| Material Information
||Factors influencing micronutrient use in tropical foliage production
||ARC-Apopka research report
||5 leaves : ; 28 cm.
||Conover, Charles Albert, 1934-
Poole, R. T ( Richard Turk )
Agricultural Research Center (Apopka, Fla.)
||University of Florida, IFAS, Agricultural Research Center
||Place of Publication:
||Foliage plants -- Nutrition -- Florida ( lcsh )
||government publication (state, provincial, terriorial, dependent) ( marcgt )
non-fiction ( marcgt )
||Statement of Responsibility:
||C.A. Conover and R.T. Poole.
| Record Information
||University of Florida
||All rights reserved by the source institution and holding location.
||oclc - 71064092
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R oi FACTORS INFLUENCING MICRONUTRIENT USE IN TROPICAL FOLIAGE PRODUCTION
C. A. Conover and R. T. Poole
University of Florida, IFAS
ARC-Apopka Mimeo Report PIH-1973-1
Micronutrients (also called minor, trace or secondary el ments) are needed
in small, but critical amounts, by green plants and include er(N.j(j/ja|
zinc, copper, boron, molybdenum and chlorine. In recent ye rs micronutrients
Have been recognized as an important part of foliage produce ion, a t
commonly used in fertilization programs. IAS. O U I
The need for micronutrient additions to organic soil mixturesTa n~
established in many areas of crop production. Present micronutrient recommend-
ations for foliage growers are designed to provide a form of "crop insurance"
for those who have experienced problems with iron, manganese, copper and other
micronutrient deficiencies in previous crops. Additions of micronutrients are
especially desirable when the soil medium is composed entirely of components
such as peat, bark, shavings, perlite, vermiculite or washed sand which are<
usually low in these nutrients.
Additions of micronutrients to soil mixtures or their inclusion in fertilizer
programs require considerable planning, because low levels provide little benefit
while high levels are generally toxic to plant growth. Boron and manganese have
been shown to be phytotoxic at low levels to many plant genera and have been
implicated in recent foliage crop damage reports.
Sixth increased usage of micronutrients by foliage growers some guidelines
seem necessary, and the following points are designed to prevent crop damage
from excessive applications of any micronutrient mixture as well as provide
minimum required amounts.
1. When recommended rates of micronutrients are incorporated into the
soil medium (Table 1), use of fertilizers with micronutrients are not recommended
for 1 year because of possible phytotoxicities. Micronutrient availability is
influenced by pH, and therefore, suggested amounts in Table 1 depend on whether
dolomite, calcium carbonate or other pH influencing amendments have been added
to the potting soil.
2. Continuous use of fertilizers containing micronutrients are not
recommended unless the percentages of the various micronutrients are less than
the maximum suggested in Table 2 and the yearly amount of fertilizer applied
to the same soil is less than 9000 lbs/A/yr. Infrequent application of
fertilizers with higher levels are acceptable, provided the amounts for these
elements does not exceed the amount listed in Table 2.
3. Micronutrlents should not be incorporated into soil mixtures prior to
steam sterilization because steaming increases availability.
4. When-including sludge or other organic fertilizers containing
micronutrients in soil mixtures reduce additions of subsequent micronutrients.
Foliage growers who experience problems with micronutrient deficiencies
should remember that the one most often causing the problem is iron. In these
cases, rapid recovery can be obtained with a foliar spray of chelated iron.
Growers who tank mix their own fertilizer formulations from single components
such as ammonium nitrate, potassium nitrate, phosphoric acid etc. may utilize a
commercial soluble micronutrient additive such as Peters Soluble Trace Element
Mixture, THIS, Sequestrene or Neutral Trace Elements provided they follow the
suggestions in Table 2 concerning percentages of each element. Some commercially
prepared micronutrient mixtures are too high in certainelements such as boron,
which limits their use because the correct boron level does not provide desired
levels of other micronutrients.
Table 1. Suggested rates of micronutrient mixtures or single components
to include in soil media at various pH levels.
Rate Ibs/cu yd
Trade or pH pH
common name 4.0 to 5.5 5.5 to 7.0
Es-Min-El 3/4 to 1 1 to 1 1/2
FTE-503 1/5 to 1/4 1/4 to 1/2
Perk 1 1/2 to 2 2 1/2 to 3
Vigoro Supplement X 3/4 to, 1 1 1/2 to 2
Single'elements add all 4
Copper Sulphate (C8S04) 1/2 oz. 1 oz.
Iron Chelate (Sequestrene 33b) 1/2 oz. 1 oz.
Manganese Sulphate (MnS04) 1/2 oz. 1 oz.
Zinc Sulphate (ZnSO4) 1/2 oz. 1 oz.
iable 2. Levels of micronutrients to include in fertilizer formulations used on tropical
fciogeS when yearly fertilizer amount applied does not exceed 206 lbs/1000 s.
ft, (9000 lbs/A/yr) .
percent sq, ft/,vyr
percent sq ft/yr
percent sq ft/yr
LiMoi.ybde .i (Mo03)
khen less total poundage is used, proportionally higher percentages of the individual
elements may be used as long as the yearly amounts do not exceed those suggested.
Table 3. Comparison of contents in percent of mixtures that may be
incorporated into growing media for a micronutrient source.
Es-Min- FTE Supplement X
Element El No. 503 Perk with FTE
(B203) 1.6 9.75 0.7 0.25
(cuo) 2.8 3.75 0.3 0.45
(Fe203) 3.0 25.70 5.2 9.00
(MnO) 9.3 9.50 3.0 4.0
(Mo03) None 0.30 0.003 .001
(ZnO) 3.5 9.75 0.9 2.00
(CaO) None None None 15.0
(MgO) 2.4 None 15.2 25.0
(SO2) None None 4.5 6.4