Phytophthora sojae also produces oospores that can remain dormant in the soil over the winter, or longer, and germinate when conditions are favourable.

[2] Phytophthora sojae is a diploid organism with a genome size of 95 Mbp (Millions of base pairs).

[3] The natural chemical farinomalein (a metabolite from entomopathogenic fungus Paecilomyces farinosus[3]) has shown potent and selective inhibition (0.15-5 μg/disk) against eight isolates of plant pathogenic Phytophthora sojae.

[2] These results suggest that farinomalein might be useful as a candidate pesticide for the treatment of Phytophthora stem rot in soybean.

Phytophthora sojae infects soybean plants (Glycine max) and many members of the genus Lupinus.

[6] Foliar blight is also a symptom of Phytophthora sojae, especially when the plant has recently experienced heavy rain.

Microscopic identification of an oospore that measure around 40 micrometers in diameter from a soybean plant sample is a definite sign of Phytophthora sojae.

They possess thick cell walls with cellulose that enables them to survive harsh conditions in the soil without germinating for several years.

[8] Once zoospores have made contact with the host root, they encyst on the surface, break down the plant cell wall with proteolytic enzymes and begin to germinate.

The host plant will begin to exhibit secondary symptoms such as stem canker, wilting, and chlorosis as Phytophthora sojae continue to reproduce.

Solving it only by creating optimal drainage does not restrict the pathogen because the field may be subject to continuous heavy rain which induces flooding.

Metalaxyl is most effective when applied to the soil as it allows the plant to take it up through the roots and elongate the control period in comparison to a seed application.

As with all fungicides, Metalaxyl is effective for prevention only and should be applied before the disease has established itself inside the tissues of the soybean plant.

Improving field drainage and soil tillage are cultural practices that can help minimize the effect of Phytophthora sojae.

[1] Recently there's been evidence that soybean plants from South Korea and China had a diversity of resistance that is much higher in these countries compared to other soybean-cultivating nations.

[6] This indicates that soybean plants have been around in these areas longer and thus had more time to develop resistance against a variety of diseases including Phytophthora sojae.