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Copyright 2005, Board of Trustees, University
Agricultural Research & Education Center
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Bradenton AREC Research Report BRA1982-19 October, 1982
NUTRIENT DEFICIENCY SYMPTOMS AND NUTRITIONAL IMBALANCES
IN TOMATO SEEDLINGS
S. S. Woltz1
The tomato has been the guinea pig of research scientists for many years;
deficiency symptoms of mid- to full-size plants have been well described.
Seedling nutrition for this crop has been described (1-7) but not comprehensively
nor with full regard to the very early appearance of symptoms. Nutrient element
sources and media have undergone changes in usage in the mass production of
seedlings of tailored quality, increasing the possibility of early deficiencies.
It seemed timely, therefore, to study early responses of tomato seedlings to
nutritional situations that could be encountered in practice by growers as well
as seedling production specialists.
'Walter' tomato seeds were germinated in 2" pots of washed perlite (5
replicates), thinned to 1 seedling per pot and were irrigated with nutrient
solutions, either complete or from which nutrient elements had been omitted
one at a time. Nutrient elements were furnished at the following ppm rates:
nitrogen (N)-200, phosphorus (P)-50, potassium (K)-150, calcium (Ca)-200,
magnesium (Mg)-75, sulfur (S)-75, boron (B)-0.2, copper (Cu)-0.2, iron (Fe)-2,
manganese (Mn)-l, molybdenum (Mo)-O.1, and zinc (Zn)-lppm. Nutrient stock solutions
were purified of chemical contaminants by autoclaving with CaCO 2g/L or by
re-crystallizing chemical salts where appropriate. Nutrient soTutions were applied
twice weekly to run-through (30 to 50 ml per pot) and watered with deionized
water as needed, the remainder of the week. Data were collected and seedlings
were harvested at 5 weeks from planting.
Nitrogen. N deficiency is evidenced by the pale green or yellowish color
of seedlings, sometimes tinged with a red-purple pigment but not as much of the
latter as With P deficiency. Stems are tinged with a purple coloration.
Seedlings/grown in the absence of N develop very little growth past the cotyledons
which are pale green to yellow. When present in excess or out of balance,
ammonium sulfate was more restrictive of growth than ammonium nitrate and in turn
than calcium nitrate. Excess calcium nitrate caused elevated soil pH and iron
deficiency. Calcium compounds are necessary to growth of tomato seedlings.
Phosphorus. Deficiency of this element is characterized by stunting,
dull green leaves and considerable amounts of the red-purple pigment most
noticeable on the under surface of the leaves. Stems are also purplish in
-'Professor of Plant Physiology.
Potassium deficiency causes a scorch at the ends of cotyledons with a
dull gray coloration towards the tips of the cotyledons. Seedlings are short
and stunted but green with green leaves (other than cotyledons). Deficiencies of
this element are aggravated especially by an imbalance (relatively higher levels)
of nitrogen, calcium, magnesium, and the ammonium ton in particular.
Calcium deficient seedlings have severely stunted cotyledons and root systems.
Tips of roots are brown. Cotyledons have a gray-green upper surface, occasional
necrotic spots but not at the tip of the cotyledon as in the cases of potassium
and magnesium. Marginal areas are necrotic on both sides at the middle of the
cotyledons. Later leaflets are narrow twisted, yellow colored with some necrosis
and may be mistaken for boron deficiency. Calcium deficiency is aggravated by
imbalancing high levels of potassium, magnesium and ammonium nitrogen.
Magnesium deficiency is characterized by a marginal-tip necrosis of cotyledon
leaf areas. Cotyledons and lower true leaves turn yellow; the lower true leaves
have green veins that are indistinctly outlined compared to iron and manganese
deficiency. Roots are stunted with some brown breakdown suggestive of a type of
soft rot. Magnesium uptake by roots is easily disrupted by cold, wet conditions
as well as by imbalances of competing cations, namely, potassium, calcium and the
Sulfur deficiency is expressed as a general yellowing of all leaves and a
stunting of seedlings. The mid-rib of cotyledons is greener than the rest of
the cotyledons grading to a yellow margin. Sulfur requirements for protein
synthesis are elevated by-,higher nitrogen levels. Sulfur deficiency effects
are much less acute than those of nitrogen.
Boron deficiency is characterized by narrow, yellow twisted and somewhat
bronzed leaves and leaflets. A general yellowing of leaves and cotyledons
is symptomatic. Frequently, the growing point ceases growth leaving a necrotic
stub. Onset of the deficiency may be surprisingly early and severe indicating
seeds are deficient in boron. If the medium, fertilizer and water lack boron,
that seedling may be affected by the time of transplanting. Alkaline irrigation
water containing sufficient amounts of bicarbonate and calcium will favor the
appearance of boron deficiency; the irrigation water may, however, contain
quite significant amounts of boron and should be analyzed for the element.
High pH and calcium levels in the medium also favor boron deficiency; high levels
of nitrate nitrogen also predispose to boron deficiency.
Copper. Although growth of tomato seedlings was depressed, overt deficiency
symptoms failed to develop.
Iron deficiency of seedlings is expressed_as the customary green veins against
a chlorotic leaf background. The green veins grade out in color to a yellow
intercostal area in mild iron deficiency. Veins are not heavy, dark green
as they are in manganese deficiency. Iron deficiency is more often due to high
pH of medium and irrigation water than to an absolute deficiency. Iron deficiency
is aggravated by levels of manganese that are proportionately too high. Nitrate
nitrogen as the sole source may aggravate iron deficiency.
Zinc deficiency is symptomatically associated with a chlorosis, bronzing and
downward curvature of leaves. Alkalinity of media, water and use of nitrates
at higher levels as the sole nitrogen source favor the appearance of zinc
Symptom development occurred in the following order from first to last
appearance in the 5 week growing period: N, Ca, K, P, B, S, Mg, Fe and Zn.
Since irrigation water is one significant source of nutrients, growers most
likely will not experience the same relative order of appearance of deficiency
symptoms. Additionally, nutritional imbalance may delay or prevent the appearance
of symptoms as, for example, when limitation of nitrogen supply prevents certain
deficiencies from occurring.
1. Halsey, L. H. 1971. Single harvest yields of several tomato cultivars
in relation to seed size. Proc. Fla. State Hort. Soc. 84:110-112.
2. Jaworski, C. A. 1966. Yield and growth uniformity of tomato transplants
in relation to nutrition levels. Proc. Amer. Soc. Hort. Sci. 89:577-583.
3. Locascio, S. J. and G. F. Warren. 1959. Growth pattern of the roots of
tomato seedlings. Proc. Amer. Soc. Hort. Sci. 74:494-499.
4. Locascio, S. J., G. F. Warren, and G. E. Wilcox. 1960. The effect of
phosphorus placement of uptake of phosphorus and growth of direct-seeded
tomatoes. Proc. Amer. Soc. Hort. Sci. 76:503-514.
5. Wilcox, G. E. and R. Langston. 1960. Effect of starter fertilization of
early growth and nutrition of direct seeded and transplanted tomatoes.
Proc. Amer. Soc. Hort. Sci. 75:584-594.
6. Wilcox, G. E. 1966. Tomato seedling response to phosphorus rate and
placement of fertilizer bands. Proc. Amer. Soc. Hort. Sci. 88:521-526.
7. Woltz, S. S. and J. P. Jones. 1972. Response of Manapal tomato seedlings
to variations in inorganic nutrition. Proc. Fla. State Hort. Soc. 85:175-177.