Protection method

• During cultivation 

As soon as you observe the first symptoms induced by Cladosporium cucumerinum , the presence of free water on the plants should be avoided as much as possible. For this, must be well the shelters ventilated, and heat them as much as possible, especially at night in order to avoid water condensation on the plants. Indeed, whatever the type of crop, the presence of water on the plants should be avoided. For the same reasons, in the open field, if sprinkler irrigations must take place, they will be carried out in the morning or in the morning in order to allow the plants to dry quickly, in no case at the end of the day. Under shelters, it is advisable to close the doors before the rains.

treatments Fungicide * must be carried out quickly ( e-phy ). Young fruits must be particularly well protected. Note that only preventive treatments are effective. In addition, the efficiency of chemical protection is not always good, it would be particularly less in periods of cool night temperatures, below 14 ° C.
Respect the doses and frequencies of treatments.
- As a preventive measure up to the fruit set stage (and beyond in a period of low risk), treat with a contact product every 7 days.

Particularly affected plants and fruits should be removed and destroyed. This operation should be generalized at the end of cultivation, in particular for diseased fruits. Deep burial of plant debris would reduce the proportion of primary inoculum subsequently available.

• Next crop

If the attacks took place in a nursery and under shelter, it will absolutely be necessary to disinfect the equipment used and the structures of the shelters ( e-phy ). Particular attention will be paid to the nursery, the plants will be well heated and excessive humidity should be avoided at all costs. Preventive treatments can be carried out with the aforementioned fungicides.

Although C. cucumerinum is not a seminicolous fungus, the seeds collected from fruits from traditional or even extensive crops affected by cladosporiosis will be disinfected with bleach (2% sodium hypochlorite) for two minutes, or treated with fungicide.

Of crop rotations with non-host plants will be desirable. This measure will not be difficult to implement because C. cucumerinum is very specific to cucurbits. You should wait at least 2 to 3 years, if not longer, before cultivating a susceptible cucurbit again. It should be avoided to plant crops in poorly drained plots, poorly exposed, located in poorly ventilated places, conducive to maintaining water on the plants and allowing the formation of pockets of fog in particular. In addition, the soil of future plots will be well prepared and drained in order to avoid the formation of puddles favorable to attacks by C. cucumerinum . The rows of plantation should be oriented if possible in the direction of the prevailing wind so that the vegetation cover is well ventilated.

The climate of the shelters and the irrigation sprinkler will be managed as well as possible in order to avoid cold and humid atmospheres, and the presence of water on the plants. Under cover, you will have to close the doors before a rain. Localized drip irrigation or sprinkling is preferred. Debris from diseased plants and fruits should be removed.

Treatments based on the fungicides proposed above will be carried out preventively, especially at the start of cultivation, during cold and humid periods ( e-phy ).

Among the cucurbits, only the varieties of cucumber marketed are resistant to cladosporiosis. In addition, resistance or tolerances have been reported in Cucurbita pepo , C. maxima and C. moschata , but no resistant commercial cultivar is currently available in these species, such as in melon.

Of plant extracts , some microorganisms , were more or less effective towards C. cucumerinum , none of them is currently used in production, probably because of a very partial efficacy in epidemic conditions.


* 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.