Germination Testing for Wheat Seed

Some producers may be anxious this year to find out the germination percentage of the wheat they harvest, to see if it will make suitable seed. If they do a home germination test too soon after harvest, they may be shocked at the low germination percentage – unless the test is done correctly. That’s because wheat has a post-harvest dormancy requirement (some varieties more so than others). Even high-quality seed will not germinate at its maximum capacity right after harvest in most cases. This post-harvest dormancy reduces the risk of pre-harvest sprouting when the harvest is delayed by weather or other factors.

To get around that, for the first several weeks after harvest, it’s important to make sure the wheat is pre-chilled before taking a germination test. Producers testing their seed at home should also pre-chill the wheat by planting it and refrigerating it at about 40 degrees for 5 days. If the seed is not pre-chilled, producers should wait a month and a half after harvest before testing for germination.

There are differences among varieties in the duration of their post-harvest dormancy, so much so that some varieties are more prone to pre-harvest sprouting. Hard white wheat varieties with poor sprouting tolerance, for example, have almost no summer dormancy requirement. They will germinate almost as soon as the seed is harvested. Other varieties have a relatively long summer dormancy requirement and may not germinate well for five or six weeks after harvest unless the seed is pre-chilled. By Labor Day, all varieties will have lost their summer dormancy and should germinate unless the seed is defective.

If there is any question about the seed's viability, it is well worth the cost to have it tested for germination by a professional seed laboratory. This is especially true in areas where there was freeze damage, severe drought, heat stress during grain filling, a rain delay at harvest, or wheat head scab.

Professional Lab Testing

Having your seed professionally tested for germination is always a good practice, and with the wet conditions and thunderstorms during wheat harvest in most Kansas areas this year, it is highly recommended.

To have an official germination test on the seed, send a two-pound sample to:

Kansas Crop Improvement Association
2000 Kimball Ave.
Manhattan, KS 66502

A sample submittal form can be printed off from the KCIA website: www.kscrop.org/seed-lab.html

Other seed quality tests are also available and are listed on the submittal form.

Home Testing: Doing It Correctly

If producers want to test their seed for germination at home, it needs to be done correctly to be of value.

  • Place two moistened paper towels (on top of each other) on a flat surface. The towels should not have free water in them.
  • Arrange fifty (50) seeds on the towels, leaving approximately an inch border around the edges.
  • Place two more moistened towels over the seeds.
  • Make a ½ to ¾ inch fold at the bottom of the four paper towels. This will keep the seed from falling out.
  • Starting on one side, loosely roll the paper towels toward the other side (like rolling up a rug) and place a rubber band around the roll(s).

Place the roll in a plastic bag. Seal, but not completely, to keep moisture in while still allowing some air into the bag.

For newly harvested seed:

  • Place the bag upright in the refrigerator for 5 days and then remove and place it upright at room temperature for an additional 5 to 7 days.
  • Remove the sample from the bag and unroll the towels.
  • Count and record the number of healthy seedlings (adequate root and shoot development and NOT overtaken by disease).

For carryover seed, or after September 1:

  • Place the bag upright at room temperature for 5 to 7 days.
  • Remove the sample from the bag and unroll the towels.
  • Count and record the number of healthy seedlings (adequate root and shoot development and NOT overtaken by disease).

To calculate the germination percentage: divide the number of healthy seedlings by the number of seeds tested and multiply by 100.

Example: (42 healthy seedlings ÷ 50 seeds testing) X 100 = 84% germination

This may be repeated multiple times for each sample to obtain more accurate results, with testing up to 400 seeds. If the seed is treated with a fungicide before planting, the test should be performed after the treatment is applied, as it can increase the germination percentage.

 

Romulo Lollato, Extension Wheat and Forages Specialist
lollato@ksu.edu

Logan Simon, Southwest Area Agronomist
lsimon@ksu.edu

Jeanne Falk Jones, Northwest Area Agronomist
jfalkjones@ksu.edu