Carrot Yield, Harvest, and Post-Harvest Handling

Carrots are a valuable vegetable crop grown in various climates. Their yield and post-harvest quality depend heavily on factors like soil preparation, weather, and variety cultivated. For a successful carrot harvest and optimal post-harvest handling, it’s crucial to understand the specifics of yield potential, harvest timing, and the proper techniques for storage and transportation.

Global Carrot Production

Globally, the top carrot-producing countries play a significant role in meeting the increasing demand for carrots. China leads by a substantial margin, producing over 18 million metric tons (over 39 billion lbs) annually, which accounts for nearly half of the world’s total carrot production. Following China are countries like Uzbekistan, the United States, Russia, and Ukraine, each contributing significantly to the global supply. The United States, for example, produces over 1.3 million metric tons (over 2.8 billion lbs)  of carrots annually, with California being the primary state for production.

Yield – How Much Carrots Can Yield? 

Carrot yield per hectare and acre

Carrot yields can range significantly from 30 to 100 tons per hectare (approximately 26,760 to 89,217 lb/ac) in major carrot-growing countries. In contrast, many developing countries experience yields well below the world average of 36.5 tons per hectare (around 32,560 lb/ac). With proper soil preparation, irrigation, fertilization and plant protection, higher yields can be achieved.

Harvest 

When to Harvest Carrots

Carrot harvesting is determined by the maturity of the roots and the market requirements. The time to harvest typically ranges between 90 to 120 days after sowing, depending on the variety and environmental conditions. For fresh market carrots, harvesting is generally done when the roots reach a diameter of at least 0.8 inches or 2 cm or larger at the upper end. Smaller varieties should have a diameter of at least 0.4 inches (1 cm). Still, the size and type of carrot harvested may vary depending based on market demands. Harvest can be delayed by a few days to allow for sugar content increase, particularly in mild climates​.

Harvest Techniques – How to Harvest Carrots

Carrots can be harvested manually or mechanically. 

Manual harvesting involves loosening the soil using a fork or spading tool and gently pulling out the roots. This method is particularly common when harvesting in small-scale farms or when roots are being hand-picked for certain market demands, such as baby carrots. For large-scale commercial farming, mechanical harvesters are used. Care must be taken to ensure the tops are in good condition, as mechanical harvesters rely on them for efficient pulling​.

Topping (removing the carrot tops) is crucial to prevent disease entry and excessive water loss. The tops should be fully removed during harvesting, as incomplete topping can lead to increased transpiration and potential entry points for decay​.

Mechanical Harvesting

Carrot harvesting is often conducted using specialized machines known as carrot harvesters. These machines can be either top lifters or share lifters and tractor-mounted, trailed behind a tractor, or self-propelled. A typical harvester can handle between one and six rows of carrots at once.

• Top Lifting Harvesters
  Top lifters utilize rubber belts to grab the green tops of the carrot plants and pull them from the soil. A share (a component of the harvester) pushes underneath the carrot root to loosen the plant. The belt then transports the carrots, still with their tops, into the machine, where the tops are cut off and directed along a waste path, subsequently dropped back onto the field.
• Share Lifting Harvesters
  In contrast, share-lifting harvesters extract carrots from the ground from underneath. This method requires a prior operation using a topper to cut off the green tops of the carrot plants. Once the tops are removed, the carrots travel along a longer web to help separate the soil from the roots.

Post-Harvest Handling

Post-harvest handling of carrots is essential to maintaining their quality during storage and transport. After harvesting, carrots should be carefully washed to avoid damaging the delicate root surfaces. Any mechanical damage opens the carrots to moisture loss and decay, so ensuring that all handling equipment is operating correctly ​is vital.

Sorting and Grading
Carrots are usually sorted by hand to remove any broken or split roots, which could lead to rapid spoilage. The marketable carrots are then graded according to size and appearance. Carrots with uniform root sizes are preferred in markets due to their visual appeal. They are either sold as bunched carrots, with the tops intact, or topped carrots, where the tops are removed. Topped carrots are trimmed to a length of no more than 4 inches ​(10 cm).

Packing
After sorting, carrots are packed in perforated plastic bags, mesh pockets, or cartons, depending on the market requirements. Ensuring uniformity in root size during packing enhances the presentation is key for retail markets. Carrots intended for fresh consumption should be handled with care to avoid mechanical injury, as even minor damage can lead to spoilage during storage and transport​.

Storage

Carrots are highly perishable and must be stored in conditions that maintain their freshness and prevent decay. Ideally, carrots should be stored at a temperature of 32°F (0°C) with a relative humidity of 95-100%. Under these conditions, carrots can be stored for four to six weeks. 

To preserve their quality, freshly harvested carrots should be pre-cooled to remove field heat before dense packaging. Hydrocooling or using cold water (at a temperature of 40°F or 4°C) in drum washers is commonly employed for precooling. It’s important to avoid condensation, which can promote decay during storage. Ensuring good air circulation is critical to prevent moisture buildup and decay.

Post-Harvest Defects
Several quality defects can occur in carrots if proper handling and storage measures are not followed. Common defects include growth cracks, insect damage, non-uniform shape, and poor color. Additionally, carrots may become limp or shriveled due to moisture loss. Storing carrots near ethylene-producing crops, such as apples, should be avoided, as even a small concentration of ethylene can impart a bitter taste to the carrots

References

• https://www.tridge.com/intelligences/carrot/production
• Tegen, H. & Jembere, M. (2021). Influences of spacing on yield and root size of carrot (Daucus carota L.) under ridge-furrow production. Open Agriculture, 6(1), 826-835. https://doi.org/10.1515/opag-2021-0062
• https://ec.europa.eu/growth/tools-databases/tbt/en/search/
• https://extension.uga.edu/publications/detail.html?number=B1175&title=commercial-production-and-management-of-carrots
• https://www.dalrrd.gov.za/phocadownloadpap

Learn more about carrot cultivation

Carrot Plant Information and Variety Selection
Nutritional value & Health Benefits of Carrots
Growing Carrot in Your Backyard
Carrot  Soil Requirements, Soil Preparation and Planting
Carrot Water Requirements and Irrigation Systems
Carrot Nutrient Needs & Fertilizer Requirements
Carrot Common Pests, Diseases and their Management
Carrot Common Weeds and Weed Management