Protection methods

• During cultivation 

It should be noted above all that the struggle during cultivation against Athalia rolfsii soil , a fungus, is practically impossible, no means being sufficiently effective to stem the evolution of this parasitic fungus.

We can still offer to manage the irrigation as best as possible (optimal quantity, localized supply, etc.).

The healthy or diseased plant debris (especially rotten fruit, altered collars ...) likely to harbor or encourage the development and conservation of the fungus in the soil should preferably be eliminated during and at the end of crop as well as potential host weeds.

• Next crop

The wide range of potential hosts and the limited number of non-host plants make crop rotations seldom effective against this fungus. In new plots or in plots that are little or not affected, crop rotations will be recommended with maize or other cereals described as not very sensitive. Note that the sensitivity of corn and wheat seems quite controversial in the literature. Although onion is susceptible, winter crops of this vegetable at a time not conducive to the development of A. rolfsii would reduce the viability of sclerotia. The latter would be more sensitive to soil antagonists under the effects of exudates excreted by this Allium.

The heavy, wet soils are drained . Deep plowing will be done so that plant debris and sclerotia can be destroyed more quickly by burying them deep.

In heavily infested soils, it may be considered before planting to eliminate or reduce as much as possible the inoculum present, for example by carrying out solarization in sunny regions. It consists of covering the floor to be disinfected, which will have been carefully worked and moistened beforehand, with a polyethylene film 25 to 50 µm thick. The latter is kept in place for at least a month at a very sunny time of the year. This economical and efficient method should make it possible to get rid of this colonizing fungus from the surface area of ​​the soil. In fact, it seems that it is only removed in the first few inches of the ground. This therefore implies planting immediately after solarization, before this stratum is recolonized. This situation would be such as to limit the use of this method in the climate of France. Note that solarization has been successfully combined with the contribution of antagonistic fungi to the soil, such as Trichoderma harzianum .

A. rolfsii does not appreciate alkaline pH, liming the soil is frequently recommended. For the same reason, certain fertilizations rich in calcium would reduce the incidence of this fungus by raising the pH, especially if the rate of inoculum in the soil is low. It would be the same for certain soluble nitrogenous fertilizers brought to the surface of the soil (urea, ammoniacal salts). To maintain the partial effectiveness of the latter, we will split the inputs and avoid leaching the soil.

In the case of fruit rots in particular, the use of plastic mulch will probably reduce the incidence of the disease by creating a screen between the infected soil and the fruit. In any case, such mulching will also increase the temperature and maintain soil moisture, and reduce weeds.

To our knowledge, there is no variety melon resistant to A. rolfsii .

* 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 products phytopharmaceuticals and their uses, fertilizers and growing media approved in France. This also applies to all biological products based on microorganisms or natural substances.