Germination and Vigor Testing Trends

SGS Mid-West Seed Services (SGS MWSS) has been tracking thousands of corn test results since 2001 (Table 1). This data set helps us understand relationships in quality over past years and is a gauge on the percentage of samples which meet quality standards.

In the past eight months, 92.2% of the warm tests averaged 93% or higher on germination.  This is the highest average warm germ in the past seven years.   In prior years, the percentage of warm germs 93% or higher for a full 12 month period has been as low as 89.1% with a six year average of 90.9%.  

Tray cold test data is presented in Table 2 and 84.7% of samples tested during the past eight months averaged 85% or higher and is lower than any of the past six years.  The 84.7% is similar to results from the 2001-2002 season and could be a normal fluctuation.  The six year mean for colds equal to or above 85% is 87.0%.

Saturated cold test results are shown in Table 3 and show a decrease similar to the tray cold.  The percentage of samples meeting 80% germination or higher for 2007-08 is 69.4%.  The six year average for saturated cold tests equal to or greater than 80% is 76.3%.

One possible explanation for slightly lower cold and saturated cold tests this year (aside from normal annual variation) may be an increase in carryover seed treated with seed applied insecticides (SAI’s).   SAI treated seed and laboratory vigor testing can result in slightly lower testing percentages with certain pedigrees and seed sizes.  If this is a concern with one of your seed lots, SGS-MWSS recommends trying our sand/peat cold test (Figure 1.) as an additional quality assessment test.

Figure 1.  Sand/Peat Cold Test

Table 1.  Corn Warm Germ Testing

Sample year	% of Warm Tests >93%
2007-08	92.2
2006-07	91.9
2005-06	91.7
2004-05	91.1
2003-04	89.1
2002-03	91.4
2001-02	90.4

Table 2.   Corn Tray Cold Testing

Sample Year	% of Cold Tests >85%
2007-08	84.7
2006-07	86.6
2005-06	85.5
2004-05	88.4
2003-04	89.6
2002-03	87.3
2001-02	84.8

Table 3.   Corn Saturated Cold Testing

Sample year	% of Cold Tests >80%
2007-08	69.4
2006-07	74.6
2005-06	73.7
2004-05	77.6
2003-04	76.4
2002-03	75.6
2001-02	80.1

Note: Data from these tables contain results from seed lots which are company inventory and may not be offered for sale, including aged seed lots, frost damaged lots and lots with numerous other sources of damage.

Brad Farber - Corn Laboratory Manager