the growing point is killed.

Sodium & Aluminum

Although beneficial to plant development both elements do not meet all the requirements for essentiality.