Phytophthora capsici Leonian, (1922)

Sources of semis,
Root and crown rots
Lesions on leaves and fruits

- classification : Chromista, Oomycota, Oomycetes, Peronosporomycetidae, Peronosporales, Peronosporaceae
- synonymie : Phytophthora parasitica var. capsici (Leonian) Sarej., (1936)
- dénominations anglaises : crown and root rot, seedling damping-off, phytophthora blight



Phytophthora capsici soil-borne is a polyphagous fungus especially known in France to affect peppers on which its attacks in crops can sometimes be devastating. This chromist, favored by the conditions of humid production, also affects tomatoes, eggplants, but also several Cucurbitaceae. Note that its first attacks were reported on pepper in 1922 in New Mexico; it is now widespread in many production areas around the world , both in nurseries and in the field. Its damage can be considerable on Cucurbitaceae, this is particularly the case in the United States, where total crop losses are reported in certain plots. This situation is partly due to the rapid spread of the disease (plants often die a few days after the onset of the first symptoms), but also to a critical lack of very effective protection methods. The majority of Cucurbitaceae species are sensitive, those belonging to the genus sensitive, Cucurbita would be particularly cucumber and melon much less.

Let add that in France us , we have only very observed occasionally damage due to P. capsici on Cucurbitaceae, mainly on courgette. Unlike other countries, this oomycete does not pose a threat to the cultivation of species of this botanical family.

This fungus exhibits great genetic diversity, the different strains studied notably exhibiting different host ranges and aggressiveness.