Spatiotemporal modelling of the quality and ripening of two cultivars of “Algarve Citrus” orchards at different edaphoclimatic conditions

Nondestructive Assessment of Citrus Fruit Quality and Ripening by Visible–Near Infrared Reflectance Spectroscopy

“…However, all QA vary greatly inside the same orchard, either in terms of absolute values and/or in terms of spatial and temporal distribution, and even in the same tree. This has been shown in citrus orchards of 'Shiranuhi' mandarin (C. unshiu  C. sinensis)  C. reticulata [17], 'Ortanique' (Citrus reticulata Blanco x Citrus sinensis (L) Osbeck) [18], mandarin (Citrus reticulata Blanco) [19], and 'Newhall' and 'Valencia Late' orange [20]. Multiple factors, such as the level of sunlight exposure and the associated fruit temperature on the tree, fruit yield and size, tree vigor and age, rootstocks, site-specific nutritional requirements and micro topographies within the orchard, are reportedly associated to this variability [21][22][23][24].…”

“…Multiple factors, such as the level of sunlight exposure and the associated fruit temperature on the tree, fruit yield and size, tree vigor and age, rootstocks, site-specific nutritional requirements and micro topographies within the orchard, are reportedly associated to this variability [21][22][23][24]. Furthermore, the location of the orchards and their edaphoclimatic conditions, as well as the cultural practices also induce variability on the fruit maturation process, leading to different levels of QA and different ripening rates observed for the same cultivar at different sites [20,21]. Consequently, the number of tested fruits with the standard methods is seldom statistically representative of the orchard, leading to the sub-representation of the effective ripening stage of the fruit within and between orchards, which results in a limited assessment of their ripening, heterogeneous fruit quality, a deficient OHD management and a weak traceability in the citrus supply chain [25][26][27].…”

Ripening assessment of ‘Ortanique’ (Citrus reticulata Blanco x Citrus sinensis (L) Osbeck) on tree by SW-NIR reflectance spectroscopy-based calibration models

“…Juice pH exhibited some similarities with MI pattern (higher in VJ on 0 d, and higher in G on 57 d and 79 d) but tended to the same level in both orchards afterwards (106 d and 162 d). In contrast, G tangors exhibited higher firmness and thicker rind, only on 57 d. Differences in these IQA in fruit from orchards located at various sites have also been reported in' Newhall' and 'Valencia Late' orange (Citrus sinensis (L) Osbeck) (Cavaco et al, 2018(Cavaco et al, , 2021aDomingues et al, 2021), 'Kinnow' mandarin (Nawaz et al, 2020), and Satsuma mandarin (Li et al, 2021) as a consequence of different soil types, relative humidity, total precipitation and temperature.…”

“…The current approach to establish the OHD of 'Ortanique', similarly to other citrus varieties, is to collect a small number of fruit from each orchard at the beginning of the harvest season and to determine the mandatory IQA by standard destructive and time-consuming methods (Ladaniya, 2008). However, due to the large variability inter-and intra-tree within each orchard, as shown for 'Ortanique' (Pires et al, 2019), or between orchards, as reported for two varieties of sweet orange (Citrus sinensis (L) Osbeck) (Cavaco et al, 2021a), the current number of fruit measured seldomly accounts for the whole orchards' heterogeneity. Inadequate fruit sampling can result in a limited assessment of their ripening, heterogenous quality, a deficient OHD management and a weak traceability in the citrus supply chain (Canavari et al, 2010;Haleem et al, 2019).…”

Valorization of Bio-Residues from the Processing of Main Portuguese Fruit Crops: From Discarded Waste to Health Promoting Compounds

“…In Portugal, citrus is mainly grown in the country’s southern region, namely in Algarve, where oranges are classified as a Protected Geographical Indication (PGI) fruit, granting a significant economic impact. As non-climacteric fruit, “Algarve Citrus” (“ Citrinos do Algarve ”) are harvested at their optimal ripe stage, when fruit internal quality attributes (IQA) comply with the requirements of the respective PGI normative reference [ 23 , 24 ]. During orange juice production, only about half the weight of fresh orange is transformed into juice.…”