Preliminary Report - 1998 Seed Treatment Trial - Corvallis, OR.

Eight seed treatments were compared on Stephens wheat during the 1997-1998 growing season. Plots were planted on October 16, 1997 and harvested on July 23, 1998. Plots were part of the 1998 winter grain variety trial at Corvallis, OR.

Barley yellow dwarf virus (BYDV) pressure was high in the trial. This probably resulted from high aphid populations due to warmer than average fall and winter weather. Septoria and take-all disease pressures were also high. We speculate that early BYDV infestation predisposed plants to other diseases. Other wheat varieties and grain species with less susceptibility than Stephens to septoria had yields in excess of 90 bu/a in a larger trial on the same field (Data from larger trial at Corvallis)

Imidacloprid (Gaucho) insecticidal seed treatment resulted in a 20 bu/a yield increase. This was probably due to aphid control and lowered BYDV pressure. There were no differences among fungicide seed treatments or the untreated control. The only measured parameter affected by the seed treatments was yield (bu/a).

This trial was paid for by Gustafson, Inc.

report prepared by Ernie Marx, Faculty Research Assistant, OSU Cereals Extension

Seed treatment

 Yield
(bu/a)

Test weight (lb/bu)

 Protein
(percent)

 1000 K
(g)

 Height
(cm)
Vitavax + Gaucho 68 55.1 10.7 32.5 108
Raxil-Thiram + Gaucho 66 56.8 10.1 37.6 110
Dividend 48 54.7 10.9 32.0 109
Baytan 47 54.0 10.6 34.3 113
Untreated 47 55.2 10.6 28.3 109
Raxil XT 47 53.8 10.8 31.7 108
Raxil-Thiram 45 54.5 10.9 31.3 110
Vitavax 42 55.3 10.8 29.9 107
Raxil-Thiram + Kodiak 39 55.7 10.8 33.7 106

Average 50 55.0 10.7 32.4 109
PLSD (5%) 15 NS NS NA NS
PLSD (10%) 12 NS NS NA NS
CV 17 2 4 NA 3
P-value 0.01 0.22 0.39 NA 0.58

NS = no significant difference
NA = not applicable