My Top Ten and Keeper Lists

I have FINALLY organized my Top Ten and Keeper lists!
They are available online at:  http://photobucket.com/MyFavoriteViolets

Fall 2012 Violet Voice Round Robin

The Violet Voice is half-way through their 2012 Fall Round Robin Boxes.... and here is my 'loot':
The black tray on the right and the 'half-tray' in the middle are the RR leaves and plants.  The tray on the left are leaves I ordered this month from commercial AV vendors.  (OKAY... I know:  I need more leaves like I need a hole in my head!  But since I had the RR leaves to becare for in the isolation area, why not take this chance to get a few other varieties that I had lost or been coveting!)

Total count of leaves set.. is approx. 82!  Gulp!
Please pardon the 'feathers' on the floor and windowsill... the leaves must share the window area with my canaries!

The AV Story

As The African Violet Story Unfolded..... (Sections quoted from The Colourful World of African Violets by A.G.W. Simpson) "Walter von Saint Paul sent a collection of African Violets to his father, the Baron von Saint Paul, who owned estates on German Upper Silesia. We must assume that the baron had glasshouses, as that German province is one of the coldest parts of Germany. Baron von Saint Paul was intriqued by the plants and sent part of his collection to Herr Herman Wendland, at that time director of the Royal Botanic Gardens at Herrenhausen."

"....giving the generic name of Saintpaulia meant that Herr Wendland also had to give it a specie name as well, and when he studied the plant he saw that the most characteristic part was its violet blue flower. Thus he called it ionantha. "Ion" is Greek for violet and "antha" means flowering. Thus we have the descriptive name of "Violet-flowering Saintpaulis", or Saintpaulia ionantha."

"The original African violet found growing in Tanganyika was Saintpaulia ionantha. Saintpaulia confusa, another specie, was also found. Once the specie S. ionantha was crossed with the specie S. confusa a range of plants was produced which are known as "varieties", or more correctly, "cultivars". Varieties are bred by nature in the wild, whereas cultivars are bred by man. Modern cultivars are Blue Boy, Amethyst, Sweetheart Blue and many more."

"...We are told that von Saint Paul sent more than one species of African Violet to his father. Two species for sure were S. ionantha and S. confusa. therefore from those humble beginnings Suttons and Ernst Benary developed their various cultivars."

"Armcost and Royston, a famous Californian grower, imported hybrid seed from Suttons (UK) and Ernst Benary (Germany) and bred them on. and from more than 1000 seedlings, they could select only 10 good cultivatars. They were Admiral, Amethyst, Blue boy, Commodore, Mermaid, Neptune, Norseman, Sailor Boy, Viking, and No. 32. ...."

"In 1939 a gentleman named Ed Wangbickler was sorting through a batch of African Violets he had grown, when, clustered in a group of Blue Boy, he saw a strange mutation. It was a beautiful double blue...."

"...In 1940 the famous nursery of Holton and Hunkel was sorting through a batch of Blue Boy, and there, standing like a beacon in a blue night, was the first recorded single clear pink...."

"We are still in the '40's. Peter Ruggeri discovered and grew a white culivar, which he named White Lady."

"....The Fischeer Greenhouses produced a ruffled flower known as the Fringette Series. The DuPont strain with its begonia-like leaves appeared. The Fantasy types with their "splashed" petals made a great impact. And the Rhapsodies, with their elegant habit and extravagant floral abundance, took the African Violet world by storm."

"In 1954 a gentleman named Lyndon Lyon exhibited four African Violets at the National African Violet Show in Saint Louis. It triggered off great excitement. Why? The plants were the first elusive double pinks. And one in particular which caused quite a stir was Ohio Beautiful."

(The following is adapted from an AVM article in the Jan/Feb 2003 issue written by Dr. Jeff Smith, entitled 'Thank Goodness for Sports'. Includes photos and info regarding Janet Stromborg's recent series of sports. Please read it, it is interesting!)

Table 2. Important Sports or Mutations in African Violets

Double Flowers 1939 Mutant of 'Blue Boy'

Pink Flowers 1940 Mutant of 'Blue Boy'

Girl Foliage 1941 Mutant of 'Blue Boy'

Fantasy Flowers 1949

Geneva Edges 1950

Star-Shaped Flowers 1952

Fringed Flowers 1953

Bustled Foliage 1957

"Tommie Lou" 1959 Found as a sport of 'White Pride'
Varigation by Tommie Louise Oden
Varigation is on leaf edges.

"Lillian Jarrett" or 1961 Found in a sport of 'Lilian Jarrett'
Mosiac Varigation
Varigation is the center areas of the leaf blade.

Coral Pigments 1963

Yellow Flowers 1989

Hybridizing History ~~ 3/1964 GSN

 

Trail of Progress

George Wessale
March 1964 Gesneriad Saintpaulia News, pgs. 24-25

At the sight of each new cultivar we express surprise and admiration and cannot help but wonder what is coming next or where the path of this plant's fascinating development will lead us. In our ecstasy, we are apt to forget that this has been going on for quite a long time and that once upon a time there was an humble and uncertain beginning for this Cinderella.

To pick up the thread of history of our favorite plant, we must go back to the year 1892, when a young German nature lover and colonial official in the service of his country, found the first African violet plants. He did so while walking through the beautiful primeval forests of the Usambara Mountains and the shaded Coastal Plains near Tanga in Tanganyika, German East Africa. Plants were found in both localities. His name was Baron Walter von Saint Paul-Illaire. He was the Imperial District Captain of Usambara, a province of East Tanganyika, Territory of East Africa. Knowing that his father, Hofsmarsehal Baron Ulrich von Saint Paul-Illaire, of Fisehbach in Silesia, Germany would be interested in his discovery, he sent him some of the plants or seeds. There seems to be some disagreement as to whether the plants were sent in a dry state as botanical specimens or whether an attempt was made to deliver them in living condition. The boat trip required several weeks and it seems doubtful that proper care could have been given them to survive the long trip as live plants.

Be that as it may, there undoubtedly were some seed pods sent along with the plants to the father. Specimens of these plants were sent to the Hofsmarschal's good friend Herman Wendland, a noted botanist of his day and at that time, Director of the Royal Botanical Gardens of Herrenhausen (Hanover), Germany. Wendland grew the plants he received. A year later he identified and named the genus Saintpaulia, in honor of the Saint Paul family, and because of its violet-like flowers he gave it the species name lonantha. In 1393 they were exhibited at the Ghent Quinquennial Exhibition, held from April 16 to 23, 1893, where they created much interest. The firm of Ernst Benary, Erfurt, Germany was assigned the commercial rights for distribution of seeds.

It is not known just how much progress was made in the propagation and selective breeding of Saintpaulias during the next number of years, in either England or Germany. Plants were brought to America about 1894 by a New York florist George Stumpp who purchased then. in Germany. Two plants of this shipment were sold to a Philadelphia florist William K. Harris, who probably grew some and sold them to his customers.

There was quite a gap in the trail of events before we again pick it up about 1927, when Walter Armacost of Armacost and Royston, Inc. Los Angeles, California obtained seeds from both England and Germany. His first attempt to grow them produced about a thousand plants. He noticed considerable variation in the lot selected and saved about a hundred of the most likely ones for further propagation and breeding.

Several years later, he made his final selection of plants and in 1936 issued a price list offering them to growers across the country. Of course, among them was the old pioneer, Blue Boy. Others were Admiral, Amethyst, Sailor Boy. Commodore. Neptune, Norseman. Mermaid, Viking and No. 32. Popularity of the plants spread rapidly and they were soon grown in considerable numbers.

About this time Mrs. William K. duPont of Wilmington, Delaware purchased seeds from Suttons of London, England. Among the seedlings raised was one with outstanding heavy foliage. Through hybridizing and selection Mrs. dupont developed the duPont strain of Saintpaulias from this plant.

On May 5, 1942 plant patent No. 514 was granted to Frank Brockner, assignor to Holton & Hunkle Company, Milwaukee, Wis., for Pink Beauty a mutant of Blue Boy. Pink Beauty was the first clear true pink. The inevitable soon happened and Nature asserted itself in a greenhouse bench of a mid-west grower by producing the first break or mutant to the girl type foliage from Blue Boy. Thus Blue Girl was born. The Ulery Greenhouses, Springfield, Ohio was granted a plant patent No. 535 on July 28, 1942 on Blue Girl. Another mutation, resulting from the hybridizing efforts of Peter Ruggeri, Silver Terrace Nursery, produced a pure white African violet — White Lady. Mr. Ruggeri applied for the patent and assigned the rights to the Fred C. Gloeckner & Company, Inc., New York, N.Y. who were granted plant patent No. 597, August 3, 1943.

Events followed in rapid succession with the appearance of Red Head and the many. many intermediate shades of reds, orchids and blues. It was an exciting and enchanting time in the Saintpaulia world.

In 1948 we received another even greater surprise with the introduction of the first doubles — Duchess and Double Neptune. A number of various color shades on double flowers were soon available and the clamor for the first double pink was on. . . . Rumors were flying hard and fast but strangely enough, it was not until 1954 when not one but at least five double pinks were announced simultaneously.

There may be some significance in this, because a short time previously we were told, by a noted mid-west geneticist, how to proceed to obtain double pinks with the plants we already had on hand by applying the principles of Mendel's Laws of Inheritance. Many growers heeded his advice and got the desired results promptly

The writer knows of one instance, however, where this was not necessarily so. A beautiful double pink, as fine as any, appeared among a few seedlings of a local amateur grower, from seeds purchased of a commercial producer. Here the correct cross may have been made accidentally, or it may possibly have been another mutation.

After the flurry of double pinks subsided somewhat, it appeared, for a time, that we were entering a period of monotony and stagnation of interest because hundreds of new cultivars were being introduced with practically no variation of flower or leaf from older plants. The larger growers, no doubt sensed this and set out to correct the situation, at least to some extent, by striving toward more floriferous plants, larger blooms and variegated or multicolored foliage.

Results from such radical attempts as chemical treatment and radiation, so far as is generally known, have been disappointing but who can tell what the future will bring to a house plant with such universal popularity? And to think that it all probably started with a few little shriveled seed pods long ago!

Hunger Signs In Violets~~1/1998 AVM

What Happened to My Plants
Hunger Signs in Violets
January/February 1998 African Violet Magazine, pgs 43-45
By Dr. Charles Cole

Providing good nutrition for our African violet plants involves more than purchasing a fertilizer product and applying it to the plants. We need a basic knowledge of what a plant needs and how a specific nutrient effects a plant under a given set of conditions. If we understand how to use specific fertilizer elements we may use them to obtain a desired response from our plants. A familiar example of this is seen when we reduce the use of nitrogen in our fertilization program in an effort to enhance variegation in certain cultivars.
There are 16 chemical elements which are essential for plant growth. Often we see them grouped into two groups, the non- mineral elements and the mineral elements.
The 3 non-mineral elements are Carbon (C), Hydrogen (H), and Oxygen (0). These elements are obtained from water and from the air. They are utilized in the form of H20, water and C02, Carbon dioxide, in the process of photosynthesis. A deficiency of carbon dioxide, water or light can result in reduced growth but may produce no other visible symptoms.
The 13 mineral elements essential for normal plant growth are absorbed from the soil (potting media). These elements are divided into 3 groups; the primary nutrients, the secondary nutrients and the micronutrient.
Primary Nutrients are often called the fertilizer nutrients. They consist of Nitrogen (N), Phosphorus (P) and Potassium (K). The percentages reported on many commercial fertilizer containers refer to these nutrients. For example, 5-10-5 refers to the percent of N, P & K respectively in the product.
Secondary Nutrients are often deficient in soils but not nearly so often as the primary nutrients. These nutrients are: Calcium (Ca), Magnesium (Mg) & Sulfur (5). These nutrients are utilized in many processes which takes place in the plant and deficiencies seriously effect plant health.
Micronutrient are often called minor elements or trace elements. Many commercial products have one or more of these elements added. Micronutrient included; Mn - Manganese, Iron (Fe), Zinc (Zn), Copper (Cu), Boron (B), Molybdenum (Mo) and Chlorine (Cl).
Although essential in trace amounts these micronutrient in excess amounts can be toxic to plants, resulting in damage to the plants which is as serious or more serious than if they occurred in deficient amounts.
The availability and utilization of all plant nutrients are affected by water, temperature, light and pH.
In general water which is often called the universal solvent is necessary for dissolution and transport of nutrients throughout the plant system and for the completion of many of the continuous processes which go on within a plant. Temperature, within its tolerant range regulates the speed of reactions within a plant; initiating some reactions, speeding up reactions, slowing reaction and stopping some reactions. Light acts as a power source, also effecting reactions.
These 3 factors have been discussed in detail in a previous article in the AVSA Magazine (Vol. 50, No. 6, pp 12-14).

SOIL pH
The pH is a measure of the acidity or alkalinity of a substance; soil, water, etc. It is measured on a scale of from 0 -14. A pH of 7 is neutral. A pH above 7 is alkaline, like ammonia and a pH below 7 is acid, like vinegar.
When soil particles are saturated with ions of calcium, magnesium, potassium or sodium it has a high pH and is said to be basic or alkaline. These soils are often referred to as 'sweet' soils. When these ions are replaced with hydrogen ions the soil has a low pH and is said to be acid. These soils are often referred to as 'sour' soils. Leaching is a common cause of sour soils, as the ions creating a high pH are leached out and are replaced with H ions.
The pH of the media in which plants are grown can greatly affect their health. The pH plays an important role in determining which nutrients are available and in what amounts.
This is especially true in the case of K, C, Mg and S. Nutrients can either be tied up and unviable or released in toxic amounts, depending upon the pH.
The most favorable pH for nutrient uptake by plants ranges from 6.3 - 6.7. However, certain plants prefer more acid conditions while others thrive in higher alkaline conditions. African violets prefer a pH of 6.5-6.7.

PLANT NUTRITION
It is extremely difficult to induce nutrient deficiency symptoms in the African Violet. Research has shown that you may grow AV's in sterile soil for 18-24 mos. and still show no symptoms and a specific nutrient deficiency.
The African violet stores nutrients in its stems, petioles and leaves. This makes the plant a very well buffered system which is capable of 'borrowing' nutrients from one part of the plant to feed another part. This movement of nutrients and 'food' from one part of the plant to another is known as translocation. Seldom do symptoms of nutrient deficiencies appear in AV's while the deficiency occurs, however symptoms may occur much later, sometimes even after the problem has been corrected.

PLANT FOOD
When we fertilize African violets we put nutrients into the soil not plant food. African violets, like other plants, manufacture their own food. Nutrients are taken up by the roots and transported to the leaves. Here in the presence of light, using chlorophyll as a catalyst the nutrients are, through the process of photosynthesis, manufactured into amino acids, proteins, starches, sugar, carbohydrates and other products that plants use as food for plant growth and development. The products of photosynthesis, plant food, is then translocated to other areas of the plant where they are used by the plant or stored for future use.

FERTILIZATION
The soil or potting media in which plants grow serves as a pantry to accumulate and store nutrients for use by plants.
Of all of the essential nutrient elements only Nitrogen moves freely through the soil in the form of nitrates. Nitrogen is readily water soluble and can travel anywhere water can go. The other nutrients move little to none and are available only where plant roots reach them. The availability of nutrients in the soil is effected by temperature and soil pH.

PRIMARY NUTRIENTS
Nitrogen is abundantly available in nature but not in a form available to plants. Plants take up N in the form of nitrate salts and ammonium salts. These are converted into amino acids. Amino acids are combined to form proteins. Proteins are used to build plant tissues.
Nitrogen is often referred to as the 'foliage' nutrient. Fertilizing a plant deficient in N often results in a quick spurt of plant growth and an intensification of the green color as N is found in the chlorophyll molecule which gives a plant its green color.
A deficiency in N produces a condition called chlorosis. This is manifest in a loss of green color and the plants appear 'yellowed' or faded in color. The older leaves of a plant are the first affected because nitrogen, is translocated from older tissue to the younger actively growing tissue in the crown of a plant, leaving the older leaves deficient in the element.
Phosphorus is necessary for the utilization of energy in plant metabolism. It is necessary for the photosynthetic reaction which transforms the energy of light into carbohydrates. Phosphorus is essential for proper cell division. A deficiency in P results in reduced growth, thin stalks, small leaves and in severe deficiencies a stunned growth.
A deficiency in P often results in a reddish, purplish or brown color developing in plant leaves, especially along the leaf veins. Phosphorus is often referred to as the 'root' nutrient and is often applied to give the root system of young plants a boost.
Potassium is needed for protein and carbohydrate formulation. Potassium activates specific enzymes in a plant and regulates a number of chemical reactions necessary for
metabolism and growth. Potassium enhances the plant's ability to resist disease, cold temperature and other adverse conditions.
Plants deficient in K may show a dark green or blue- green color. Necrotic (dead) spots may occur on leaves or along the leaf margin. Plant growth is slowed under severe conditions. Blossom and seed formulation can be affected.
Symptoms will appear on the older leaves first as K is translocated from the older to the younger leaves.
Potassium is often referred to as the blossom or seed nutrient.

SECONDARY NUTRIENTS
Calcium is a component of the cell wall. It is necessary for cell division and elongation. Calcium acts as a cement to hold cell walls together and to hold one cell to another, building tissue.
As Ca is not translocated in appreciable amounts, symptoms are found first and most severely in the youngest leaves or crown of a plant. In severe deficiencies the growing part of plants may die. Plants deficient in Ca may have very poor root growth and damaged roots making them very susceptible to infection by bacteria and fungi.
A delicate balance in Ca is necessary in plants. A deficiency may create a toxicity of aluminum, boron, magnesium or potassium.
Magnesium is the key element in the chlorophyll molecule. It is often called the 'companion for phosphorous' as the two combine, facilitating their movement to their proper site in a plant for utilization. Magnesium is necessary for amino acid and fat synthesis. It also affects the viability of seeds.
Magnesium is readily translocated so symptoms will be found in the oldest leaves first. Deficient plants may show marginal chlorosis or chlorosis may appear as yellowish blotches on a leaf. Damaged leaves often show a yellow, orange or red pigmentation.
Sulfur is needed for the formation of new cells and chlorophyll. Sulfur is a component of certain amino acids which are found in most protein molecules.
Symptoms of S deficiency appear much like those of N. deficiency. Plants are chlorotic, spindly and grown poorly.

MICRONUTRIENT
Iron, although needed in very small amounts, is most essential to the health of plants. Iron functions as a catalyst in the formation of chlorophyll. It also acts as an oxygen carrier within the plant. In acid conditions iron is readily available but under alkaline conditions iron is held in a form not available to most plants.
Deficient plants show symptoms in the youngest tissue first, as iron is not readily translocated within the plant.
The first signs of a deficiency appears as a pale green color of the tissue between the leaf veins while the veins themselves remain green. Under severe deficiency entire leaves or even an entire plant will become yellow to almost white and the leaves may begin to die from the tip back.
Manganese activates enzymes involved in chlorophyll formation. Symptoms appear in the youngest leaves first and look much like iron deficiency with yellowing between the leaf veins. Sometimes brownish or blackish spots may occur along a leaf. The tissue in the spots may eventually die causing dead spots or streaks between leaf veins.
Zinc deficiency may cause conditions called 'little leaf' and 'rosette'. These conditions are the result of abnormal tissue growth. Leaves may become twisted and may have necrotic spots within the leaf.
Copper deficient plants often have leaves which are dark green in color and have their margins rolled up. Flowering and fruiting are curtailed.
Boron deficiency may be seen as damaged plant terminals. Tissue may appear hard, dry and brittle. Leaves may become distorted and the stems may be rough and cracked: Corky ridges or spots may appear on the plant stem.
Molybdenum deficiency will appear as a chlorosis between leaf veins. Leaves often appear mottled and their margins tend to curl or roll up.
Chlorine deficiencies apparently do not occur naturally. Only artificially induced deficiencies have been observed in plants.

When all of the above information has been digested you may want to go to the following key to plant-nutrient deficiencies and try your hand at identifying some plant- nutrient problems.
To use this key read 1 a and l b. Observe your problem plant and see which of the statements your plant fits. Then proceed to the next couplet of statements as directed by your choice (1 a or 1 b). Continue in this manner until a statement indicates the specific nutrient responsible for your set of plant symptoms.

Key to Plant-Nutrient Deficiencies
1a. Problem effect is general on entire plant, or are confined to older or lower leaves.....2
lb. Problem effect is localized on younger (terminal) leaves or plant.....6
2a. Problem effect general on entire plant; lower leaves shows yellowing and drying up (firing). Acute stages develop reddish to purplish color on lower leaves.....3
2b. Problem effects localized, appears as a loss of green color or mottling (chlorosis). May have dead (necrotic) spots on lower leaves. Very little if any drying-up of lower leaves.....4
3a. Color is faded, beginning with tips and margins of leaflets until all foliage becomes a lighter green than normal. Over time, the color may fade to pale yellow. In extreme cases margins of lower leaves become devoid of chlorophyll and curl, sometimes the leaves will 'fire-up'. Stunted growth and defoliation are characteristics of prolonged problems.....Nitrogen
3b. Foliage crinkly and dark green. In acute cases lower leaves become purplish. Plants stand stiffly erect. Leaflets, leaf margins and petioles take an upward direction. Leaflets are often cup-shaped. Leaves fail to expand to normal size. With acute deficiency growth is seriously affected.....Phosphorus
4a. Foliage darker green than normal. Leaf reduced in size. Internodes short. Plants have a humped-up, recurved appearance. Foliage becomes crinkled and veins become sunken. If prolonged the deficiency causes a slight yellowing of the leaves, then a bronzing develops from the tips of the plant. Plants become weakened and are more susceptible to disease organisms....Potassium
4b. Lower leaves lighter green than normal....5
5a. Chlorosis begins at tips and margin of leaves and progresses between the veins toward the center of the leaflet. If prolonged the tissue between the veins is filled with brown and dead areas. A definite bulging between veins and thickening of the leaves occurs. Effected leaves are brittle.....Magnesium
5b. The lower leaves are chlorotic and may develop grayish-brown to bronze irregular spots. This usually occurs first on leaves mid way into the center of the plant (midway up the stem) but will eventually affect most of the plant. Spots become sunken and the tissue eventually dies. Leaves may be small, thick. Spots may develop on leaf petioles and stem. Margins of leaves may curl upward....Zinc
6a. Unusual distortions at the tips or bases of young leaves making up the terminal bud. Terminal bud dies.....7
6b. Terminal bud remains alive. Chlorosis occurs on newer leaves. Chlorotic leaves may have spots of dead tissue. Veins light to dark green.....8
7. The young leaves of the terminal bud are lighter green than normal. The lighter color is more pronounced at the base of the leaves. Stem tip may die or have distorted growth. Leaves become thickened and curl upward. The leafstalks become brittle. Purple coloration may develop. Tips and margins of leaves (especially lower leaves) die prematurely.....Boron
8a. No pronounced general or uniform yellowing of the leaves.....9
8b. If chlorosis is present it is only slight and uniform through out the leaf.....10
9a. No pronounced chlorosis. Young leaves become limp and remain permanently wilted. Terminal leaves wilt as flower buds are being produced. Tips of leaves dry up and turn brown if deficiency persists.....Copper
9b. If leaves turn yellow it is a slight, general yellowing similar to nitrogen deficiency and leaves do not dry up. Growth is stunted. Some spotting of leaves occurs in advanced stages of deficiency.....Sulfur
10a. A slight uniform chlorosis on young leaves. Tips and margins of leaves remain green longest. Principle veins retain normal green color. Tissue gradually becomes pale yellow, almost white in extreme cases. No dead spots are found in leaves.....Iron
10b. Leaves become lighter green than normal between the leaf veins. This is most pronounced in the center of the plant. These areas may become yellow to white in severe cases and may develop small brown spots. The outer leaves are the last to be affected.....Manganese

Ammonium Toxicity~~11/1997 AVM

Ammonium Toxicity in African Violets
November/December 1997 African Violet Magazine, pgs 26-27
By Kent and Joyce Stork, Fremont, NE

     For some time we have received questions from individuals who have grown African violets successfully for years who now find that their plants will no longer grow as large as they once did. The plants described exhibited a number of symptoms related to foliage, but those symptoms were not consistent with the usual problems associated with violets. We consulted several sources who suggested the possibility of ammonium toxicity... a condition linked to the use of urea or ammonium based fertilizers.
     At this time, we can find no studies of ammonium toxicity specifically targeting African violets. The condition has been studied in florists’ gloxinias, and we thank Dr. Paul Nelson of North Carolina State University for sharing the results of his studies. He believes that ammonium toxicity does affect African violets. The symptoms he described closely resemble the problems violet growers brought to us.
     In florists' gloxinias, the ammonium toxicity causes lower leaves to curl downward stiffly (not limply). The lower leaves will exhibit irregular and highly unpredictable patterns of chlorosis (lighter green patches). The leaf margins of the most mature leaves will be burned, and as the toxicity becomes more pronounced the leaf burning shows up on younger and younger leaves until it affects the crown itself. The plant may die completely. The root structure will be reduced in size and will have an orange- brown tone that is distinctly different from normal root color.
     Dr. Nelson stated that other plants which have been studied show similar patterns, although some plant types react by leaf curl that goes upward rather than down. The lighter patches of color on the leaves are consistently unpredictable on all plants studied.
     Ammonium toxicity can have a phantom-like quality. The grower may not note any changes in growing methods or conditions when plants develop symptoms. Similarly, symptoms can disappear temporarily before returning. This can lead a grower to believe that a fungus, an unseen insect, or a virus has invaded. It can also cause a grower to believe that something caused an improvement, when in fact it had no effect at all.
     The extent of the reaction can vary in different hybrid strains of one plant type. Since many African violet growers have several hybrids in their collection, it would be
expected that the pattern of symptoms would vary from plant to plant.
     Several growers who attended the 1997 AVSA convention in Florida reported very similar symptoms. They were completely puzzled until they discovered that their standard fertilizer had changed. The company producing it was bought out by a larger corporation who changed the source of the nitrogen to a much cheaper ammonia form. This change was not advertised or promoted but it had serious consequences for growers.

WHAT CAUSES AMMONIUM TOXICITY?
     Ammonium toxicity is generally linked to the use of urea-based or ammonium fertilizers along with the absence or ineffectiveness of soil bacteria. The active soil bacteria can break ammonia down into a usable nitrate form as long as the soil temperature stays above 70 degrees Fahrenheit and as long as the soil pH is 6.0 or above. When the soil temperatures cool to below 70 degrees or the pH drops into a more acid range, the soil bacteria becomes progressively less active and less able to process ammonia. This results in a build-up of ammonia to toxic levels.
     Growers in areas that experience wide seasonal temperature swings might note the problem during the winter season, but not as much in the summer. Farmers in areas with very acid water conditions (often areas that receive lots of rain yearly) report very serious problems with ammonium toxicity in field crops. Violet growers can almost certainly predict similar problems where water supplies are acid. Similarly, if the soil or potting mix is very acid (peat moss can vary in pH in somewhat unpredictable ways), the ammonium toxicity can become a problem even if the water is neutral.

HOW TO CONTROL AND ELIMINATE AMMONIUM TOXICITY
     If you grow violets in an area with well-regulated room temperatures and do not have an acid water supply, you will probably not have to deal with this problem. There is no reason to panic if you see no symptoms.
     If you must deal with seasonally cool temperatures, be aware of how it may affect your violets. Do not use the lowest shelves in your growing area during the cool months since the coolest air is always closest to the floor.
     You may wish to use less fertilizer since the soil bacteria will be less efficient at processing the ammonia. If possible, warm the room so that soil temperature does not sink below 65 degrees Fahrenheit. Avoid using cold water to water plants or refill reservoirs. (Hot water is also not acceptable.. .do not use water warmer or cooler than ten degrees from the air temperature.)
     If you must deal with persistent acid pH in your soil or water, you would be wise to consider using one of the nitrate-based fertilizer products. Read the ingredients on the label. You will need a brand that lists at least one of its sources of nitrogen using the word 'nitrate'. These will not add the excess ammonia to your soil, and are not so dependent upon soil bacteria.
     If you suspect a problem, try leaching the soil. Pour an amount of water at least equal to the size of the pot into the top of the soil and allow it to run through the plant. It is best to do this when the plant is somewhat moist so that all salts will be dissolved and flushable. Do not allow plants to stand in the runaway water. If you note an orange tone to the water that is running out, you may assume that there is some sort of fertilizer build-up in the soil. Leaching should reduce the toxic build-up and may cause symptoms to go away. It is wise to leach until the runoff water is no longer colored.
     Once recognized, ammonium toxicity should be easy to control and avoid. Best of all, the treatment is inexpensive and safe. There's no reason to panic!