US to approve ethaboxam as a seed treatment

Seed treatments have been used as a way to protect seeds from soil-borne fungi and to protect the farmer’s seed investment. But combating seedling diseases can be complicated when dealing with the either multiple fungi or multiple species of fungi in a field.

"When we deal with plant diseases, quite often we are dealing with a single organism that’s causing a disease,” said Jason Bond, plant pathologist, Southern Illinois University. “But in the area of seedling diseases, there are multiple pathogens and multiple species of a particular genus, so you would have a huge complex in any given field that could be potentially involved in a seedling disease complex.”

However, not all pathogens are fungi, Bond explained. “We have some organisms that are oomycetes, and then we have some organisms that are true fungi, like Fusarium and Rhizoctonia.

Then in each one of those we have multiple species. So, that’s a challenge with regard to us doing control measures, to manage them and also to find out what in the world is going on in the field when we’re dealing with problem situations.”

Controlling both fungi and oomycetes can be challenging for seed treatments, but a new active ingredient may help offer new protection for seeds as of spring 2014.

Ethaboxam, which was awaiting federal registration from the US Environmental Protection Agency(EPA) for use as a seed treatment on corn, soybeans, cereals (excluding rice and wild rice), sorghum, canola and wheat, is expected to be approved by the end of 2013.

Valent USA plans to introduce ethaboxam to the industry in combination with metalaxyl as a seed treatment in a limited capacity for 2014. The combination of the two actives, yet to be given a name, will provide two different mode of actions to fight off disease development and fungicide resistance. The name for this combination will be announced soon.

Ethaboxam is a novel thiazole carboxamide fungicide and is the first Phytophthora and Pythium seed treatment fungicide to be introduced in more than 30 years, according to Dair McDuffee, seed treatment specialist, Valent USA. Ethaboxam is expected to significantly improve disease control against the most prevalent fungal species.

“We haven’t had any new active ingredients that are targeting oomycetes in the seed treatment industry for a good number of years,” said McDuffee.

Valent has had ethaboxam in research for eight years and has tested it in the field in combination with its metalaxyl fungicide active for six years, McDuffee said. During the research on ethaboxam, it provided good control of oomycetes, but when combined with metalaxyl, the combination offered better results.

Research shows the two actives are very complementary products. “Their physical properties mix well and you’re really going to get consistency, you’re going to increase the number of situations where you get adequate control even when you’re planting early and into problem soils or you have moisture issues early in the year,” McDuffee contended.

He explained that the two modes of action combination works well on multiple species to better protect the seed/seedling from oomycete pathogens such as Pythium and Phytophthora.

"We’re finding that a farmer could be battling up to five to 10 different Pythium species in a field. So, we think our two modes of action system will offer a broader spectrum of control, and based on the different physical properties of ethaboxam and metalaxyl together, you’re going to be able to control seedling diseases better and get that early stand establishment.”