Sulphur and common scab reduction – The Facts
Irrigation is still the main tool some growers have to reduce the incidence of common scab. However, water usage issues have now put the spotlight very much onto alternative methods of controlling scab in potatoes.
Boothmans Agriculture have pioneered the use of sulphur in the UK over the last 15 years to locally acidify soils and thereby discourage the development of the fungus which causes the disease. Many companies have now latched onto the idea and assume that any sulphur formulation will “do the job”. This is certainly not the case and Boothmans have tested many different products over this time before settling on Brimstone Rapide as our first choice product only used for scab reduction in potatoes.
Growers should not think that applying sulphur in fertiliser overall will also address common scab. To get scab reduction applications need to be targeted precisely. This is not achievable with solid or liquid fertilisers applied overall as any effect is diluted over thousands of tonnes of soil. Brimstone Rapide is the specialist product for improving skin finish.
Best advice is to “use fertiliser for yield and Brimstone Rapide for cutting scab”
How does Brimstone Rapide reduce common scab?
Click on the image to enlarge
Soil pH has long been regarded as a major factor concerning the severity of common scab with scab incidence intensifying from pH 5.0 – 8.0.
Brimstone Rapide trials demonstrate it’s ability to lower pH by approximately one pH point.
There is also also some belief that the sulphur could also be acting a fungicide in it’s own right on the Stretomyces fungus which causes scab.
Effects of Brimstone Rapide on Common Scab
Boothmans supplied product to an independent trial commissioned by Solanum where it was found:-
- Increasing levels of elemental sulphur lowered the pH of the soil throughout the tuber initiation period – see Graph 1
- Brimstone 90 applied at increasing rates successively lowered the incidence of common scab at harvest – see Graph 2
- Higher rates of Brimstone 90 increased tuber yield by 19% over the Untreated. Whilst not being used as fertiliser, there are very useful spin-off yield benefits gained from placing large quantities of sulphur where the developing daughter tubers can benefit. This negates the need for any additional sulphur to be added to the base fertiliser saving money.
- Please see our ph trials PDF here
Application and dose rates
Application of Brimstone Rapide is made simple by using the Rotormeter.
- Machine applies Brimstone Rapide to two or three rows of potatoes depending on model
- Electrically powered by 12 volts from a tractor battery mounted on a planter or power-ridger
- Variable dose control switch in cab
- Accurately positions Brimstone into ridge in a concentrated band
- Purchase price of the unit is subsidised if Brimstone Rapide is purchased at the same time
- Dose rates range from 75-150kg/ha depending on soil pH, irrigation regime, variety, end market etc.
- Prices range from £1-£2 per tonne of maincrop potatoes produced
“Brimstone Rapide – The original and still the best”
Our 15 years of evaluating various sulphur formulations for scab reduction has built up a good level of knowledge within this field.
- Beware of unrealistic claims – overall applications of micronized sulphur in a liquid fertiliser form cannot achieve the same levels of soil acidification and scab reduction as a concentrated dose of product placed directly where the daughter tubers are developing.
- Beware of other companies using Boothmans trials data to promote their products.
- Beware of some irregular and abrasive sulphur granules that can damage application equipment – simply try to crush these granules in your figures and then decide how these will break down in soil water. Brimstone Rapide was thoroughly tested for its water solubility before it ever made it into the field.
Why choose Brimstone Rapide from Boothmans over other sulphur products
- Boothmans is the company with 15 years experience in this field
- Boothmans is the company with independent trials proving scab reduction
- Brimstone Rapide is a mini-pastille and specifically developed for potato market, not just a sulphur fertiliser made to fit
- Brimstone Rapide is band-applied in a concentrated area to maximise the effect at least cost
- Brimstone Rapide has a small individual particle size giving rapid and sustained soil acidification
- Brimstone Rapide can be farmer applied with accurate application machinery – no contractors required