Fruit production today is facing numerous challenges worldwide. Among the most concerning and widespread production issues faced by farmers is fruit cracking. Splitting and cracking are physiological phenomena, which occur under specific conditions, affecting the fruit skin and flesh integrity. Fruit cracking compromise not only the aesthetic appeal of the produce, but also allow water loss and pathogen invasion, decrease storability and shelf life, thus reducing fruit marketability.
Climate change is an imminent threat that continues to reshape our planet’s natural systems, including our agricultural landscapes. Rising temperatures, heatwaves, and intensifying extreme weather events are becoming the new norm, leaving farmers and researchers concerned about the potential consequences for crop production. Of particular concern is the impact of climate change on fruit crops, as their development and yield can be heavily influenced by shifting climatic variables. The fruit cracking seems to be largely affected by sudden surges of heat and heavy rains, and once in a few years aggravates to more than 50 % of the fruits.
According to European Statistics, Europe produced approximately 42.7 million tonnes of fresh fruit in the 2020/2021 season. This highlights the significant contribution of the European agricultural sector to fruit production on a global scale. A closer look at fruit crops reveals that fruit cracking can result in a potential loss ranging from 10% to 30% across different fruit varieties, sometimes going to hard extremes.
Fruit cracking in citrus crops can result in yield losses ranging from 10% to 30%, often initiated by slight skin discoloration. Pomegranate crops are susceptible to a potential loss of 10% to 40%, however, some cracked produce can be repurposed for processing, providing a modest reduction in economic loss. Cracking in table grapes starts after the onset of ripening, which can cause over 50% yield loss and later be followed by lower incidence seasons, while in sweet cherry yield loss caused by fruit cracking ranges from 10% to 30%. Severe rainfall seasons affect cherry yield even above 45%.
Causes of fruit cracking and the interaction between the climatic variables, management and temporal fruit development remain unclear. Some of the key factors affecting the fruit cracking incidence are the following:
• Rapid moisture fluctuations are one of the primary causes of fruit cracking. This occurs when there is a sudden influx of water after a period of drought or heavy rainfall. The rapid absorption of water causes the fruit to expand quickly, leading to the development of cracks on its surface.
• Varietal susceptibility – some fruit varieties are more prone to cracking than others. Certain genetic traits make fruits more susceptible to cracking under environmental stressors. For example, varieties with thin or fragile skin are more likely to crack compared to those with thicker, more elastic skin.
• Nutrient imbalance – decreased nutrient availability can weaken the fruit’s skin, making it more prone to cracking. Deficiencies in calcium, magnesium and boron have been linked to increased cracking incidence. Ensuring proper nutrient management is crucial in preventing this issue.
Fruit loss caused by the fruit damage affects several aspects of fruit production and influence the entire value chain:
• Reduced marketability – cracked fruits are aesthetically unappealing and may not meet the quality standards required for commercial sale. This can result in significant financial losses for farmers, as consumers are less likely to purchase blemished produce.
• Increased vulnerability to pathogens – cracks in the fruit’s skin create entry points for pathogens, such as bacteria and fungi. These microorganisms can cause rot and spoilage, leading to post-harvest yield losses and decreased shelf life
• Wasted resources – the efforts put into cultivating the crop, including labour, water, fertilizers, time and finantial aspect, pose a significant loss in case of yield loss due to cracking. This not only affects the current harvest but may also impact the productivity of the tree plant in subsequent seasons and, in some cases, complete abandonment of certain fruit variety cultivation and production.
The significance of fruit production in Europe and the potential losses caused by fruit cracking are being brought into the limelight due to challenges faced by growers in a changing climate. As climate shift drives the impact on our agricultural systems, it is an imperative to develop adaptive strategies, invest in research and innovation and prioritize sustainable practices. Through understanding the causes behind this phenomenon and implementing proper preventive measures, farmers can minimize the impact of fruit cracking and improve the overall quality and yield of their produce. By taking into consideration all factors and externalities affecting fruit production in pomegranates, citruses, cherries and table grapes, CrackSense will delve deep into the fruit cracking phenomenon and ultimately provide key resources for fruit cracking mitigation in other fruit crop species as well.