Protection methods

• During cultivation

If symptoms of Colletotrichum orbiculare are observed on young fruits or even other aerial organs, sprays fungicide should be made. Several active ingredients or combinations of active ingredients * are approved for “anthracnose” use on courgette in France ( e-phy ). Note that the applications must be renewed every 10 days and after each rain. Their effectiveness is sometimes limited because it is often difficult to reach the fungus on the fruits.

Sprinkler should be avoided irrigation . If they are essential, they will be carried out in the morning so that the vegetation dries up quickly during the day. If the attacks take place under shelters, which is rather rare, it is desirable to aerate and ventilate them.

Whatever the location of the affected plot, workers must not work in it if the vegetation is wet. In addition, severely affected plants and especially diseased fruits must be removed from the crop and destroyed. At the end of the crop, crop residues will also be removed from the crop and destroyed. It should be noted that deep plowing is recommended in the days following the harvest in order to bury the remaining debris, and therefore ultimately reduce the rate of inoculum in the soil. Note that this last measure must be combined with crop rotation.

• Next crop

Anthracnose does not normally require special preventive measures in our country. In the plots already affected and in the countries where it is still a limiting factor of production, we propose to follow the following measures:
- do not use seeds contaminated taken from infected fruits and produce the latter in areas of anthracnose-free crops. It should be noted that treatments of christophine fruits in hot water at 51 ° C and with a chlorine product at 1.5% for 30 sec make it possible to inhibit the development of C. orbiculare ;
- introduce rotations crop not involving cucurbits for at least one year. This measure is not difficult to implement because C. orbiculare is relatively specific to this botanical family;
- ensure good drainage to cultivated plots;
- destroy spontaneous cucurbits sometimes harboring this fungus in or near the crop;
- set up, mainly in the plots and in the production areas particularly affected, a preventive fungicidal protection rather early ( e-phy ). The treatments will be renewed every 10 days and after each heavy rain;
- avoid irrigation by sprinkling, prefer the localized supply of water, and do not intervene in the plot when the plants are wet.

If one is interested in the sensitivity of cucurbitaceae to anthracnose, they do not all appear to have the same receptivity. Thus, most wild species ( Luffa acutangula , Lagenaria siceraria , Benincasa hispida , Momordica charantia ) would be less sensitive than cultivated species. Cucurbita ecuadorensis and Cucurbita lundelliana have good resistance. Cucumis anguria (Caribbean cucumber) and Cucurbita martinezii (pumpkin) would be sensitive. It should be noted that these differences in behavior have been observed in a variety of contexts, certainly involving strains with different virulences. This information must therefore be used with due diligence.
The resistance to C. orbiculare was mainly worked in cucumber and watermelon in China, the United States (North Carolina), Poland, Bulgaria in particular. The different varieties marketed do not all present the same level of resistance. If the climatic conditions are favorable for C. orbiculare , more or less serious attacks can be observed. Note that it seems difficult to work on anthracnose resistance in melons. Resistant material has nevertheless been described in China on melon and bitter melon.
Let us add that the oriental melon, the squash and the pumpkin in particular would be less sensitive.

Some bio-pesticides have been tested on anthracnose of cucurbits in vitro and in the field in several countries of the world, with more or less success: Trichoderma viride , Streptomyces sp., Streptomyces roseoflavus ... It was the same for various plant extracts: Azadirachta indica (neem or neem), Carya cathayensis , Asarum sieboldii , Anemarrhena asphodeloides (Zhi mu) ...