Great Lakes Expo
Nutritional Deficiencies:
What They Look Like
The Tomato Magazine
February 2006
By Jonathan M. Frantz
USDA-ARS
One of the most useful skills to have when wandering a greenhouse is
the ability to visually detect nutrient deficiencies in plants. If skilled
at this, a grower can correct nutritional problems during production
without a major loss of plant yield and quality.
I believe the best way to develop this skill is to cause the problems,
on a small scale of course, on a few plants and watch as the symptoms
develop over time. Only then can one see patterns, feel the leaves
and roots, and learn when and how to correct the problem. Each species,
and
occasionally, different cultivars, can behave differently in the absence
of specific nutrients. But who has time to grow each variety in controlled
conditions to learn what each plant “says” when it is low
in nutrients?
To begin learning the symptoms, I think it is helpful to learn all the
nutrients and, briefly, what each nutrient does for the plant. It can
be helpful also to learn how nutrients move in the plant and, at times,
how they get into the plant. With this information in hand, you can begin
to learn patterns that are common to all plants for specific nutrients.
This will also give us direction on how to correct problems when they
do show up. For example, if we see an iron deficiency, is it best to
apply foliar spray, apply Fe to the root zone or just water differently?
While a nutrient deficiency may be an obvious visual symptom, knowing
what other stresses cause these symptoms may allow us to fix a problem
rather than just treat its symptoms. This way, a tomato grower knows
the symptoms for not only tomatoes, but for bedding plants, nursery plants
and native species. It is so much easier learning a handful of characteristics
than memorizing specifics on each plant species.
This presentation supplements a list of reference materials (see list
below) that, together, can give you a clear overview of what you need
to do. To be certain of a visual diagnosis, it is often helpful to follow
up with a plant tissue, water, and/or soil analysis. I have included
a brief section on how to take a sample as well as how to interpret (and
not over-interpret) the data.
Web Sites:
http://www.back-to-basics.net/nds/# - includes alfalfa, apples, canola,
citrus, coastal Bermuda grass, corn, cotton, forages, peanuts, potatoes,
rice, small grains, soybeans, sweet corn, tobacco, tomatoes, tree fruit,
vegetables, wheat
http://www.ces.ncsu.edu/depts/hort/floriculture/def/ - for floriculture
crops
http://extension.agron.iastate.edu/soilfertility/nutrienttopics/deficiencies.html
- corn and soybean
www.unce.unr.edu/publications/FS02/FS0265.pdf - this is a pdf file, so
you need Adobe Acrobat Reader.
http://muextension.missouri.edu/explore/agguides/hort/
index.htm - extensive information
Lots of other sites with excellent text descriptions.
Books:
Epstein, E. and A.J. Bloom. 2005. Mineral nutrition of plants: principles
and perspectives. 2nd edition Sinauer Associates, Inc. Sunderland,
Mass.
Handreck, K and N. Black. 2002. Growing media for ornamental plants and
turf. 3rd edition. UNSW Press, Sydney, Australia.
Marschner, H. 1995. Mineral Nutrition of Higher Plants. 2nd edition.
Academic Press, Cambridge, UK.
Reed, D.W. 1996. Water, media, and nutrition for greenhouse crops. Ball
Publishing, Batavia, Ill.
Nelson, P.V. 1998. Greenhouse Operation and Management. 5th edition.
Prentice Hall, Upper Saddle River, NJ.
Aldrich, R.A. and J.W. Bartok Jr. 1994. Greenhouse Engineering. Natural
Resource, Agriculture, and Engineering Service, Cooperative Extension,
Ithica, NY.
Mills, H.A. and J.B. Jones, Jr. 1996. Plant Analysis Handbook II. MicroMacro
Publishing, Inc., Athens, GA.
Mengel, K. and E. A. Kirkby. 2001. Principles of plant nutrition. 5th
edition. Kluwer Academic Publishers.Dordrecht, The Netherlands.
Essential Elements
Essential elements have been defined as any element that a plant needs
in order to complete its life cycle under controlled conditions (Arnon
and Stout, 1939). Recently, a slightly new definition has been introduced:
either the nutrient is contained as part of a molecule in a plant or
growth of the plant without that nutrient is abnormal compared to plants
not deprived of that nutrient (Epstein, 2005). In this presentation,
I will use this second definition of essentiality; as a result, the
list of nutrients discussed here is slightly different from what some
readers may know. In Table 1, I have listed the essential elements,
a brief description of what each is used for and a general pH range
in which, ideally, the nutrient is available.
I have found that Table 1 and Table 2, together, can help predict where
symptoms may occur for any plant species and greatly assist in predicting
how quickly
and thoroughly recovery can be for plant yield and quality. There are generally
one or two tricks for each nutrient that can push the visual diagnosis from
a “maybe” to a “probably”. Table 3 holds those keys.
It is extremely important to know your crops. Confucius is credited with saying
that “the footsteps of the farmer are the best fertilizer.” Basically,
this means that you can help the plants grow well by seeing them regularly.
Certain crops have propensities for certain nutrient deficiencies. For example,
tomato and Ca (blossom end rot) seem to go hand in hand as does lettuce with
Ca/B deficiencies (tip burn). Looking at Table 1 and understanding how each
of these nutrients is used in the plant provides insights into why these deficiencies
occur where they do. We might try to push growth as fast as we can to maximize
the number of turns for a space and have conditions that allow more B and Ca
(not mobile in the plant) to follow water streams in the plant rather than
high growth activity.
Nutrient Analysis
Finding a good plant, soils, and water analysis lab can be as important as
finding a reliable media supplier. Speed, accuracy, and price are important
considerations when attempting to find an analysis lab, but, in spite of the “easy
to read” reports and printed guidelines, the interpretation of analyses
is largely up to you. Before reaching that stage, it is important to send the
lab the right samples. The discussion in this report is limited to plant tissue.
Most recommendations are developed based on results from surveys, using many
varieties, at various stages of development and are on recently matured leaves.
This is important to know because, if you send in tissue from a young, developing
leaf or root, the report you get back will be in relation to these survey results
or “accepted values”. The survey results should serve only as loose
guidelines. In other words, compare similar tissues and realize that the guidelines
you receive may not be of a similar tissue. What do the wide ranges mean? At
times it may mean that there is a wide range of acceptable values, but more
likely it means that we just don’t know what an acceptable amount is.
As an example, we analyzed 104 varieties of geranium and found a range of 3x
in the macronutrients (i.e., P) and a range of about 10x for the micronutrients
(i.e., Mn) (Figure 1). So, based on this survey, what is acceptable for a particular
variety of geranium? I couldn’t conclude, definitively, a particular
value for a given geranium.
Even within a plant, values for nutrients vary and should be based on the tissue’s
needs. For example, it is not uncommon to have B concentrations in mature leaf
tissues of 100 ppm (mg kg-1) and only about 15 to 20 ppm in flower tissue.
Both are healthy, and both are correct. Ironically, deficiencies in both tissues
may be a value of 10 to 15 ppm, which suggests there is little room for error
in some tissue types for some nutrients.
Prior to sending tissue to a lab, rinse the tissue with the cleanest water
available to remove fertilizer deposits on the leaf surface, dirt and dust.
This will enable you to have faith that the numbers you receive in the analysis
are truly of what is in the plant rather than what happened to be on the tissue
surface. If you are fortunate enough to have some healthy (symptom-less) appearing
plants with unhealthy plants, send the same tissue type of both healthy and
unhealthy tissue. This will show differences and potential problems much better
than comparing “sick” tissue to a random book value.
Other Problems
Many other things can manifest themselves as nutrient deficiencies and
can potentially confuse some diagnoses. For example, various root pathogens
can result in a plant appearing as though it is experiencing Ca or
B deficiencies in the roots and Fe deficiencies in the shoot. Lack
of oxygen in the root zone caused by heavy media, over watering or
a broken water pump can lead to Fe and K deficiency symptoms. High
EC can result in Ca deficiency. Air pollution can cause Mn, S and P
symptoms, while growth regulators can cause unusual chlorotic patterns
akin to many nutrient deficiencies. pH problems can cause both deficiency
and toxicity problems. High light can cause photobleaching that appears
like S, Mg, Zn and other deficiencies, and viral infections can seem,
at times, like Mn deficiency. So while visual diagnosis can be helpful,
it is not a cure-all and only tells us part of the story; to make a
complete diagnosis, seek more information such as foliar environment
conditions, media and watering patterns, spray history, pest history
and varietal specifics.
Disclaimer
Mention of a trademark, proprietary product, or vendor does not constitute
a guarantee or warranty of the product by the USDA, and does not imply
its approval to the exclusion of other products or vendors that also
may be suitable.
References
Arnon, D.I. and P.R. Stout. 1939. The essentiality of certain elements
in minute quantities for plants with species reference to copper. Plant
Physiology 14:371-375.
Epstein, E. and A.J. Bloom. 2005. Mineral nutrition of plants: principles
and perspectives. 2nd edition Sinauer Associates, Inc. Sunderland, Mass.
Lambers, H., F.S. Chapin, and T.L. Pons. 1998. Plant Physiological Ecology.
Springer Publishing, New York, NY.
Lucas, R.E. and J.F. Davis. 1961. Relationships between pH values of
organic soils and availabilities of 12 plant nutrients. Soil Science
92: 177-182.
Editor’s note: Jonathan M. Frantz, with the
USDA-ARS, can be contacted at: 2801 W. Bancroft, Mail Stop 604, Toledo,
OH 43606;
e-mail: jonathan.frantz@utoledo.edu.
One of the most useful skills to have when wandering a greenhouse is
the ability to visually detect nutrient deficiencies in plants. If skilled
at this, a grower can correct nutritional problems during production
without a major loss of plant yield and quality.
© 2006 Columbia Publishing
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