Oranges, lemons, grapefruits, tangerines… Today in GESTIRIEGO it is time to talk about the cultivation of citrus fruits. Its fruits have multiple benefits for health and are loaded with flavor, which makes them a very interesting complement in the kitchen.
From a nutritional point of view, citrus fruits are characterized by being a source of vitamin C, folic acid and vitamin A. In addition, they stand out for their antioxidant properties, take care of cholesterol, favour the absorption of iron and combat constipation.
Spain is a leader in citrus exports with very strong competition and a world supply that has not stopped growing.
In terms of citrus-growing area, Spain has a total of 307,560 hectares, 1.8% of the total cultivated land. As far as production is concerned, in 2018 our country produced more than 7.5 million tonnes of citrus.
Citrus fruits are a very important crop at an economic and social level in our country. Therefore, it is important to know the needs and care that these plants require.
Citrus cultivation and its origins
The word citrus comes from the Latin citrus (lemon). It is used in scientific Latin to refer to the family of sour fruit plants such as lemon or orange.
The genus citrus, whose common term is citrus, refers to species of large shrubs or perennial trees of the Rutaceae family whose fruits have a high content of vitamin C and citric acid, which gives them that characteristic acidic taste.
They come from the tropical and subtropical areas of Asia and the Malayan archipelago, and from there they have spread to all the regions of the world where they are grown today.
The origin of the citrus fruits cultivated, hybridized and selected is difficult to specify. However, almost all of them derive from three wild species: Citrus máxima (grapefruit tree), Citrus medica (citron) and Citrus reticulata (mandarin).
There are different types of Citrus trees that, in addition, usually form hybrids, which explains the great variety of fruits that can be found. Below we show the most common citrus fruits:
Main soil and climate requirements of citrus cultivation
According to data from the Ministry of Agriculture, Fisheries and Food (MAPA), climate is a very important factor to take into account when choosing to plant citrus crops in a given region.
The resistance of plants to low temperatures depends largely on their vegetative state; plants in budding state suffer more damage than plants in a resting state. In addition, the different parts of the plant vary in their reaction; flowers and small fruits are very sensitive, being damaged with temperatures of -1ºC.
Fully developed fruit can spoil at temperatures of -3°C. Perhaps the most important factor in all cases is the duration of the frost; that is, the time the plants can withstand temperatures below 0ºC. If these are of short duration they do not manage to produce appreciable damage. On the other hand, if they are maintained for a longer period, they cause serious damage. Therefore, places or areas affected by heavy frosts should be avoided when planting citrus fruits.
A sudden rise in temperature can cause the death of leaves and a decrease in the quality of the fruit. The optimum temperature range for the development of citrus fruits is between 23ºC and 34ºC.
Relative humidity is generally between 60 and 80%, which is considered a good level for citrus cultivation.
As far as rainfall is concerned, it is considered that citrus fruits need around 1200 mm per year, with good distribution also being essential (around 100 mm per month).
With regard to the right soil, it is better to plant citrus fruits in virgin soil. In areas where there have already been citrus fruits (especially if they have been abandoned or decayed), pieces of roots remain in the soil which then decompose, facilitating the proliferation of harmful fungi and nematodes.
Physical and chemical properties must also be taken into account. Citrus roots are very demanding in terms of oxygen and soils that allow good aeration must be chosen. They require soils that are naturally rich in nutrients.
Water requirements of citrus cultivation
It is precisely the climatic conditions (temperature, humidity, radiation and wind speed) and plant characteristics (leaf area, aerodynamic characteristics and stomata regulation of the leaves) that determine the water needs of the citrus crop.
Generally, the water needs of crops are estimated from the sum of soil evaporation and plant transpiration, a process known as evapotranspiration.
Citrus fruits are perennial plants that require large amounts of water to carry out their physiological functions. A water stress of the trees affects negatively the vegetative growth, the production and the quality of the citrus fruits.
When the soil moisture is insufficient to meet the water needs of the trees, it is necessary to supply additional amounts of water through irrigation techniques. And the most efficient technique is drip irrigation.
The efficiency of drip irrigation is due to the fact that it supplies water drop by drop constantly and periodically
Did you know that the drip irrigation system is the most suitable for citrus crops?
Currently, the most efficient irrigation system is drip irrigation, so its use has spread widely to different crops, including fruit trees. Water savings are significant, since only about 33% to 50% of the surface of the plot is wetted, that is, only in rows where the plants are established. If we talk about underground irrigation, the savings are even greater, because both run-off and surface evaporation are eliminated.
The use of this irrigation technique in citrus fruits has started to take great momentum due to its high efficiency, besides allowing a fast, efficient and uniform injection of fertilizers through the technique of fertigation, directly in the root zone. Next, we explain other advantages of drip irrigation in the citrus crop:
- Increased irrigation efficiency: Because of the fact that the emitters are buried, we avoid water being on the surface of the soil exposed to evaporation, that is, better water distribution, less runoff, greater uniformity. In addition, it is closer to the roots that absorb the water needed for plant growth.
- Better assimilation of nutrients: In the case of elements that are not very mobile, such as phosphorus or potassium, we make them available to the root. There are also lower levels of nutrient leaching.
- Decrease in the presence of weeds. The soil surface is kept dry and therefore the germination of weed seeds is considerably reduced. It has a direct impact on saving herbicides and labour.
- Decrease in fungal diseases. As in the previous case, by keeping the soil surface drier than with the use of surface emitters, the proliferation of these organisms is avoided.
- It makes soil tillage easier. In crops that require weeding or superficial tilling of the soil, we eliminate the obstacle of the superficial drip line.
- Longer life for pipes and installations. As they are buried, the pipes are much more protected from aggressions.
In GESTIRIEGO we can help you and give you the necessary advice to install the most suitable irrigation system for your crop, but also, help you to convert or modernize your current irrigation system.