Proper Storage Important to Keeping Seeds Viable

July 12, 2002

COLUMBUS, Ohio - Keeping a plant seed dry is the most important storage rule in maintaining its viability.

Susan Stieve, curator of the Ohio State University Ornamental Plant Germplasm Center, said that too much moisture is the biggest contributing factor behind seed deterioration that floriculture professionals can avoid through proper seed storage.

"The higher the seed moisture content, the quicker the seed quality will degrade," said Stieve. "The most important thing is to keep the seed as dry as possible."

Stieve will discuss the basics of seed storage, factors behind seed deterioration, rules of thumb to follow when maintaining seed quality and the storage life of various plants at the 2002 Ohio Florists' Association Short Course. Her presentation will be held on July 16 at 8 a.m. The educational event and trade show will take place from July 13-July 17 at the Greater Columbus Convention Center and will bring together professionals from around the country to discuss a wide variety of topics pertaining to the floriculture industry. Over 180 seminars will be presented.

Seed deterioration is an unavoidable and progressive biological process that growers and seed companies can better manage by recognizing factors behind seed deterioration and following basic storage rules to improve longevity and enhance performance.

Stieve said that relative humidity and temperature are the two main causes of seed deterioration, although many other factors such as genetics, seed structure, seed chemistry and physical and physiological qualities can be a predisposition for seed deterioration.

"Rate of seed degradation depends on the type of seed that you have and the overall storage life of the plant," said Stieve. "Understanding what type of seed you have and its relative storage life is the first step to effective seed storage."

Stieve said that growers and seed companies can also follow a few basic rules of thumb when keeping temperature and relative humidity in check. Every 10 degrees Fahrenheit decrease in storage temperature doubles the seed storage life at temperatures above freezing. Every 1 percent decrease in seed moisture content doubles seed storage life.

"Basically, the colder the storage conditions are, the longer the seed will remain viable," said Stieve. Researchers at the Ohio State Ornamental Plant Germplasm Center maintain seed storage a few degrees above freezing which allows for seed storage of up to 20 years. The National Center for Genetic Resources Preservation, based in Fort Collins, Colo., stores seed at zero degrees Fahrenheit, maintaining seed viability for at least 50 years.

"Most growers won't have a need to store seed for that long of a period of time," said Stieve. "They should leave such storage concerns to seed companies and determine seed needs on a yearly basis."

She added that seeds represent only 5 percent of production costs, so growers should consider the risk of planting stored seed as opposed to purchasing new seed.

"Seed viability is economically important in the floriculture industry. On an agronomic scale as a whole, it is estimated that 25 percent of the annual value of inventoried seed is lost because of poor seed quality, much of which is a result of poor storage conditions," said Stieve.

The floriculture seed industry worldwide is estimated to be a $500 million-a-year business. According to the International Seed Federation, the value of seed in 2002 was estimated at $4 billion and is expected to increase to $20 billion by 2010.

"That's quite a lot of money for such a small product," said Stieve.

To help reduce seed losses, Stieve recommends that growers use opened seed within six months and unopened seed within 12 months, retest all stored seed prior to sowing, allow seeds to reach room temperature before opening package and store opened seed packages with a seed desiccant - a product that helps keep the seeds dry.

For more information on the 2002 OFA Short Course call (800) 737-9486 or log on to http://www.ofa.org.

Author(s): 
Candace Pollock
Source(s): 
Susan Stieve