Plant Health Initiative

Seedling diseases - Agronomic impact

Soybean seedlings at emergence. Stand reductions may or may not reduce yield. Photo credit: University of Nebraska

Pre- and post-emergence diseases of soybean are common in all soybean-growing areas of the United States.

Seed and seedling diseases reduce stands in the spring, with severity varying from year to year. However, a stand reduction does not always mean a lower yield since the soybean plant is able to compensate for space.

Infection by major soybean pathogens such as Fusarium solani f. sp. glycines (the causal agent of sudden death syndrome), and Phialophora gregata, the brown stem rot pathogen, also occurs in early vegetative growth stages but can remain latent. Disease development and subsequent yield loss can be signficant later in the growing season when the plant reaches reproductive growth stages.