How to prevent and control root rot in clivia? Master these methods

It occurs in all clivia growing areas, damaging the roots and causing rot, even leading to the death of the whole plant.

Symptoms: The plant is affected starting from the roots. Brown necrotic spots appear on the fleshy roots and gradually expand, causing the cortex of the entire root to rot. When the stem is pulled out of the soil, the rotted roots mostly remain in the soil. The above-ground part shows dull leaves that rapidly turn yellow and wilt.

Disease pattern: The pathogen is a fungus, Fusarium. The pathogen attaches to diseased residual tissue and spreads in the soil. When clivia is poorly managed, such as lack of fertilizer, especially extreme nutrient deficiency after flowering, poor drainage in the nursery or flower pot, damp and waterlogged conditions; or drought and water shortage during the growing period, freezing damage, insect damage, and weakened growth, it is susceptible to this disease. The disease is severe when the soil remains highly wet for a long time, the environment is stuffy and hot, the air is not circulating, and the humidity is high.

Prevention and control methods:

(1) Strengthen cultivation management. The optimal growing temperature for clivia is 15-25°C. It has poor cold tolerance and is also not strongly heat tolerant; at high summer temperatures it enters a semi-dormant state. In winter it needs to go through a semi-dormant period, that is, the temperature should be kept at 8-10°C. Below 5°C it is prone to freezing damage, and above 15°C the dormancy is broken, which is unfavorable for flowering. It likes semi-shade and avoids exposure to scorching sun. It likes loose, fertile soil rich in humus. It is slightly drought tolerant and not tolerant of waterlogging. Plant it in deep pots. Spring and autumn are its growing seasons. The potting soil can be slightly moist, but do not let it become too wet or even waterlogged. Apply liquid fertilizer once every 20-30 days. In midsummer and after the beginning of winter, suspend topdressing, and the potting soil should also be on the dry side. Apply phosphorus fertilizer once 20 days before flowering. In spring, summer, and autumn, attention should be paid to ventilation, and in summer, protect it from scorching sun. In winter, place it indoors in a sunny spot, and the room temperature must not be lower than 5°C. In summer, prevent rain from causing the heart to rot. During usual watering, avoid spraying from above.

(2) When diseased plants are found, dig them out promptly, rinse with clean water, cut off the diseased fleshy roots, soak them in a 200-fold dilution of 50% carbendazim wettable powder for 3 minutes to sterilize, then dry them in the air for 2-3 days; discard the original potting soil, disinfect the old pot (by burning it with fire or soaking it in 1% copper sulfate solution for 24 hours), or use a new pot with new soil to replant.