In this post we are going to know the nutritional requirements requested by citrus fruits in general, that is, the fertilizer of citrus fruits . We will provide a little information regarding climatic needs, we will know the effect of the deficiencies of each element and we will provide data on fertilizer doses.
CLIMATIC REQUIREMENTS OF CITRUS
The climate is a critical factor for citrus and can be limiting for its cultivation. The most important climatic variable in determining vegetative development, flowering, fruit setting and fruit quality is temperature. A temperature range between 25º C and 30º C is considered optimal for photosynthetic activity, higher temperatures, above 35º C reduce it.
The water requirements of citrus fruits are estimated at 5,000 – 8,000 m 3 ha / year, equivalent to a rainfall of around 500 – 800 mm. Although everything will depend on the area where we are.
NUTRITIONAL DEFICIENCIES IN CITRUS
It is characterized by a reduction in the size of the leaves and a general yellowing of the leaves, more pronounced on the veins.
Its detection in the field is difficult, in addition to not being a common lack in citrus. In trees with this deficiency they have less intense flowering, larger fruit size but with less juice.
They are not very detectable in the field, so they require laboratory detection. The old leaves are the main affected, wrinkling and curling, and the fruits develop smaller.
Magnesium deficiency: it is detected by a yellowing of the leaves, mainly in the old ones that does not reach the entire surface, leaving a “V” filled in green. With magnesium deficiencies, the fruits are smaller and lower in sugars.
With this deficiency, the citrus reduces its development, loses vigor and the tips of the branches dry out, and defoliation may appear.
It shows a behavior similar to nitrogen deficiency. The leaves show a pale green color and the tips of the leaves are curved.
Lack of iron
It is manifested by the yellow tones that young leaves acquire, except for their nerves that do not change color.
It is manifested by the appearance of irregularly shaped yellow lagoons distributed on the young leaves, but without altering their size or shape. This deficiency usually coexists with Zn deficiencies.
They do not usually appear due to the antifungal applications applied to combat such diseases.
It is not very specific, appearing translucent spots, yellowing of the veins, deformation of leaves and a tan color in young leaves.
Presents deficiencies in citrus fruits similar to nitrogen deficiencies.
CITRUS FERTILIZER DEPENDING ON THE MAXIMUM DEVELOPMENT OF THE TREES
Annual maximum dose ( grams per tree ) standard for citrus fertilizer. It is based on the fact that we have a tree farm in maximum development, with each plantation framework, and in an informative and generic way. Each variety may have other needs, although similar.
Interpreting these data is relatively simple, since we are talking about quantities (grams per year) and fertilizers. However, you must have the fertilizer units (as we have been doing on the blog), to know the total amount to add.
For the previous example, if we go to the cultivation of the orange tree and the dose of nitrogen applied in fertigation (drip, for example), we see that for a 6 × 4 plantation frame it is necessary to apply 577 grams per tree (240 kg / ha ).
This means that, in the case of ammonium nitrate , 1.67 kg per tree of said fertilizer should be applied, at 34.5% nitrogen richness, or what is the same, 695 kg / ha.
Now, the next problem will be to correctly distribute the fertilizer during cultivation, since it is a pattern that will define the success or failure of the cultivation.
Monthly distribution of nutrients over the total dose (%), in seedlings
Monthly distribution of nutrients on the total dose in early varieties (%)
Monthly distribution of nutrients on the total dose in late varieties (%)
As you can see, the sum in a full year of all the% must give 100. Now taking the previous table and this we can know the amount to add of each element, according to the time we are.
We return to the example of ammonium nitrate . If in a year we have to add 240 kg / ha of Nitrogen, for the month of June (20%), we have to pay with 48 kg of Nitrogen. This, with the ammonium nitrate fertilizer units (34.5%), gives us an exact amount of 139 kg in that month.
As in June it is already getting hot, we will surely be watering almost every day or every 2 days (this will depend on the farmer, the available water and the climate where it is).
Let’s say that you water every day (30 irrigations a month), the amount to be added in each irrigation of ammonium nitrate will be 4.6 kg. Now, everything will depend on the state of the crop, the variety, etc. Although basically, this would be the way to make a fertilizer plan for citrus fruits.
STANDARD ANNUAL DOSE (Y = G / TREE) AS A FUNCTION OF CROWN DIAMETER (X = CM)
If you want to perform the citrus fertilizer calculations in Excel, automatically, you can do it by clicking on the following image