Best Ways For Storage Of Potatoes

Industrial storage of fresh potatoes (Solanum tuberosum L.) is designed to maintain their quality, prevent spoilage, and minimize weight loss. Key factors include temperature, humidity, ventilation, and light control. Following harvesting, the aim of anyone storing potatoes is to delay sprouting or dormancy break, to limit weight loss through water loss, to reduce the chance of rotting and minimise biochemical changes including the build-up of reducing sugars and thus to and minimise sweetening.

Potatoes are one of our most important non-grain crops. They are the fourth largest food crop after corn, wheat, and rice (Tian et al., 2017). Potatoes are one of the main crops in the USA and are grown in the states of Idaho, Maine and Colorado. We can look online on sites such as ‘The Potato Association of America‘. India is the second largest producer of about 50 million metric tons; MMT of potato and contributes to 14% of the world’s annual production. The European Association for Potato Research (EAPR) is another essential resource of information on the subject.

Senescence sweetening is a natural process occurs in any stored tuber irrespective of sprouting. It is irreversible and occurs  because of cellular breakdown. Storage carbohydrates, both structural and non-structural depolymerize through catalytic action of hydrolytic enzymes. It is the delay of enzyme activity which is dictated by storage conditions.

The Stages of Dormancy

The stored tubers can be at different stages of dormancy. These can include stages of endodormancy, ecodormancy, and paradormancy. Endodormancy, or true dormancy, is regulated by endogenous signals that prevent growth of the meristems even under growth-promoting conditions.

The meristem is a region of undifferentiated plant cells that are capable of continuous division and growth. These cells are responsible for producing new tissues and organs in plants. Meristems are found in areas where growth occurs, such as the tips of roots and shoots, and contribute to both primary and secondary growth.

Types of Meristems

1. Apical Meristem – Found at the tips of roots and shoots, responsible for the primary growth (lengthening of the plant).
2. Lateral Meristem – Found in the vascular and cork cambium, responsible for secondary growth (thickening of stems and roots).
3. Intercalary Meristem – Found at the base of leaves or internodes (mainly in grasses), allowing regrowth after damage.

Meristematic cells are small, densely packed, and have a high rate of cell division, making them essential for plant development and regeneration.

Ecodormancy is regulated by exogenous signals (Lang et al., 1987), such that meristems will grow if conditions are conducive.

Following the break of either endo- and ecodormancy, a seed tuber typically enters the stage of apical dominance, i.e. paradormancy, when the sprouting of the apical eye suppresses the sprouting of lateral eyes. So, paradormancy, also known as apical dominance (AD), occurs when growth of lateral buds is inhibited by signals originating from the growing apical bud (Lang et al., 1987). Unlike other plants, the termination of endodormancy and initiation of ecodormancy in potato tubers do not require any specific environmental cues such as chilling hours. Rather, the duration of different dormancy stages is governed by the genetic makeup of cultivars and pre- and post-harvest conditions that contribute to the physiological age of the tubers.

Sprouting capacity can be defined as the amount of sprout material produced by a seed tuber in a test used to infer its growth vigour (Krijthe, 1962, Hartmans and Van Loon, 1987), and growth vigour is the potential of a tuber to produce sprouts and plants rapidly under favourable conditions (Van der Zaag and Van Loon, 1987).

The relative concentration of several biochemical compounds such as plant growth regulators [viz. abscisic acid (ABA), auxins, cytokinins (CKs), gibberellins (GAs), ethylene, and strigolactones (SLs)] and other compounds (viz. carbohydrates and organic acids) are believed to orchestrate the onset and further development of dormancy break (Pasare et al., 2013).

Sprouting occurs at 8ºC and as the temperature rises, so the potential for sprouting rises up to 25ºC. Strangely, any higher temperatures up to 31ºC actually delays sprouting.

Potato Varieties for Storage

The characteristics of good storage potatoes are:-

• limited metabolism n the potato.
• Long periods of dormancy after reaching maturity
• low to moderate tendency to sprout
• Resistance to mechanical damage during any form of harvesting

The factors affecting the maturation of tubers also affects dormancy from start to finish. In some years, the same variety can start sprouting whilst still in the field and under the parent plant.

Dry and hot summers strongly reduce the the period of dormancy. Wet and cold weather especially in the latter half of summer prolongs the dormancy period.

There are varieties characterised by a short dormancy period with an easy tendency to sprout. In the Northern hemisphere, tubers of such varieties will start sprouting at the beginning of December and will continue to do so on subsequent storage. The varieties of moderately long dormancy period and with a moderate tendency to sprout will begin sprouting 4 to 6 weeks later. The intensity and degree of sprouting during further storage is slight.

Varieties with a longer dormancy period and slight tendency to sprout will begin sprouting in mid-February which is 8 to 10 weeks later than the first group of tubers.

Several potato varieties grown in Europe have a long dormancy period, which helps with extended storage without premature sprouting. These varieties are ideal for processors and retailers who need long-term storage. Some key long-dormancy European varieties include:

Long Dormancy Potato Varieties in Europe

1. Kennebec – A white-fleshed, high-yielding variety with good storage properties.
2. Innovator – A popular processing variety with excellent dormancy, commonly used for French fries.
3. Fontane – Another processing variety with a long dormancy, high dry matter, and good frying qualities.
4. Markies – Favoured for crisp and fry production, it has an extended dormancy period.
5. Agria – A yellow-fleshed variety known for its versatility and long storage life.
6. Maris Piper – A well-known UK variety with good dormancy and excellent frying qualities.
7. Desiree – A red-skinned variety with moderate to long dormancy, suitable for multiple uses.
8. Challenger – A processing variety with high yield and long dormancy.
9. Ramos – Used for crisping and French fries, with a very long dormancy period.
10. Lady Claire – Ideal for crisp production, known for its very long dormancy.

Long Dormancy Potato Varieties in USA

In the USA, potato varieties with a long dormancy period (typically longer than 120 days) are preferred for extended storage without premature sprouting. Some of the key varieties include:

Russet Varieties (Long Dormancy)

1. Russet Burbank – One of the most widely grown potatoes in the U.S., known for its long dormancy (120–140 days).
2. Russet Norkotah (Improved strains) – While the original has a moderate dormancy, some newer strains have longer dormancy.
3. Ranger Russet – A high-yielding variety with a dormancy period of around 140 days.
4. Umatilla Russet – Developed for processing, it has a longer dormancy (130–140 days).
5. Blazer Russet – Good for fresh and processing markets, with a dormancy of around 130 days.

Red and Yellow Varieties

6. Red Norland (Late-maturing strains) – Some late-season strains exhibit longer dormancy.
7. Yukon Gold – While not as long as russets, it still has a decent storage life with proper conditions.

Chipping Potatoes (Long Dormancy)

8. Snowden – Popular for chip processing, with a dormancy period of 120–140 days.
9. Lamoka – A long-dormant chipping variety with excellent storage stability.
10. Atlantic – Used in the chip industry, with a moderate-to-long dormancy.

Harvesting begins about 2 or 3 weeks after the vines have dies. This is required because the tubers need to reach full maturity with a corked or conditioned skin. Tuber are also more resistant to physical damage when dug out.

Varieties that are resistant to cold induced sweetening (CIS) are Verdi, Lady Claire and Kiebitz which are found in Europe. They have good crisp colour quality. Reconditioning from 4 °C to 15 °C reduced glucose and acrylamide contents in tubers from the CIS-susceptible variety Markies.

Potato Harvesting Technologies Relevant to Storage & Processing for Sprout Prevention

Several modern harvesting technologies play a role in minimizing damage to potatoes, which directly impacts their storability and sprout prevention. The key factors include gentle handling, minimizing bruising, and controlling mechanical stress, as damaged potatoes are more prone to moisture loss and sprouting.

1. Gentle Harvesting Systems

• Elevator Harvesters with Cushioning Systems
  • Modern harvesters use soft belts, reduced drop heights, and rubberized surfaces to prevent impact damage.
  • Examples: Grimme, AVR, Dewulf, and Standen harvester models incorporate gentle conveyor technology.
• Air Sep Harvesters (Air-Assisted Separation)
  • Uses airflow instead of mechanical agitation to separate soil and clods, reducing bruising.
  • Example: Grimme’s Ventor 4150 harvester includes air separation technology.
• Haulm Toppers with Adjustable Heights
  • Cutting vines before harvesting ensures potatoes detach easily from the plant, reducing pulling stress.
  • Helps prevent skinning injuries, which increase moisture loss and trigger sprouting.

2. Soil Management for Damage Reduction

• Pre-Harvest Irrigation Management
  • Keeping soil slightly moist (but not wet) prevents excessive abrasions and bruising.
  • Dry, compact soil increases mechanical stress and damage during harvesting.
• Use of Ridge Formers & Bed Tenders
  • Properly formed beds allow potatoes to be harvested without excessive force, preventing injuries.
  • Examples: AVR’s Multivator and Grimme’s BF series bed formers.

3. Automated Sorting & Damage Prevention Before Storage

• Optical & Sensor-Based Sorting
  • Removes damaged, green, or diseased potatoes before storage, preventing spoilage and ethylene build up (which can trigger sprouting).
  • Examples: TOMRA, Newtec, and BBC Technologies use infrared and multispectral imaging for sorting.
• Low-Drop Handling Systems
  • Conveyor belts with adjustable speed and soft rollers minimize the impact during transfer to storage bins.
  • Some systems use bin fillers with variable speed control to reduce bruising risk.

4. Storage-Specific Harvesting Considerations

• Delayed Harvest for Stronger Skin Set
  • Potatoes should be left in the ground for 10–20 days after vine kill to allow the skin to toughen, reducing damage and sprouting risk.
• Selective Harvesting for Different Storage Uses
  • Potatoes intended for long-term storage should be harvested separately from those meant for immediate processing.

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Most Gentle Potato Harvesting Methods

For minimal bruising and skin damage, the following methods are the gentlest:

1. Two-Step Harvesting (Low-Impact Method)

• Step 1: Use a Haulm Topper to remove vines before digging (prevents pulling stress).
• Step 2: Use a Slow-Speed Belt Elevator Harvester with cushioned conveyors to dig and transport the potatoes.

2. Hand Harvesting (Traditional & Minimal Damage)

• Used for high-value or delicate potato varieties (e.g., fingerlings).
• Common in small farms and organic production, but labour-intensive.

3. Semi-Automated Harvesting with Soft Lifting Systems

• Digger-Lifter Systems use forks or rubber-padded tines to gently lift potatoes while leaving soil behind.
• Reduces impact injuries compared to high-speed mechanical diggers.

Transport

Tuber transport is always a bulk operation using lorries and trains. Loading and unloading are usually the points where most tuber damage occurs. Tubers really need to be treated gently to avoid bruising. Temperature reggulation should be regualted carefully during transport. If the temerpature is too low, the sugar accumulation starts. A temperature below freezing causes irreversible damage from freezing and can completely destory a load. If the temperatyre is too high as in say 25C, then conditions favour storage diseases especially those causing black spots in the tuber.

The air temperature duiring transport must be constant epecially if the potatoes are to be fried and it should equal the temnperature of the soil whenere the potatoes grew or, in case of transportaion of already stored tubers, air temperatrure is similar to the storage house. A temperature of less than 7C is ideal. Any short cooing times where temperature drops below 0C will affect colour if the potatoes when fried.

The Process of Preparing and Storing Potatoes

The main features are:

1. Curing Before Storage

• Freshly harvested potatoes are cured at  a relatively warmer temperature of between 12°C – 18°C (54°F – 64°F) for 10–14 days to heal wounds and reduce rot (Meijers, 1989).
• Curing strengthens the skin and promotes longer-term storage.
• Potatoes are usually cleaned if they are heavily soiled. These can be washed or brushed free of soil.
• After a few weeks the potato tubers are stored but at a much lower temperature.

2. Temperature Control

• Storage temperature: Typically between 3°C and 10°C (37°F – 50°F) with a 90% rel. humidity, depending on the intended use.
  • For fresh market or table potatoes: 4°C – 7°C (39°F – 45°F) to prevent sprouting and decay but ensure good eating quality.
  • For processing potatoes (e.g., chips, fries): 7°C – 10°C (45°F – 50°F) to prevent sugar build-up, which causes dark frying colours.
  • For seed potatoes: 3°C – 4°C (37°F – 39°F) to maintain dormancy but keep them viable for planting.
  • Avoid temperature fluctuations because this breaks dormancy.

Temperature management of potatoes in particular dictates the intended market for potatoes. we can see how warmer storage temperatures are needed for potatoes that are to be processed.  Potatoes intended for the fresh market are stored below 7ºC whilst potatoes required for processing require warmer temperatures (8 to 13ºC) so as to preserve frying quality. Even at low temperature storage some sprouting is observed. Some varieties tend to sprout more than others even at very low temperatures such as 1 or 2 C.

Quality loss is also caused by ‘cold-induced sweetening’ because sucrose hydrolyses to various reducing sugars. It is reversed by temperature reconditioning (Driskill et al., 2007). The choice of variety for cold storage is vital because as a storage method it is not ideal for processing avrieties ie for frying whe storage induces sweetening and tehre is the risk of production of toxic compounds during potato frying (Wiberley-bradford & Bethke, 2017). THose varieties not sensitive to sweetening are easily stored at low temperatures withpout issue (Visse-Mansoaux et al., 2019).

Internal disclouration known as Mahogany browning occirs in all potato cultivars when stored for 20 weeks or longer at 0 to 1.1C. Pantastico recommended storing potatoes at temperatures of 3.3 to 4.4C at 85% RH for about 34 weeks.

Controlled Atmospheric Storage (CA)

Controlled atmosphere storage is not a proven technology for maintaining storage of potatoes destined for table use. Concentrations of less then 5% oxygen in inhibit periderm formation and wound healing. Oxygen levels below 1 % produce off-flavours and increase decay, surface mould and blackheart during 1 week at moderate temperatures of 15 to 20 C. At 5ºC, deleterious effects of low temps were less pronounced or absent. Oxygen levels less than 10% increased sprouting but no real effect on seed potatoes.

High CO₂ of 10% or more enhances decay at 4.4C and aggravated the effects of low oxygen at higher temperatures. A level of 12% CO₂ (8% or more) and low O2 (5% or less) for 6 months causes complete failure of seed potatoes.

High CO₂ (15 – 20% prevents greening of prepackaged potatoes at 10 to 16C. The incidence of bacterial soft rot increases at lower CO2 (10%) and lower temps (4.4C)

3. Humidity Control

• The effect of humidity is most pronounced on the degree of sprouting observed when potatoes are kept in the temperature range of between 18 and 22 ºC. The effect of humidity at any other temperature outside the range has little impact on the level of sprouting.
• Potato tubers stored under conditions of too high a humidity sprout earlier than those stored at lower humidity. High humidity results in the occurrence of branched sprouts with a large number of side roots. The worst temperature range for sprouting is 18 to 22 C when humidity is high. Temerpatures around 4 or above 30 C are impacted very little by the effect of humidity. Other factors become evident.
• Relative humidity: Keep potatoes stored at 90% – 95% to reduce water loss and prevent shrinkage. Some storage sites use a relative humidity which is lower, of 60 to 80%.
• Too high a humidity can encourage fungal and bacterial growth, while too little can cause shrivelling.
• Balanced airflow is required alongside good ventilation.

4. Ventilation & Airflow

Air composition affects sprouting. A low oxygen concetration acceldertae sprouting. However, lack of oxygen causes deterioration and decay of the tuber. An oxygen concetration with the range of 2 and 10% is optimal for sprouting.

• Constant air circulation is necessary to remove CO₂, moisture, and heat.
• Airflow rates typically range from 15 to 25 m³ per tonne per hour.
• CO₂ levels should be kept below 0.5%, as excessive build-up can cause spoilage especially sprouting. Likewise, a low oxygen concentration in storage also accelerates the sprouting process.
• Ventilation offers optiiaml oxygen concetration and removes undesirable carbon dioxide because it is heavier than air and accunulates in the lower parts of the storage house. A coincetration of carbon diozxode of 8% accelerastes/intensifies potato sprouting but at higher concetrations delays sprouting.
• Unfortunately, carbon dioxide levels as low as 5% affects the biology of the tuber, diminishes their resistance, causes eye death, internal necrosis of the tissues etc.

5. Light Management

• Potatoes should be stored in complete darkness to prevent the production of solanine, a toxic compound that turns potatoes green. Some of the greening is due to chlorophyll production.

6. Sprout Inhibition

• Chemical methods: CIPC (Chlorpropham; isopropyl-N-chlorophenyl carbamate) was widely used, but is now restricted in many regions. Others inlcude maleic hydrazide (MH), tectrachloronitrobenzene (TCNB), MENA methyl ester of alpha-napthalene acetic acid, amyl or nonyl alcohols. CIPC is only effective at low temperatures and loses effectiveness at 15C. The EU banned CIPC because of the appearance of breakdown products such as aniline in the skin (Paul et al., 2014).  Visse-Mansiaux et al. (2021) reported that residues of the maleic hydrazide anti-sprouting molecule have been detected in tubers at the end of the storage period, even though these residues were below the authorized maximum residue limit (MRL).
• SmartBlock® (3-decen-2-one), an aliphatic alpha-beta unsaturated ketone has been registered for use in USA, Canada and Israel to control sprouting of potatoes in storage since 2013 in
  USA/Canada and 2015 in Israel.
• Natural methods: Ethylene gas, spearmint oil and peppermint oil (e.e. Biox-M), or 1,4-Dimethylnaphthalene (1,4-DMN) are used as alternatives. Ethylene gas (10 to 15 ppm is used in some commercial storage facilities to inhibit sprouting. Some essential oils containing carvone could be an alternative to CIPC. Caraway oil is the most effective system. and can prevent sprouting for up to 180 days (Sanli & Karadogan, 2019). Other essential oils of interest include orange oil (D-limonene) (Visse-Mansiaux et al., 2020). The residues of essential oils persist in the skins causing off-taints
• Radiation: Tubers can be bombarded with low energy radiation which kills the tuber and stops sprouting (Kumar et al., 2009). The optimal radition dose is abot 500 to 1000 rads. radiation is slective in the microbes and fungi killed. It does not affectr Fusarium or Pythium, nor Erwinia species. It does inhibit the spawn of the fungi.
• Cold storage alone can delay sprouting, but additional inhibitors extend dormancy further.

Physical sprout suppression has been reported with ultraviolet (UV-C) radiation, high pressure treatment (100 MPa) and high magnetic field (330–350 mT). However, all these methods have severe limitations and are highly regulated.

7. Storage Types

• Clamping: The original and most often used method where potatoes are stored in heaps with straw or earth covers and overwintered. There is no temperature control and it is manually intensive but it is one of the cheapest techniques.
• Bulk Storage: Potatoes are stored in large piles (4-6m deep) with aeration ducts.
• Box Storage: Wooden or plastic crates with controlled airflow, often used for higher-quality storage.
• Refrigerated Storage: Used when temperatures need precise control, common for seed potatoes.

Letterbox systems

Used in the UK and Europe. Conventional method for positive ventilation. Air drawn into inlet louvres into an air blending chamber running the lebgth of the letterbox duct. Use fansmounted horizontally on top of the letterbox duct which draws air into the duct. Air is forced around the system fro the pressure of the fans via recatngular slots which are similar in shape to letterboxes hence the name at a height to match the pallet apertures of the boxes. Alternate air flow between box layers. Use foam bungs to control direction of air flow. Pivoted flaps on letterbox duct outlets allow air to be directed to all or some of the rows and layers of boxes.

There are upward flow systems, and upward and downward flow systems. In the UK, boxes are ventilated using the latter system. Air flows upwards in the top layer and are flows vertically downwards in the bottom layer. Duct arrangements vital.

Typical commercial systems include ambient-air or fridge cooled space-ventilated box stores. These ttypes are used for ware potatoes for the pre-packed market. They are spray foam-insulated, portal frammed buildings with an ambient-air/fridge cooled system. Incoming ventilation air is mixed with store air to ensure incoming air is not that much cooler than the crop. Or you can keep the refrigeration system switched on with the ventilation system switched to recirculation. Any air distribution is over the top of the boxes with return air to the intake of the aur/fridge cooling unit via ‘ducts’ formed by the pallet apertures of vboxes making up the stack.

The boxes add considerable additional cost of storage over bulk storage but give better skin finish and reduction in damage.

The other storage system is the ambient-air/fridge-cooled space-ventilated box store. This is the 1512-t positively ventialted box store. used for seed potato production where tubers and voids are small.

8. Disease & Pest Prevention

• Regular monitoring for rot, mould, and pests. The fungi are Pythium,
• Using sanitized storage facilities to prevent contamination.

9. Evaporation

• Tubers lose three times the amount of water immediately after storage and then the rate drops a month into storage. The reason is too thin a skin and is too loosely bound to the flesh.
• One of the main reasons for curing is to promote the corky layer that retards evaporation. It also helps with skin repair. Evaporation is also a consequence of sprouting.
• Loss of water produces changes in consistency and shape

Monitoring Potatoes During Storage

Monitoring the composition of potatoes during storage is essential to assess quality, detect spoilage, and prevent economic losses (Meijers, 1989).

Sampling and Inspection

• Visual inspections: Regular checks for physical damage, diseases, and pest infestation are conducted. Damaged potatoes are removed to prevent affecting the whole batch.
• Sampling for sugar content: Potatoes are sampled to test for reducing sugars (like glucose and fructose) which increase with improper storage conditions or aging. High sugar levels can cause browning during frying.

Measurement Of Size and Shape

The determination of the physical dimensions of agricultural materials such as tubers is very complex because of their irregular shape and variability in size. Presently, no single standard method is applied when determining the physical dimensions of agricultural products.

Various analytical tools are used to track changes in starch, sugar content, moisture, and other biochemical properties. These tools include:

1. Spectroscopic Techniques

• Near-Infrared (NIR) Spectroscopy: Measures moisture, starch, and sugar content non-destructively.
• Fourier Transform Infrared (FTIR) Spectroscopy: Identifies chemical changes in starch and sugar composition.
• Raman Spectroscopy: Detects biochemical changes, including lipid oxidation and sugar accumulation.

2. Chromatographic Methods

• High-Performance Liquid Chromatography (HPLC): Used to quantify sugar content, particularly reducing sugars like glucose and fructose that influence browning.
• Gas Chromatography-Mass Spectrometry (GC-MS): Detects volatile compounds related to spoilage and metabolic changes.
• Ion Chromatography (IC): Measures organic acids and other metabolites.

3. Electrical and Imaging Techniques

• Electrical Impedance Spectroscopy (EIS): Measures cell membrane integrity, indicating tissue degradation.
• Hyperspectral Imaging: Monitors moisture loss, bruising, and sugar accumulation.
• X-ray Computed Tomography (CT): Detects internal defects such as hollow heart and bruising.

4. Enzymatic and Biochemical Assays

• Glucose and Sucrose Enzymatic Kits: Measure sugar content changes that impact fry colour.
• Peroxidase and Polyphenol Oxidase Activity Tests: Indicate enzymatic browning.
• Amylase Activity Assays: Assess starch breakdown during storage.

5. Physical and Thermal Analysis

• Differential Scanning Calorimetry (DSC): Monitors starch gelatinization and retrogradation.
• Texture Profile Analysis (TPA): Evaluates firmness and mealiness.
• Water Activity (aw) Meters: Measure moisture availability to predict microbial growth.

6. Gas Analysis

• Electronic Nose (E-Nose): Detects volatile organic compounds (VOCs) that signal spoilage.
• CO₂ and O₂ Sensors: Monitor respiration rates and detect early spoilage.

These analytical tools help optimize storage conditions, prevent quality deterioration, and ensure that potatoes meet processing standards.

Monitoring Tools Needed For Potato Storage

Monitoring tools for potato storage help track and regulate temperature, humidity, oxygen (O₂), carbon dioxide (CO₂), and airflow to prevent disorders like blackheart and maintain potato quality. Below are key categories of tools available:

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1. Temperature Monitoring Tools

Maintaining proper storage temperature (4–10°C / 39–50°F) is crucial to preventing excessive respiration and blackheart.

• Digital Temperature Sensors – Measure temperature at different points within storage bins.
  • Example: ThermoWorks Thermapen, LogTag Trix-8
• Infrared Thermometers – Quickly measure surface temperatures without direct contact.
  • Example: Fluke 62 Max, Etekcity LaserGrip
• Wireless Temperature Loggers – Continuously track temperature with remote access via a mobile app.
  • Example: TempStick WiFi Sensor, HOBO MX2301A
• Automated Climate Control Systems – Adjust temperature automatically using preset thresholds.
  • Example: Tolsma Storage Systems, Agri-Stor Temperature Controllers

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2. Humidity Monitoring Tools

Maintaining 85–95% relative humidity prevents excessive moisture loss but avoids condensation.

• Hygrometers (Humidity Meters) – Measure humidity levels inside storage rooms or bins.
  • Example: Extech RH390, AcuRite Digital Hygrometer
• Humidity Loggers – Track long-term humidity trends for better storage adjustments.
  • Example: Lascar EL-USB-2, HOBO MX1101
• Humidifiers & Dehumidifiers – Adjust humidity levels when necessary.
  • Example: Fral FDNF62 Dehumidifier, Fogmaster 6200 Humidifier

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3. Oxygen (O₂) and Carbon Dioxide (CO₂) Sensors

Low O₂ or high CO₂ can cause blackheart by creating anaerobic conditions.

• Oxygen Sensors – Measure oxygen concentration to ensure levels stay above 5%.
  • Example: GASERA One O₂ Sensor, SST OXY-Flex
• Carbon Dioxide Sensors – Ensure CO₂ levels stay below 2%.
  • Example: Telaire T6615 CO₂ Sensor, Vaisala GMP343
• Handheld Gas Analyzers – Portable tools to check O₂ and CO₂ levels in different areas of storage.
  • Example: Geotech GA5000, GasBadge Pro Multi-Gas Monitor

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4. Airflow Monitoring Tools

Good ventilation prevents oxygen depletion and CO₂ buildup.

• Anemometers (Airflow Meters) – Measure airflow rate in storage areas.
  • Example: Testo 405i Hot Wire Anemometer, Kestrel 3000
• Ventilation Control Systems – Automate fans and vents based on airflow data.
  • Example: Tolsma Grisnich Ventilation Systems, Agri-Stor SmartStor Fans

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5. Remote Monitoring and Automation Systems

For large-scale storage, integrated monitoring and control systems provide real-time data and automatic adjustments.

• Smart Storage Systems – AI-driven controls that manage temperature, humidity, and gas exchange.
  • Example: Croptimiz-R by AgroVent, Tolsma Vision Control
• Cloud-Based Monitoring Platforms – Remote tracking of storage conditions with alerts.
  • Example: FarmHQ, Agri-Stor Remote Monitoring

6. Texture Analysis

Potatoes can be monitored using texture analyzers. Reliable producers of texture analysers include Instron and Stable Micro Systems. Texture is a key requirement of those potatoes to be used further for frying. It is also a reliable indicator of freeze-thaw damage because potatoes turn grey and lose structural integrity when damaged by freezing.

Using a combination of temperature loggers, humidity meters, gas sensors, and airflow monitors helps maintain optimal storage conditions, preventing blackheart and ensuring high-quality potatoes.

What Factors Govern Dormancy?

Dormancy is an important way for plants to keep their storage organs ready during times when conditions would mean poor growth, until the time they can start sprouting. Breaking dormancy is a physiological phenomenon. It is regulated by both exogenous (environmental factors) and endogenous signals (Sonnewald & Sonnewald, 2014) .

Premature sprouting is one of the main causes of tuber losses with post-harvest storage of potatoes. The amount of potato tubers suitable for sale alongside loss of fresh weight because of water loss from the sprouting surfaces and the conversion of starch to sugars.

The main sprouting suppressant is CIPC which has been commercially amongst stored tubers as thermal hotfog. This chemical helps to prolong potato storage.

The removal of CIPC now means that strategic alternatives to other methods of potato storage are needed because of the seriousness of what is a major loss in an effective chemical treatment. Better natural dormancy and improved low temperature tolerance reduces the need for chemical solutions and lower the risk from acrylamide. The issue with CIPC has been the reliance on a single treatment and that more holistic thought is needed to address the issue (Cunnington, 2023).

Potato Genomics

Potatoes are continually being bred with the objectives of storage, processing and eating quality in mind. Great strides have been made in improving productivity, pathogens- and stress-resistance. It has taken decades to fully understand the complexity of the potato genome. Understanding geno-phenotypic relationships along with new genomic analysis methods have now led to ‘precision breeding’. Precision breeding raises the efficiency in selection of targeted traits through genetics techniques. These include marker assisted selection, (MAS) and shorten the selection cycle. Disease resistance genes have been crossed from wild relatives into current potato varieties.

The rise in gene editing technologies such as CRISPR and gene insertion methods are changing the landscape for potato breeding.

There is a correlation between VInv gene expression and glucose content in tubers (Visse-Mansiaux et al., 2024) .

References

Alamar, M. C., Tosetti, R., Landahl, S., Bermejo, A., & Terry, L. A. (2017). Assuring potato tuber quality during storage: A future perspective. Frontiers in Plant Science, 8, 2034.

Booth, R. H., & Shaw, R. L. (1981). Principles of Potato Storage.

Cunnington, A. (2023) Developments in Automated Potato Storage Management. Potato Res. 66, pp. 1305–1314 (Article).

Driskill, E. P., Knowles, L. O., and Knowles, N. R. (2007). Temperature-induced changes in potato processing quality during storage are modulated by tuber maturity. Am. J. Potato Res. 84, pp. 367–383. doi: 10.1007/BF02987183

Ezekiel, R., Paul, V., Singh, J., & Shekhawat, G. S. (1999). Potato storage in India. Indian Farming, 49(9), pp. 21-25

Golmohammadi, A., & Afkari-Sayyah, A. H. (2013). Long-term storage effects on the physical properties of the potato. International Journal of Food Properties, 16(1), pp. 104-113  

Kumar, S., Petwal, V. C., Kaul, A., Behere, A., Promod, R., Bapna, S. C., … & Sharma, A. (2009). Sprout inhibition in potato (Solanum tuberosum L.) with low energy electrons. Journal of Food Science and Technology-Mysore, 46(1), pp. 50-53.

Lang, G.A., Early JD, Martin GC, Darnell RL. (1987). Endo-, para-, and ecodormancy: physiological terminology and classification for dormancy research. HortScience 22, pp. 701–377 .

Meijers , C.P. (1989). Diseases and defects liable to affect potatoes during storage. In Storage of Potatoes: Post-Harvest Behavior, Store Design, Storage Practice, Handling Edited by: Rastovski , A. and Van-Es , A. pp. 223 – 251 . Wageningen. The Netherlands.

Mohsenin , N.N. (1986). Physical Properties of Plant and Animal Materials , 742 New York : Gordon and Breach Science Publishers.

Olsen N, Kleinkopf G (2020) Storage management. In: Stark, J., Thornton, M., Nolte, P. (eds) Potato Production Systems. Springer, Cham. (Article).

Pasare, S. A., Ducreux, L. J., Morris, W. L., Campbell, R., Sharma, S. K., Roumeliotis, E., et al. (2013). The role of the potato (Solanum tuberosum) CCD8 gene in stolon and tuber development. New Phytol. 198, pp. 1108–1120.

Paul, V., Ezekiel, R., Pandey, R., (2016). Sprout suppression on potato: need to look beyond CIPC for more effective and safer alternatives. J. Food Sci. Technol. 53 (1), pp. 1–18 (Article). 

Pinhero, R. G., Coffin, R., & Yada, R. Y. (2009). Post-harvest storage of potatoes. In Advances in Potato Chemistry and Technology (pp. 339-370). Academic press.

Rastovski, A., Rastovski, A., & Van, A. (1981). Storage of potatoes (pp. 280-294). Wageningen: Pudoc.

Şanlı, A., Karadoğan, T. (2019) Carvone Containing Essential Oils as Sprout Suppressants in Potato (Solanum tuberosum L.) Tubers at Different Storage Temperatures. Potato Res. 62, pp. 345–360 (Article). 

Sonnewald, S., and Sonnewald, U. (2014). Regulation of potato tuber sprouting. Planta 239, pp.27–38. doi: 10.1007/s00425-013-1968-z

Sonnewald, U. (2001). Control of potato tuber sprouting. Trends Plant Sci. 6, pp. 333–335 (Article). 

Tian, J., Chen, J., Ye, X., & Chen, S. (2016). Health benefits of the potato affected by domestic cooking: A review. Food Chemistry, 202, pp.165–175 (Article).

Visse-Mansiaux, M., Ballmer, T., Tallant, M., Shumbe, L., Vanderschuren, H., Dupuis, B., 2019. Sprouting control of the potato varieties using cold storage. In: Harper, G., Hofman, T. (Eds.), EAPR Post Harvest section meeting 2019, the Maids Head Hotel, Norwich, UK. AHDB Potatoes, Sutton Bridge, UK & Certis Europe BV, Maarssen, Netherlands (12–14 March 2019). 〈https://emmabates6.wixsite.com/mysite/abst
racts>

Visse-Mansiaux, M., Shumbe, L., Brostaux, Y., Ballmer, T., Smit, I., Dupuis, B., & Vanderschuren, H. (2024). Identification of potato varieties suitable for cold storage and reconditioning: A safer alternative to anti-sprouting chemicals for potato sprouting control. Food Research International, 184, 114249.

Visse-Mansiaux, M., Soyeurt, H., Herrera, J. M., Torche, J. M., Vanderschuren, H., & Dupuis, B. (2022). Prediction of potato sprouting during storage. Field Crops Research, 278, 108396. 

Wiberley-Bradford, A.E., Bethke, P.C., 2017. Rate of cooling alters chip color, sugar contents, and gene expression profiles in stored potato tubers. Am. J. Potato Res. 94 (5), 534–543. https://doi.org/10.1007/s12230-017-9591-3

Wustman, R., & Struik, P. C. (2007). The canon of potato science: 35. Seed and ware potato storage. Potato Research, 50, pp. 351-355