The causative agent: asporous bacteria Pseudomonas syringae pv. Lachrymans.
Only a representative of the cucurbits family is exposed to this widespread disease. Bacterial disease can develop on all overground parts of the plant during growing season. Often the disease affects the crop with gummosis of cucumber.
High humidity (95%) contributes to the spread of disease.
The development of the disease begins mainly from the lower leaves, in which brown or dark gray spots appear in an angular form.
With increasing humidity, the spots are made oily, and when it is lowered - the drops of isolation dry up, turning into a glaze. Dry spots easily crumble. As a result of the bacteriosis, the damaged leaves die off.
The disease can be in form of shallow small iodine, round form on the fruit.
At high humidity, on the underside of the leaves and on the fruit, sticky droplets of a cloudy yellowish exudate are released, with the help of which they spread to the neighboring plants when flushing with water. Exudate is a cluster of bacterial cells and products of their livelihoods.
The causative agent gets into the plant through minor damage and stomach.
Infected seeds can be primary source of infection, in which the pest can save pathogenicity up to 3 years. Also, bacteria can persist in waste of vegetable origin, but not in the soil itself.