Tiptop
TerminatedCucurbita maxima Duchesne · Giant pumpkin
Diseases
Powdery mildew of large-fruited pumpkin
Cucurbita maxima Duchesne
A fungal disease caused by the obligate parasites Podosphaera xanthii and Erysiphe cichoracearum. It manifests as a white powdery coating on plant organs, leading to leaf senescence and reduced productivity.
In the reference 26 varieties crop Giant pumpkin, where this is mentioned in the description.
The pathogens belong to the Erysiphaceae family. The most aggressive and prevalent pathogen for Cucurbita maxima is Podosphaera xanthii, which is often found in combination with Erysiphe cichoracearum. Fungal populations are genetically variable, which accounts for differences in their virulence across different regions.
Initial symptoms present as white or grayish-white mycelial patches on both sides of the leaf blades. As the infection progresses, the spots coalesce, affecting petioles and stems, which causes browning and tissue necrosis. Secondary effects include stunted growth, loss of foliage, sunburn of fruits, and poor fruit development.
Genetic resistance in the crop is more often quantitative and polygenic in nature. In breeding programs for Cucurbita maxima, there are no widely used alphanumeric designations for major resistance genes; therefore, selection is based on screening accessions from germplasm collections and evaluating field tolerance.
General information about the subject — on the page Powdery mildew.
Varieties of Giant pumpkin 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.
Cavili
TerminatedCucurbita maxima Duchesne · Giant pumpkin