Biology, epidemiology

• Conservation, source d'inoculum 

This fungus is preserved in the soil in particular on plant debris thanks to its chlamydospores. Unlike many other Fusarium , such as Fusarium oxysporum f. sp. melonis , it would stay there for a short time, of the order of 2 to 3 years. The role played by its rare sexual form (both in ensuring its conservation and dissemination) is not known. The seeds can be infected with both races of this Fusarium , which does not appear to interfere with their survival and germination. Its durability on these would not exceed more than one, or even two years.

• Penetration, invasion

The hyphae of this fungus penetrate through the epidermis, or via wounds. The mycelium in place in the tissues develops inter and intracellularly and invades and destroys the latter. In fruits, it gains flesh and colonizes the cavity where the seeds are located. F. solani f. sp. cucurbitae subsequently infects the latter.

• Sporulation dissemination

This Fusarium sporulates profusely on altered tissues where nearby, sporodochia (figure 1), macroconids, microconidia, and chlamydospores can be formed. This potential inoculum represents major sources of contamination at the origin of the very easy dissemination of this fungus. It is dispersed via wind, splash and runoff of water, equipment and tools. Note that during tillage, the inoculum is redistributed in the plot and disseminated by the tillage equipment.
The seeds can be contaminated and ensure the transmission and conservation of this Fusarium wilt.

• Conditions favorable to its development

This fungus likes heat, its optimum temperature for growth is between 26-28 ° C. It also appreciates soils and wet periods.