Importance of carnations and market demands
Flowers represent a fundamental part of the international cut flower trade. Countries like Spain and Italy have historically stood out as major producers in Europe, while other countries like Colombia have managed to position themselves as leaders in global trade.
The market imposes a constant demand for quality flowers, varietal innovation, and cost reduction. This requires growers to invest in production methods. genetic improvement, incorporate new cultivation techniques and be alert to the appearance of Emerging pathologies and resistance to phytosanitary products.
Main pests that affect carnations
- Thrips (Frankliniella occidentalis)Thrips are tiny insects that hide in flower buds and damage the petals from within, causing spots and deformations.
- Red spider (Tetranychus urticae and T. cinnabarinus): Mites that, when feeding, generate yellowish spots on leaves, weakening and in severe cases defoliation.
- Caterpillars (European and South African Tortrix, Cacoecimorpha pronubana and Epichoristodes acerbella): The larvae of these lepidopterans roll up leaves and attack buds, becoming difficult to combat.
- Aphids (Myzus persicae): They feed on plant juices and promote the transmission of viruses and the formation of honeydew that promotes fungi such as sooty mold.
- Leafminers (Psedonapomyza dianthicola): Larvae that form galleries in the leaves, rapidly weakening the plant.
The control of these pests can be done by integrated management (combined use of biological, cultural and chemical methods), highlighting the use of natural enemies such as Phytoseiulus persimilis (red spider predatory mites), Amblyseius swirskii, Orius laevigatus, and the use of chromatic traps.
Most important diseases of carnations
- Fusarium wilt (Fusarium oxysporum f.sp. dianthi): Soil fungus considered the most serious disease in clavel, provokes withering, root rot, and plant death. There is no absolute chemical treatment; prevention is based on the use of sterile substrate, healthy plant material, and crop rotation.
- Rust (Uromyces caryophyllinus): It manifests as brown pustules on leaves and stems, diminishing the decorative value of the plant and spreading rapidly in high humidity. Control includes removing diseased parts, reducing humidity, and preventive applications of fungicides such as chlorthalonil, mancozeb, azoxystrobin and myclobutanil.
- Leaf spot (Pseudomonas andropogonis): Bacterium that produces necrosis and circular lesions with reddish edges on leaves; its spread is facilitated by sprinkler irrigation.
- Leaf fungi (Alternaria dianthi, A. dianthicola, Botrytis cinerea, Heterosporium echinulatum): They cause staining, necrosis, and defoliation. They are controlled by reducing moisture, maintaining healthy material, and using preventative treatments with biological compounds or products such as iprodione and potassium carbonate.
It is important to highlight the presence of other diseases caused by viruses and viroids, such as Carnation mosaic virus (CarMV), Carnation marbling virus (CRSV), and viroid-mediated weakening, which are spread mainly by cuttings, undisinfected pruning, or insect vectors.
Cultural factors and physiopathies that favor pests and diseases
- Environmental conditions: High relative humidity levels (over 70%), low air movement and excessive irrigation significantly increase the risk of fungal diseases.
- Poor drainage and waterlogging: They promote the appearance of neck and root diseases, such as Rhizoctonia solani y Fusarium.
- Excess nitrogen fertilizer: Increases susceptibility to rust and other fungal diseases.
- Lack of luminosity: It causes weak stems, excessive foliage development and reduced overall resistance.
Proper environmental management, choosing aerated substrates, using healthy seeds/cuttings, and maintaining tool hygiene are key pillars for maintaining a healthy crop.
Integrated prevention and control methods
Nowadays, phytosanitary regulations limit the indiscriminate use of certain chemical products, which forces us to adopt strategies for integrated management including:
- Varietal selection: Use of more disease-resistant varieties.
- Biological methods: Selective release of beneficial insects as predators of thrips, aphids and mites.
- Post-harvest care: Use of preservative solutions and cold storage to prolong the life of the flower and prevent the development of fungi.
- Rational intake of nutrients: Avoid imbalances in fertilization, especially in the use of nitrogen.
- Rotation and disinfection: Cleaning floors, tools, and changing planting locations periodically.
As support, organic phytosanitary products and natural solutions (plant extracts, beneficial microorganisms such as Trichoderma harzianum for the control of fusarium and beauveria bassiana for thrips treatment). For more in-depth information on managing specific pests and diseases, see our section on pest control plants.
The reputation of the flower as easy to grow doesn't mean it's problem-free. Rapid intervention in response to abnormal symptoms, along with a comprehensive preventive strategy, prevents most serious situations that can jeopardize the viability of the crop or as a home decoration. Studying the physiology and life cycles of pathogens and knowing the management practices adapted to each area are the best tools for those who want to enjoy this flower. healthy, resistant and colorful carnations.
