A complete guide to petunia pests and diseases

White rust

White rust is most harmful to the leaves, petioles and tender stems of petunias. The infected leaves will initially develop small light green spots, which will then slowly turn into light yellow. As the disease progresses, they will turn into large spots. In the later stage, there will be white scar-like protrusions on the back of the infected parts of the leaves. The affected tender stems will cause the flowers and stems to grow distorted. When the spots spread and surround the petioles and tender shoots, they will cause abnormal growth of the host part above the ring section until it shrinks and dies.

Workaround

At the early stage of infection, spray 1% Bordeaux mixture or 500 times 50% Phytophthora net solution. The prevention and control effect will be better if spraying once every 10 to 15 days.

White mold

White mold causes the most serious damage to leaves. The initial infection of the pathogen appears as patches of white spots, which worsen in the later stages and cause the infected leaves to fall off.

Workaround

After the initial signs of infection appear, remove the diseased leaves as soon as possible and spray them with 600-800 times diluted 75% thiophanate-methyl.

Leaf spot

Leaf spot disease mainly harms the leaves of petunias, and in severe cases it can also lead to the death of the entire plant.

Workaround

Remove diseased leaves promptly and burn them, and remove surrounding fallen leaves as soon as possible; spray 1000 times diluted 50% concentration of mancozeb.

Viral diseases

If the petunia plant shows signs of slow growth and weak rhizomes, it is very likely infected with a viral disease, and in severe cases the leaves may turn yellow.

Workaround

Spray a 1000 times solution of 40% concentration of omethoate.

aphid

Aphids are the most common and main insect pest of petunia, which can cause serious damage to the leaves and tender stems of petunia.

Workaround

When a large number of aphids appear, isolation measures should be taken and spray with 1000 times diluted 10% oxydemeton-methyl emulsion, 1000 times diluted dichlorvos emulsion, 1000-1500 times diluted malathion emulsion, or 15000-20000 times diluted imidacloprid (70% concentration) water dispersible granules.

Conclusion

I believe that after understanding these common diseases and pests that threaten the health of petunias, flower lovers can keep their petunias very healthy and let this beauty accompany them for a long time.