The symptoms of Fusarium wilt can be expressed in well seedlings as as in adult plants .

In the nursery, the seedlings affected see their growth reduced ; their old leaves may turn yellow, wilt and more or less curl. Young plants can completely wilt and die. A cut in the stem reveals a rather marked brown tint of the vessels.

The adult plants suffer symptoms quite similar to those previously described on seedlings. Thus, some old leaves show unilateral yellowing, that is to say affecting the leaflets located on one side of the leaves and a sector of the blade (figures 1 and 2), this is one of the characteristics of vascular diseases. These yellowing of tissues leaf are often associated with more or less severe wilting which tends to be accentuated at the hottest times of the day. Leaves eventually dry out completely, but do not fall. Subsequently, these secondary symptoms spread to the other leaflets and eventually spread to the plant, which can dry out completely and die (Figure 3).

Longitudinal lesions that are first chlorotic and then gradually necrotize are also visible on one side of the stem (Figures 4 to 7). They can extend over several tens of centimeters. Adventitious roots can form on the stem.

The vascular system is particularly affected. It takes on a dark tint brown (Figure 8), which differentiates Fusarium wilt from Verticillium wilt. The marrow is not affected, unlike the “black marrow” or, to a lesser extent, the “bacterial canker”, caused respectively by Pseudomonas corrugata and Clavibacter michiganensis subsp. michiganensis .

Note that F. oxysporum f. sp. lycopersici would also be responsible for rots on fruits .


1. Two nomenclatures are used in the literature to define the races of Fusarium oxysporum f. sp. lycopersici. The most frequent is the one we used in this sheet: races 1, 2, 3. The other designates the first by race 0, the second by race 1 and the third by race 2.