• During cultivation

No control method can eradicate this disease during cultivation. We can always try to block its development by providing a solution fungicidal * ( e-phy ) at the foot of the plants or via the drip irrigation system,. In addition, light baths can be carried out at the hottest times of the day in order to reduce leaf wilting.

Tools used in contaminated plots should be thoroughly cleaned before being used in other still healthy plots. It is the same for the wheels of tractors. Careful rinsing of this material with water will often suffice to rid it of soil and Verticillium dahliae .

Crop residues , commonly buried in the soil, are abundantly colonized by V. dahliae, which produces numerous microsclerotia there. Their elimination limits this phenomenon and helps to reduce the inoculum left in the plots.

• Next crop

The crop rotations will prevent or delay the onset of this disease. To be effective, they will be long enough - at least 4 years - and will not involve sensitive crops such as eggplant, potatoes, peppers, cucurbits, strawberries, etc. Monocots, and in particular cereals, do not seem unaffected by this vascular fungus. Peas, beans and cabbage could be used in the rotations as they would not favor the maintenance of the inoculum in the soil.

The destruction of certain weeds such as black nightshade and pigweed will be considered as they are hosts of V. dahliae .

We will ensure a balanced manuring in order to avoid obtaining young plants with too succulent tissues. Irrigation should be optimal during hot periods in order to also limit wilting.

The disinfection of the soil with a fumigant; dazomet, metam-sodium alone or combined with dimethyl polysiloxane ( e-phy ), will only exhibit partial and not very durable efficacy, and its cost may be high. Note that no Verticilliose use is available in general soil treatments in the database e-phy . Disinfection by solarization , recommended to fight against other soil fungi such as Rhizoctonia solani , reduces the incidence of V. dahliae . Let us add that it will be advisable not to work too deeply the disinfected grounds before the setting in culture, under penalty of causing microsclerotia to rise in the treated stratum.

The immersion of contaminated plots for several days would help to limit the number of microsclerotia present in the soil, by reducing the quantity of oxygen available and by increasing the quantity of CO ₂ . However, this measure does not appear to reduce the incidence of the disease sufficiently to be adopted. The remaining propagules are sufficient for V. dahliae to develop on its host.

A fungicide is authorized for “soil treatment” use on tomatoes ( e-phy ).

The most effective solution will be to use resistant varieties . Indeed, many varieties currently cultivated have a dominant monogenic resistance conferred by the “ gene Ve ” (derived from Lycopersicon pimpinellifolium and located on chromosome 9). They make it possible to control the common strain (race 0, mistakenly called "race 1"). This resistance is effective against V. dahliae , but also against V. albo-atrum . A race 2 capable of bypassing this resistance gene was described in the late 1950s; it is now rife in several production areas around the world: North America (United States and in particular California) and South, North and South Africa (Tunisia ...), Australia and southern Europe (France, Greece ... ).

The grafting a tomato rootstock, intra- or interspecific hybrid, can be used to control Verticillium wilt. Note that these rootstocks only have the “ gene Ve ” and can therefore be attacked by race 2.

In addition, several antagonist microorganisms are reported to be more or less effective against V. dahliae in the literature: Trichoderma viridae, Talaromyces flavus, Bacillus subtilis, Streptomyces griseoviridis, Pseudomonas fluorescens, Gliocladium roseum, Glomus mosseae, Penicillium oxalicum … They are not not currently used in the field in France.


* Chemical control : As the number of pesticides available for a given use is constantly changing, we advise you to always confirm your choice by consulting the e-phy site of the Ministry of Agriculture and Fisheries which is an online catalog of plant protection products and their uses, fertilizers and growing media approved in France. This also applies to all biological products based on microorganisms or natural substances.