Pomegranate fruit cracking, also known as ‘cracking,’ is a relatively common physiological disorder in the cultivation of this tree. As pomegranates approach maturity, they often develop cracks on their skin, resulting in significant damage. This cracking issue is generally attributed to water stress and, to a lesser extent, nutritional factors. In this article, we’ll explain why pomegranates crack while still on the tree and discuss the agronomic interventions to limit this problem.
How Pomegranate Fruit Ripens
Pomegranate fruits reach full maturity in early autumn. During ripening, the outer part, the tough skin, changes color, as do the arils (the seeds), which develop the characteristic reddish pulp (initially white). They form in summer, following the flower pollination, and continue to grow until autumn. Pomegranates are typical of Mediterranean cultivation, highly resilient and drought-resistant, and typically do not require additional water to grow vigorously and mature their fruits. However, their cultivation has expanded to regions with more variable climates, leading to issues like fruit cracking.
What Causes Pomegranate Skin Cracking?
The skin of a pomegranate fruit is tough and semi-woody in consistency. Once it reaches its full size, it hardens. When there’s a sudden excess of water, the grains inside the fruit swell abnormally, causing cracks on the skin. In our central-northern regions, where pomegranates are grown without issues in family orchards, it’s quite common to experience severe summer storms towards the end of summer. These sudden, heavy rains, combined with high humidity levels, can cause pomegranates in their final stages of maturation to crack. This phenomenon is even more severe if it occurs after a prolonged period of drought. Therefore, we are dealing with a physiological disorder, a problem resulting from abiotic factors, rather than a disease affecting the pomegranate itself.
Consequences of Pomegranate Fruit Cracking
Pomegranate fruits can crack at different times. If this happens when the fruit is nearly ripe, the problem is minimal (in a home setting). You can simply harvest the pomegranates from the tree, consume them, or transform them into pomegranate liquor or pomegranate jelly. In this case, cracking is a signal that it’s the best time for harvesting. However, if cracking occurs before complete ripening, the problem is more severe. These fruits cannot be harvested as they are either unusable or still too tart. Additionally, cracked pomegranates are susceptible to rot or attacks by birds and insects. In essence, you lose the production of cracked fruits, which unfortunately becomes common with the arrival of late summer rains.
How to Prevent Pomegranate Fruit Cracking
Let’s explore the agronomic interventions to prevent pomegranate fruits from easily cracking when the rains arrive. Firstly, we can work on the soil to prevent waterlogging around the collar and root system. The soil for pomegranate cultivation should be well-draining. Proper drainage can be achieved by correctly transplanting the tree. For instance, placing gravel at the bottom of the planting hole aids in excess water drainage. This is a proactive intervention.
Once our trees are established, we can avoid waterlogging by facilitating water drainage, perhaps by creating specific channels around the plant with a hoe.
As mentioned earlier, pomegranates are hardy, drought-resistant plants native to warm countries, theoretically not requiring irrigation. However, in specialized plantations where pomegranates are intensively grown, irrigation is practiced. Economically, it’s not feasible to deal with fruit cracking issues. With proper drip irrigation systems, water is regularly supplied during the summer, ensuring that the soil never dries out excessively. This prevents water stress, even when the inevitable rains arrive. If the plant is accustomed to receiving water, it enlarges and matures its fruits gradually when the skin is still softer, avoiding sudden stress and subsequent cracking. Controlled summer irrigation effectively solves the issue of fruit cracking.
In a Home Setting
This strategy can also be applied in a home setting by watering regularly, in the evening, without overdoing it. A little water doesn’t hurt and prevents more significant problems. Of course, when the rains come, irrigation should be suspended if you notice that the soil remains moist, especially with cooler nighttime temperatures.
In specialized orchards, it has been observed that pomegranates are more prone to cracking when there’s a deficiency of potassium (K), calcium (Ca), and magnesium (Mg) in the soil. In a family orchard, this deficiency can be addressed by fertilizing our trees once a year with some wood ash. It’s a simple yet effective intervention.
Choosing Pomegranate Varieties Resistant to Cracking
When deciding to plant a new pomegranate tree or establish a large-scale plantation, it’s advisable to choose varieties that are more resistant to fruit cracking. For example, the Wonderfull variety, which produces large fruits with vibrant red skin, is less susceptible to cracking. When purchasing a tree, consult a knowledgeable nursery that can recommend the best variety based on your orchard’s characteristics.