The move towards using lower application rates of active ingredients developed for seed treatment use only is clearly illustrated by the latest additions to the barley seed treatment market, agree commentators.

Newly approved Rancona i-Mix, from Chemtura AgroSolutions, and last year’s addition Raxil Star, from Bayer CropScience, both bring considerable benefits either in the seed plant or to the supply chain, as well as performing in the field for the grower.

In addition to their all-important broad spectrum disease control properties, both of the new seed treatments have very low application rates, making them easier to store, handle and use. And that, believes Iwan Jenkins of Chemtura AgroSolutions, is a clear advantage in a competitive market.

“The end result of much lower rates is that fewer packs are required, which improves disposal and logistics, reducing the packaging burden and making the treatment process simpler. And in the case of Rancona i-Mix, which is based on novel micro-emulsion formulation technology, there is also far less dust.”

Containing ipconazole and imazalil, Rancona i-Mix has been approved for use on winter and spring barley and is the second product introduction in Chemtura’s Rancona range of seed treatments.

The triazole chemistry in the product has been developed for seed treatment use only, points out Mr Jenkins, so will not be used in foliar sprays during the growing season.

“It contains just 20g of ipconazole and 50g of imazalil per litre, giving both protectant and curative activity, as well as controlling leaf stripe, loose smut and seedling blights.”

He believes it is the first treatment of its kind to combine the control of seed-borne diseases in barley with application benefits.

“The advanced formulation is really important. As well as allowing a low application rate, the micro-emulsion technology results in a very small emulsion droplet size, keeping dust levels to a minimum and contributing to better operator working standards.”

It also means that sedimentation doesn’t occur, even during storage, so minimal agitation is required. Low viscosity, regardless of temperature, simplifies handling and use, making the treatment easy to pump and simplifying equipment clean down, he adds.

“For the grower, it results in excellent seed flow through the drill, preventing any delays once drilling is underway. Advanced formulations allow accurate delivery and coverage on the seed from a very low application rate.”

Rancona i-Mix is applied at a rate of 1l/tonne, he advises. “We’ve seen good efficacy against target diseases and excellent crop safety. In the field, that translates into rapid, even crop establishment.”

Bayer’s Raxil Star, which contains the first SDHI to be used in a seed treatment, is a direct replacement for Raxil Pro, reflecting the market need for barley-specific treatments, says the company’s Peter Stacey.

“It was approved last year for winter barley, but was only available in very limited quantities,” he reports. “Autumn 2012 plantings will be the first time that many growers have the opportunity to try it.”

Spring barley is not on the current label, he notes, although it is in the approval system and he hopes that it will materialise before too long.

Containing fluopyram, prothioconazole and tebuconazole in a 3-way mix, the triazoxide element that was found in its predecessor has been replaced by the SDHI, fluopyram, in Raxil Star, he explains.

“It brings in the leaf stripe control. It also helps to make it a very strong barley product, offering more than 98% control of loose smut, leaf stripe and covered smut, allowing the treatment to be used for retrieval purposes.”

Fluopyram is not a foliar active SDHI, he stresses, nor will it be developed as one. “As a company, we don’t think that it’s helpful to use SDHIs with foliar activity in seed treatments. We have to be mindful of the resistance threat and the number of applications that can be applied to a crop.”

This last point is a grey area and still to be resolved, admits Mr Stacey. “FRAC is debating whether a seed treatment counts as one application of an SDHI or not. In France, for example, only one application per crop will be allowed and seed treatment use will count as one.”

Raxil Star has a very low application rate of 0.5l/tonne, continues Mr Stacey, setting a new low dose standard.

“It means that it also brings transport and storage benefits to the supply chain and makes logistics easier. So in Raxil Star we have a strong product for the field, as well as for the seed trade.”

Nutrient trials promise results

A new plant growth stimulant combining phosphite with zinc, manganese and other important nutrients is available as a seed treatment for 2012 autumn drilling.

Manufactured by micronutrient specialist Fielder, Kickstart is compatible with all fungicide and insecticide seed treatments and is suitable for cereals, oilseed rape and most other crops.

Alongside generous levels of phosphite, zinc and manganese, it also provides phosphate, nitrogen, potassium and amino acids, all of which have an important role, says the firm’s Barrie Hawkin.

“This is a seed treatment that provides a complete nutrient package for the emergence and establishment phases,” he says. “It could avoid the need for certain other applications.

“Trials we are carrying out this year show an improvement in the evenness of crop establishment and a dramatic increase in root growth. It has clearly demonstrated an ability to help crops overcome early manganese deficiency.