Seed Vigor Assessment Quicker, More Accurate with New System

August 29, 2001

COLUMBUS, Ohio - A new system that assesses seed vigor may improve the way seed companies evaluate overall seed quality and growth performance.

Ohio State University crop production and computer science researchers have developed an automated image-scanning system that is quicker and more accurate than manual tests and improves upon existing commercial automated systems.

Seed companies conduct rigorous stress tests on seed varieties, including cold tests and accelerated aging tests, to determine which varieties have the highest percentage of germination, thus providing farmers and greenhouse growers the best opportunities for a larger yield.

"When you see the percent germination on the back of a seed package that tells you how alive that seed is, the stress tests to obtain that number are usually done by hand," said OSU seed scientist Miller McDonald. "They are not very accurate and it's a time-consuming, laborious process." The image scanning system combines an inverted flatbed scanner that records digital images of germinating seeds with a computer which then processes the data and gives a quantitative measurement of overall seed vigor. Such a process eliminates the need to conduct stress tests by hand. The system can calculate overall seed vigor within three to four days of germination, as opposed to seven to 14 days if tested by hand.

The researchers believe the system is also an improvement upon existing commercial tests, which only examine certain seedling parts, such as root length or the cotyledon (the part of the seed that produces the plant's first leaves). The new system has the capabilities of measuring all seedling parts, providing more accurate and reproducible seed vigor data.

"We wanted to develop technology that will benefit the seed industry. With this system, seed companies can provide their customers with more accurate germination information, and hence, the highest-quality seed lot," said McDonald.

Added OSU horticulturist Mark Bennett, "Farmers can't afford to have 10 percent of their seeds being dogs, and seed companies want to be known as quality seed providers." The image-scanning system measures growth of the seed; the roots; and the hypocotyl, or the plant stem located just below the cotyledon. A numeric index of zero to 1,000 (zero indicating poor germination and 1,000 indicating ideal germination) is given to each plant part, and then a final number is given for the seed variety that identifies its overall vigor.

"Seed quality varies -- one year it could be high and the next year it could be low. We've had farmers tell us how their old tried-and-true variety they use year after year goes bad. It may say 80 percent germination on the package, but only 30 percent of the crop comes up," said Bennett. "The system provides a good predictor of what will go into the field or greenhouse. For example, long roots uniformly emerging indicate a more vigorous seed lot." In addition to the system being quicker and more accurate, it is also cost effective. Kikuo Fujimura, a visiting computer science professor who helped develop the software, said a scanner; a computer and the software to analyze the data are the only components needed to make the system work. "We worked on the project using a digital camera, but found that to get the precision you need, you have to spend thousands of dollars on a good digital camera," said Fujimura. "We found that a flatbed scanner can be just as precise, but it only costs about $100." The prototype developed by the researchers measures seed vigor of lettuce seedlings. The researchers chose this crop for study because it has a very simple root structure. The system is currently being modified to measure seed vigor of soybean and cotton, which have more complex root structures. The system will also be refined to calculate such variables as soil type and weather impact on seed growth.

"Variable seed growth can be a huge cost for growers," said Bennett. "They want to know what seeds can overcome stress, especially when they are wanting to plant as early as possible and they have cool, wet spring weather to contend with." The researchers have applied for a patent, and several seed companies have expressed interest in testing the system on their products. The project is being funded by a $100,000 Ohio Agricultural Research and Development Center grant and $45,000 from the American Seed Research Foundation.

Author(s): 
Candace Pollock
Source(s): 
Mark Bennett, Miller McDonald