As part of a renewed effort to help users avoid problems with hard water, Bayer is issuing updated guidance on the mixing sequence for its biological insecticide FLiPPER (fatty acids C7-C20).
The latest advice, which highlights the most suitable time to add a water conditioner when filling the spray tank, follows the production of detailed advice on application best practice outlined at the Bayer vegetable conference in February this year.
The need for clearer guidance when adding FLiPPER to the spray tank reflects the extent to which hard water can impair performance if left uncorrected, explained Claire Matthewman, Bayer campaign manager for horticulture.
“There has been great interest in FLiPPER since its launch at the end of 2019 because of the advantages it offers such as having no harvest interval and the absence of a residue limit, but as a contact-only insecticide containing fatty acids, there has also been questions as to how it should be applied to make the most of its contribution,” said Ms Matthewman.
The mixing sequence for X-Fusion, a non-acidifying water conditioner developed by De Sangosse specifically for use with FLiPPER, has recently been updated.
The advice is still to condition the water before adding FLiPPER to the spray tank, but where the recommendation before was to add more than half the required water volume before adding X-Fusion, the new advice is that it can be done after only a quarter of the required water volume has been added. Sufficient FLiPPER to ensure a 1% inclusion rate should be added once the water conditioner has been thoroughly mixed. The remaining water volume can then be added.
“The important point is to ensure the water is properly conditioned before FLiPPER is added to the spray tank because the flocculation caused when the polyvalent cations in hard water react with the fatty acids in FLiPPER cannot be undone,” said Ms Matthewman.
The advice reflects the largely unknown affects hard water can have on product performance. Growers have for many years appreciated that some herbicides require the inclusion of a water conditioner to support performance, but it is less well understood how other products can be affected.
Earlier this year, independent spray consultant Tom Robinson was asked to explain how application technique influenced performance. This was considered especially relevant to FLiPPER because good coverage is essential to supporting performance, but not at the expense of dose rate.
“In some cases, coverage can be improved by moving to finer sprays, but with this comes a loss of control. As a result, ensuring coverage is optimised means increasing the water volume, typically to no less than 400 L/ha,” Mr Robinson explained to those attending the Bayer vegetable conference.
“Where insects are on the underside of the leaves, the spray needs to be directed upwards from underneath the canopy. There are several ways to perform this with drop leg systems being the most effective, followed by air assistance nozzles and last, angled nozzles.
“Where insects are deep in the crop, as is often the case with carrots for example, a high energy spray will be needed to give the penetration required,” he said.