Seed Vigor Tests Research Articles

Navy Bean Seed Vigor and Field Performance in Relation to Microwave Radiation1

AbstractThe effects of microwave irradiation of seed have been evaluated for many years on numerous crops, but information is limited concerning the effect on navy bean (Phaseolus vulgaris L.). Seed lots were exposed to 2450‐MHz electric fields of three intensities for various time periods and tested for germination, vigor, and seed yield in laboratory and field studies for 2 yr. Seed exposed to temperatures ranging from 38 to 49°C had significantly increased germination percentage. Seed vigor tests were less conclusive. Exposure of seed to a high power level (500 W) or to seed temperatures above 62°C reduced germination and vigor. The effect of radiation at high seed moisture content (180 g kg−1) was similar to the low moisture content level (90 g kg−1).

The volatile exudates from germinating pea seeds of different viability and vigor

Pea seeds var. Kriter were stored aseptically at 92% relative humidity and 30 °C. After 0, 4, 6, 8, or 10 weeks of storage, viability, vigor, and volatile exudates were determined on sublots of seeds. As storage time increased, vigor, as measured by dehydrogenase activity, growth of embryonic axes, and conductivity decreased. Later, viability also decreased. Imbibing and germinating pea seeds produced ethanol, acetaldehyde, and lesser amounts of methanol. No qualitative differences in volatile exudates were observed from germinating seeds regardless of age or storage condition. Nonaged seeds with highest vigor produced the smallest amounts of volatiles, but with increased aging the quantities of ethanol and acetaldehyde gradually increased. Dry seed produced small quantities of both volatiles. The amount of these compounds produced reached a maximum between 12 and 48 h of germination. Infestation of seed samples with Enterobacter cloacae or Trichoderma harzianum reduced the quantities of these compounds measured. These results indicate that determinations of acetaldehyde and ethanol in the space over germinating seeds by means of gas chromatography may be a useful seed vigor test.

Relationship of Soybean Germination and Vigor Tests to Field Performance1

AbstractA number of soybean (Glycine max (L.) Merr.) seed vigor tests are available through seed testing laboratories for use by seed producers and farmers. In order to determine if these tests provide more information on field performance than the standard warm germination test, seed lots differing in quality were planted in different field environments at a constant seeding rate (350,000 seeds/ha) and evaluated for percent emergence, final stand at maturity, and grain yield. Several germination tests, including the warm germination test (also evaluated for percent strong seedlings and percent diseased seeds), cold test, accelerated aging test, and tetrazolium test were conducted by seed analysts and statistically correlated with field performance.Experiments were conducted on Cisne silt loam (Mollic Albaqualf) at Brownstown, Ill. and Proctor silty clay loam (Typic Argiudoll) at Urbana, Ill. When the same seed lots were planted at different planting dates and locations, field performance differed markedly depending on seedbed conditions. Stress seedbed conditions were difficult to predict in advance. For example, at one location poorer emergence was observed with a warm, dry seedbed than with a cold, moist seedbed. A greater number of laboratory tests correlated with field emergence in favorable seedbed environments than in unfavorable environments. The cold test showed a consistent high correlation with field emergence and final stand. In general, reduction in yield was associated with a loss in stand. The cold test was the most effective germination test for identifying seed lots that would perform well in the field and should provide more assistance than the standard warm germination test in identifying problem seed lots.