90-day RhiNo restriction lifted

The restriction limiting potato seed treatments with RhiNo (flutolanil) to within 90 days of planting has been lifted, allowing applications to next season's seed to be made from now on.

According to Scottish Agronomy the benefits of treating in advance of 90 days include tuber safety, more flexibility, better disease control and the option to apply at the same time as other treatments.

"The freedom to treat well before the break of dormancy is a distinct advantage," says Eric Anderson of Scottish Agronomy.

He explains that if infection is allowed to develop, the rhizoctonia fungus grows on the tuber skin towards the eyes, often without displaying visible symptoms. "Therefore, early treatment prevents the disease spreading into the eyes that can eventually lead to stolon pruning and stem canker. There is also no danger of damaging chitted seed – a risk that increases the closer treatment is to planting."

He adds that an extended treatment window offers growers more time and flexibility to treat, relieving workloads. Treating seed can fit around grading and applications can be made at the same time as other treatments, such as imazalil for silver scurf and dry rot control as seed goes into store. "It also reduces pressure during the busy planting period," says Mr Anderson.


Treating earlier does not reduce the efficacy of RhiNo compared to treating closer to planting says Peter Shakespeare of Certis which markets the product. "Compared to other rhizoctonia treatments RhiNo has a totally different mode of action and delivers not only preventative activity, but also curative and systemic action as well." He adds that growers opting not to treat seed themselves can request RhiNo treatment from seed suppliers.