Seed Applied Insecticide (SAI) Laboratory Test

SEED APPLIED INSECTICIDE (SAI) LABORATORY TEST AND FIELD EMERGENCE RELATIONSHIP STUDY 2007

Laboratory test results of commercially conditioned and treated dent corn seed lots were compared with field emergence data.

Each lot’s seed quality was evaluated utilizing standard (warm) germination, tray cold [70% media water holding capacity (WHC)], reduced moisture test (50% media WHC), and saturated cold test. Additionally, four replicated plots containing two rows of 33 seeds were planted by KMR (Carroll, Iowa) at five locations: Lake City (LC), IA, Manilla (MA), IA, Logan (LO), IA, Elk Point (EP), SD, and Tekamah (TE), NE.

The five field locations emergence responses were averaged and compared to laboratory test results for each representative sample. Standard (warm) germination responses over estimated all seed lot grand field mean values by 3 to 19 percentage points and 9% overall. This outcome would be expected since the warm germination test is designed to evaluate the seed lot maximum germination potential under ideal laboratory conditions. Cold (70% WHC) germination responses tracked both higher (8 times) and lower (9 times) than grand mean percentages for seed lots and overall averaged 1% lower. A vigor test would be expected to provide this type of response since warm soil temperatures existed at planting. Reduced moisture test germination responses track nearly equal or higher on 15 out of the 17 seed lots and the overall mean was 3% higher than the overall mean field emergence. Saturated cold, as expected under low stress field emergence conditions, tracked lower on 12 out of the 17 seed lots and had a mean 11% lower than mean field emergence.

View the complete study results (PDF 228 KB).

MWSS hopes to continue this laboratory and field comparison study in 2008. The study will have two planting dates one early and one late to collect the needed imbibitional chilling stress and low stress field conditions data.

Information gained in the 2007 study has initiated internal research on potential non-regime modifications to the MWSS tray cold test and the development of an alternative standard germination test for SAI treated seed.

Corn Tray Cold Test

Amanda Patin - Research Coordinator