Having launched its orange oil potato sprout control solution, ARGOS, in the UK last autumn, below, UPL customers and potato growers discuss their experiences with the product.
ARGOS is a natural product that contains pure, food grade orange oil with d-limonene as the active ingredient. To produce ARGOS, oil is extracted from oranges by vacuum distillation without the need for heat or solvents.
It is applied as a hot fog through fogging machines operated by specialist contractors using suitable temperature-controlled fogging equipment. The fog machine puts the oil into a vapour state which can remove potato sprouts by desiccating the soft growing points on the tubers.
According to UPL, crop inspections should be made regularly and carefully, so that the break of dormancy is spotted instantly and the ARGOS is applied at the ideal timing of 20% of tubers at the very first ‘white points visible’ stage. This will more quickly kill sprouts and allow for longer intervals between ARGOS applications.
Longer sprouts have also been well controlled by ARGOS, particularly if thin and quick growing, but, the best timing for an application remains to be at the first signs of dormancy break.
It is worth noting too that during applications there should be a good amount of space around the fogging port so that ARGOS can develop a good quality light, dry fog before it is drawn into the boxes.
UPL also want to make growers aware that the fogging efficiency of new products can be affected by stores which are either too full or part empty. So, amid the rising costs of energy, UPL say that it remains important that fans stay on and that the full cooling and curing period is completed before fogging begins.
Jonathan Kemp of Mercian – a supplier of potatoes to the UK crisping industry – used ARGOS last season. He said: “We started last season expecting only to apply BIOX-M, but we were keen to try ARGOS oil to compare products so we purchased the latest Synofog 2HV hot fogger adapted for use with ARGOS.
“Flowrates are similar for both products, 25-30 l/hour, although application times can be longer for ARGOS with a higher use rate (100 ml/T vs 60-90 ml/T).”
Once Mercian has applied ARGOS, the potato stores are closed for between 36 and 48 hours – reduced from last season’s 72 hours. In comparison to last season’s BIOX-M applications, Mr Kemp said: ” ARGOS has the advantage in box stores as it seems to be more mobile and has improved the effectiveness in the corners of the stores which BIOX-M failed to reach. In bulk stores, both work really well and future ARGOS applications could have a reduced rate to cut application times and cost.”
He concludes with a word of warning: “Make sure the ARGOS fog isn’t hitting the crop in large quantities because it will scorch or burn the potatoes. We fogged many stores last season and experienced crop damage issues in just two. We feel confident with our current knowledge it will not happen again.”
Tim Kitson, an independent potato storage consultant, storage expert and director at Potato Solutions, has also extensively used ARGOS.
He said of his experience with the product: “It shows good efficacy in store and controls sprouting within a specific range.
“With the new oil sprout suppressants good air flow is fundamental to provide that full coverage of a contact kill. Moisture, condensation, and damp refrigeration coils can cause ‘crop scorch’. Refrigeration coils on certain units are narrow, so cooling and fall out has been seen on the tops of crops.”
However, Mr Kitson reduces any such risks by putting good store practices in place prior to and during applications.
He continued: “Certain varieties and stores had a field MH application followed by only 1 application of ARGOS, and left the store in April without sprouting. Fry colour is unaltered during the season which, for certain end users, is critical; where my customers require a minimal harvest interval for flexible marketing it fits well.”
“The ability to ‘sit and wait’ for movement rather than proactively treat, can also be advantageous and save money in shorter term storage. I will continue to use ARGOS again this season and be mindful as with any chemical of its usage.”
