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Q and A with seed lab manager
Kansas After a season of freeze, disease, and rain delays, seed quality is a major issue for producers across Kansas. Eric Fabrizius, seed lab manager at the Kansas Crop Improvement Association, said that during this post-harvest period, he has received a steady stream of phone calls concerning seed quality. Here, Fabrizius addresses what he says have been the most common concerns.
What seems to be the main issue that producers are bringing to you? The biggest problem I've heard is that they're not getting good germ test results. This year, because of all the stress it's been under, the wheat plant's natural protective reaction is to induce more dormancy in the seed, and this has created many problems for "at-home" germ tests. Oftentimes, putting seed in a paper towel at home would work fine, but under this year's circumstances, we need to take dormancy into account to get the germ test to work accurately.
Can you explain the concept of dormancy? Basically, wheat needs a period after harvest in which it goes through an after-ripening process. Until it goes through that, there is a portion of seed that is dormant. If you have your seed tested in a reputable lab, however, seed analysts will break this dormancy so that you will get an accurate germ test result. This year there is a deeper level of dormancy than usual, and if that's not taken into account, you will get lower germ results than normal. We break the dormancy by planting the seed so that it has imbibed water and then putting it in a temperature of 40-50° F for five days. After that period, we do the germ test at about 68° F, which is close to room temperature. It is important to understand that the seed naturally loses this dormancy by the time the seed is planted.
To what extent does dormancy affect the outcome of the germ test? In a year like this, it makes a significant difference. Some people who have planted their at-home germ tests right after harvest have been getting as low as 10 percent germination, and they think that means that they have bad seed. In reality, if they were to break the dormancy, they might find much higher germination, closer to 90 or 95 percent.
What makes lab testing better than at-home testing? I'm happy to talk to people on the phone about this if they want to learn more about using the lab. Getting your seed tested by a trained analyst is always a good idea, but with all the stress seed has gone through this year, and the potential disease infection, understanding the attributes of a good seedling is even more important. Technical skill in reading a germ is more than simply counting the number of seedlings that emerge. During an unusually stressful year, analyzing seedlings to be sure there is a good root and shoot is more critical than usual.
Is germination going to be lower this year because of the quality issues? From what we know so far, we don't expect any real germ problems other than if there's disease in the wheat. We've heard talk of a fair amount of Fusarium (head scab) in the fields, and out of the handful of samples we've completed so far, there's indication of that in the seed as well. Other than that, however, we expect germination to be pretty normal.
What other types of questions have producers been asking you? A few producers have requested vigor tests, and we're happy to provide that service with our accelerated aging test. Typically, vigor isn't highly evaluated, but again, because of seed quality issues, there has been some interest in that. With an accelerated aging test, we will subject seed to a high-temperature, high-moisture stress for three days before planting it in a regular germ test. That kills off the weaker seedlings and may help provide some answers for questions that a producer may have about the quality of his seed. Date: 7/19/07
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