*2.2. Cracking Index and Crack Type Incidence*

The CI (cracking index) of both sweet cherry cultivars after an immersion in distilled water during 6 h and the crack type incidence are presented in Figure 2. The cv. Lapins presented a significantly higher cracking index than cv. Early Bigi (*p* = 0.001), with a fold increase of 440%, despite being considered as a moderately resistant cultivar to cracking.

**Figure 2.** (**A**) Cracking index (%) and (**B**) crack type incidence (%) of two sweet cherry cultivars (Early Bigi and Lapins). SCR—stem cavity region, SSR—stylar scar region, and CR—cheek region. Data are expressed as mean ± standard deviation. Different letters indicate statistically significant differences (*p* < 0.05) between cultivars for each variable, according to Tukey's test.

Taking into account the different types of cracking, in the present work, the SSR cracks were the most frequent in both cultivars (86.41% in cv. Early Bigi and 96.12% in cv. Lapins). This can be explained by the higher osmotic concentration of solutes in this part of the fruit, which accounted for a more rapid water absorption through the skin, resulting in a quicker formation of cracks [15]. Furthermore, cv. Early Bigi also presented 13.59% of CR cracks and no SCR-type cracking was found in this cultivar, while cv. Lapins presented 3.1% of SCR cracks and only around 0.78% of CR cracks. According to [15], the small cracks at the base and top end of the fruit (SCR and SSR cracks) often occurred at a very early stage, when the fruits were not yet mature. The same author [9] also suggested that cherries with these two types of cracks were tolerated by consumers since no fungal infection is present. However, fruit with CR cracks (more predominant in cv. Early Bigi than in cv. Lapins) are usually rejected by the consumers.

Despite the higher cracking index of cv. Lapins observed in the present work and determined in the laboratory, it is necessary to take in account that cracking of fruit attached to the tree and that of fruit detached and submerged differs significantly. In fact, according to [16], fruit attached to the tree cracked more slowly and required more water to crack.

#### *2.3. Cracking Index and Biometric Attributes*

Fruit size is considered as the main benchmark in commercial cherry grading, being a large factor in consumer preference, and is a huge determinant of both farm gate and market price.

The correlations between the CI and the fruit width and its weight are presented in Figure 3A,B. In Figure 3A, it is possible to observe that cv. Early Bigi presented simultaneously lower values of CI and width, which means that these two parameters were positively correlated (R<sup>2</sup> = 0.9529, *p* = 0.001). The same profile was observed in Figure 3B. Indeed, CI and fruit weight were also positively correlated (R<sup>2</sup> = 0.9482, *p* = 0.001), with the highest values of both parameters to be observed in cv. Lapins. In fact, the weight of fruits from cv. Lapins was significantly higher (11.12 g of average weight) than in cv. Early Bigi (6.10 g of average weight) (*p* = 0.000). According to several authors, the fruit size depends on cultivar, maturation stage, agricultural practices, and environmental conditions [17–19]. In this work, the higher CI observed in cv. Lapins may have been influenced by the big fruit size of this cultivar (29.00 mm of average width) in contrast to cv. Early Bigi (24.46 mm of average width), thus there were significant differences between cultivars (*p* = 0.000). In fact, according to [20] and [21], larger fruits are more prone to cracking than small ones. In fact, in big fruits, the physical stress on the enclosing membrane (the skin) is bigger, and consequently, cracks occur in areas of the fruit where stress is the greatest [4]. However, the first author also suggested that the correlation between the CI and the fruit size was greater within a cultivar than between cultivars, since it is necessary to take into account the specificities of each cultivar.

**Figure 3.** Correlation between (**A**) the cracking index (%) and the fruit width (mm) and (**B**) the cracking index (%) and the fruit weight (g) of two sweet cherry cultivars: Early Bigi and Lapins.
