Download Phytophthora root rot and heavy-clay, water

Phytophthora root rot and heavy-clay, water-saturated soil
Summary: To select a variety to plant on a Fargo-clay type soil, find one with
phytophthora root rot resistance. Then evaluate the yield data that NDSU provides
for this soil type.
Some company varieties that yield well on a Fargo-clay soil in a normal year, do not
yield well on this soil type in a wetter-than-average year. However, we did find some
company varities were good yielding on a Fargo-clay soil for both wet and dry
conditions. The varieties that were high-yielding under wet conditions either had majorgene resistance to phytophthora root rot or good tolerance. Major gene resistance
includes genes like the Rps1k (K-gene), Rps6, or Rps1c. Tolerant types do not have
major gene resistance, but still yield well when phytophthora root rot is present. We also
found that some varieties that have major gene resistance to phytophthora root rot, did
not yield well on a Fargo-clay soil under wet conditions. For this reason, we test 40
private company varieties for yield each year at Fargo, under both wet and dry
conditions. This information is available in the ‘North Dakota Soybean Performance
Trial’ booklet (A-843) each year and is also available online at
http://www.ag.ndsu.edu/varietytrials/soybean.