How To Recognize Petunia Diseases?

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

Bright petunia is a wonderful guest from South America, which has taken root well in our latitudes. However, from time to time we observe manifestations of a wide variety of ailments on our favorite flowers: petunias can attack gray, wet or white rot, as well as the ill-fated bacterial spot or even late blight. And the seedlings of this garden beauty are periodically struck by a black leg. How to recognize the symptoms of these ailments in order to start fighting them in time?

Gray rot

On petunia stalks and leaves with flowers, the formation of various-sized light brownish spots or a characteristic rash begins, which are subsequently covered with a fluffy gray bloom of fungal sporulation. The infected parts of petunias first fade, and after a while they begin to rot, transforming into an unpleasant brownish mass covered with a gray bloom.

Sometimes the development of a harmful fungus also begins in internodes - this contributes to the rapid withering away of the parts of petunias located above the areas attacked by the disease. And with a particularly severe defeat, bright flowers often die. By the way, petunias can be affected by gray rot at any stage of their development - from the stage of cotyledon leaves to the time when the seeds begin to ripen.

White rot

Petunias attacked by this ailment are covered with brownish, weeping spots. If beautiful flowers develop in humid conditions, then the specks on top may be covered with a whitish bloom of mycelium. After a while, the infected tissues of petunias noticeably soften and turn white.

Both inside the stems and on their surfaces, a destructive whitish mycelium forms, on which, in turn, the reproductive organs of the harmful fungus - tiny sclerotia - gradually appear. When the sclerotia begin to ripen, tiny droplets of highly refracting light liquid form on them. All shoots located above the lesion sites will soon die off.

Brown spot

This attack manifests itself on petunias in the form of numerous specks formed on their leaves, painted in rusty-brown tones. Initially, all the spots are round, but after some time their shape changes to oblong. There are also well-marked concentric zones on the specks. And in the light areas of these spots, the formation of fungal sporulation begins, as a result of which the diseased leaves gradually fade and dry out quickly.

Blackleg

The root parts of petunia stalks become watery, after which they begin to darken and gradually rot. As a result, beautiful plants die and die quickly. The mushroom mycelium spreads over the substrate at a truly lightning speed - if you do not start a timely fight against this scourge, you can lose all seedlings.

Wet rot

In the cotyledonous stage, wet rot usually develops in a manner similar to the black leg. And from the very beginning of the pick and until the end of the growing season, a harmful infection provokes rotting of the root necks. Petunia leaves droop and immediately shrivel, turning into grayish-greenish tones with a slight lead tinge. And on the root collars, the formation of oily specks of light brown color begins, quickly becoming covered with a brownish tomentose coating of fungal mycelium. A little later, the development of tiny black sclerotia begins on the mycelium. Sick petunias noticeably lag behind in growth and, turning yellow, fade.

Late blight

The bases of petunia stalks affected by late blight turn brown and slowly rot, as a result of which the plants begin to wither and eventually die. The unfortunate attack affects petunias at any age, so you must always remain vigilant.