Days After Full Bloom Research Articles

Effects of Promalin on Fruit Growth and Cuticle Properties of ‘Pinova’ Apple

Promalin (Valent BioSciences, Libertyville, IL, USA) is a proprietary mixture of gibberellin A4 + 7 and 6-benzyladenine that is widely used in apple production to improve the fruit shape, size, and skin quality. Promalin typically increases fruit size and length. However, the increased growth likely increases the strain in the fruit skin, which may exacerbate microcracking of the cuticle and, consequently, russeting. This study aimed to monitor the growth-stimulating effect of Promalin in three different regions of fruits and investigate whether Promalin affects cuticular microcracking via effects on the deposition of cuticular components or via the accumulation of strain in the cuticle. Four Promalin sprays (20 mg⋅L−1) were applied to runoff; the first was applied at full bloom, and the remaining sprays were applied at approximately weekly intervals thereafter. Fruit surface areas and fruit surface area growth rates of the Promalin-treated fruits were higher than those of the untreated control fruits. Promalin increased the fruit length, but it had no effect on the fruit equatorial diameter. In Promalin-treated fruits, the base of each sepal extended, thickened, and became fleshy as early as 15 days after full bloom (DAFB). Allometric growth analyses revealed higher constant differential growth ratios of the pedicel and calyx length (before 36 DAFB) in Promalin-treated fruits than in control fruits. After 36 DAFB, the difference in constant differential growth ratios between Promalin-treated fruits and control fruits decreased. Cuticle mass per unit area increased with time in all regions of the fruit surface and was slightly (+3.3%) but significantly higher in fruits treated with Promalin than in control fruits. Additionally, the biaxial strain release was slightly and significantly lower in Promalin-treated fruits than in control fruits. When the isolated, cuticle was ablated from the inner surface and dewaxed, strain relaxation in the control fruits was higher than that in the Promalin-treated fruits. It was concluded that Promalin treatment increases the length of the fruit by increasing the lengths of the pedicel and calyx regions early during fruit development. Promalin only slightly increased cuticle deposition and fixation of cuticular strain. Promalin had no effects on microcracking or russeting.

The role of CitMYC3 in regulation of valencene synthesis-related CsTPS1 and CitAP2.10 in Newhall Sweet Orange

CsTPS1 (Cs5g12900) is a gene encoding a sesquiterpene synthase involved in generating valencene, a key volatile compound in sweet orange fruit. Here, a citrus basic helix-loop-helix (bHLH) transcription factor (CitMYC3), is characterized as a positive regulator of CsTPS1. Dual-luciferase assays showed that CitMYC3 transcriptionally activates its own promoter, also the CsTPS1 promoter and, in addition, the promoter of a second transcription factor, CitAP2.10, which in turn positively regulates the CsTPS1 expression. During the developmental period, CitMYC3 transcripts were detectable at 60 days after full bloom (DAFB) and increased gradually to 120 DAFB, while CsTPS1 mRNA rapidly increased from 90 to 150 DAFB. Exogenous ethylene accelerated the expression of CitMYC3 (peaking at 4 h) before CsTPS1 expression (at 24 h). Furthermore, CitMYC3 and CitAP2.10 were also shown to activate the promoter of Arabidopsis AtTPS11, a homolog of CsTPS1, which is in charge of the synthesis of over fifteen different sesquiterpenes, indicating that CitMYC3 and CitAP2.10 have a likely conserved function in the regulation of sesquiterpene genes across a variety of plant species.

Effects of Different Pre-Harvest Bagging Times on Fruit Quality of Apple.

Pre-harvest bagging can improve fruit color and protects against diseases. However, it was discovered that improper bagging times could lead to peel browning in production. Using the Ruixue apple variety as the research model, a study was conducted to compare the external and internal quality of fruits bagged at seven different timings between 50 and 115 days after full bloom (DAFB). Our findings indicate that delaying the bagging time can reduce the occurrence of peel browning in Ruixue apples. Compared to the control, the special bag reduced the browning index by 22.95%. However, the fruit point index of Ruixue fruits increased by 65.05% at 115 DAFB compared to 50 DAFB when bagging was delayed. The chlorophyll content of Ruixue fruits in special bags generally increased and then decreased, with the highest chlorophyll content of Ruixue fruits in special bags at 90 DAFB, which was 26.02 mg·kg-1. When the bagging process was delayed, the soluble solids, total phenols, and flavonoids content in the fruits increased, while the number of control volatiles decreased by 10. After two years of testing, results show that using special fruit bags at 90 DAFB bagging can significantly improve the fruit quality of Ruixue apple.

A geometric modelling approach to estimate apple fruit size by means of LiDAR 3D point clouds

ABSTRACT Remote sensing in agriculture aims to search new methods to monitor fruit at the tree, thus improving the estimation of yield-related variables. Light detection and range (LiDAR) scanning was introduced to obtain geometric and radiometric information from fruit surfaces by means of 3D point clouds. A geometric model to estimate apple size by means of segmented 3D point cloud of fruit is proposed in the present study. The model consists in the approximation of 3D point clouds to a reference shape given by 2D Fourier series expansion. Each point cloud was approximated to its reference shape using an iterative error minimization routine. The geometric model was applied to laboratory and field data of spheres and apples during fruit growth, ranging from 60 to 151 days after full bloom (DAFB). An overall RMSE between measured and predicted fruit radius of 20.1, 76.8, and 119.1% was found for the geometric model, mean, and maximum Euclidean distance approaches, respectively, including all studied growth periods in field conditions. Moreover, the linear regression on measured and predicted values showed considerably improved coefficient of determination ( R 2 ) of the geometric model in comparison to Euclidean distance calculations with R 2 values of 0.76 and 0.49 for laboratory and field scanned apples, respectively. The data processing method enables fruit monitoring and their application of terrestrial LiDAR sensing in precise orchard management.

A Comparative Study of Five Apple Cultivars Linking Biochemical Changes at Different Developmental Stages with Storage Textural Quality

Biochemical changes in the cell wall composition and activity of cell wall-modifying enzymes of five apple cultivars, Royal Gala (Gala), Aurora Golden Gala (Aur), Splendour (Spl), Honeycrisp (HC), and Ambrosia (Amb), collected from the 2016 growing season in the early growth phases, namely 40 and 70 days after full bloom (DAFB), at harvest maturity, and after 20 weeks of storage were investigated in relation to the textural changes at harvest maturity through to 20 weeks of storage. Assessing apple texture with a single-point measurement of firmness using a penetration test to a depth of approximately 8 mm in apples may not be an ideal measurement for assessing apple textural quality. Pectin methyl esterase (PME) activity at early developmental stages may be predictive of textural quality after storage. This work also found that β-D-galactosidase (BGAL) and α-L-arabinofuranosidase (AFAS) activities at early developmental stages may be important factors affecting textural quality after storage. Additionally, the degree of methylesterification (DME) assessed with FTIR on apple flesh material at the early developmental stages was strongly positively correlated (r2 ≥ +0.891 to +0.963, p ≤ 0.05) with textural quality after storage, including crispness, indicating that FTIR could serve as a rapid screening tool for textural quality at early developmental stages on minimally processed starting material.

Analysis of Petiole Sap Nutrients Using Rapid and Standard Methods and Its Relation to Leaf Analysis of Fertilized Malus domestica cv. Gala

Currently, fertilization decisions in apple orchards are based on soil and leaf analyses while the leaf material is sampled after the growing season, usually in June–July (90–110 days after full bloom). This approach is inefficient, as the information becomes available later than the growing season and is therefore only useful in supporting fertilization decisions for the next year, not the current one. To establish a method that provides useful information for fertilization decisions earlier in the growth cycle, our research focused on the assessment of the nutrient content of petiole sap using different methods, the standard method and the rapid method using a reflectometer. For this study, in 2021, four ‘Gala’ orchards were fertilized with different N–P–K levels. Macro and micronutrients were determined in leaves and petiole sap at 45 and 90–110 days after full bloom (DAFB) using standard laboratory methods and the reflectometer. When leaf analysis at 45 and 90–110 DAFB was compared with petiole sap analysis at the same time point, no significant correlations were found between the nutrient contents in leaf material and petiole sap, with the exception of calcium. However, positive results were obtained regarding the correlation between reflectometer determination and standard laboratory analyses. The regression analysis revealed high determination coefficients for N-NO3− (R2 = 0.703), K+ (R2 = 0.705), Ca2+ (R2 = 0.715), and Mg2+ (R2 = 0.780) between standard laboratory methods and the reflectometer. These results suggest that the reflectometer enables a real-time diagnostic tool for monitoring nutrient status throughout the growth cycle, particularly key nutrients related to fruit quality. The N–P–K fertilization strategies had no influence on the nutrient content of leaves or petiole sap. The nutrient content of both sample types varied depending on the orchard.

The dynamic changes of mango (Mangifera indica L.) epicuticular wax during fruit development and effect of epicuticular wax on Colletotrichum gloeosporioides invasion.

Mango fruits are susceptible to diseases, such as anthracnose, during fruit development, leading to yield reduction. Epicuticular wax is closely related to resistance of plants to pathogenic bacterial invasion. In this study, the effect of mango fruit epicuticular wax on the invasion of Colletotrichum gloeosporioides was investigated, followed by to understand the changes of wax chemical composition and crystal morphology during mango fruit development using GC-MS and SEM. Results showed that the epicuticular wax of mango fruits can prevent the invasion of C. gloeosporioides, and 'Renong' showed the strongest resistance to C. gloeosporioides. The wax content of four mango varieties first increased and then decreased from 40 days after full bloom (DAFB) to 120 DAFB. In addition, 95 compounds were detected in the epicuticular wax of the four mango varieties at five developmental periods, in which primary alcohols, terpenoids and esters were the main wax chemical composition. Furthermore, the surface wax structure of mango fruit changed dynamically during fruit development, and irregular platelet-like crystals were the main wax structure. The present study showed the changes of wax content, chemical composition and crystal morphology during mango fruit development, and the special terpenoids (squalene, farnesyl acetate and farnesol) and dense crystal structure in the epicuticular wax of 'Renong' fruit may be the main reason for its stronger resistance to C. gloeosporioides than other varieties. Therefore, these results provide a reference for the follow-up study of mango fruit epicuticular wax synthesis mechanism and breeding.

Lenticels are sites of initiation of microcracking and russeting in 'Apple' mango.

The mango cultivar 'Apple' is an important fruitcrop in Kenya, but it is highly susceptible to russeting. The objective was to establish whether lenticels predispose cv. 'Apple' mango to russeting. Fruit mass and surface area increased in a sigmoidal pattern with time. The frequency of lenticels per unit surface area decreased during development. The number of lenticels per fruit was constant. Lenticels were most frequent in the apex region and least common in the cheek and nak (ventral) regions. The cheek region also had lenticels with the largest core areas, whereas the lenticel core areas in the apex region were significantly smaller. Microscopy revealed stomata became covered over with wax deposits at 33 days after full bloom (DAFB). By 78 DAFB, periderm had formed beneath the pore. At 110 and 161 DAFB, cracks had developed and the periderm had extended tangentially and radially. The presence of lenticels increased the strain released upon excision of an epidermal segment, further strain releases occurred subsequently upon isolation of the cuticle and on extraction of the cuticular waxes. The number of lenticels per unit surface area was negatively correlated with the fruit surface area (r2 = 0.62 **), but not affected by fruit size. Mango cv. 'Apple' had fewer, larger lenticels and more russet, compared with 'Ngowe', 'Kitovu' or 'Tommy Atkins' mango. In cv. 'Apple', the lowest lenticel frequency, the largest lenticels and the most russeting occurred at a growing site at the highest altitude, with the highest rainfall and the lowest temperature. Moisture exposure of the fruit surface resulted in enlarged lenticels and more microcracking of the cuticle. Our results establish that russeting in 'Apple' mango is initiated at lenticels and is exacerbated if lenticels are exposed to moisture.

Integration of cell wall fraction, organic matter content, and membrane to understand crispness changes in apples

Crispness is a crucial commercially property of the apple fruit texture, but the dynamic change of apple crispness and contributing factors during fruit development and storage remain poorly understood. In this study, we examined the crispness of ‘Hanfu’ apples from fruitlet to senescence and analyzed the physiological and biochemical indexes involved in crispness change. The results indicate that ‘Hanfu’ apples exhibited the lowest crispness at 98 days after full bloom (DAFB), then gradually reached the highest crispness at 178 DAFB, followed by a decrease during storage. Crispy fruit features large cells and low contents of cell wall material, cellulose, and hemicellulose, which reduces the cell wall resistance. High sugar and low hydrogen peroxide (H2O2) contents improve the cell turgor and membrane stability. At the molecular level, the relative expression of genes associated with cell wall expansion (MdEXPA2), water transport (MdPIP1;3), and sugar accumulation (MdHK2) was significantly low level at 178 DAFB, whereas genes related to membrane stability maintained a relatively high expression level. This outcome may be linked to cell wall swelling, sugar accumulation, and rapid reactive oxygen species scavenging at 178 DAFB. Therefore, apple crispness depends on cell wall fractions, organic matter content, and membrane stability rather than a specific cell component. The results of this study provide a foundation for the improvement of the fruit quality, and postharvest management strategies.

Difference in calcium accumulation in the fruit of two apple varieties and its relationship with vascular bundle development in the pedicel

Calcium (Ca) is an essential mineral element for plant growth and development that plays a key role in fruit growth and quality formation. To study the absorption and transport of Ca in ‘Tonami’ (susceptible to bitter pit (BP)) and ‘Fuji’ (resistant to BP), fruiting branches of ‘Tonami’ and ‘Fuji’ were injected with 0.05% 44Ca at the fruitlet stage (37 days after full bloom (DAFB)) and fruit expansion stage (72 DAFB). At the fruitlet and fruit expansion stages, the 44Ca content of fruiting branches increased from high to low in leaves, shoots, and fruit. In fruit, the 44Ca content was highest in the peel and lowest in the flesh. In both ‘Tonami’ and ‘Fuji’, Ca uptake was more efficient at the fruitlet stage than at the fruit expansion stage. ‘Tonami’ had a shorter growth and development time and earlier loss of fruit pedicel xylem structure and functionality than ‘Fuji’, resulting in less Ca accumulation in the fruit. The low Ca uptake efficiency of ‘Tonami’ fruit, the short Ca accumulation time, and the high Ca dilution resulted in low 44Ca content in the fruit, which may explain the susceptibility of ‘Tonami’ fruit to BP disease.

QTL mapping combined RNA-seq technology identified potential genes involved in regulation of apple size

Fruit size is an important external indicator of apple quality. However, fruit-size breeding is complicated because multiple factors, including cultivar management, plant hormones and genetic factors, influence the final fruit size. Genetic factors are the most fundamental determinants of fruit size, mainly through cell division and expansion. Hence, the genes involved in regulation of cell development and plant hormone signalling are important regulators of fruit size. This work presents a dense genetic linkage map constructed using a 'Golden Delicious' × 'Fuji' population. Two algorithms: Kruskal-Wallis (KW) and Interval Mapping (IM) was used to identify the quantitative trait loci (QTL) for fruit size. Several size QTLs were detected, generating three genomic regions for fruit size and analysing the biological functions revealed 339 genes from the three regions as possible candidate genes controlling apple fruit size. Meanwhile, the transcriptome profiles of fruit flesh between large (LF) and small fruits (SF) at 30 and 60 days after full bloom (DAFB) revealed 2635 and 3922 DEGs at 30 DAFB and 60 DAFB, respectively. The 339 genes identified by QTL-Mapping revealed 41 DEGs, with 23 genes at both 30 and 60 DAFB (five genes in common), as the final candidate genes controlling fruit size. These results maybe reveal the molecular regulation mechanism of fruit size and provide basic evidence for developing gene markers for apple breeding.

Changes in Physico-Chemical Parameters During Fruit Development Stage in Ber (Zizyphus Mauritiana Lamk.) Cultivars in Tarai Region

ABSTRACT The study on changes in physico-chemical parameters of fruit on eight ber cultivars viz. Chhuhara, Chinese, Kalagola, Nazuk, Sanaur-2, Sanaur-4, Umran and ZG-2 was conducted at Horticulture Research Centre, Patharchatta, G. B. Pant University of Agriculture & Technology, Pantnagar, U.S. Nagar, Uttarakhand, India during the season of 2017–18 and 2018–19. The experiment was laid out in two factors Randomized Block Design (RBD) with three replications. Sampling dates and cultivars were considered as the treatments. There were 11 sampling dates ranging from 28 to 168 days after full bloom (DAFB), with observations taken at biweekly interval. In pooled data at 168 DAFB, Sanaur-2 recorded the maximum (6.89) pH while the minimum (6.62) in Kalagola. Umran recorded the maximum (83.55) ascorbic acid while the minimum ascorbic acid content was found in Sanaur-4 (66.50). Chhuhara recorded the maximum (9.31) total sugars while the minimum (7.55) in Umran. Chhuhara recorded the maximum (4.45) reducing sugars while the minimum (3.19) in Kalagola. Chinese recorded the maximum (5.08) non-reducing sugars while the minimum (4.06) in Umran. Chhuhara recorded the maximum (138.38) TSS: acid ratio (Total soluble solids: acid ratio) and minimum (75.78) in Kalagola. The findings therefore imply that matured ber could be used for naturally occurring antioxidants and that the advanced ripening stage is the best time to collect fruit for fresh consumption or for commercial processing. Breeders will be helped by these kinds of studies to create new breeding programmes, find potential cultivars for breeding, and choose the best time to harvest for domestic and international markets.

Transcriptome Analysis Identifies Genes Associated with Chlorogenic Acid Biosynthesis during Apple Fruit Development

As a predominant phenolic compound in apple fruits, chlorogenic acid (CGA) benefits human health due to its various antioxidant properties. However, little has been known regarding the molecular mechanism underlying the CGA accumulation in apple fruits. In this study, we measured the CGA content and relative enzymes’ activities during fruit development in two different flesh-colored cultivars ‘Huashuo’ and ‘Red Love’. The CGA content in both cultivars decreased sharply from 30 days after full bloom (DAFB) to 60 DAFB. Notably, the CGA content in fruit flesh was relatively higher than that in the peel. Further, the activities of C3H and HCT enzymes downstream of the CGA biosynthesis showed the similar changing trend as CGA content. Based on the transcriptome data of ‘Huashuo’ fruit at 30 DAFB and 60 DAFB, 23 differentially expressed CGA synthesis-related genes were screened. Gene expression analyses further showed that MdHCT1/2/4/5/6 and MdC3H1/2/3 were positively correlated to the variation of CGA content in two cultivars. These findings establish a theoretical foundation for further mechanism study on CGA biosynthesis and provide guidance for nutrient improvement in apple breeding programs.

Water Potential, Osmotic Potential, and Cell Turgor in Developing European Plums

Neck shrivel is a fruit disorder of european plum (Prunus domestica L.). We investigate whether an asymmetrical distribution of osmolytes might explain the observations of a turgid stylar end and a flaccid stem end, in a selection of 17 plum cultivars sourced from two sites. The osmotic potential (ΨΠ) of the juices expressed from stem or stylar end fruit samples decreased (became more negative) during development. The cell turgor (ΨP) slightly increased during development up to 352 ± 42 kPa at 78 days after full bloom (DAFB) in the stem end and up to 331 ± 51 kPa at 92 DAFB in the stylar end, and then decreased. At maturity, ΨP averaged 22 ± 3 kPa in the stem end and 22 ± 4 kPa in the stylar end. These values are negligibly low compared with the very negative values of ΨΠ in the stylar end (−3188 ± 73 kPa) and stem end (−3060 ± 74 kPa). There was a transient gradient in ΨΠ between stylar end and stem end that almost disappeared by maturity. Marked differences in ΨΠ and its distribution were measured across 17 cultivars. In the majority (14), ΨΠ was more negative at the stylar end than at the stem end. A more negative ΨΠ in the stem was only detected in ‘Aprimira’, ‘Topfive’, and ‘Tophit’. Our results demonstrate that cell ΨP is very low and is essentially independent of ΨΠ in developing european plums. In most cultivars, ΨΠ in the stylar end is more negative than in the stem end. The absence of an axial gradient in ΨP and the small differences in ΨΠ between the stem and stylar end make both factors unlikely candidates for explaining neck shrivel.

Flower Thinning Improves Fruit Quality and Oil Composition in Camellia oleifera Abel

Camellia oleifera is a woody oil tree with overlapping flower bud differentiation and fruit maturation. Therefore, mechanical harvesting of fruits leads to flower abscission. The present study investigated the effects of flower number per tree on fruit growth, yield, nutrient accumulation, and oil fatty acid composition in C. oleifera. Here, we set different flower numbers per tree by thinning flowers. Heavy flower thinning (T2 and T3) significantly reduced fruit yield and the proportion of palmitic, palmitoleic, linoleic, and linolenic acid in fatty acids compared with other treatments. However, heavy thinning favored an increase in fruit size and weight, seed and dry kernel rate of fresh fruit, soluble protein and oil accumulation in seeds, and the proportion of oleic acid and stearic acid in fatty acids, and it had no significant effect on oil yield per tree compared with light thinning (T1) and control (T0). T2 and T3 decreased soluble sugar content in the kernels at the later stage of fruit development (260–320 days after full bloom (DAFB)) in contrast to the rapid fruit growth period (200–230 DAFB). As the crop load decreased, fruit ABA content increased continuously during 260–320 DAFB, while fruit IAA content increased during 260–300 DAFB and then decreased during 310–320 DAFB. These data suggest that the abscission of a few flowers during mechanical harvesting will not affect fruit production efficiency in C. oleifera.

Apple fruit periderms (russeting) induced by wounding or by moisture have the same histologies, chemistries and gene expressions.

Russeting is a cosmetic defect of some fruit skins. Russeting (botanically: induction of periderm formation) can result from various environmental factors including wounding and surface moisture. The objective was to compare periderms resulting from wounding with those from exposure to moisture in developing apple fruit. Wounding or moisture exposure both resulted in cuticular microcracking. Cross-sections revealed suberized hypodermal cell walls by 4 d, and the start of periderm formation by 8 d after wounding or moisture treatment. The expression of selected target genes was similar in wound and moisture induced periderms. Transcription factors involved in the regulation of suberin (MYB93) and lignin (MYB42) synthesis, genes involved in the synthesis (CYP86B1) and the transport (ABCG20) of suberin monomers and two uncharacterized transcription factors (NAC038 and NAC058) were all upregulated in induced periderm samples. Genes involved in cutin (GPAT6, SHN3) and wax synthesis (KCS10, WSD1, CER6) and transport of cutin monomers and wax components (ABCG11) were all downregulated. Levels of typical suberin monomers (ω-hydroxy-C20, -C22 and -C24 acids) and total suberin were high in the periderms, but low in the cuticle. Periderms were induced only when wounding occurred during early fruit development (32 and 66 days after full bloom (DAFB)) but not later (93 DAFB). Wound and moisture induced periderms are very similar morphologically, histologically, compositionally and molecularly.

PbrARF4 contributes to calyx shedding of fruitlets in ‘Dangshan Suli’ pear by partly regulating the expression of abscission genes

Fruitlet calyx shedding in pear plants is apparently regulated via numerous pathways that involve both environmental triggers and phytohormones cues such as auxin. In this study, we found at 10 days after full bloom (DAFB) higher levels of indoleacetic acid (IAA) and tryptophan (Trp) in calyx persistence fruitlet (CPF) than calyx shedding fruitlet (CSF) of ‘Danshan Suli’ pear (Pyrus bretschneideri Rhed.). Consisting with this, the activity of indolealdehyde oxidase (IAAIdO), which promotes IAA synthesis, was remarkably increased, and that of peroxidase (POD), which degrades IAA, dropped markedly in CPF but not in CSF. Further, qRT-PCR results revealed that most of 31 PbrARFs (encoding auxin response factors) in Pyrusbretschneideri were highly expressed in CPF, whereas PbrARF4, PbrARF24 and PbrARF26 were significantly down-regulated in CPF vis-a-vis CSF. Phylogenetic analysis revealed that 6 PbrARFs clustered in the group Ⅲ, where PbrARF4 showed the closest affinity with AtARF1 that promotes organ abscission, indicating a putative role of PbrARF4 in mediating the process of calyx shedding in pear. In fact, the ectopic overexpression of PbrARF4 in Solanum lycopersicum resulted in an earlier-formed and deeper abscission layer (AL) in the transgenic plants, whose calyxes were more prone to wilt at the mature red stage (MR) compared with the control plants (wild-type). More importantly, expression levels of the abscission genes SlLS and SlCel2 in transgenic plants overexpressing PbrARF4 were significantly up-regulated in comparation with the WT, whereas those of SlBI and SlTAPG2 were considerably inhibited. Further, PbrJOINTLESS and PbrIDA, the two genes related to calyx shedding in pear, were up-regulated more in CSF than CPF. The findings contribute to a better understanding of PbrARFs involved in fruitlet calyx shedding of pear, which could prove beneficial to improving the quality of pear fruit.

Variation in Physical-Chemical Parameters and Phenolic Compounds in Fruits of Four Calafate Clones

Calafate (Berberis microphylla G. Forst) is an evergreen shrub with blue berries that grows naturally in Patagonia, in South America. It has beneficial nutraceutical characteristics for human health. The objective of the research was to evaluate the effect of different harvest dates of calafate clones in the south-central zone of Chile on the polyphenolic content, antioxidant capacity, quality parameters and fruit yield. To meet this objective, during three consecutive years, four wild calafate clones located in the town of San Ignacio, Chile, were selected. Where a harvest period was established from 110 to 140 days after full bloom (DAFBs), each of the harvests carried out were used for the following measurements: antioxidant capacity, determination of anthocyanin content, concentration of polyphenols, phenolic compounds, soluble solids, total titratable acidity, pH, fruit yield and quality. Among the main results, it can be highlighted that clone 2 was the one that obtained the highest concentration of soluble solids, with 38.0 °Brix at 140 DAFBs. Together, it was the one that obtained the highest content of total polyphenols and concentration of anthocyanins, with 1121 g GAE kg−1 fw and 714 g cy-3-glu 100 g−1 fw, respectively.

Cultivar-Specific Assessments of Almond Nutritional Status through Foliar Analysis

Mediterranean almond growing is increasing, as confirmed in Italy where new almond orchards in areas not previously interested in this nut crop have been recently established. In these new areas, as in the coastal of Latium region, the knowledge of eco-physiological behavior as a complex interaction among cultivars, pedoclimate conditions and orchard management is still poor. Optimizing fertilization strategies according to cultivar needs is one of the main key factors to guarantee high yields and nut quality, as well as to reduce environmental pollution. With this aim, an almond field collection has been established planting medium- and late-bloom cultivars. During the growing seasons 2019–2020, leaf samples were collected at 90 and 120 days after full bloom (DAFB) analyzed for biometrical and eco-physiological traits and leaf nutrients content through foliar diagnostics. Differences in foliar nutrient content depend on both cultivar and phenological stage. According to Pearson correlation heatmap, leaf nitrogen content showed a medium–high positive correlation with Nitrogen Balance Index (NBI) either at 90 or 120 DAFB, highlighting reciprocal influences among leaf nutrient contents and some eco-physiological traits. The findings of this study will help to develop novel environmentally friendly nutrition and fertigation strategies supported by foliar diagnostics which also consider accurate cultivar requirements.

Nutrient Content with Different Fertilizer Management and Influence on Yield and Fruit Quality in Apple cv. Gala

Assessing a plant’s nutritional status and fertilizer rates and types that can optimize fruit quality and yield are critical in intensive apple orchards. The aim of this work was to identify correlations between nutrients in the different organs that allow the early diagnosis of the nutritional status and to assess the impact on the optimal nutrient content in apple leaves, as well as in the yield and quality of chemical and organic fertilization. Five orchards of ‘Gala’ were fertilized with different levels of NPK over a period of four years. Macro and micronutrients of buds, flowers, 45 and 90–110 days after full bloom (DAFB) leaves and 60 DAFB and 15 days before harvest (DBH) fruits were determined. Boron was the only element for which strong correlations, 0.7 < r < 0.9, were observed between all organ pairs. The fertilization treatments did not affect the nutrient concentrations in the leaves of 90–110 DAFB other than P, Ca and Mg and did not affect the macronutrients in the fruit. In one of the five orchards, the yield increased by 26% with double fertilization compared to standard fertilization and, for the other four orchards, the impact depended on the year. Fruit size was more related to crop load than to fertilization and TSS and firmness were not affected by the type or amount of fertilizers. Replacing part of the chemical fertilizer with organic materials did not affect productivity or fruit quality.