Sprout inhibitors are designed to delay the sprouting of potatoes, but they do not stop sprouting indefinitely. These chemicals or natural substances suppress the growth of sprouts during storage.
The effectiveness and duration of sprout inhibition depend on the type of inhibitor used, the concentration applied, storage conditions, and the inherent characteristics of the potato variety.
Most sprout inhibitors aim to extend dormancy and maintain the quality of the potatoes for a specific period, typically to match commercial or planting schedules. Once the effect of the inhibitor wears off or if the potatoes are moved to conditions favourable for sprouting (warmer temperatures and higher humidity), sprouting will commence.
Who uses sprout inhibitors?
I have never needed to use a sprout inhibitor, as all my potatoes were sold before the temperatures began to heat up in springtime. The vast majority of farmers who use sprout inhibitors don’t have cold storage. Potatoes kept in cold storage at 4 degrees centigrade naturally prevents the potatoes from sprouting.
Using sprout inhibitors on seed potatoes
For seed potatoes, the use of sprout inhibitors is generally limited or avoided, especially since the goal is to encourage healthy sprouting before planting. Farmers planning to store seed potatoes for the next growing season should focus on creating optimal storage conditions, (cold) to naturally extend dormancy as long as possible, rather than relying on chemical sprout inhibitors.
Types of sprout inhibitors
Sprout inhibitors are used to control the growth of sprouts on potatoes during storage. Here are some commonly used sprout inhibitors and guidance on their application:
Chlorpropham (CIPC):
Usage: Widely used in the commercial potato industry until it was banned in the UK in 2019. It’s applied as a fog or spray in storage facilities.
Application: It requires precise dosage and proper ventilation to ensure uniform coverage and safety.
Ethylene:
Usage: A naturally occurring plant hormone. It can be used in storage facilities to suppress sprouting.
Application: Requires continuous monitoring and controlled introduction into the storage environment to maintain effective levels.
1,4-Dimethylnaphthalene (1,4-DMN):
Usage: A naturally occurring compound found in potatoes. It’s used for its efficacy in inhibiting sprout growth.
Application: Applied as a fog similar to CIPC, and should be managed with proper equipment for even distribution.
Spearmint oil (Carvone):
Usage: An organic option derived from spearmint oil, known for its sprout suppression capabilities.
Application: Can be applied through the storage facility’s ventilation system. It requires multiple applications throughout the storage period and is suitable for organic farming.
Essential Oils:
Usage: Certain essential oils, such as clove oil and eucalyptus oil, have been researched for their sprout inhibiting properties.
Application: These can be applied by misting or through the storage area’s air circulation systems. Their effectiveness varies, and they may require frequent reapplication.
Important Considerations:
- Dosage and Timing: Follow the manufacturer’s recommendations closely for dosage and timing. Incorrect application can harm the potatoes or leave residues.
- Regulatory Approval: Ensure that the sprout inhibitor is approved for use on potatoes in your region, as regulations vary.
- Safety: Some chemical inhibitors require handling and application by trained professionals to ensure safety and effectiveness.
- Organic Farming: For organic farming, options like spearmint oil may be preferred. Check with local organic certification standards before use.
Key points..
The use of sprout inhibitors is slowly being phased out, as modern cold stores with accurate temperature monitoring will be as effective without the need for another chemical applied to the potato.
