Orchid Pests and Diseases Special: Diagnose by Looking at the Pictures (Part 1)

 Picture 1: Southern blight
 

Preventive medication for southern blight in normal times: pesticide name: tolclofos-methyl EC; mode of action: systemic 20% fungicide; method of use: dosage: 800 times dilution / 2-3 applications / 10-day interval. Drench the roots and stems; it can also prevent: fusarium wilt, damping-off;

Southern blight: supplementary notes on control: southern blight is a disease cause that arises inside the soil "potting medium"; potting medium that is too acidic is more prone to infection; suggestion one: you can choose to sprinkle rice straw ash on the pot surface, or soak in water to flush out the ammonia and acidity in the pot, and neutralize the pH quality in the pot.

Two: in normal times, about every 20 days use a mixture of Dexon 1000 times plus Antaisheng 70% 500 times, drench the roots and wet the crown, which can achieve a certain effect.

Picture 2: Brown spot + anthracnose
 

Brown spot + anthracnose, preventive medication in normal times: pesticide name: 77% Keshade wettable powder; mode of action: broad-spectrum protective fungicide; method of use: 1000 times solution / 3-4 applications / 7-day interval spray / leaf undersides, leaf surfaces; it can also prevent: brown spot, anthracnose, leaf spot, ring spot, bacterial brown spot;

Pesticide name: 25% propiconazole EC; mode of action: broad-spectrum systemic fungicide; method of use: 1500 times / 2-3 applications / 8-day interval spray / leaf undersides, leaf surfaces; it can also prevent: brown spot, round spot, anthracnose, leaf spot, leaf tip blight;

Brown spot + anthracnose, supplementary notes on control: One: when using emulsifiable concentrate pesticides, try to apply them in the early morning or evening, which can avoid damaging tender shoots and reduce pesticide damage

Two: in normal times, pesticides need to be used alternately, which can avoid the development of resistance

Picture 3: Brown rust
 

 

Preventive medication for brown rust in normal times: pesticide name: 20% myclobutanil EC; mode of action: systemic fungicide; method of use: 2500 times solution / 2-3 applications / 7-day interval spray / leaf undersides, leaf surfaces; it can also prevent: brown rust;

Picture 4: Black spot
 

Preventive medication for black spot in normal times:

Pesticide name: 80% mancozeb wettable powder; mode of action: broad-spectrum protective fungicide; method of use: 800 times / 3-4 applications / 6-day interval spray / leaf undersides, leaf surfaces; it can also prevent: anthracnose, leaf spot, sooty mold, black spot, round spot, ring spot.

Pesticide name: 10% Shigao water-dispersible granules; mode of action: broad-spectrum systemic fungicide; method of use: 3000 times / 2-3 applications / 8-day interval spray / leaf undersides, leaf surfaces; it can also prevent: brown spot, leaf spot, black spot, round spot, leaf blight, ring spot, leaf tip blight, sooty mold; ⟦18 Pesticide name: 25% Shibaoke EC; mode of action: broad-spectrum fungicide; method of use: 1500 times / 2-3 applications / 8-day interval spray / leaf undersides, leaf surfaces; it can also prevent: anthracnose, leaf spot, sooty mold, black spot, round spot, ring spot;

Pesticide name: 25% Sportak emulsifiable concentrate; mode of action: broad-spectrum fungicide; application method: 1500x dilution / 2-3 times / 8-day interval spray / leaf undersides, leaf surfaces; it can also prevent: anthracnose, leaf spot, sooty mold, black spot, circular leaf spot, ring rot;

Pesticide name: 50% Shibaogong wettable powder; mode of action: broad-spectrum fungicide; method of use: 2000 times / 2-3 applications / 8-day interval spray / leaf undersides, leaf surfaces; it can also prevent: anthracnose, leaf spot, sooty mold, black spot, round spot, ring spot;

Supplementary notes on black spot: in general, the symptom structure of black spot, round spot and leaf spot is roughly the same, and the damage suffered by orchid leaves is also much the same, so in normal times, if fungicides can be properly selected for regular sterilization, these 3 diseases areorchidrelatively easy-to-control diseases.

Picture 5: Black spot + anthracnose
 

Preventive medication for black spot + anthracnose in normal times:
Pesticide name: 50% Shibaogong wettable powder; mode of action: broad-spectrum fungicide; method of use: 2000 times / 2-3 applications / 8-day interval spray / leaf undersides, leaf surfaces; it can also prevent: anthracnose, leaf spot, sooty mold, black spot, round spot, ring spot;

Pesticide name: 25% Shibaoke EC; mode of action: broad-spectrum fungicide; method of use: 1500 times / 2-3 applications / 8-day interval spray / leaf undersides, leaf surfaces; it can also prevent: anthracnose, leaf spot, sooty mold, black spot, round spot, ring spot;

Pesticide name: 80% mancozeb wettable powder; mode of action: broad-spectrum protective fungicide; method of use: 800 times / 3-4 applications / 6-day interval spray / leaf undersides, leaf surfaces; it can also prevent: anthracnose, leaf spot, sooty mold, black spot, round spot, ring spot.

Supplementary notes on black spot + anthracnose: One: in general, black spot, round spot and leaf spot are easy to control, but when anthracnose occurs at the same time, you must pay close attention to the medication, because most of the control formulas for anthracnose are of the EC or mancozeb type, so when applying pesticides you must pay attention to the weather temperature and UV index.

Two: when the temperature exceeds 30 degrees, try to avoid EC and copper-based pesticides; when the UV from the weather is too high, try to chooseto apply pesticides before 5 a.m. or after 6 p.m. Picture 6: Ring spot

Picture 6.1 Ring spot "late stage"

Preventive medication for ring spot in normal times:

Pesticide name: 77% Keshade wettable powder; mode of action: broad-spectrum protective fungicide; method of use: 1000 times solution / 3-4 applications / 7-day interval spray / leaf undersides, leaf surfaces; it can also prevent: brown spot, anthracnose, leaf spot, ring spot, bacterial brown spot;

Pesticide name: 25% Shibaoke EC; mode of action: broad-spectrum fungicide; method of use: 1500 times / 2-3 applications / 8-day interval spray / leaf undersides, leaf surfaces; it can also prevent: anthracnose, leaf spot, sooty mold, black spot, round spot, ring spot;

Pesticide name: 50% Shibaogong wettable powder; mode of action: broad-spectrum fungicide; method of use: 2000 times / 2-3 applications / 8-day interval spray / leaf undersides, leaf surfaces; it can also prevent: anthracnose, leaf spot, sooty mold, black spot, round spot, ring spot;

Pesticide name: 80% mancozeb wettable powder; mode of action: broad-spectrum protective fungicide; method of use: 800 times / 3-4 applications / 6-day interval spray / leaf undersides, leaf surfaces; it can also prevent: anthracnose, leaf spot, sooty mold, black spot, round spot, ring spot;

Supplementary notes on ring spot: before the leaves of a diseased orchid dry up, if you do not look carefully, ring spot is often mistaken for ordinary leaf spot or black spot; ring spot is a disease spot with a wet yellow spot on the outer ring, but it is also one of the relatively easy-to-control diseases.