Nutrients

The Plumeria > Plumeria Care > Nutrients

Sixteen chemical elements are known to be important to a plant’s growth and survival. The sixteen chemical elements are divided into two main groups: non-mineral and mineral.

Potassium deficiency guide

Potassium deficiency guide

It is necessary for all activities having to do with water transport and the opening and closing of the stomata.

Potassium takes care of the strength and the quality of the plant and controls countless other processes such as the carbohydrate system. 

About potassium in short

What is it and what does it do?
Potassium takes care of the strength and the quality of the plant.
Controls countless other processes such as the carbohydrate system.
What can you see?
Dead edges on the leaves.
What can you do?
In case the EC in the substrate or potting mix is high, you can rinse it with clean water.
Add potassium yourself.

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Symptoms of a deficiency

Evaporation is reduced if there is a shortage of potassium. A consequence is that the temperature in the leaves will increase and the cells will burn. This occurs mostly on the edges of the leaves, where normally, evaporation is highest.

Development of a deficiency

  • Tips of the younger leaves show gray edges.
  • Leaves turn yellow from the edge in the direction of the veins and rusty colored dead spots appear in the leaves.
  • The tips of the leaves curl up radically and whole sections of the leaves begin to rot. The leaves keep on curling and ultimately fall off.
  • An extreme shortage produces meagre, unhealthy-looking plants with strongly reduced flowering.

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Reasons for a deficiency

  • Too little, or the wrong type of fertilizer.
  • Growing in potassium-fixed potting mixes.
  • An excess of sodium (kitchen salt) in the root environment, as sodium slows down potassium intake.

Solutions for a deficiency

  • In case the EC in the substrate or potting mix is high, you can rinse with water.
  • Add potassium yourself, either in inorganic form: Dissolve 5 – 10 grams of potassium nitrate in 2.5 gallons of water. In acidic potting mixes, you can add potassium bicarbonate or potassium hydroxide (5ml in 2.5 gallons of water).
  • Add potassium in organic form: Add a water solution of wood ash, chicken manure or slurry of manure (be careful not to burn the roots). Extracts of the grape family also contain a lot of potassium.

For your information

  • Potassium is absorbed quickly and easily by the plant. In a hydroponic system results get visible within several days. Potassium supplementation by leaf fertilization is not recommended.
  • Too much potassium will cause salt damage, calcium and magnesium deficiencies and acidification of the root environment!

Manganese deficiency guide

Manganese deficiency guide

Manganese is an essential trace element for all plants. Manganese acts as an activator for different enzyme reactions in the plant, for example in water-splitting during photosynthesis, the synthesis of amino acids and proteins and the build up of plant cell membranes and chloroplasts.

Manganese is generally taken up via the roots. Once inside the plant it is difficult to transport but not as difficult as calcium or iron for example. Silicon and molybdenum improve the transport possibilities for manganese in the plant.

About manganese in short

What is it and what does it do?
The metal manganese is an essential trace nutrient and acts as an activator for different enzyme reactions in the plant.
What can you see?
Yellow stripes appear between the leaf’s side veins.
What can you do?
Using products that contain trace elements (Tracemix).

Manganese deficiency guide

Symptoms of a deficiency

A manganese deficiency causes different physiological changes in the plant due to a decrease in protein production. Among others, this causes less nitrate to be fixed in the plant, which can lead to dangerously high levels of nitrate. Additionally, a lot of chemical reactions in plant cells slow down which may result in a build up of organic acids.

Development of a deficiency

The progression in chronological order:

  • Yellow stripes appear between the leaf’s side veins on the larger leaves at the top of the plant.
  • The yellowing between the side veins spreads further over the leaf and small, yellow/brown necrotic spots can form.
  • The final result is a small plant (-10%) with minimum fruit/flower production.

Manganese deficiency guide

Reasons for a deficiency

In practice, the most common reason is that the pH in the substrate is too high. Like iron, manganese is easily dissolved at a low pH value in the substrate. If the pH is too low, a risk of excess manganese may occur. At high pH values manganese precipitates into manganese oxide (MnO2) which cannot be taken up by the plant which can cause deficiency.

Solutions to resolve a deficiency

  • Check the medium’s pH when the first symptoms are noticed. High pH values mean that there is less manganese available for the plant. By lowering the pH of the nutrition (pH minus (down)) the medium’s pH can be lowered to 5.0 – 5.5.
  • Low substrate temperature can be the cause of reduced manganese absorption. If a deficiency is noticed, check that the substrate temperature is sufficiently high (68 – 77 oC) during the day.
  • Using products that contain trace elements may also help. A manganese deficiency is usually not a problem on its own. To facilitate manganese transportation in the plant, molybdenum is needed. Thus, the problem may well be a molybdenum deficiency. High levels of phosphorus may also result in a reduced availability of trace elements like zinc, copper and (of course) manganese. CANNA advises to use a mix of all needed trace elements. Trace elements can be given to the plant both in the feeding and by spraying the leaves. Spray the plant at the end of the day and spray daily with water after spraying to prevent burning.

Excess Manganese!

When there are high concentrations, manganese precipitates into manganese oxide (MnO2 or black manganese) which causes yellow-brown spots on the leaves. Initially, small spots will appear along the main and side veins of the leaf, following this, the spots will spread out from the veins. Excess manganese can be a result of a low pH in the substrate.

Florigen, the flowering hormone

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Many plants are ‘short-day’ plants, meaning that the plant starts to bloom once the days shorten. This is why horticulturists cut the amount of light from eighteen hours a day to twelve when they want to start the flowering phase. It’s actually a shame from the plant’s perspective: six fewer hours of light a day is six fewer hours of photosynthesis, and thus less energy for your plants in the form of sugars. There is also a substance that can get your plants blooming without your having to cut down on their light.

D. Kroeze, CANNA Research

 

What really happens when the days get shorter or when you cut back to 12 hours a day? When the light goes down to 12 hours or less, the leaves start to manufacture a substance that triggers flowering, which gets transported to all over the plant. This substance is called florigen or flowering hormone.

 

The term ‘short-day plant’ isn’t completely ac- curate. It’s not the fact that the days are getting shorter that makes the plant decide to flower, but that the nights are getting longer. Although the difference may seem trivial, it does explain why a night-time visit to your growing space will delay flowering for your plants. When you turn on the light, the plant’s night is over; it has now become too short to stimulate flowering. The plant has to start over counting the hours of darkness from zero.

 

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Other short-day plants include maize, chrysanthemum and chicory. There are also long-day and day-neutral plants.

Examples of long-day plants are spinach, let- tuce and barley. One day-neutral plant is tobacco.

 

Julius and the discovery of florigen

 

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In 1865 a German scientist named Julius von Sachs discovered that when he transferred sap from a flowering plant to a non-flowering plant, the non-flowering plant started to flower as well. This even happened when the two plants were from different species. Unfortunately, no matter what he tried, he never succeeded in isolating the substance responsible for flowering.

 

Many after him also have tried in vain to isolate florigen, which made it into something of a mystery. It got to a point where the question was not only what the substance actually was, but whether it even existed – at least until a few years ago. Now, one of the greatest mysteries of plant biology seems to have been solved.

 

Julius von Sachs (pictured top-left) made other major discoveries besides the existence of florigen. For example, he discovered chloroplasts and the fact that they produce sugar. He also discovered that glucose is stored in the form of starch in granules. In other words, the mystery of florigen was as old as much of the fundamental knowledge in plant biology.

 

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Chloroplasts

The information superhighway

 

During the quest for florigen, it became clear that the sap flowing through the phloem (vessels) of the plant contained more than water and the sugars produced by photosynthesis in the leaves. As it turned out, many semiochemicals (substances that send signals to the plant) are dissolved in the phloem sap. These are mostly small molecules in very low concentrations. The phloem transports information from one place in the plant to another, including the signal to flower, in the form of these substances. This is why the phloem is also known as ‘the information superhighway.

 

Actually, florigen had been found a few years earlier, but its function had not been discovered until recently. You may wonder why it took so long to find florigen. Here’s the reason: Once the night length has crossed a certain threshold, the leaves produce a signal to start manufacturing florigen. The substance is only made in the growing points of the plant; a different substance, which reacts with the substance from the leaves, occurs only in the cells of growing points. The two substances together are actually the real florigen.

 

In addition, but no less important, is the fact that these are very tiny molecules, which were only discovered in the last few years. Until then, laboratory equipment was simply not advanced enough.

 

articles-florigen_text_4The phloem (red) is the living vascular tissue of the plant, through which mainly sugars and water are transported from the top down. Besides the phloem there is also xylem (pink), dead tissue that transports nutrients and water up from the roots.

 

The future is smiling?

 

After more than 140 years, the quest for florigen is finally over. A great mystery has been solved. This is fine for science, but what does it mean for your average person? The answer is easy: a lot! Manipulating florigen has enormous potential.
Its discovery will bring about a revolution, in particular for conventional agriculture. Greenhouse horticulture will see increased yields from more hours of light. Scientists are especially thinking about growing crops in places where it was previously impossible, such as growing some tropical crops in Northern Europe. But a lot may change for tropical regions as well. The shortened growth time will mean that more crops can be grown in one growing season than is possible now.

 

Besides this immediate effect on food production, there will also be a revolution for seed companies. For example, fruit trees could be made to flower in the first year and so can be crossed with each other within months instead of the usual years breeders spend waiting for the first flowers.
For hobbyists, it will of course be the higher yields that make the applications of florigen most interesting.

 

We should not get carried away. It will be many years before we can make practical use of florigen. One thing is certain: its discovery will change agriculture and plant breeding forever.

 

From Gentech to hunger

 

Why the question mark after ‘the future is smiling?’ because florigen can’t simply be added to a plant. Biotechnology companies will have to provide crops with the information they need to make florigen themselves independent of day length, using genetic modification. Since this gene will initially be put into one or two crop varieties, these few varieties will quickly drive out local varieties (genetic erosion).

 

This will mainly be a problem for developing countries where agricultural production is now less than optimum, and where these new crops could greatly improve food production. At first, these monocultures of just a few varieties on such a huge scale will produce lots of food, but in the long term will lead to enormous problems from diseases. And what are you going to eat when the food crops are gone?

That’s the next challenge!

The Role of Potassium (K)

Potassium is a chemical element with symbol K (derived from Neo-Latin, kalium) and atomic number 19. It was first isolated from potash, the ashes of plants, from which its name derives.

Phosphorus (P) Fallacies

A brief review of the macronutrients included in complete fertilizers: nitrogen (N) is involved in photosynthesis as part of the chlorophyll molecule and promotes vegetative growth; phosphorus (P) supports the transfer of energy throughout the plant for root development and flowering; and potassium (K) is an important part of plant metabolism, strengthening its overall health.

The History and Science of Epsom Salts

The History and Science of Epsom Salts

This natural mineral, discovered in the well water of Epsom, England, has been used for hundreds of years, not only to fertilize plants but to treat a range of human and animal ailments. Who hasn’t soaked sore feet in it at least once?

Chemically, Epsom salts are hydrated magnesium sulfate (about 10 percent magnesium and 13 percent sulfur).

Magnesium is critical for seed germination and the production of chlorophyll, fruit, and nuts. Magnesium helps strengthen cell walls and improves plants’ uptake of nitrogen, phosphorus, and sulfur.

Sulfur, a key element in plant growth, is critical to the production of vitamins, amino acids (therefore protein), and enzymes. It’s also the compound that gives vegetables such as broccoli and onions their flavors. Sulfur is seldom deficient in garden soils in North America because acid rain and commonly used animal manures contain sulfur, as do chemical fertilizers such as ammonium sulfate.

The causes and effects of magnesium deficiencies vary. Vegetables such as beans, peas, lettuce, and spinach can grow and produce good yields in soils with low magnesium levels, but plants such as tomatoes, peppers, and roses need high levels of magnesium for optimal growth. However, plants may not show the effects of magnesium deficiency until it’s severe. Some common deficiency symptoms are yellowing of the leaves between the veins, leaf curling, stunted growth, and lack of sweetness in the fruit.

Magnesium tends to be lacking in old, weathered soils with low pH, notably in the Southeast and Pacific Northwest. Soils with a pH above 7 and soils high in calcium and potassium also generally have low magnesium levels. Calcium and potassium compete with magnesium for uptake by plant roots, and magnesium often loses. Sometimes, a soil test will show adequate magnesium levels in soil, but a plant grown in that soil may still be deficient because of that competition.

Gardeners add magnesium when they apply dolomitic lime to raise the soil’s pH. However, this product (46 percent calcium carbonate, 38 percent magnesium carbonate) breaks down slowly, and the calcium can interfere with magnesium uptake. For soils with a pH above 7, many gardeners use Sul-Po-Mag (22 percent sulfur, 22 percent potassium, 11 percent magnesium) to increase magnesium. Although dolomitic lime and Sul-Po-Mag are inexpensive ways to add magnesium, Epsom salts’ advantage over them is their high solubility.

When diluted with water, and especially when applied as a foliar spray, Epsom salts can be taken up quickly by plants. Epsom salts’ magnesium content, high solubility, and ease of application as a foliar spray are the main reasons for the positive results many gardeners see in their plants.

Too Much Nitrogen in Plumeria

Nitrogen is a key player in producing chlorophyll; this pigment absorbs sunlight for basic photosynthesis needs. Gardeners must make sure that nitrogen, one of the three macronutrients in soil, is available for root uptake by choosing the right fertilizer. Saturating a garden with high nitrogen levels, however, does not improve plant growth. In fact, it can actually harm a garden more than leaving it to its natural elemental state. Too much nitrogen in plants is apparent both above and below the topsoil.