Are you curious about the knowledge of flower clinics regarding flowers, such as how to prevent and control nematode diseases in flowers? Let's take a look together.
Flowers play an important role in beautifying the environment and developing the economy, with the types and area of cultivation increasing year by year, but the damage caused by nematodes is also becoming more severe.
Symptoms: Plant nematodes mainly damage flowers from families such as Asteraceae, Primulaceae, Rosaceae, Impatiens, and Begoniaceae. This disease affects roots, leaves, flower buds, and flowers. There are mainly two types of symptoms:
1. Above-ground symptoms: Symptoms caused by slip nematodes include angular necrotic spots on leaves, malformed buds, and dwarfing of the entire plant, damaging chrysanthemums, dahlias, early chrysanthemums, etc., with nematodes invading leaves and buds. Stem nematodes cause leaf deformation, dwarfing of flowers, and even failure to bloom, damaging tulips, hyacinths, gladioli, narcissus, etc., with nematodes invading bulbs and tubers.
2. Root symptoms: Roots become swollen and deformed like chicken claws, with root tissue turning black and rotting, such as damage to peonies, Chinese peonies, Begonias, roses, impatiens, cyclamen, etc., with nematodes invading plant roots. Some roots also develop ball-like root knots.
Occurrence characteristics: Nematodes have different generations in different regions and different flowers, generally ranging from a few to more than ten generations, overwintering in eggs, larvae, and adults in diseased plants and soil. The nematodes are spread through rainwater, irrigation, tools, soil, seedlings, bulbs, etc. In the following spring, when the soil temperature rises, the eggs hatch, and the larvae invade through stomata, lenticels, wounds, etc. Soil temperatures between 15-30°C are favorable for the development and infection of root-knot nematodes and stem nematodes. Under suitable conditions, one generation can be completed in 20-30 days. Generally, sandy soil is more severely affected. Some nematodes can also transmit viruses. From spring to autumn, the population size shows an increasing trend, and the population structure is diversified.
Comprehensive control measures
1. Strengthen quarantine: New flower varieties must be quarantined and approved by the inspection agency before being isolated and trial planted in designated locations.
2. Use healthy seedlings without disease: Establish a disease-free seedling raising area in disease-free land and use healthy seedlings for planting.
3. Keep the flower field and nursery clean: Remove dead flowers and weeds and trees inside and outside the nursery.
4. Use clean water: Use groundwater for irrigation, improve drainage facilities, and prevent external polluted water from flowing into the flower field and nursery.
5. Pay attention to the disinfection of seedlings and growing media.
(1) Seedling disinfection: Before potting, the roots can be soaked in a 3% carbosulfan granule (furadan) solution diluted 30 times for 30 minutes (carbosulfan is highly toxic, so safety precautions must be taken when using it).
(2) Growing media disinfection: Twenty days before potting, place the growing media in a boiling pot, add water to completely submerge it, then boil until the water dries up. After removing it, apply a 35% carbendazim emulsion diluted 50 times, cover with black plastic film for fumigation. Before using the growing media, uncover the black film and ventilate for 7-10 days.
6. Disinfect finished flowers: Every 30 days, apply 3% milbemycin granules (clomazone) for control, with a dosage of 6-9 grams per square meter, applied in a triangular pattern.
7. Ground disinfection with black plastic film: Before planting, apply 3-4 kilograms of 35% nematode control emulsion per mu for ground disinfection, then cover with black plastic film for 3-5 months, which has a relatively obvious control effect.
8. Use a rolling cultivation frame: Adopting an off-ground and hardened planting method can effectively prevent the spread and occurrence of nematodes and other diseases.
The above is a detailed explanation of how to prevent and control nematode diseases in flowers, for reference and suggestion only!