A large group of trees and shrubs whose fruits are widely consumed is citrus. One of the reasons why they are so widely consumed is their high content of vitamin C and citric acid, which is the reason for the typical flavor of their fruits. These species are also widely cultivated as fruit trees in orchards and gardens. However, they also face significant pests and diseases.
Popularly known as citrus fruits, the genus Citrus includes large species of shrubs and perennial trees with a height of between 5 and 15 meters, which are within the family of Rutáceas. Citrus fruits are highly appreciated species for their fruits, which have high content of vitamin C and citric acid (which gives them their typical acid flavor).
Regarding the origin of citrus fruits , these are native to tropical and subtropical Asia and include three species and a large number of hybrids, many of which are among the most commercialized species in the world, such as orange, lime, lemon, grapefruit or tangerine.
Citrus pests and their control
Among the main pests that affect citrus are:
The fruit fly
The fruit fly ( Ceratitis capitata ) is a species of dipteran native to Africa, which affects numerous trees and shrubs, among which there are several species of citrus. This fly lays its eggs on the fruits and causes them to rot prematurely, as their larvae consume them. It is possible to control this pest by some chemoattractant trapping methods, biological methods such as predators and parasites or chemical methods.
It is a species of mealybug and is also known as serpeta or louse. It forms like a limpet that adheres to the branches, fruits or leaves of the plant. There are several species of this louse and they can be fought by pruning those affected areas, using chromic or soap traps or using two parasitoid wasps, Camperiella bifasciata and Aphytis melinus .
It is a species of lepidopteran that affects, above all, small citrus trees, easily expanding between their leaves digging galleries. For its control there are biological methods such as the use of diatomaceous earth and chemical methods such as the use of potassium soap, Neem extract or the Bt insecticide.
It is a small bug that damages the leaves of different citrus fruits by feeding on their sap and generates deformations, causing them to acquire a rough appearance. Its treatment is difficult because it affects the lower parts. The first thing is to remove the affected leaves and apply different treatments.
Among these, the best known is a mealybug with a large whitish body and a kind of channels. Due to its rapid spread throughout the plant, this mealybug is able to quickly dry it out. For its treatment the first thing is to prune the affected parts. If we do not want to use pesticides, we can use diluted potassium soap or biological methods, which are very effective.
Citrus diseases and their control
The main diseases that affect citrus fruits and are caused by microorganisms, fungi and other factors, as well as their control, prevention and treatment, are:
A fungal growth occurs around the trunk of the tree, forming a kind of gum. This fungus can appear due to an excess of stagnant water around the trunk. There are fungicide treatments to apply to the affected area.
It is produced by the growth of a fungus, which develops due to sugary liquids. It can also be accompanied by other pests such as aphids or mealybugs. These infections are fought with milk or horsetail fungicides.
The brown rot is produced by a group of fungi that damage the roots and produce gums and cankers on the trunk. In addition, they weaken the trees and cause their leaves to fall. Its ecological treatment is difficult, since a systemic fungicide that penetrates the roots is necessary.
The plant is unable to capture the iron it needs from the soil, so the leaves turn yellow with green veins. It can be solved by providing fertilizers that reduce the pH of the soil, iron chelators or replacing the substrates with one for acidophilic plants.
Virus transmitted by aphids to bitter orange. This virus causes premature flowering, chlorosis, and leaf drop. It is very dangerous and kills the plant in a matter of weeks. There is no cure.
Penicillium produces the so-called gray mold of fruits and can be treated by using copper sulfate .