## 2 Results and Discussion
This color matrix results in the grouping tree shown at the top of the figure, which groups the phenological maturation stages that do not differ significantly from each other on the same branch, and separates stages that do differ significantly on different branches; (**a**) heat map for var. Albion; (**b**) heat map for var. Festival; (**c**) heat map for var. Frontera. It can be seen that stages AL4 and AL5 are grouped on the same classification branch, and therefore their VOC profiles are not significantly different; on the other hand, AL6 is not paired with any other stage, so the AL6 variety/stage is different from the rest in terms of its VOC profile (Figure 1a). This could indicate that the aroma of this variety does not completely finish developing until the fruit reaches 43-44 DAA. This classification can be explained based on the fact that the compounds with the strongest positive correlation in the AL6 stage are esterified compounds. It has been reported that this chemical group is one of the most influenced by fruit maturation, and esterified VOCs are considered to be characteristic of mature fruits and are responsible for fruity aromas [30]. At the same time Figure 1a, shows valuable information for each stage of maturation that could be used to optimize cultivation and harvest. An example is the use of nutrients deployed to the crop during fertilization. [PERSON] and [PERSON] [31] discovered that fertilization of strawberry fruits with nitrogen of the Florida radiance variety is effective only up to 30 DAA, and using the same amount of nitrogen after that point had no effect on strawberry fruit production. Using the VOC profile in Figure 1a could help to identify the moment when applying nitrogen will no longer have a significant effect on the crop; this tool shows that while stages AL2 and AL3 present the same coloration, they do not share the same VOC profile, and the AL3 profile belongs to the 30-35 DAA time frame, which would provide a cue of when to decrease the amount of fertilizer. In the case of stages AL4 (41-42 DAA) and AL5 (43-44 DAA), the surface color of the fruit is no longer the same since AL4 has 30% of the surface red and AL5 has 60% of the surface red. However, their VOC profiles do not differ significantly, so these stages could be used as export quality fruit since according to [PERSON] and [PERSON] [32] the quality of fruit for export only takes into account the fruit color, some companies have opted for treatment with modified atmospheres to finish the development of red coloration during the shipping time of strawberry fruits, leaving aside organoleptic characteristics like aroma. In the case of the Albion variety, the fruits could be harvested in stage AL4 and their profile would not differ significantly with respect to AL5, giving producers a wider harvest margin. Interestingly, having worked with different varieties allowed us to observe that stages FE5 (41-42 DAA) and FE6 (43-44 DAA) are found on the same branch of the classification tree in Figure 1b, which indicates that there is no significant difference between these stages in aroma-related VOC profile. This shows that in the Festival variety, the VOC profile can reach its final state before fruits reach 100% red surface color. This contrasts with the Albion variety, in which the aromatic profile is not fully developed until fruits are in the last maturation stage; thus, fruit variety is a determining factor when it comes to maturity [33]. One way to utilize the information in 1b as a tool to optimize strawberry cultivation in greenhouses is the adequate timing of pest management measures. Work by [PERSON], et al. [34] reveals that strawberry fruits are attacked by the pest _Galerculella_ spp. when fruits present maximum herbaceous aroma, which is a characteristic of stages FE0 and FE1. The VOC profile of the Festival variety could be used to develop a more adequate pest control program as a function of the stage during which the pests are most attracted.