How To Recognize Diseases Of Dill? Part 2

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

In the first part of the article, we got acquainted with the main signs of such diseases of dill as phomosis, often rampant powdery mildew, fusarium wilting and destructive cercospora. Now is the time to take a closer look at such destructive ailments as peronosporosis, black leg, rust and verticillium wilting. Indeed, in order not to lose the long-awaited harvest, it is extremely important to learn how to recognize the main signs of these dangerous diseases

Peronosporosis of dill

Peronosporosis is also called downy mildew. In its manifestations, it is in many ways similar to ordinary powdery mildew. This ailment attacks only the aerial parts of dill, and bursts of infection with this harmful scourge are noted when humid weather is established and at temperatures ranging from eighteen to twenty degrees.

The foliage of dill, as the ill-fated ailment develops from the outside, either turns yellow or turns brown. And on the backs of the leaves, you can notice a white and rather thick bloom. Identical lesions are found on umbrellas, as well as on seedlings. Some time later, the diseased dill begins to dry out.

The spread of a harmful disease occurs through diseased seeds, as well as through weeds or plant debris. That is why it is important to make every effort to prevent the appearance of particles of infected tops or weeds on the ground.

Black leg of dill

This attack is especially harmful when cultivating dill in hotbeds and greenhouses. The source of infection is seeds attacked by a fungal infection. During the period of activation of the pathogen, the root necks of the growing dill begin to rot, as a result of which the greens turn black, and the dill stalks noticeably weaken and dry out in the very first days after the appearance of tiny shoots. The ill-fated black leg continues to actively develop until the opening of the first true leaves. Often, up to half of the crops die from this scourge, especially in conditions of high humidity.

The development of this harmful scourge is facilitated by a great variety of factors: excessive watering, lack of good ventilation in greenhouses, low illumination, high soil acidity, sharp temperature fluctuations, insufficient thinning of dill crops, which forms on the soil surface due to the lack of proper loosening of the crust, as well as repeated use the same soil when growing seedlings and in greenhouses or hotbeds. And if you sow dill from untested seeds, the risk of infection will increase several times more, because such seeds can be infected with cercospora or phomosis.

Dill rust

This ailment is easy to recognize at first glance - characteristic pads, painted in yellow-brown tones, appear on the undersides of the stems, petioles and leaves at the beginning of summer.

Dill verticillary wilt

The fungus-causative agent of verticillosis mainly affects the vessels of growing dill. As the pathogen develops, wilting dill bushes completely lose their ability to receive moisture and nutrition, and their vascular system quickly becomes clogged.

The very first symptoms of the disease can be observed closer to mid-June, and the disease usually begins to progress in the second half of summer, during the flowering of dill or at the stage of seed formation. At first, the diseased dill turns yellow exclusively in the heat, and a little later the dill leaves turn brown, curl and wither completely.

The main source of infection by verticillium wilt is soil infected with the fungus Verticillium dahliae, as well as poorly rotted compost or manure.