What are the control methods for stem rot in dragon tree?
Dragon tree stem rot: After the dragon tree (Dracaena) is infected, small brown spots first appear on the leaves, mostly starting from the leaf margins. When humidity is high, they rapidly expand into elongated or irregular dark brown water-soaked patches, and in severe cases cause the leaves to turn yellow and die. Stem infection mostly enters through wounds, producing irregular black lesions in the phloem, with grayish-white to black mold layers. In severe cases the phloem peels off and black rot develops, and the affected xylem becomes water-soaked and slightly turns brown. After the pathogen invades the xylem, it rapidly spreads upward and downward, causing rot, and a large amount of black mold develops at cuts or wounds.
Control methods:
(1) Strict quarantine; destroy diseased plants promptly when found. Dragon trees transported north must be strictly inspected to prevent diseased plants from being transported to the north.
(2) Use refrigerated containers during long-distance transport, maintaining a temperature of 15°C. Also try to avoid man-made wounds during transport.
(3) Maintenance in a greenhouse is recommended.
(4) Pay attention to checking for damage by fried flat moth larvae and eliminate them as early as possible. For control methods see fried flat moth in this book.
(5) In the early stage of disease, spray 10% Score water-dispersible granules at 3000 times dilution, or 27% Copper Hydroxide suspension at 600 times dilution, or 50% Thiophanate-methyl sulfur suspension at 800 times dilution, 80% Lüheng No. 2 (Duofuxin) wettable powder at 800 times dilution, 50% Shajunwang (chlorobromoisocyanuric acid) water-soluble powder at 1000 times dilution, applying once every 10 days or so, for 2~3 consecutive applications.
Control methods for stem rot in dragon tree
Dragon tree stem rot: After the dragon tree (Dracaena) is infected, small brown spots first appear on the leaves, mostly starting from the leaf margins. When humidity is high, they rapidly expand into elongated or irregular dark brown water-soaked patches, and in severe cases cause the leaves to turn yellow and die. Stem infection mostly enters through wounds, producing irregular black lesions in the phloem, with grayish-white to black mold layers. In severe cases the phloem peels off and black rot develops, and the affected xylem becomes water-soaked and slightly turns brown. After the pathogen invades the xylem, it rapidly spreads upward and downward, causing rot, and a large amount of black mold develops at cuts or wounds.Control methods:
(1) Strict quarantine; destroy diseased plants promptly when found. Dragon trees transported north must be strictly inspected to prevent diseased plants from being transported to the north.
(2) Use refrigerated containers during long-distance transport, maintaining a temperature of 15°C. Also try to avoid man-made wounds during transport.
(3) Maintenance in a greenhouse is recommended.
(4) Pay attention to checking for damage by fried flat moth larvae and eliminate them as early as possible. For control methods see fried flat moth in this book.
(5) In the early stage of disease, spray 10% Score water-dispersible granules at 3000 times dilution, or 27% Copper Hydroxide suspension at 600 times dilution, or 50% Thiophanate-methyl sulfur suspension at 800 times dilution, 80% Lüheng No. 2 (Duofuxin) wettable powder at 800 times dilution, 50% Shajunwang (chlorobromoisocyanuric acid) water-soluble powder at 1000 times dilution, applying once every 10 days or so, for 2~3 consecutive applications.
Control methods for stem rot in fragrant dracaena
Symptoms:It damages the stem. When the disease occurs, irregular black lesions form in the phloem of the stem, with grayish-white to black mold layers. In severe cases the phloem peels off and black rot develops, and the affected xylem becomes water-soaked and slightly turns brown. After the pathogen invades the xylem, it rapidly spreads upward and downward,causingrot, and a large amount of black mold develops at cuts or wounds.
Disease characteristics:This disease is caused by a fungus, the pathogen being Thielaviopsis paradoxa. The pathogen overwinters in diseased tissues or enters the soil with diseased stem remnants, and infects through wounds, cuts or poorly sealed wax areas the following year. In yellow-edged varieties planted or maintained indoors, the leaves are also affected.
Control methods:
(1) Horticultural control:Strict quarantine; destroy diseased plants promptly when found. Maintenance in a greenhouse is recommendedmaintenance。
(2) Chemical control:Spray in the early stage of disease. The following fungicides can be used: 10% Score water-dispersible granules at 3000 times dilution, 27% Copper Hydroxide suspension at 600 times dilution, 50% Thiophanate-methyl sulfur suspension at 800 times dilution, 50% Shajunwang (chlorobromoisocyanuric acid) water-soluble powder at 1000 times dilution. Spray the above fungicides once every 10 days or so, for 2~3 consecutive applications.