Leather Berry Indication Model

Leather Rot caused by Phytophthora cactorum

The fungal pathogen P. cactorum is able to infect more than 200 species, including strawberry and woody ornamentals and fruit crops. This pathogen occurs worldwide, but is most common in temperate regions. P. cactorum forms zoospores, which originate from hyphae or germinating oospores and sporangia. In many cases, the pathogen may enter a field through infected transplants. Infection by P. cactorum usually occurs during warm periods with prolonged wetness. Zoospores are released from sporangia during saturated soil conditions and enter the plant through wounds. Once the zoospore gets in contact with a host, it enters the host and developing hyphae of the fungus colonize the host.


P. cactorum oospores form sporangia in water saturated soil. This sporangia will release its zoospores into free water in the soil. Free water in the upper soil layer is the limiting factor for the spread of this disease. Release and mobility of zoospores can only take place if the temperature in the surrounding media is warm enough.

Leather Rot caused by Phytophthora cactorum Infection Model

  • 3 day average temperature higher than 12 °C,
  • assessing free water in the soil:
    • More than 10 mm of rain today => 1 day infecton period or
    • More than 14 mm of rain on 3 rainy days or
    • More than 17 mm of rain on 2 rainy days out of 3 or
    • More than 20 mm of rain on 1 rainy day out of 3 => 3 day Infection period

In a high pressure situation every infection period has to be taken serious. In situation with a lower disease pressure a 3 day infection period has to be taken serious.

In fieldClimate.com we calculate infection days with "yes" or "no"- so it is always no infection (0) or infection (100).