What causes tomato fruits to crack?

When your garden tomatoes reach maturity, it’s exciting to see the fruits of your labor ready for harvest. However, sometimes mature tomatoes start splitting, exposing the fruit to rotting microbes. This splitting is a physiological disorder caused by growing conditions rather than pests or diseases. Factors like improper watering, lighting, temperature fluctuations, and nutrient imbalances can cause tomato fruits to crack. Tomato fruit cracking can also occur due to high intensity of solar radiation.

Moreover, the highest frequency of tomato splitting occurs during times when the soil is very wet, such as following intense monsoonal rainstorms in the late summer. Fruits that break before they are ripe should be removed from the vine to prevent rot. When tomatoes are harvested as soon as they start to crack, rot can be stopped, and the fruit can be preserved for eating or processing.

Tomato fruit cracks can significantly affect the commercial value of tomatoes for the fresh market, as cracked fruits are often unappealing and can only be sold locally or processed.

Both commercial farmers and household gardeners deal with the common issue of tomato cracking. When there are sudden variations in soil moisture, the fruit expands more quickly than the skin can cope with the expansion, which results in cracks and splitting. This problem is mostly caused by environmental conditions, which include frequent rainfall, erratic watering, and uneven maintenance. While some tomato varieties are more resilient than others, improper handling can cause any tomato to shatter. The cracking of tomatoes occurs in two different patterns. To take preventative action and preserve a high-quality crop, it is imperative to comprehend the underlying causes.

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Types of cracking

There are two main types of cracking that commonly occur in tomatoes: radial cracking, which involves vertical splits along the sides of the fruit, and concentric cracking, which appears as circular splits around the stem area.

Radial Cracking

Vertical splits that run along the sides of tomatoes are referred to as radial cracks, and they are the most severe type of cracking. Radial cracks usually start from the stem end and extend down toward the blossom end of the fruit. These types of cracks are particularly harmful as they greatly diminish fruit quality. They also make tomatoes more vulnerable to insect damage and increase the risk of decay and rotting caused by microorganisms. While radial cracks are the most damaging, any form of cracking lowers the overall quality of the fruit by creating entry points for pests and pathogens.

Concentric Cracking

Concentric cracking appears as circular splits that form around the stem scar of the tomato fruit.

What Causes Tomato Fruits to Crack?

Here are the main reasons why tomato fruits crack:

Irregular Watering

A common reason for tomato cracking is irregular watering. When tomato plants go through a period of drought followed by heavy watering or rainfall, the fruits take in water too quickly, causing the skin to stretch faster than it can expand, leading to cracks or splits. To avoid this issue, it’s important to water tomatoes consistently, keeping the soil evenly moist without making it waterlogged.

Water level fluctuations also contribute to cracking, and these are often beyond the gardener’s control, especially during unexpected heavy rains or dry spells.

Use of Excessive Fertilizers

Excessive use of nitrogen-rich fertilizers can cause tomatoes to grow too quickly, leading to rapid fruit development. When the fruit’s internal growth outpaces the skin’s ability to expand, the skin may crack. To avoid this problem, it is important to use a balanced NPK (Nitrogen, Phosphorus, Potassium) fertilizer and avoid over-applying nitrogen. Properly balanced fertilization helps manage growth rates and reduces the chances of cracking in tomatoes.

Temperature Fluctuations

Rapid changes in temperature, such as hot days followed by cool nights, can cause tomato skins to crack as the fruit struggles to adjust to these shifts. To help prevent this, using mulch can keep the soil temperature more stable, which reduces stress on the tomatoes and lowers the risk of cracking.

Variety of Tomato

Certain tomato varieties are more susceptible to cracking than others. To reduce the risk of fruit cracking, it is advisable to choose cultivars that are more resistant and still have good fruit quality for planting.

Overripe Fruits Left on the Vine

Tomatoes left on the plant for too long after ripening are more susceptible to cracking because their skins become softer and more fragile. To avoid this, it is best to pick tomatoes as soon as they are ripe, ensuring firmer skin and better overall quality.

Poor Soil Structure

If the soil is too hard or doesn’t drain well, it can stress out tomato plants and cause their fruits to crack. Using soil that is loose, well-drained, and full of organic matter helps keep moisture levels steady and lowers the chance of cracking.

Mechanism of Tomato Fruit Cracking

Splits result from the tomato’s inner flesh expanding more quickly than its outer layer, a process known as cracking. The top or the area where the stem was joined is usually where this splitting happens. The fruit’s rapid absorption of water and nutrients, coupled with the tomato’s ripening skin that grows weaker and less flexible, is the primary cause of this physiological problem. Variations exist in the sensitivity of tomato varietals to breaking.

Any stage of fruit development can experience cracking, although mature tomatoes are more prone to do so, particularly as they begin to change color. Some tomato kinds are more tolerant and won’t crack until they’re almost ripe, while others are quite prone to splitting and may even split when still green.

Select cultivars that are less prone to crack to reduce significant variations in growth rates and control cracking. Additionally, to preserve the fruit—tomatoes exposed to direct sunlight are more likely to split—maintain consistent soil moisture levels and make sure there is adequate leaf cover.

Tips to Prevent Tomato Fruit Cracking

It is essential to apply sound orchard management strategies in order to effectively decrease fruit cracking. This entails managing and reducing stress associated with water retention, nutrition, and physiological elements that cause fruit cracking. Growers may greatly lower the risk of cracking and raise the fruit’s overall quality by properly controlling these factors. Here are the details:

Crop nutrition

Effective crop nutrition plays a crucial role in reducing the incidence of tomato cracking. Boron, which is essential for the production of nucleic acids and plant hormones, as well as the movement of plant sugars and carbohydrate metabolism, can significantly influence fruit quality. Additionally, the application of calcium, boron, and potassium fertilizers has proven to be an effective strategy for minimizing tomato cracking by enhancing overall plant health and resilience.

Mulch Around Plants

Mulching is a useful method for keeping the soil moist and avoiding sharp changes in water levels, which can cause fruit to break. You may preserve soil moisture, lower evaporation, and keep regular soil moisture levels by mulching the base of tomato plants with a 2-inch-thick layer. This reduces the possibility of tomato skin cracks by ensuring uniform hydration and encouraging healthy fruit growth in conjunction with appropriate irrigation techniques.

Water Consistently

Consistent soil moisture levels and avoiding heavy irrigation after fruit has set are key to minimizing the risk of fruit splitting. By deeply and frequently watering tomatoes, you can assist maintain constant moisture conditions and prevent cycles of flooding and dryness, which lowers the chance of splitting.

Use Drip Irrigation

This technique provides uniform watering while keeping the foliage and fruit dry, thereby minimizing the risk of cracking.

Harvest Promptly

To keep tomatoes from getting overripe and breaking off the vine, harvest them when they are fully ripe.

Choose Crack-Resistant Varieties

Choose tomato varieties that are resistant to breaking without sacrificing desired fruit qualities in order to increase fruit output. Selecting fruit kinds that are less likely to break can help to increase the overall quality of the fruit.

By understanding these causes and taking preventive measures, you can reduce the risk of cracking in your tomatoes and enjoy a healthier, more bountiful harvest.