Fusarium wilt is rife on all continents, especially in many countries in America, Asia and Europe, it is even reported in Australia
It can be very damaging, it is not uncommon to observe in affected crops mortalities in plant outbreaks, eventually spreading to all melon stems.

This vascular disease is very common in France where it is rife in the open as well as under shelter. It is currently the most serious disease for this production. This situation would be due both to the preponderance of the yellowing race 1-2 in the different production areas, but also to an increase in the aggressiveness of the strains collected in the field.

Four physiological races of Fusarium have been characterized using differential hosts: races 0, 1, 2 and 1-2 (formerly race 3). Race 1,2 is subdivided into 2 sub-races: 1.2 W (wilt = wilting) and 1.2 Y (yellows = yellowing). Several of these breeds have been described in each melon producing country. Breed 1-2 is now the majority in many producing countries of the Mediterranean basin: in France, but also in Italy, Greece, Israel, Turkey. Race 2 appears to be rarer.

It should be noted that the determination of races in the laboratory can prove useful in certain countries to guide the choice of varieties or to understand parasitic situations. Finally, let us add that the parasitic specificity of F. oxysporum f. sp. melonis is important, but this fungus would still be able to attack some other Cucurbits, but on plants in the juvenile state.

In addition, vegetative compatibility groups (VCGs) have been characterized in F. oxysporum f. sp. melonis .

Other species of Fusarium have also been described on melon plants and / or fruits: Fusarium incarnatum (Desm.) Sacc. (syn. Fusarium semitectum Berk. & Ravenel), Haematonectria haematococca (Berk. & Broome) Samuels & Rossman (syn. F. solani ), Fusarium culmorum (WG Sm.) Sacc. 1892.