Watermelon Anthracnose

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

Anthracnose is especially hard on watermelons during wet seasons. To a large extent, its development is favored by abundant dew. By the way, sometimes this disease is also called a watermelon copperhead. The harmfulness of anthracnose is expressed in the fact that the assimilation surface of the plants affected by it decreases markedly, young seedlings die rather quickly, and the commercial qualities of the fruits deteriorate significantly - they often rot during storage and transportation. And in especially wet years, the harvest of watermelons can die completely

A few words about the disease

On the watermelon leaves affected by anthracnose, yellowish or light brown round spots are formed, which after some time slowly begin to merge, covering the entire leaf. Brown infected leaves crumble quite easily. Most of the specks can usually be seen on the undersides of the leaves.

On the petioles, stalks and fruits, the spots are most often depressed, have a brownish or black color and resemble ulcers in appearance. When wet weather is established, they are often covered with reddish-yellow or pinkish pads formed in the form of concentric circles.

If anthracnose attacked growing watermelons with special force, then the fruits slowly begin to rot, and the stalks with leaves dry up. The stalks that are condensed at the sites of lesions can sometimes break off. The root collar is also often affected - in this case, the plants often wilt and dry out quickly.

Fruits on infected plants usually ripen prematurely and are characterized by a rather low sugar content.

The causative agent of anthracnose is a phytopathogenic fungus that parasitizes equally actively on vegetation at any stage of its development. During the growing season, the spread of the pathogen occurs by conidia carried by insects, rain and wind. By the way, this harmful mushroom is also capable of infecting cucumbers with melons.

The duration of the incubation period for the development of watermelon anthracnose at an air humidity in the range of 85 to 90 percent and at a temperature of twenty-five to twenty-seven degrees is approximately three to four days. If the air humidity is rather low, the plants usually do not become infected. And the main source of infection is considered to be plant remains and infected seeds. Sclerotia of the fungus, as a rule, is located on plant residues, and mycelium is located inside the seeds.

How to fight

Control over the development of this harmful scourge on watermelons is significantly complicated by the absence of potent fungicides allowed for use in watermelon anthracnose. Accordingly, the main emphasis in the cultivation of watermelons should be placed on various phytosanitary measures.

To prevent the development of anthracnose, it is necessary to follow the rules of crop rotation, returning watermelons to their former areas no earlier than after six to seven years. Moreover, the watermelon plantings of the current year in no case should border on the plots on which the watermelons were cultivated last year. Wheatgrass and alfalfa are considered excellent precursors of watermelon - these legumes tend to accumulate nitrogen in the soil, which in turn contributes to the development of anthracnose-suppressing microorganisms.

Seeds must be disinfected before planting. This can be done using the drug "Fundazol". And in protected ground, it is necessary to disinfect the soil, as well as thoroughly disinfect containers, equipment and cultivation rooms. The elimination of post-harvest residues is another important preventive measure, since the anthracnose pathogen often overwinters on them.

And only at the very beginning of the manifestation of a harmful misfortune, watermelon plantings can be treated with the "Previkur" preparation.

During the collection of fruits, as well as during their transportation, care should be taken to prevent possible mechanical damage, then the likelihood of being damaged by anthracnose will be much less.