Control methods of stem rot of dragon blood tree

Dragon blood stem rot: after the dragon blood tree is infected, the primary brown spots on the leaves start from the leaf edge, and rapidly expand to grow or irregular black-brown water-like patches when the humidity is high, which seriously causes the leaves to wither and yellow and die. Stem infection is mostly caused by □ invasion, resulting in irregular black spots in the phloem, with grayish white to black mildew layer. Severe phloem peeling and black rot, and the damaged bast showed water stains and turned slightly brown. After invading the parenchyma, the pathogen spread rapidly up and down, causing rot, and a large amount of black mold layer was produced at the site of cutting □ or injuring □.

Prevention and control methods:

(l) strict quarantine and timely destruction of diseased plants. Dragon blood trees transported to the north should be strictly inspected to prevent diseased plants from being transported to the north.

(2) use refrigerated containers during long-distance transportation and keep the temperature at 15 degrees Celsius. And try to avoid man-made injury to □ during transportation.

(3) advocating conservation in greenhouse.

(4) pay attention to the damage of fried flat moth larvae found by inspection, it should be eliminated as soon as possible. For prevention and treatment, see fried flat moth in this book.

(5) at the initial stage of the disease, spraying 3000 times of 10% Shigao water dispersible granules or 27% copper noble suspension or 50% methyl thiophanate sulfur suspension, 80% Luheng 2 (Duofu zinc) wettable powder, 50% chlorobromoisocyanuric acid (chlorobromoisocyanuric acid) water-soluble powder, control 1 times every 10 days or so, control 2 times continuously for 3 times.

Prevention and control methods of stem rot of dragon blood tree stem rot of dragon blood tree: after the dragon blood tree is infected, the primary brown spots on the leaves start from the leaf edge, and rapidly expand to grow or irregular black-brown water-like plaques when the humidity is high, which seriously causes the leaves to wither and yellow and die. The stem infection mostly invades from the wound and produces irregular black spots in the phloem with grayish white to black mildew layer. Severe phloem peeling, black rot, damaged xylem showed water stains, slightly brown. After invading the xylem, the bacteria spread rapidly up and down, causing decay and producing a large amount of black mildew layer in the incision or wound. Prevention and control methods: (1) strict quarantine and timely destruction of diseased plants. Dragon blood trees transported to the north should be strictly inspected to prevent diseased plants from being transported to the north. (2) use refrigerated containers during long-distance transportation and keep the temperature at 15 ℃. And try to avoid man-made wounds in the process of transportation. (3) advocating conservation in greenhouse. (4) pay attention to the damage of fried flat moth larvae found by inspection, it should be eliminated as soon as possible. For prevention and treatment, see fried flat moth in this book. (5) at the initial stage of the disease, spray 3000 times of 10% Shi high water dispersible granules or 27% copper noble suspension or 50% methyl thiophanate sulfur suspension, 80% Luheng 2 (Duofu zinc) wettable powder, 50% chlorobromoisocyanuric acid (chlorobromoisocyanuric acid) water soluble powder 1000 times, control once every 10 days, 2 times in a row. Control methods of stem rot of Xianglong blood tree

Symptoms: damage to the stem. When the disease occurs, there are irregular black spots in the phloem of the stem, with grayish white to black mildew layer. In severe cases, the phloem peeled off and black rot, and the damaged xylem showed water stains and turned slightly brown. After the pathogen invades the xylem, it spreads rapidly up and down, causing rot, and a large number of black mold layers are produced in several incisions or wounds.

Disease characteristics: the disease is caused by true feelings, and the pathogen is Candida albicans (Thielaviopsis paradoxa). The pathogen overwintered in the diseased tissue or entered the soil with the diseased stump, and invaded from the wound, incision or loose wax seal in the second year. The leaves of the yellow-edged varieties planted or maintained indoors are damaged.

Prevention and control methods:

(1) Horticultural prevention and control: strict quarantine and timely destruction of diseased plants. Advocate conservation in the greenhouse.

(2) Pharmaceutical prevention and treatment: spraying at the initial stage of the disease, 10% high water dispersible granule 3000 solution, 27% copper noble suspension 600x solution, 50% thiophanate methyl. Sulfur suspension 800x liquid, 50% chlorobromoisocyanuric acid (chlorobromoisocyanuric acid) water-soluble powder 1000 times, the above agents are sprayed every 10 days or so, continuous prevention and control for 2 times.