With planting progress behind in many parts of the UK and soils well stocked with water, growers are likely to be faced with a number of late potato crops, making desiccation more difficult. It’s a reason to welcome new desiccation product Quickdown, says agronomist John Keer of Richard Austin Agriculture Ltd.
”The very late planting experienced so far this season will mean natural senescence will be much later in a lot of potato crops across the country,” warns John.
“The saturated soils, even without irrigation, could mean a ‘growy’ season of leggy crops lie ahead, particularly on the fertile land of south Lincolnshire where potato haulm can be unusually vigorous,” he reports.
“A stark contrast to last season where dry conditions and much earlier plantings meant the destruction of potato haulm wasn’t a massive challenge,” notes John.
This season John is recommending growers introduce an application of diquat to kick off the programme of potato haulm destruction. “Once the correct tuber size distribution has been achieved we need to very quickly stop the plant from progressing to avoid any over-sizing occurring. This is where diquat fits as a fast acting initial desiccant.
“Then we will be looking to go on with an application of pyraflufen-ethyl (Quickdown) as the second treatment.
“Here Quickdown will do a better job of desiccating the stems and completing the haulm destruction, which is crucial to ensure ease of lifting in the following weeks,” explains John.
“It will ensure that, at lifting, that the haulm is completely senesced – dry and brittle – and with ‘give’. This means that there’s minimal interference with working processes which can otherwise happen if the haulm and in particular plant stems, aren’t completely destroyed,” he says.
John comments that because Quickdown only received registration towards the end of last season, very few growers will have had the opportunity to evaluate the product, making it the first opportunity to build it into their programmes.
“It’s likely to be a useful option for growers in the coming season,” he notes. “A welcome addition extending the otherwise limited range of treatments available, which is especially the case following the demise of sulphuric acid.
“Trials conducted at the end of last season gave us a good chance to review the performance of Quickdown against the existing market standards.
He reveals that the results show Quickdown performs very well in terms of its speed of action and efficacy, certainly stacking up ‘at least equivalent’ to the use of carfentrazone-ethyl (Spotlight).
Quickdown is approved for use as herbicide in potatoes as well as a contact-acting desiccant for the destruction of potato haulm.
Growers must observe maximum individual dose of 0.8l/ha when using Quickdown as a potato desiccant. If growers have used the product earlier in the season as a herbicide, it’s important to note that the maximum total dose is 1.6l/ha.
Applications of Quickdown should be made with the use an adjuvant, such as Toil (A0284), at a minimum rate of use of 1.5l/ha of adjuvant.