Phosphorus and the importance for your plant
Phosphorus plays an important role in how the plant breathes and in the energy supply of the plant. For example, phosphorus is very important for good root growth and youth growth and that with names in early spring. Phosphorus is also involved in the formation of proteins and DNA.
In nature, the element occurs in the form of phosphates: compounds of phosphorus with oxygen.
The growth and development of the crop stagnates if there is a lack of phosphate.
What is the proportion of Phosphorus in a plant
Phosphorus is what is called a macro nutrient, just like nitrogen and potassium. In practice, this means that a plant needs a relatively large amount of phosphorus for its development. If we look at the dry weight of a plant, this is 0.2% phosphorus. Depending on the crop, this average varies between 0.1 to 0.5%.
Vegetables and crops that have a phosphate need are for example vegetables from the open ground such as lettuce, spinach and endive that are often grown on sandy soils.
Due to a limited root package, these crops must absorb a relatively large amount of phosphate in a short time. Other crops with a high phosphate requirement are, for example, potatoes, onions and maize.
Promotion of root growth and youth growth
Phosphate, especially in the spring, has a stimulating role in root growth. It is precisely this period in which the root development of the plant gets underway and it is essential that this goes well, because this again has a direct effect on the absorption of water, nitrogen and nutrients. Phosphate is especially important for the young plant, because it absorbs a lot of phosphate, especially at this stage. It has now been shown that when the plant has only produced 25% of its dry matter, 75% of the total amount of phosphate has already been absorbed.
A rapid growth start generally results in good tuber formation, root formation and seed formation. This gives the plant sufficient stalks and leaves for photosynthesis and therefore good yielding power. Phosphate thus ensures a timely completion. Phosphate is extra important for crops that have problems with our climate.
Below you can see a number of examples of what a Phosphorus shortage can do with your crop
How do I recognize phosphate deficiency and phosphate excess?
Recognizing Phosphate Deficiency is not always easy.
Phosphate deficiency can be reflected in a discolouration of the leaf from dull, dark green to red purple.
Furthermore, leaf growth and the leaf surface remain limited by curling of the leaf, so that it appears to remain small.
In some cases, leaf tips can turn brown and die off.
If there is a lack of phosphate, the crop development will lag behind and the ripening will be delayed. The crop does not form a head (lettuce), forms fewer and smaller tubers or bulbs (potato, flower bulb), is less suitable (grain), produces less seed (grain, commercial crop) or forms less biomass (grass, maize). In grassland the botanical composition deteriorates, viewed from the feed of the cattle.
In case of phosphate deficiency, the leaves turn to dark green or even red purple, as the example below shows
How a Phosphorus develops shortage
- It starts with changing the green of the plant to a dark green or blue / green.
- The growth of the plant is inhibited in its entirety, both in height and in the development of plant shoots.
- If nothing is done, after a week or two to three dark purple / almost black spots appear in the older and medium-sized leaves.
The necrosis will spread to the stalks of the leaves. The leaves turn, curl considerably and then die off.
- Dead leaves are curled, shriveled and have a typical ocher / purple color and eventually the leaf will fall off.
- The plant will just as well go into flower, but the yield will be minimal.
- Reasons for shortages
Obviously, causes can be identified for the development of a shortage. In nature, phosphate is present in low concentrations. Plant cells ensure that the phosphorus can be absorbed through the entire root. Phosphorus deficiency is therefore not a frequent shortage. Deficits can, however, arise due to:
- A growth medium with a too high pH value (higher than pH 7). In those cases, the plant can not take Phosphorus because insoluble phosphorus compounds are formed.
- A too acidic soil or substrate or soil that is too rich in iron and zinc. As a result, the phosphor absorption capacity of the plant is impeded.
- The soil or substrate has become too hard so that Phosphate can no longer be taken up.
How to deal with a Phosphorus shortage
- Always use inorganic phosphates to ensure that they are easy to absorb
- Always mix inorganic phosphate fertilizers thoroughly
- Choose products with a guaranteed phosphate percentage on the packaging. This instead of alternative phosphate fertilizers such as Guano or manure.
- If the pH is too high, acidify the medium with a dilute solution of phosphoric acid
For treatment of Phosporus deficiencies we advise the use of CANNA Fosfor.