Control Methods for Boxwood (Buxus sinica var. parvifolia) Wilt Disease

Boxwood wilt disease has been a common disease of boxwood in recent years. It is characterized by rapid onset, fast spread, and a major impact on landscaping effects. Although this disease is stubborn, if correct measures are taken, targeting the pathogen and applying multiple approaches simultaneously, satisfactory control results can still be achieved.

Symptoms: Initially, only the upper three leaves of a single branch of an affected boxwood turn green and dry out from water loss, and then the entire branch and three branches of the whole plant show green wilt and water-loss symptoms. In the late stage of the disease, the three leaves turn yellow-white, and severe infection can lead to plant death.

Disease occurrence pattern: The pathogen is Fusarium present in the soil. The fungus mostly invades through root wounds, but can also directly invade the plant. The disease generally begins in mid-May, with the peak incidence in July and August. Some plants take no more than a week from onset to death.

Control methods: 1. Strengthen epidemic inspection and strictly prevent diseased plants from entering non-epidemic areas; 2. Strengthen water and fertilizer management to improve plant disease resistance. The cultivation site should remain moist but not waterlogged; 3. If diseased plants are found, they should be promptly removed and burned. The cultivation site can be irrigated and disinfected with 75% chlorothalonil wettable powder at 600 times dilution, using 5 to 6 kg per square meter, applied three times consecutively with an interval of 5 days each time; sulfur powder 0.5 kg can also be thoroughly mixed with the soil for disinfection; 4. For unaffected plants, 50% carbendazim at 500 times dilution or 65% mancozeb at 000 times dilution can be used for alternating spraying to control the disease, spraying 2 to 3 times.