Peach Cultivars Research Articles

Optimizing nitrogen application for improving yield and fruit quality in different peach cultivars

Optimizing nitrogen application for improving yield and fruit quality in different peach cultivars

Genome-Wide Identification of AGO, DCL, and RDR Genes and Their Expression Analysis in Response to Drought Stress in Peach

Small RNAs (sRNAs) control a wide range of development and physiological pathways in plants. To address the response of sRNA biogenesis to drought stress, we identified sRNA biogenesis genes, including 11 encoding argonautes (AGO), 8 encoding Dicer-like proteins (DCL), and 9 encoding RNA-dependent RNA polymerases (RDR) in the peach genome. Notably, the largest numbers of sRNA biogenesis genes are located to chromosome 1. The PAZ, PIWI, and MID domains were identified in PpAGOs, while the ribonuclease IIIa and IIIb domains were characterized in PpDCLs. The RDRP domain was recognized in PpRDRs. Orthologous similarity and collinearity analyses between Arabidopsis and peach revealed 5, 1, and 2 collinear blocks in AGOs, DCLs, and RDRs, respectively. Moreover, 41, 40, and 42 cis-acting elements were located in the promoters of PpAGOs, PpDCLs, and PpRDRs, respectively, with the majority related to drought stress response. Analysis of RNA sequencing (RNA-seq) data revealed that sRNA biogenesis genes were involved in drought stress response in different tissues. Furthermore, the expression of candidate genes was verified in two peach cultivars, Beijing 2-7 (BJ2-7) and Sinai (SN), which are tested as drought-tolerant and sensitive cultivars, respectively, based on the physiological and biochemical analyses, which revealed that the Chinese peach cultivar ‘BJ2-7’ exhibits greater drought resistance compared to the Egyptian peach cultivar ‘SN’. Interestingly, the expression of PpAGO2b, PpDCL2b, PpDCL4, and PpRDR4 genes was induced in ‘BJ2-7’ but inhibited in ‘SN’ under drought stress. Overall, this study provides insight into the roles of sRNA biogenesis genes in response to drought stress in peach.

Exploring the potential of peach gum polysaccharides in β-carotene emulsions encapsulation during storage

Oil-in-water (O/W) emulsions have emerged as a viable method for encapsulating β-carotene. To achieve stable emulsion systems, the development of latent emulsifiers is essential. This study collected three peach cultivars (Mixture cultivar (MC), Zhonghpan 11# (ZP11), and Yingqing (YQG)) to extract peach gum polysaccharides (PGP) for the encapsulation of β-carotene without the need for additional emulsifiers. The research aimed to investigate the emulsions' physicochemical stability (including particle size, zeta potential, turbidity, color, and retention rate of β-carotene (RR)) during storage. The findings revealed that the ZP11 emulsion exhibited the highest emulsion efficiency (EE) at 89.08% and displayed a more vibrant color. After 35 days of storage, YQG emulsion exhibited better emulsion stability with the highest zeta-potential (>35 mV, negative), RR of β-carotene (43.44%), and longest half-life period (t1/2, 32.31d) among three cultivars. Correlation analysis showed that molecular weight (Mw), polydispersity coefficient (Mw/Mn), and arabinose (Ara) of PGP would have an influence on its emulsifying capacity and stability of β-carotene emulsion. The information was significant for PGP of great potential as an emulsifier and stabilizer to provide possibility regarding designing a proper delivery system.

Plum pox virus (sharka) resistance in peach by grafting ‘Garrigues’ almond as interstock

Sources of resistance to sharka (Plum pox virus, PPV) have not been identified among peach [Prunus persica (L) Batsch] cultivars to date. However, several studies have shown the possibility of inducing resistance to PPV by grafting with the ‘Garrigues’ almond [P. dulcis (Mill) D. A. Webb] cultivar. The so-called “Garrigues effect” progressively reduces the symptoms of the disease and the accumulation of the virus in ‘GF305’ peach plants highly infected with PPV Dideron after grafting ‘Garrigues’. In addition, grafting 'Garrigues' onto ‘GF305’ before inoculation completely prevents infection by the virus. In this work, the ‘Garrigues’ cultivar has been used as an interstock to prevent PPV infection in peach. We have evaluated a collection of peach cultivars representing red and yellow skin, white and yellow flesh, and free and cling stones, in addition to platycarpa peaches (‘Maya’, ‘Transvalia’, ‘Romea’, ‘Catherine’, ‘Astoria’, ‘Tirrenia’, ‘Maruja M13’, ‘Levante 30′, ‘Alisio 15′ and ‘Carioca’). The cultivars were grafted onto ‘Garrigues’ that was already growing on ‘GF305’, ‘GF677’ and ‘Garnem’ rootstocks. Once the assayed plants were ready and fully developed [rootstock + interstock (‘Garrigues’) + peach cultivars], we graft inoculated the rootstocks and the growing peach plants with PPV at least three times. We were not able to obtain symptoms or detect the virus by RT-PCR in any of the cases, despite the proven susceptibility of these cultivars. In view of the results, we can affirm that using the ‘Garrigues’ graft as interstock could act as a kind of "vaccine" against PPV-Dideron in peach that is ready to be used commercially.

Temporal changes in the proanthocyanidins to anthocyanins ratio during dormancy associate with bloom time variations in peach

Our previous research demonstrated that fall applications of ethephon, an ethylene-releasing plant growth regulator, delay bloom in peach, accompanied by changes in endogenous hormones, ROS, sugar metabolism, and transcriptomic profiles during bud dormancy phases (endodormancy and ecodormancy). In this study, floral bud tissues were collected from ethephon-treated and untreated trees at three time points (200, 600, and 1000 chilling hours, CH) during endodormancy and two points (1000 and 3000 growing degree hours, GDH) during ecodormancy. Using ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOF/MS), we aimed to unravel the untargeted metabolic changes explaining ethephon-mediated bloom delay. Metabolite set-enrichment analysis (MSEA) revealed significant chemical group variations between dormancy phases, with a threefold increase in flavonoids during endodormancy and a doubling of organic and amino acids during ecodormancy. Further analysis of genes associated with the biosynthesis and transcriptional regulation of the flavonoid pathway showed that ethephon treatment upregulated genes associated with proanthocyanidin (PA) biosynthesis and downregulated genes related to anthocyanins (ACNs). We quantified PA and ACN contents in 12 peach cultivars with contrasting bloom times and chilling requirements (e.g. 727–1308 CH). Late-bloom cultivars had higher PA levels during endodormancy, while early-bloom cultivars had higher ACN levels during ecodormancy. Staining buds with 4-dimethylaminocinnamaldehyde (DMAC) dye revealed a decline in the PA/ACN ratio at later ecodormancy stages, correlating with bloom time. Integrated analysis of metabolite content and gene expression in late-bloom 'KV021779' and early-bloom 'John Boy' cultivars validated that late-blooming cultivars have higher PA levels during endodormancy, extending dormancy-release periods and resulting in later blooms.

Midwinter Flower Bud and Shoot Tissue Cold Hardiness in 33 Peach Cultivars Grown in New Hampshire, USA

Cold tolerance was measured midwinter in a New Hampshire, USA, orchard collection of 33 peach and nectarine cultivars over 3 years using natural and artificial freezing methods. Flower bud survival and xylem and cambium hardiness were based on the inflection point from nonlinear regression, as well as comparisons of injury at about −20 °C. Flower bud hardiness was greatest in ‘BuenOs’, ‘Contender’, ‘Cresthaven’, ‘Redhaven’, and ‘Scarlet Rose’. The lowest hardiness occurred in ‘Brigantine’, ‘Desiree’, ‘Emeraude’, ‘Evelynn’, ‘Galaxy’, ‘Glenglo’, ‘Jade’, ‘PF5D’, ‘PF23’, ‘Silverglo’, ‘Spring Snow’, and ‘Sugar May’. Other cultivars had either intermediate or inconsistent year-to-year bud hardiness. Bud hardiness in 2021 was weakly correlated with bud hardiness in 2023, but neither were correlated with bud mortality in 2022 after a severe freeze. Cambial hardiness in one year was not correlated with hardiness in other years. ‘August Rose’, ‘BuenOs’, ‘Cresthaven’, ‘Desiree’, and ‘Silverglo’ had the hardiest cambium which was consistent from year to year. Xylem hardiness was greatest in ‘BuenOs’, ‘Contender’, ‘Desiree’, ‘John Boy’, ‘PF17’, ‘Redhaven’, ‘Silvergem’, and ‘TangOs’. Xylem injury was significantly correlated across years indicating that this tissue responds more consistently to midwinter freezing temperatures than flower buds and cambium.

Analyzing cold hardiness (Based on DTA) of one-year-old branches of peaches.

In this study, we conducted a low-temperature exothermic (LTE) investigation on 1-year-old (1a) branches of sixteen peach cultivars through a differential thermal analysis (DTA) procedure. We used a three-point approach to determine the lethal injury temperature (LT-I) of the xylem, the LTE correlation indexes, and the subordinate function value method were applied to compare cold hardiness of sixteen peach varieties. The results showed that the slope of the LT-I for the xylem of sixteen peach cultivars was different, and the LTE indexes were significantly different. Among all the studied varieties, the cold hardiness was strongest in Donghe No.1, followed by Wangjiazhuangmaotao No.2 and Hunchun. Qiuyan and Yanhong are second, and belong to the cold-resistant type; Qiuyi, Okubo, Zhongnongjinhui, and Chunmei, exhibited medium cold hardiness. Zhongtaohongyu, Spring snow, Yufei, and Zhongyou No.8 varieties exhibited low hardiness; while the 21st century, Golden Honey No. 1 and Zhonghuashoutao have the worst cold hardiness and are the weakest cold-hardiness types. In addition, the injury degrees of xylem from LT-I analysis were significantly related to the browning rates (BR) and electrolytic leakage (EI) from traditional low temperature freezing analysis. It is demonstrated that the LTE analysis is a simple, accurate, and practical method for identifying the cold hardiness of 1a branches of peach.

Deciphering aroma complexity between melting flesh and stony hard peach (Prunus persica L.) fruit through integrative analysis of volatile contributions

Stony hard peach is favored in production for resistance to storage and transportation, but presents a challenge of lacking fragrance compared to traditional fragrant peach i.e., melting flesh peach. Addressing this concern necessitates material composition analysis from the perspective of volatile composition and aroma characteristics. However, the complex relationship between volatile compounds and aroma profiles in melting flesh and stony hard peach cultivars remains poorly understood. To address this gap, we examined contribution of volatiles to their aroma. The application of multiple analysis methods, including distribution, odor importance, and partial least squares discriminant analysis facilitated a comprehensive understanding of the contribution of 30 volatiles to aroma; and hierarchical clustering analysis revealed relationships among the compounds within the two types of peaches. The primary differential volatiles between them were cis-3-hexenol, pentyl acetate, prenyl acetate, trans-2-hexenal, cis-3-hexenyl acetate, dihydro-β-ionone, benzaldehyde, and a range of lactones (γ-decalactone, γ-hexalactone, γ-octalactone, δ-decalactone and γ-undecalactone). Overall, the melting flesh peach exhibited more pronounced aroma than the stony hard type. This study underscores the significance of understanding the intricate interplay between volatile compounds and aroma characteristics across cultivars with different textures, offering valuable insights into cultivar selection, flavor enhancement, and consumer preference assessment within the peach industry.

Origins and Genetic Characteristics of Egyptian Peach.

Peach (Prunus persica), a significant economic fruit tree in the Rosaceae family, is extensively cultivated in temperate and subtropical regions due to its abundant genetic diversity, robust adaptability, and high nutritional value. Originating from China over 4000 years ago, peaches were introduced to Persia through the Silk Road during the Han Dynasty and gradually spread to India, Greece, Rome, Egypt, Europe, and America. Currently grown in more than 80 countries worldwide, the expansion of peach cultivation in Egypt is mainly due to the development and utilization of peach varieties with low chilling requirements. These varieties exhibit unique phenotypic characteristics such as early maturity, reduced need for winter cold temperatures, low water requirements, and high economic value. In this study, a systematic analysis was conducted on the genetic characteristics and kinship relationships of peaches with low chilling requirements in Egypt. We conducted a comprehensive evolutionary and Identity-by-Descent (IBD) analysis on over 300 peach core germplasm resources, including Egyptian cultivars with low chilling requirements, to investigate their origin and genetic characteristics. The evolutionary analysis revealed that 'Bitter almond' is closely related to China's wild relative species Prunus tangutica Batal, while 'Early grand' shares one branch with Chinese ornamental peach cultivars, and 'Nemaguard' clusters with some ancient local varieties from China. The IBD analysis also indicated similar genetic backgrounds, suggesting a plausible origin from China. Similarly, the analysis suggested that 'Swelling' may have originated from the Czech Republic while 'Met ghamr' has connections to South Africa. 'Desert red', 'Early swelling', and 'Florida prince' are likely derived from Brazil. These findings provide valuable insights into the genetic characteristics of Egyptian peach cultivars. They offer a significant foundation for investigating the origin and spread of cultivated peaches worldwide and serve as a valuable genetic resource for breeding low chilling requirement cultivars, which is of considerable significance for the advancement of peach cultivation in Egypt.

The Training Systems Affect Fruit Quality, Yield, and Labor Efficiency in Peach (P. persica L. Batsch)

In the Vase system, the most common training system for peach-growing countries for more than a century, light distribution to the canopy is uneven, and access to the canopy for pruning, thinning, and harvest labor is difficult. It is important to identify alternative systems to the Vase system considering the cultivar and growing environment to facilitate labor and enhance productivity and quality. In Türkiye, one of the important centers of peach growing worldwide, detailed research has yet to be published on the applicability of training systems alternative to the widely used Vase system. Therefore, this study aimed to evaluate the effect of different training systems (Vase, Catalan Vase, Quad-V, Tri-V) on growth, yield, fruit quality, and labor costs of peach cultivars (Extreme® 314, Extreme® 436, Extreme® 568). The experiment was conducted from 2017 to 2022. Although the distance between rows in all training systems is 5 m, the distance between trees on the row is determined as 4 m in Vase, 3 m in Catalan Vase, 2.5 m in Quad-V, and 2 m in Tri-V. In the experiment, vegetative development parameters, such as canopy volume, trunk sectional area, and the amount of winter pruning weights, differed according to the training system. In the final year, the Vase system, which produces the most pruning weight, generates 48.0% more pruning weight compared with the Tri-V system, which produces the least. Concerning yield per tree and hectare, trained to the Vase system yielded higher fruit per tree regardless of cultivar, while the Quad-V and Tri-V systems yielded more fruit per hectare. The training system and cultivar affected the fruit size; the largest fruits were obtained from the Extreme® 568 cultivar trained according to the Vase system. The most time needed for winter pruning was obtained from the Vase (79.4 min/tree) system, and the Tri-V (57.4 min/tree) and Quad-V (60.3 min/tree) systems required the least time. The Catalan Vase (31.1 min/tree) system required the least time for summer pruning. The most fruit harvest in an hour was obtained from the trees trained according to the Tri-V (164.5 kg/h) and Quad-V (132.02 kg/h) systems. These results suggest that Quad-V and Catalan Vase systems performed well and could be alternatives to the Vase system.

Effect of Potassium Silicate, Glycine Betaine and Proline on Fruit Quality of Peaches in Newly Reclaimed Land Exposed to Heat Stress

The current study was performed on a 6-year-old "Florida" peach cultivar (Prunus persica) during 2022 and 2023 respectively. Twenty-four peach trees uniformly were selected and sprayed two times at the beginning of pit starts hardening and at the end of phase two of fruit growth with the following treatments: the control, glycine betaine at 400 mg l-1, potassium silicate at 200 mg l-1, potassium silicate at 400 mg l-1, potassium silicate at 200 mg l-1 + glycine betaine at 400 mg l-1, potassium silicate at 400 mg l-1 + glycine betaine at 400 mg l-1, proline at 400 mg l-1 and potassium silicate at 200 mg l-1 + proline at 400 mg l-1. The results indicated that both treatments of potassium silicate at 200 mg l-1 + proline at 400 mg l-1 and potassium silicate at 400 mg l-1 + glycine betaine at 400 mg l-1 resulted in a significant increase in concentrations of anthocyanin and total carotenoid contents in the skin. Moreover, total soluble solid, vitamin C and total soluble solid / acidity were shown with high concentrations as compared with the control. Overall, the use of potassium silicate at 200 mg l-1 + proline at 400 mg l-1 or potassium silicate at 400 mg l-1 + glycine betaine at 400 mg l-1 two times is recommended.

Plant training systems for the peach cultivar Della Nona

Plant training systems for the peach cultivar Della Nona

UC Davis Controller Rootstocks for peach: their background and how they work

Unlike the situation with apples, until recently, there have been few commercially acceptable size-controlling rootstocks available for peach production. Nearly forty years ago a program was initiated to screen Prunus germplasm for ease of vegetative propagation, compatibility with peach and sizecontrolling potential. This initial research involved ~120 genotypes that were either various named Prunus species and cultivars or inter-specific Prunus hybrids. This collection was later narrowed down to nine selections that showed some promise for commercial production. After subsequent field trials two new rootstocks were released in 2004 (K146-43 and P30-135; Controller 5 and 9TM, respectively). Subsequently, a new breeding program was initiated based on the hypothesis that hybrids of two peach cultivars (Okinawa and Harrow Blood) would have the potential to reduce the scion vigor of peach and be resistant to root-knot nematodes. A seedling population of hybrids resulting for this cross were propagated and ‘O’Henry’ peach was grafted onto each individual genotype. Those that showed size-controlling potential were then put into a series of replicated field trials and evaluated for both size-controlling behavior and productivity characteristics. These trials resulted in the release of a series of new rootstocks (‘HBOK 27’, ‘HBOK 32’, ‘HBOK 10’, ‘HBOK 50’; Controller 6, 7, 8 and 9.5TM, respectively). Subsequent intensive research documented that a major mechanism involved in growth control of scions grafted on these rootstocks involves reduced hydraulic conductivity of these rootstocks during early spring growth caused by smaller sized xylem vessel diameters.

Comparison of Flavor Profiles of Honey Peach Cultivars by Gas Chromatography–Mass Spectrometry (GC–MS) with Odor Activity Values (OAVs), E-Tongue, and Sensory Evaluation Combined with Chemometrics

The honey peach is popular due to its unique flavor. However, the flavor characteristics of honey peaches cultivated in Yangzhou and Wuxi remain unclear. In this study, the flavor profiles in five famous honey peaches, Yangzhou Baifeng (YBF), Yangzhou Zhonghujing (YZHJ), Yangzhou Wanhujing (YWHJ), Wuxi Baifeng (WBF), and Wuxi Wanhujing (WWHJ), were investigated using gas chromatography-mass spectrometry (GC–MS) combined with odor activity values (OAVs), electronic tongue (E-tongue) and sensory evaluation. A total of 84 flavor substances were identified by GC–MS and 17 odor-active compounds were detected with OAVs more than 1. WBF samples had the highest concentration of total volatile compounds, and relatively higher OAVs of γ-decalactone and γ-dodecalactone contributed to peach-like aroma. Principal component analysis (PCA) and heatmap analysis indicated that the honey peach cultivars from different origins and varieties had distinct aroma and taste profiles. Sensory evaluation demonstrated that WBF samples had the highest scores of peach-like, fruity aroma, sweetness, juiciness and overall acceptability. Partial least squares regression (PLSR) was performed to investigate the correlation between physicochemical properties, odor-active compounds, E-tongue measurements and sensory attributes. Results indicated that linalool and umami had significant contribution to honey peach sensory attributes, and further confirmed that YBF was characterized by floral aroma and WBF was similar with peach-like and green attributes. The results of this study provide a comprehensive understanding of flavor characteristics and differences of the honey peaches, which could contribute to the further development and production of these products.

Effect of formula fertilizers on peach yield, quality, and environmental footprint

Peach production in China uses large inputs of mineral fertilizers but lower inputs of organic fertilizers, resulting in decreased peach quality and increased environmental risks. This study investigated the effects of formula fertilizers (combined organic and inorganic fertilizers) on peach yield, quality, and carbon and nitrogen footprints using three peach cultivars in two consecutive years. Two types of formula fertilizers had positive effects on improving the peach yield (5.6–13.6%), single fruit weight (9.0–32.5%), transverse diameter (3.6–13%) and longitudinal diameter (5.4–21.6%). Also, these fertilizers increased soluble solids (7.2–36.6%) and vitamin C (7.1–78%). In addition, the carbon footprint of peach decreased by 37–49%. This study demonstrates the potential of formula fertilizers to achieve balance between peach quality and environmental health.

Mineral elements in peach cultivars from Beijing, China: Profiling and health risk assessment

Peach fruits, recognized as one of the primary deciduous fruit trees grown globally, are renowned for their abundant mineral nutrients. This study delves into the comprehensive analysis of mineral elements in 20 distinct peach cultivars, including 12 nutrients (NEs), 6 toxic elements (TEs), and 16 rare earth elements (REEs). Inductively coupled plasma-mass spectrometry was utilized. The average contents of 12 NEs ranked as follows: K > Mg > Ca > B > Fe > Na > Zn > Cu > Mn > Sr > Mo > Se. TEs were identified as potential health hazards, particularly for children, with arsenic emerging as the primary source of dietary risk across diverse populations. Moreover, the presence of 16 REEs was noted across most peach cultivars, with cerium being the most abundant. Principal component analysis revealed seven principal components, contributing to a cumulative variance of 87.4 %. Cluster analysis was used to categorize the 20 peach cultivars into four groups. Excepting the 4th group, the remaining three groups exhibited the highest values for 22, 9, and 3 elements, respectively. These results contribute to a foundational understanding for the nutritional assessment of peaches and their cultivar breeding strategies.

Insights into the Transcriptional Reprogramming of Peach Leaves Inoculated with Taphrina deformans

The dimorphic fungus Taphrina deformans is the causal agent of peach leaf curl disease, which affects leaves, flowers, and fruits. An RNA-seq approach was employed to gain insights into the transcriptional reprogramming of a peach cultivar during leaf inoculation with the yeast phase of the fungus across a compatible interaction. The results uncovered modulations of specific peach differentially expressed genes (DEGs) in peaches and pathways related to either the induction of host defense responses or pathogen colonization and disease spread. Expression profiles of DEGs were shown to be highly time-dependent and related to the presence of the two forms of the fungal growth, the inoculated yeast form and the later biotrophic phase during mycelial development. In parallel, this differential reprogramming was consistent with a diphasic detection of fungal load in the challenged leaves over the 120 h after inoculation (HAI) period. Leaf defense responses either occurred during the early yeast phase inoculation at 24 HAI, mediated primarily by cell wall modification processes, or more pronouncedly during the biotrophic phase at 72 HAI, as revealed by the activation of DEGs related to pathogen perception, signaling transduction, and secondary metabolism towards restraining further hypha proliferation. On the contrary, the expression patterns of specific DEGs at 120 HAI might further contribute to host susceptibility. These findings will further allow us to elucidate the molecular responses beyond the peach—T. deformans interaction.

Oxidative stress as markers in identification of aluminum-tolerant peach tree rootstock cultivars and clonal selections

ABSTRACT Peach rootstock and scion cultivars are selected in breeding programs considering resistance to pests and diseases, salt tolerance, drought tolerance, and vigor. However, rootstock tolerance to aluminum (Al), which is markedly present in tropical and subtropical soils of the world, is not considered. Thus, it is essential to define potential markers that can contribute to the selection of Al-resistant or Al-tolerant peach rootstocks. The objective of this study was to identify Al-tolerant peach tree rootstock cultivars and clonal selections using physiological and oxidative stress variables. A completely randomized experimental design was used in a 13 (rootstock cultivars and clonal selections) × 2 (with and without Al) factorial arrangement, with three replications. Nursery peach trees of own-rooted ‘BRS Mandinho’ (without rootstock) and nursery trees of ‘BRS Mandinho’ grafted on different rootstock cultivars and clonal selections were grown in a hydroponic system, consisting of two treatments, with and without 100 mg L -1 of Al. Dry biomass, photosynthetic variables, pigment concentration, hydrogen peroxide content, membrane lipid peroxidation, and activity of the antioxidant enzymes were evaluated. The total dry matter production of the own-rooted ‘BRS Mandinho’ trees and the SS-CHI-09-39 and SS-CHI-09-40 selections is affected by the Al presence, representing a decline of 35.4, 37.2, and 24.4 %, respectively, compared to the treatment with Al. The highest total dry matter production in Al presence was observed for the ‘Sharpe’ rootstock. ‘Capdeboscq’, DB-SEN-09-23, FB-ESM-09-43, JB-ESM-09-13, JAH-MAC-09-77, SAS-SAU-09-71, and VEH-GRA-09-55 rootstock selections are tolerant to Al. The use of physiological and biochemical variables shows potential for the selection of clonal rootstocks tolerant or resistant to Al.

Tainung No. 7 HongLing: A Low-chill Peach Cultivar for Early Fresh Market

Tainung No. 7 HongLing: A Low-chill Peach Cultivar for Early Fresh Market

Yield and biochemical fruit quality of irrigated peach cultivars subjected to conventional farmer’s fertilization practices in warm production area

Water and fertilization management are the main concerns of farmers in order to achieve an economic yield and high fruit quality. This study evaluates conventional farmer’s fertilization practices in commercial peach orchards (Regueb region) and sets suitable nitrogen (N), phosphorus (P), and potassium (K) supplies to improve yield and fruit quality. Different farmers’ N-P-K supply practices (called FarmNPK) were applied during the different developmental stages of the growing season (S1 budburst and swelling; S2 flowering and fruit set; S3 fruit development; and S4 fruit ripening). Seven cultivars (Flordastar, Plagold5, Plagold10, Plagold15, Plawhite5, Plawhite10, and UFO3) were considered. Depending on cultivars and growth stage, the ranges of total N-P-K supplies were 95–208, 44–84, and 67–103 kg ha−1, respectively. Total fresh yield was quantified, and fruit quality (pomology, phenolic composition, main sugars, and organic acids) was determined in the mesocarp and exocarp. The results revealed that NPK supplies from 95–65–76 to 165–84–103 kg ha−1 induced the highest yield that varied between 50 and 68 kg tree−1, especially with high N supplies during S2. In all cultivars, high N and K supplies in S3 and S4 induced the best weight and fruit size, with the highest total soluble solid content in the fruit, while P supply appeared to be negatively correlated with total sugar content. Analysis of phenolic composition showed that flavan-3-ols varied between 209 and 7114 mg kg−1 DW. In conclusion, the optimum supply of N, P, and K at the appropriate stages, mainly S2 for N supply, and S3 and S4 improved color and ensured appreciable quality.