EWS-Agronomy Troubleshooting Guide
Fruit Cracking in Tomato
What is Cracking?
Cracking is the splitting of the epidermis around the calyx or stem scar. It is a physiological disorder that is caused by growing conditions. This happens due to the rapid growth rate of the fruit. Genetic and environmental factors also cause this condition.
Two Types of Cracking
Concentric Cracking
A splitting of the epidermis in circular patterns around the stem scar. Concentric cracks occur in arcs around the stem scar.
Radial Cracking
A splitting of the epidermis from the stem scar towards the blossom end. Radial cracks start at the stem scar and go out like spokes on a wheel.
Fruit Cracking in Tomato (2)
Why Does Cracking Occur?
Cracking depends on the ability of the epidermis and its cells to stretch. Some varieties have an epidermis that stretches well and get very little or no circular cracking.
Cracking is caused by sudden fluctuations in soil moisture. This can be due to periods of excess rain or watering followed by periods of drought or infrequent watering and humidity. Cracks result when the fruit expands quicker than the growth of the skin. Basically, the tomato bursts at the seams.
When Does Cracking Occur?
Cracking occurs as the tomato nears to maturity. More susceptible varieties crack on mature green stage while more tolerant varieties at a later stages. The earlier the cracking the deeper and longer the crack becomes. The problem is usually more severe on the lower trusses. Circular cracking often occurs on ripe tomatoes that stayed on the vine for too long.
Fruit Cracking in Tomato (3)
What are the Reasons for Cracking?
Environmental conditions and growing conditions
Variable water supply and/or fluctuating temperatures.
Inappropriate levels of water, light, temperature and nutrients that can cause a variety of physiological disorders
The fruits are especially vulnerable as they are at the growing tips and have to compete with the new shoots for water and nutrients.
The skin can’t expand fast enough due to the rapid fruit growth
Tomatoes are exposed to hot sun which tend to crack more
Rain comes or irrigation is done right after the dry period
How to manage Cracking Management
Crop Nutrition
• Boron has a positive influence on the level of tomato cracking and shelf life of the tomato fruit. Potassium and calcium deficiencies also increase the risk of cracking in tomatoes.
Harvest before fruits are completely ripe
Healthy foliage to shade fruit
Practice protected culture
Choose a good variety
Even supply of water
Do not over prune
