Diseases

Downy mildew of spinach

Spinacia oleracea L.

The most economically significant disease of spinach, caused by the obligate oomycete Peronospora effusa, characterized by high race variability and the necessity of using genetically resistant varieties.

In the reference 387 varieties crop Spinach, where this is mentioned in the description.

The causative agent of the disease is the obligate oomycete Peronospora effusa, which infects spinach exclusively. The main symptoms are light green or yellowish spots on the upper side of the leaves and a characteristic lilac-gray or grayish-purple felt-like growth on the underside. Under favorable conditions (temperature 7–15 °C and humidity above 85–95%), the affected tissues dry out, and the leaves curl and die.

The pathogen exhibits high variability, leading to the continuous emergence of new races, the number of which reached twenty by 2024 (Pe: 1–20). Race monitoring is carried out by the International Working Group on Peronospora (IWGP). Varietal resistance is based on major genes and is denoted in descriptions by the abbreviation Pe, where the range indicates the list of races to which a given variety possesses resistance.

General information about the subject — on the page Downy mildew.

Sources8

Varieties of Spinach mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.