...From the pages of Agricultural Research magazine
Seed Saver: Iodine-based
Plant physiologist Ida Yates
and biological lab technician
Donnie Maxey inoculate corn
ears with Fusarium verticillioides
at a field site near
Corn seeds are bull's-eye targets for Fusarium verticillioides,
formerly known as F. moniliforme, a fungus that produces toxins
harmful to humans and animals. ARS
scientists are exploring Plantpro 45, an iodine-based fungicide made
by Ajay North America, LLC, as a treatment to reduce Fusarium
Because Plantpro 45 is being examined as a seed treatment,
it is vitally important that it be safe and effective. ARS plant physiologist
Ida Yates likes the idea of using the treatment because, "iodine
is the active ingredient, and it is a non-toxic, naturally occurring
Ajay, of Powder Springs, Georgia, initially tested Plantpro
45 as a foliar fungicide on bananas in 1994. The company saw indications
that the compound might have other uses and sought partners to develop
them. Ajay and ARS in nearby Athens, Georgia, combined their efforts
in a cooperative research and development agreement to investigate Plantpro
"A century of research on F. verticillioides
hasn't produced methods to control infections," said Yates. "Plantpro
45, however, shows the ability to control mycotoxin-producing fungi
in post-harvest corn seed."
Yates' studies of commercial sweet corn cultivar Silver
Queen revealed that Plantpro 45 reduced F. verticillioides growth
by almost 75 percent in infected kernels. These findings suggest a potential
postharvest use of Plantpro 45: disinfecting corn seed kernels before
storage and planting. In the studies, 10 micrograms of Plantpro 45 per
kilogram of seed was found to be optimal.
Plantpro 45 has other benefits as well. While it inhibited
F. verticillioides growth in infected corn, it didn't harm the
growth of corn plants when used at a rate of 10 micrograms per kilogram
of corn seed. In fact, compared to distilled water, Plantpro 45 increased
plant growth by 30 percent and seed viability by 100 percent.
F. verticillioides's reproductive spores are on
corn silks before kernel infection and appear to be sensitive to Plantpro
45. A concentration of just 5 parts per million was adequate to eradicate
50,000 spores under laboratory conditions. As an experimental preharvest
treatment, spraying Plantpro 45 on corn plants after appearance of the
silks could considerably lessen the amount of kernel infection. Preliminary
field studies were conducted this year, and the data is being analyzed.
In general, Plantpro 45 might fill a major need, since
growers currently have no fungicides or cultural practices to control
most mycotoxin-producing fungi in corn. "Plantpro 45 could be extremely
useful because it might be a cost-effective, alternative method for
fungal control," said Yates.By Sharon
Durham, Agricultural Research Service Information Staff.
This research is part of Food Safety (Animal and Plant
Products), an ARS National Program (#108) described on the World Wide
Web at http://www.nps.ars.usda.gov.
is with the USDA-ARS Toxicology
and Mycotoxin Research Unit, Richard B. Russell Agricultural Research
Center, 950 College Station Road, Athens, GA 30603; phone (706) 546-3523,
fax (706) 546-3116.
"Seed Saver: Iodine-based Fungicide Foils Fusarium" was published in the January 2003 issue of Agricultural Research magazine.