# Seed treatments for cereals and potatoes: approved products compared URL: https://leafwrit.com/uk/cereal-potato-seed-treatments/ Reviewed: 2026-10-29 **Of the eleven names, only Maxim, Rancona and Force have an entry in the Great Britain and Northern Ireland pesticides register, and only Maxim 100FS and Rancona are for potatoes or cereals.** Force ST is for sugar beet. Monceren was withdrawn in 2020. Dividend, Hombre, Jockey, Korit, Lumiposa, Poncho and Wakil have no register entry at all. Tests and thresholds for seed health are in the [seed treatment guide](/uk/seed-treatment-guide/). ## Maxim XL seed treatment No product called Maxim XL is on the register. The Maxim products that are: **Maxim 100FS, MAPP 15683**, fludioxonil, authorised until **31 March 2029**, and **Maxim 480FS, MAPP 16725**, fludioxonil, authorised until **15 December 2027**. Both are held by Syngenta UK Limited. The two are not interchangeable. 100FS is the potato product (next section); 480FS is a vegetable-seed product, covered on the Maxim page. The 480FS label gives 480 g/litre fludioxonil at **100 ml of product per 100 kg of seed**, one treatment per batch, before drilling, on crops such as onion, cabbage, carrot and lettuce seed. It does not cover cereals or potatoes. Seed sown under permanent protection with full enclosure needs at least 21 days before the plants are transplanted outdoors. ## Maxim 100FS on seed potatoes **Maxim 100FS contains 100 g/litre fludioxonil and gives useful control of seed-borne black scurf (Rhizoctonia solani) in potatoes.** It reduces silver scurf (Helminthosporium solani) and gives some reduction of black dot (Colletotrichum coccodes). - **Crop:** potato seed tubers used to produce ware crops. Do not apply to crops intended for seed production. - **Rate:** 0.25 litres of product per tonne, one treatment per batch, before planting. - **Timing:** apply only to dormant tubers, during storage and before chitting or planting. Dormancy has broken once a bud is greater than 0.5 mm in diameter, so apply before that point. - **Dilution:** make 250 ml of product up to 2.0 litres with water per tonne. Tubers should be dampened, not wet: over-wetting can cause bacterial soft rots, which the product does not control. - **Equipment:** low-volume hydraulic nozzles over a roller table, with the tubers rotating 2 to 3 times in the treatment area. Apply with a Team Storemaster fitted with a rotary air nozzle system over a roller table. The calibration and application must be done by an operative with N.P.T.C. PA12 certification. - **Seed condition:** clean tubers, free of soil, vigorous, without bacterial rots, viral infections or physical damage. Do not use on diseased or weak stocks. - **Processing crops:** consult the processor before using it on crops grown for processing. Maxim 100FS acts by contact, so tuber coverage decides the result. Shake the pack well before use, because the product settles in storage. No resistance to fludioxonil is known in UK populations of silver scurf, black dot or Rhizoctonia, and the label asks for use inside an overall disease management programme. Heavy soil inoculum can overwhelm the benefit of tuber treatment. Treating highly stressed, scarred or damaged seed, or seed of low vigour, may reduce germination and seedling vigour. Wear a cotton overall and rubber gloves when handling the concentrate and treated tubers. Clean the spray nozzles and lines at the end of each day and do not leave product in the application equipment overnight. Agitate the diluted solution continuously, even when no tubers are being treated, and mix only enough for immediate use. ## Monceren potato seed treatment **Monceren cannot be used.** The Chemicals Regulation Directorate ended its use as of 25 March 2020. The active substance was pencycuron. The trigger was an EU vote to cut the pencycuron residue limit to 0.01 mg/kg, one-tenth of the previous limit. The register snapshot has no Monceren entry. For black scurf on seed tubers the authorised option on this page is Maxim 100FS above. ## Rancona seed treatment The register has two Rancona products from UPL Europe Ltd: **Rancona i-Mix, MAPP 19847**, imazalil and ipconazole, authorised until **30 June 2030**, and **Rancona 15 ME, MAPP 19629**, ipconazole, authorised until **30 June 2030**. ### Rancona i-Mix on wheat and barley seed The label dated February 2020 (MAPP 15574, Arysta LifeScience) covers **barley and wheat seed**, at **1.0 litre of product per 1000 kg of seed**, one treatment per batch, before drilling. It can be applied neat or with 3 litres of water per 1000 kg, which may improve coverage. On the label it is claimed to: - **Barley:** control of loose smut (Ustilago nuda) in spring and winter barley, control of leaf stripe in spring barley and partial control in winter barley. - **Wheat:** control of seed and soil-borne bunt (Tilletia caries). - **Both crops:** useful protection against seedling blight and foot rot from Fusarium and Microdochium nivale (moderate control in wheat), and suppression of ergot germination in contaminated seed. Apply through a conventional seed treater suitable for liquid products. Wash the pump and pipeline with clean water, using a double rinse, before switching to or from Rancona i-Mix. Containers above 20 litres need mechanical handling. Restrictions on the label: - Do not treat seed above 16% moisture, or cracked, split or sprouted seed. - Drill within six months of treatment. Do not store treated seed from one season to the next. - Re-calibrate the drill with treated seed, because flow through the drill may change. - Do not pre-mix with any other seed treatment product. - Treated seed must not be used as food or feed, and must not be applied from the air. Label treated sacks with the precautions, and keep treated seed secure from people, pets and wildlife. Rancona i-Mix is approved for spring barley, including malting barley, and for spring wheat. It has lost its approval in the EU but remains approved across mainland Great Britain. Resistance: ipconazole is a triazole and imazalil an imidazole, and both belong to the DMI fungicide group (SBI class I). Later foliar sprays should use an active substance with a different mode of action. ### Rancona 15 ME Rancona 15 ME is on the register as an ipconazole-only product. ## Force seed treatment **Force ST is for sugar beet and fodder beet seed only.** It contains 200 g/litre tefluthrin and is Syngenta's MAPP 19042, authorised until **30 November 2029**. The label does not cover cereals or potatoes. The label rate is 50 ml of product per unit of seed (1 unit = 100,000 seeds), which gives 10 g of tefluthrin. One treatment per batch, before drilling. It is applied during pelleting and only in professional seed treatment facilities. The pests it reduces are springtails, symphylids, millipedes and pygmy beetle. Keep livestock out of areas drilled with treated seed for at least 80 days after sowing. Where wind or water erosion is a known problem, the label requires preventative measures such as cover cropping. Very light soils and sand have few soil pests, so treated seed may not be needed there. Treated seed not drilled in the intended season can be stored for one season, in a secure, cool, dry place. Tefluthrin is an IRAC group 3A pyrethroid. ## Lumiposa seed treatment Lumiposa has no entry on the register. It is an insecticide seed treatment for oilseed rape, applied to seed treated outside the UK and imported, not a cereal or potato product. ## Dividend, Jockey, Korit and Wakil seed treatment None of these names is on the register. A product with no register entry has no GB or NI authorisation, so there is no label to read rates from. For cereal seed, the held pages on Raxil, Redigo, Systiva and Vibrance cover treatments that do have register entries. ## Hombre and Poncho seed treatment Neither name is on the register. The only insecticide seed treatment of this group that is listed is Force ST, which is for sugar beet (see above). ## The three authorised products side by side - **Maxim 100FS:** seed potatoes for ware crops; 0.25 litres per tonne; dormant tubers; roller table; authorised until 31 March 2029. - **Rancona i-Mix:** wheat and barley seed; 1.0 litre per 1000 kg; before drilling; authorised until 30 June 2030. - **Force ST:** sugar beet and fodder beet seed; 50 ml per 100,000 seeds; applied in pelleting; authorised until 30 November 2029. ## Signal 300 ES seed treatment **Signal 300 ES is an insecticide seed treatment that reduces wheat bulb fly and wireworm damage to autumn and winter sown wheat and barley.** It is a seed treatment concentrate with 300 g/L cypermethrin, an IRAC group 3A insecticide. Signal 300 ES carries MAPP number 19631, held by UPL Europe Ltd, and is authorised until 30 April 2031. ## Rhino potato seed treatment Rhino is a Certis Belchim flutolanil product for Rhizoctonia on potato seed. In the register snapshot Rhino DS is listed as authorised, with flutolanil as its only active substance, while the entries named Rhino and Rhino DSG are marked withdrawn. Flutolanil is one of the active substances Certis names for an extra treatment of the daughter crop against Rhizoctonia when seed leaves store, alongside fludioxonil and fluxapyroxad. Maxim 100FS above is the fludioxonil option for the same disease. Whichever you choose, a Rhizoctonia treatment protects rather than cures: depending on the product and the way it is applied, it may reduce infection of the developing crop from the seed or the soil and the black scurf on the new tubers, and for some products the label promises reduction, not control. Seed tubers that already carry black scurf are still a risk, so inspect washed samples before planting and read the label of the exact Rhino product in your hands. ## How to check any name Search the [HSE register](/uk/hse-gb-pesticides-approval-register/) by product name or MAPP number. The product must be listed as authorised, the crop must be on its label, and the label rate and timing apply. ## Next step Start with the [seed treatment guide](/uk/seed-treatment-guide/) to match a diagnosis to a treatment, then read the product page: Maxim, Raxil or Redigo. ### Is Monceren still approved for potatoes? No. The Chemicals Regulation Directorate ended use of Monceren on 25 March 2020. The register snapshot of 29 October 2026 has no Monceren entry. For black scurf on seed tubers, Maxim 100FS is on the register until 31 March 2029. ### What rate is Maxim 100FS applied at on seed potatoes? 250 ml of product per tonne of tubers, made up to 2.0 litres of solution with water, one treatment per batch, before planting. ### Can Rancona i-Mix be used on spring barley? Yes. The Rancona i-MIX label covers barley and wheat seed, and the authorisation holder confirmed it for spring barley, including malting barley, and for spring wheat. ### Is Force ST a seed treatment for cereals or potatoes? No. Its label covers seed of sugar beet and fodder beet only. ### Why can't I find Dividend, Jockey or Wakil on the register? No product name starting with Dividend, Jockey or Wakil appears in the register snapshot of 29 October 2026. A name that is not on the register has no GB or NI authorisation to read a label from.