How to recognize and combat watery fruit

Phytophthora sp. is a phytopathogenic organism belonging to the oomycetes, a group of fungus-like microorganisms that can affect numerous plant species and cause significant losses under favorable conditions. Its development is closely linked to the presence of water and to soils or plant surfaces that remain moist for extended periods. The pathogen can survive between favorable periods through resistant structures, primarily oospores and, depending on the species, through mycelium present in infected tissues or plant debris. When environmental conditions are suitable, it can produce sporangia, structures capable of generating motile zoospores. Zoospores are transported by water and constitute one of the main means of dispersal and infection by Phytophthora. They can reach the surface of fruits through rain splash, irrigation, runoff, or contact with contaminated water. After reaching susceptible tissue, the zoospores can encyst, germinate, and develop germ tubes that penetrate plant tissues. Infection can also occur through direct contact with contaminated material or through small wounds and damaged areas. Once inside the tissues, the pathogen develops mycelium and progressively colonizes the cells, causing their destruction and the appearance of moist, necrotic lesions. On the affected tissues, it can produce new sporangia, which release zoospores and allow the infection to spread rapidly when water is available. Splashing can carry the inoculum from the soil to nearby fruit, while runoff can transport it between different areas of the crop. The pathogen's survival in the soil and in infected plant debris makes eradication difficult once established. High humidity, poor drainage, and moderate temperatures particularly favor its activity and can generate new foci of infection in a short time. For this reason, water management, reducing sources of inoculum, and preventing contact of fruit with contaminated soil or water are fundamental elements for limiting its development.