Biology, epidemiology

Trichothecium roseum has biological characteristics quite comparable to those of other fungi found on grape berries. It probably lives as a saprophyte on the vine and in its environment.

• Storage and sources of inoculum

This fungus is probably present in many vine production areas around the world: in the soil, on various plants and on plant debris .... It is known to affect various fruits (apple, pear, plum, cherry, etc.) and some vegetables (melon, cucumber, tomato, etc.), etc. These "alternative" hosts thus help to multiply and conserve them.

• Plant penetration and host invasion

It is observed on grape berries mainly at maturity. It settles secondarily in B. cinerea on berries already affected by gray rot, on and in the heart of the clusters. Subsequently, its mycelium grows extensively and covers the gray mold probably taking advantage of the parasitism of B. cinerea . Note that T. roseum is likely to produce a mycotoxin, a trichothecene which can be found in wine.

• Sporulation and dissemination of fungi

This fungus sporulates abundantly on the surface of rotten berries covered by gray mold of B. cinerea (Figures 1). Its conidia are dispersed by air currents and / or splashing water following rains.

• Factors influencing the development of fungi

It grows rapidly and sporulates abundantly in the presence of humidity and when temperatures are mild.