Symptom Characteristics and Control Methods of Carnation Bud Rot

Characteristics and Control of Carnation Bud Rot

Identification points:Carnation bud rot affects flower buds; affected buds fail to open, part of the outer petals turns light brown, and the buds become deformed; when a bud is cut open, the interior is tea-brown, causing the flowers to lose their commercial value; most petals of affected flowers become soft and rotted.

Occurrence characteristics:The pathogen is a deuteromycete fungus. This disease is newly emerging, occurring more in greenhouses and rarely in open-fieldcultivation.

Control methods:

(1) Cut off diseased plants and burn them in a centralized manner.

(2) Before disease onset, spray with 50% thiophanate-methyl wettable powder at 1000 times dilution, 50%carbendazimwettable powder at 500-1500 times dilution, 50% Tuzet wettable powder at 800-**** times dilution, or 12.5% diniconazole wettable powder at 2000-3000 times dilution.

Carnation Disease Control: Control of Carnation Leaf Spot and Gray Mold

Carnation is the mother's flower of our country, formerly known as Xiangshizhu (Dianthus caryophyllus), and is a perennial herbaceous plant. During the growth of carnations, we must strengthen the control of carnation leaf spot and gray mold. Today, the editor shares with you the methods for controlling carnation diseases.

Common diseases of carnations include calyx rot, rust, gray mold, bud rot, and root rot. Zineb can be used to control calyx rot, and 5 percent oxycarboxin to control rust. To control other diseases, use zineb, carbendazim, or captan for soil treatment before planting. When spider mites or aphids cause damage, generally use 40% dimethoate emulsion at 1000 times dilution to kill them.

Carnation Leaf Spot

Carnations are highly susceptible to leaf spot, which affects their growth and development and reduces the yield and quality of cut flowers. The leaf spot pathogen overwinters as mycelium and conidia on diseased plant residues and can survive in the soil for about one year. The lesions are elongated and grayish-brown; in severe cases, the lesions girdle the stem, causing the upper branches and leaves to wither and die. When it infects flowers, it often causes damage on flower stalks and bracts; when there are many lesions on the bracts, the flowers cannot open or become deformed.

Control measures:

1. Select healthy, disease-free cuttings and remove diseased plant residues. Keep the plant surface as dry as possible, and implement crop rotation for more than two years in a location with good ventilation, light, and drainage. Keep the greenhouse well ventilated, and ventilate before dusk.

2. Leaf spot can occur year-round, so a preventive fungicide must be sprayed once a week, such as mancozeb, zineb, iprodione, or chlorothalonil, etc. In particular, spray promptly after harvesting cut flowers; 75% chlorothalonil, 50% captan at 500 times dilution, or 1% Bordeaux mixture can all be used.

Virus: Cannot be treated; please use seed-sown seedlings or virus-free treated seedlings.

Carnation Gray Mold

Carnations suffer quite severe damage from gray mold. After gray mold-like substances cover the buds, petals, stems, and leaves, brown water-soaked lesions appear, causing petals to rot, buds to drop, and stems and leaves to wither and die. Infected buds cannot open, and diseased flowers lose their bright color. When temperature is high and humidity is high, the disease is severe, spreads rapidly, and causes rampant damage, so it must be controlled to protect the stems, leaves, buds, and petals, thereby promoting flowering, prolonging the flowering period, and improving ornamental value.

Specific control methods: Spray the leaves once a month with 1000 times potassium permanganate aqueous solution, or 1000 times sodium bicarbonate (baking soda) aqueous solution, or 25-30 times clarified liquid leached from dry, clean plant ash, evenly wetting all leaves, buds, and petals until water droplets begin to drip down. This can effectively control the occurrence and damage of carnation gray mold and protect the stems, leaves, buds, and petals. If there is a lot of rain, high temperature, and high humidity, and gray mold-like substances appear on the stems, leaves, buds, and petals, then continuously spray the leaves 2-3 times with a mixed fertilizer of 1000 times procymidone, 1500 times Shennongsu chelated fertilizer, and 300 times monopotassium phosphate, or a mixed solution of 1000 times procymidone, 1000 times Zhuangfengyou, and 500 times high-efficiency biological phosphorus-potassium fertilizer for control, spraying once every 7-10 days, to kill the pathogen and quickly restore normal growth to the affected parts, strengthen the stems, leaves, buds, and petals, and promote flowering.