In summer 2008, University of Arkansas (UA) researchers began using a new automated system called the Seed Vigor Imaging System (SVIS) designed to estimate seed quality, particularly seed vigor. Designed by Miller McDonald at Ohio State, SVIS captures a digital image of germinating seedlings, which is then processed by a computer.
The end goal is to help growers understand seed quality long before a seed meets the soil.
With growers facing high seed prices and Arkansas experiencing poor stands the past several years, concerns about seed quality have greatly increased.
“We're just getting into this,” says John Rupe, plant pathologist at the University of Arkansas (UA). “Seed is sold based on the standard germination test, but the farmer is not provided with any information on seed vigor. We need a way to consistently evaluate seed vigor and understand what that means to field performance.”
WITH GROWERS SPENDING as much as $50/acre on seed, they need more than standard germination numbers to determine seed quality.
“A seed is very complicated,” says Rick Cartwright, plant pathologist with the UA Division of Agriculture. “From a research standpoint, we want to know information about emergence, establishment and survival. Many factors affect seed quality, such as too much heat, poor storage and poor handling. Growers may not have thought about seed this way in the past.”
Vigor, the ability to germinate and establish plants under a stressful wide range of conditions, is equally complex. SVIS is potentially a quick, repeatable predictor of seed vigor.
From April to June 2008, the university conducted a large survey, pulling 400-500 seed samples from growers and companies then processing results at the university lab as well as two other labs.
The results were revealing. “The standard germ test results on these samples did not tell us much about whether a good stand came up in grower fields, but the accelerated aging test results on these same samples tracked stand performance better,” Cartwright says. “This certainly indicates that a vigor measurement of seed, such as AA, is potentially very important in assessing soybean seed quality in Arkansas.”
A lot of seed had high germination and vigor, but there was quite a range in vigor, says Rupe.
SVIS offers several advantages over a manual process. The process can shave off nearly a week when analyzing samples, compared to the AA test. “You can collect SVIS data in about three days as opposed to 10 days for the AA test,” says Cartwright.
The system also creates a permanent data record that researchers can easily access over time. While researchers aren't ready to give growers definitive information about seed quality in Arkansas yet, they do recognize one factor from the first year's work. “We're telling growers that vigor measurement of seed is valuable, and should be requested for seed being purchased,” says Cartwright. Some seed companies in Arkansas already provide the AA test (vigor) results for seed lots, either on a Web site or sometimes on the seed delivery invoice.
This year, bigger surveys are planned as the university team continues to validate the SVIS process. “To see how consistent our lab is in assaying seed, we are sending some of our samples to Kentucky and to the Arkansas Plant Board as well as evaluating them ourselves,” Rupe says. “Kentucky has a strong seed quality and production program. This will validate our sampling procedures. We are also looking at performance of seed with different vigor levels under a range of field conditions.”
In the future, Cartwright and Rupe hope that SVIS will provide growers more information on what to expect from their seed.