Thursday, 19 September 2019
Scientists at Sutton Bridge Crop Storage Research have been undertaking research trials on representative processing and fresh-pack potatoes to test the efficacy of alternatives to CIPC for sprout control. A range of products are being tested, including those already registered for use (ethylene, maleic hydrazide (MH), spearmint oil) and those nearing approval (DMN, orange oil). Results from the latest set of storage trials are now available and will be followed by detailed reports in the coming months.
MH as a cost-effective combination treatment
The field-applied product is effective as a stand-alone or in combination with other sprout suppressants post-harvest. As a stand-alone, it has exhibited commercially acceptable levels of sprout control particularly for longer dormant fresh-pack varieties, as well as a subset of processing varieties. Combination treatments of MH with either ethylene or spearmint oil significantly reduced sprouting in both storage trials. In the 2018-19 processing and fresh-pack trials, the same crop had both + and - MH plots allowing a direct comparison between treatments to be made.
Not all varieties respond equally
Varietal response is one of the factors to take into consideration when selecting a sprout control strategy, particularly the dormancy of the variety. In the last issue of Storage Bulletin we reported initial results from our 'dormancy ranking for potatoes' project.
What do these results mean for you?
When storing varieties for processing, the efficacy of spearmint oil will be determined to a large extent by the use of MH and variety dormancy. and variety dormancy. MH can reduce the number of post-harvest treatments and therefore reduce overall sprout suppression costs. Where spearmint oil is going to be used, MH application is likely to pay off later on in the season.
Sprout suppression in fresh-pack varieties was best with spearmint oil (or DMN) as stand-alone treatments, regardless of variety. With DMN still awaiting approval for use in the UK, spearmint oil likely remains the best option although MH should be considered as a combination treatment.
Whichever market you are growing for, the volatile nature of the alternatives currently available mean that adequate store closure and ventilation will be essential to optimise the efficacy of these products and reduce costs. MH is not volatile and provides control at store loading, unloading and shelf life.
Our sprout suppression specialists will be presenting and discussing these results in more detail at one of our upcoming storage events.