Pre-harvest Application Research Articles

Predicting infection of strawberry fruit by Mucor and Rhizopus spp. under protected conditions

Postharvest spoilage of strawberry grown under protection, caused by Mucor spp. and Rhizopus spp., has recently become more common in the UK, but there is insufficient knowledge to develop and implement integrated management against Mucor and Rhizopus. Field sampling was conducted to obtain field data for developing models to predict the infection of Mucor and Rhizopus on strawberry fruit. Fruits were exposed to naturally occurring inoculum for a period of 24 hours before surface-sterilisation and incubation to estimate the level of infection by Mucor and Rhizopus. The observed incidence data, together with climatic conditions and inoculum trap counts, were used analysed firstly within the framework of (1) generalised linear model (GLM), and (2) classification tree. Field sampling confirmed previous research that ripening/ripe strawberry fruits are more susceptible to infection by Mucor and Rhizopus. Climatic variability, particularly in vapour pressure deficit, appears to be more important in influencing the rotting incidence of both Mucor and Rhizopus. However, the predictability of both Mucor and Rhizopus, whether as a continuous variable (incidence) in the GLM analysis or as a categorical risk in classification tree analysis, is too low to be of practical value based on those predictors used in the present study. Thus, current management may have to be based on scheduled preharvest application of alternative products to reduce infection and local pathogen inoculum as well as adopting management practice to minimise pathogen inoculum in the planting. Future research is needed to develop methods for rapid yet accurate in situ quantification of pathogen inoculum to improve disease risk predictions.

Pre- and Post-harvest Elicitation with Methyl Jasmonate and Salicylic Acid Followed by Cold Storage Synergistically Improves Red Colour Development and Health-Promoting Compounds in Blood Oranges

Red blush is one of the key quality markers of blood orange fruit (Citrus sinensis L. Osbeck). Therefore, the influence of pre- (1, 2, and 3 mM) and postharvest (0.5, 1, and 1.5 mM) methyl jasmonate (MeJA) and salicylic acid (SA) (1, 2, and 3 mM) treatments on redness, colouring pigments, and health-promoting compounds in cold stored ‘Tarocco Ippolito’ blood oranges was investigated. Preharvest application of 3 mM MeJA significantly increased rind citrus colour index (CCI) by 43.3% and colorimetric coordinate a* (redness) by 3.1% and decreased h° (hue angle, 0 = red), L* (lightness), and b* (yellowness) by 13.7%, 12.6%, and 23.4%, respectively. This treatment also enhanced CCI (57.4%), reduced h° (16.5%) and L* (36.4%), and increased total anthocyanins (88%), monomeric anthocyanins (117%), and flavonoids (77%) in the juice. Postharvest dip of 1.5 mM MeJA (5 min) improved CCI of juice (53.6%) and a* (5.5%), reduced h° (15.9%), L* (19.8%), and b* (19.4%), and increased total anthocyanins (66.7%), monomeric anthocyanins (74%), and flavonoids (23.4%) in the juice. Preharvest application of 1 mM SA increased rind CCI (50.8%) and reduced L* (13.6%), b* (16.4%), and h° (29.5%). All preharvest SA treatments significantly increased total phenolics in the juice. Lycopene was increased (61.7%) by 5 min postharvest dip of 3 mM SA. In conclusion, 3 mM preharvest spray application of MeJA four weeks before harvest and postharvest dip of 1.5 mM MeJA (5 min) are effective in improving red colour of rind and juice and health-promoting compounds in blood orange juice.

Potassium phosphite in the management of green mold in citrus

Orange is among the main produced species in citriculture, a widely important area of Brazilian agrobusiness. However, postharvest diseases, particularly the green mold caused by Penicillium digitatum, result insignificant losses in the sector. Given that chemical control is still the primary type of disease management, it is vital to create varied control methods to combine disease management programs. In this context, this study aimed to apply an alternative product based on potassium phosphite and evaluate its effect on the control of green mold and the quality of postharvest oranges.'Valencia' orange trees were treated with water (control), potassium phosphite (19.5 mL L-1), and benzimidazole fungicide (at the manufacturer's recommended dosage) at the first step of this work. The frequency and severity of green mold in the fruits were evaluated in the second step. The third step involved determining the physicochemical characteristics, which included peel and pulp color, pulp firmness, pH, titratable acidity, soluble solids, and ratio (SS/AT). Green mold incidence was reduced in oranges treated with fungicide and potassium phosphite, although the pathogen was not entirely inhibited. The effects of the potassium phosphite and fungicide treatments in oranges were similar in the area under the disease progress curve. The preharvest application of potassium phosphite (19.5 mL L-1) reduced the incidence of green mold in postharvest oranges without affecting the physical and chemical characteristics of the fruits, proving that the use of the alternative product can be a promising substitute.

The Potassium Phosphite-Based Fungicide Canon Controls Basil Downy Mildew Under Greenhouse Conditions in Israel

Sweet basil downy mildew (BDM), caused by Peronospora belbahrii, is the most destructive disease of commercially produced sweet basil in Israel and, unless properly managed, may lead to 100% yield reduction. Four experiments were conducted over three growing seasons (fall 2021, fall 2022, and spring 2023) under commercial-like conditions to determine the efficacy of the phosphonic acid-based fungicide Canon following a conservative, 7-day protective spraying protocol. Although Canon did not eradicate the pathogen, treated plants had 41 to 99.9% less ( P < 0.05) disease incidence and/or severity than the untreated control plants. The disease scores on plants treated with Canon were similar ( P > 0.05) to an alternation of Revus/Cabrio in fall 2021, less ( P < 0.05) than Revus in fall 2022, and higher ( P < 0.05) than an alternation of Acrobat/Cabrio at the end of the spring 2023 experiment. The inhibitory effect of Canon, its short preharvest application interval, and its low cost compared with other fungicides make it an excellent addition and a potential replacement for controlling BDM under greenhouse conditions that should be further explored.

Impact of pre-harvest fungicide application on the storage performance of tomato fruits.

To examine the impact of pre-harvest fungicide applications on the postharvest storage performance of tomato fruits, we measured the lycopene content, hardness, soluble solids content, rotting rate, and weight loss rate of the fruits, as well as conducted a sensory assessment. Protective and systematic fungicides were sprayed on tomatoes 20 days before harvest in order to prevent rotting and weight loss during storage. Our findings showed that, the fungicide-treated tomatoes had a significantly lower rotting rate of 16.00% and a weight loss rate of 3.96%. However the control group experienced 65.33% rotting rate and 6.90% weight loss rate on 12th days of storage. Out of the pre-harvest applications, 'Zineb' a protective fungicide significantly delayed the loss of hardness and soluble solids accumulation in tomato fruits during storage, but it had no significant effect on lycopene content. On the other hand, when comparing to the examined treatment, the systemic fungicides did not have any significant effect on the postharvest storage performance of tomato fruits. Sensory evaluation results indicated that systemic fungicides improved the aroma of the fruits, while protective fungicides had a greater impact on the appearance and juiciness of the fruits. This study offers a potential novel solution for preserving fruits and vegetables which have been frequently infected by phytopathogens during storage, and consequently mitigate/reduce postharvest losses.

Quality evaluation of fresh pistachios (Pistacia vera L.) cultivars coated with chitosan/TiO2 nanocomposite

Fresh pistachios are rich in dietary fiber, minerals and unsaturated fatty acids, but they have a short shelf life. This investigation examined the effect of pre-harvest foliar application with chitosan (500 and 1000 mg. L−1), nano-chitosan (250 and 500 mg. L−1), and chitosan/TiO2 nanocomposite (250 and 500 mg. L−1) coating films on the postharvest physiology and storage of fresh pistachios (Pistacia vera cvs. Akbari and Ahmad Aghaei) cultivar during storage at 4 ± 0.5 °C. It was found that, fresh pistachios' shelf life could by increased by up to 30 days by the use of chitosan/TiO2 nanocomposite coating for foliar application. The decay index of the composite coated fruits was 4–6 % lower than that of the control group, and after 50–60 days the bacterial contamination appeared in cultivars; respectively. The nanocomposite treatments reduced the fruits weight between 30 and 40 %, which was 15 % higher that of than uncoated fruits. The pre-harvest application of chitosan/TiO2 coating reduced microbial contamination, weight loss, phenylalanine ammonialyase (PAL) activity and saturated fatty acids, and increased unsaturated fatty acids, antioxidant properties, sensory properties, essential minerals, superoxide dismutase (SOD), quality indicators and shelf life. These results demonstrated that the chitosan/TiO2 (250 and 500 mg. L−1) coating film effectively preserved the nutrient composition, sensory quality, nutritional value, antioxidant capacity and shelf life of fresh pistachio.

Preharvest Applications of Alginate, Salicylic Acid and Oxalic Acid Have a Synergistic Effect on Quality and Storability of Red Globe Grape Variety (Vitis vinifera L.)

This study aimed to evaluate the synergistic effect of preharvest spraying with alginate and in combination with salicylic acid (SA) and oxalic acid (OA), on the quality parameters and storage life of ‘Red Globe’ grape variety at 0-1°C with 85-90% relative humidity for 60 days. Data of physical and chemical quality parameters were taken at 15-day intervals. The results have shown that alginate coatings delayed changes in weight loss, firmness and berry color compared to control. Grapes coated alginate enriched with oxalic acid and salicylic acid proved to the most effective applications in restricting stem browning and decay incidence. Moreover, these formulations improved the content of phenolic compounds, contributing to the high antioxidant potential of coated grapes. These findings reveal that preharvest sprayed clusters with alginate combined with SA and OA applications may have high potential for improving storage quality of commercial grape.

Effect of PGR and Chemicals on Shelf Life, Bunch and Berry Quality Parameters of Sudhakar Seedless Grapes (Vitis vinifera L.)

The experiment was conducted on Sudhakar Seedless vines grafted on 110-R rootstock were selected for this study. The experiment was designed in randomized block design (RBD) having five treatments with four replications were carried out at MRDBS Nashik during 2020-2021. Pre-harvest application of treatments (Chitosan at 10 ppm, Naphthalene acetic acid at 100 ppm, activated Potassium salt @ 2.0 g/ liter, Salicylic acid at 2.0 ml/liter and Potassium Schoenite @ 2.0 g/liter along with untreated vines were applied at veraison stage of berry development. Application of Chitosan @ 10 ppm resulted in to the increase berry size and berry quality along with less Number of rotten berries in physiological loss in weight. Followed by the application of Naphthalene acetic acid at 100 ppm recorded less Number of rotten in this study. However, the lowest physiological loss of weight (%) were recorded with the application of Naphthalene acetic acid. The increasing dose of Naphthalene acetic acid resulted into decrease in pre- harvest berry drop. In grapevines, Application of salicylic acid significantly increase in berry weight, bunch weight, Total Soluble Solids /acidity ratio as compare to untreated vines. Biochemical composition of berries was influenced by the application of Activated potassium salt at different concentration. The application of Potassium schoenite in grapevines were found effective for increasing TSS of Sudhakar seedless grapes.

Antioxidants of blushed and unblushed sides in relation to superficial scald of ‘NY2’ (RubyFrost®) apples treated preharvest with 1-methylcyclopropene and aminoethoxyvinylglycine

The effects of plant growth regulators (PGRs) and harvest date on antioxidant contents at harvest and superficial scald development in ‘NY2’ apple during storage have been studied. Aminoethoxyvinylglycine (AVG, ReTain®) and 1-methylcyclopropane (1-MCP, Harvista™) were sprayed two and one weeks, respectively, before the first of three weekly harvests. The apples were stored at 0.5 °C for 20 weeks + 7 d at 20 °C. At harvest, color and index of absorbance difference (IAD) values, and contents of total phenolics, anthocyanins, chlorophylls, carotenoids, ascorbic acid (TAA), dehydroascorbic acid (DHA) glutathione (GSH), reduced glutathione (GSSG) and total antioxidant activity of blushed and unblushed sides of the apple were measured. The antioxidant contents increased with later harvest dates. Chlorophyll and GSSG were higher in unblushed than blushed skin tissues, while all antioxidant contents were highest in blushed skin tissues. Superficial scald incidence was highly correlated with less mature fruit, lower fruit anthocyanin, higher chlorophyll content at harvest. α-Farnesene, conjugated trienols (CTols), and IAD value index were measured at 0, 1, 2, 4, 6, 10, 15, and 20 weeks at 0.5 ⁰C for fruit from harvest 1. Scald incidence and severity was higher in AVG-treated fruit than untreated or 1-MCP treated fruit and did not decrease at later harvest dates. Using harvest management and preharvest application of plant growth regulators is a promising strategy to improve the nutritional value of 'NY2′ apples, reduce physiological disorders, and maintain fruit quality.

Effect of Pre-harvest Application on Physical Attributes of Guava (Psidium guajava L.) in cv. L–49: Plant Growth Regulators and Bagging

The present investigation was conducted to study the Effect of pre-harvest application of plant growth regulators (PGR) and bagging on Physical attributes of Guava (Psidium guajava L.) in cv. L - 49. The research was carried out at the main experiment station Horticulture, Department of Fruit Sciences, Acharya Narendra Deva University of Agriculture and Technology, Narendra Nagar, Kumarganj, Ayodhya 224229 (U.P.) India during the year 2022-23. The experiment was conducted in a Randomized Block Design with three replications and 8 treatments GA3 (50 ppm) and NAA (20 ppm) and GA3 (50 ppm) +NAA (20 ppm), GA3 (50 ppm) with bagging, and NAA (20 ppm) with bagging. GA3 (50 ppm) + NAA (20 ppm) with bagging, bagging (white polythene), and control applied on spray 45 days before harvesting. It is concluded that among the different treatments. T6 GA3 (50 ppm) + NAA (20 ppm) with bagging, was recorded maximum Fruit length (4.90 cm), Fruit width (6.62 cm), Fruit weight (158.20 gram), Fruit volume (161.60 cm3), Specific gravity (0.98 g/cm3) therefore, recommended for application to the Guava tree in the sub-tropical region of Uttar Pradesh in order to obtain better quality fruit.

Preharvest Application of Hydrogen Sulfide and Nitric Oxide Improves Floral Traits and Postharvest Performance of Cut Gladiolus Inflorescences

Preharvest Application of Hydrogen Sulfide and Nitric Oxide Improves Floral Traits and Postharvest Performance of Cut Gladiolus Inflorescences

Influence of Chemicals and Plant Bioregulators Application during the Time of Fruit Developmental Phenophase on Fruit Weight, Quality and Shelf-life of Mango (Mangifera indica. L)

The present study was conducted to know the influence of chemicals and plant bioregulators application during the time of fruit developmental phenophase on fruit weight, quality and shelf-life of Mango (Mangifera indica. L) at the fruit research station, Aswaraopet, Telangana, India during the 2022- 23. Among chemicals and plant bioregulators maximum fruit retention percentage (16.851 %), TSS (14.901 °Brix), total sugars (12.999 %) and shelf life (15.034 days) were recorded with pre-harvest application of CPPU. Maximum ascorbic acid content (49.838 mg. 100 g-1), reducing sugars (4.277 %) and firmness (5.866 kg.cm-2) were recorded with pre-harvest application of Ca(NO3)2 whereas, minimum physiological loss in weight was recorded with the application of CPPU on 12th day (16.244 %). Among different time of chemicals and plant bio regulator application, maximum fruit retention percentage were recorded with chemicals and plant bio regulator applied at 703 phenophase, maximum shelf-life was recorded with the application of CPPU at 709 phenophase, minimum physiological loss in weight was recorded with the application of CPPU at 709 phenophase.

Effect of Preharvest Treatments with Sodium Bicarbonate and Potassium Silicate in Navel and Valencia Oranges to Control Fungal Decay and Maintain Quality Traits during Cold Storage

The quality of sweet orange (Citrus sinensis L.) is determined by the presence of decay caused by phytopathogenic fungi. This can develop in the field and rapidly spread among oranges during postharvest storage. Currently, the conventional treatments applied to control this problem are chemical fungicides. However, consumers demand eco-friendly and non-polluting alternatives with low chemical residues. Therefore, the aim of this work is the preharvest application of sodium bicarbonate (SB) and potassium silicate (PS) solutions at 0.1 and 1% to Navel and Valencia oranges to elucidate the effect on fruit quality and fungal decay at harvest and after 42 days of storage at 8 °C. Results showed that oranges treated with SB 0.1%, PS 0.1, and PS 1% maintained quality traits at similar levels to the control ones. However, SB 1% reduced firmness and increased weight loss, respiration rate, maturity index, and citrus color index. The total carotenoid content significantly increased in oranges treated with SB 1%, and no differences were observed in the other treatments compared to the control. Total antioxidant activity and total phenolic content decreased in oranges treated with SB at 0.1 and 1%, contrary to the results observed in oranges treated with PS, where both parameters increased. Regarding fungal decay, the best results were obtained in oranges treated with the highest doses of SB and PS. Therefore, the use of SB and PS in preharvest sprays could be an alternative to control fungal decay without affecting orange quality.

Pre-harvest application of GABA and CaO delays senescence and maintains of physicochemical characteristics of fresh ‘‘Ahmad Aghaei’’ pistachio during cold storage

The present study was conducted to determine the effects of preharvest application of calcium oxide 1% (CaO), gamma-aminobutyric acid 20 mM (GABA), and the combined treatment of CaO and GABA on shelf life and quality of fresh pistachio in cold storage (at 4 ± 1 °C with 85 ± 5% RH) for 75 d. Post-harvest quality and biochemical characteristics of fruits were measured during 0, 25, 50, and 75 d of storage. The investigation results showed that with the increase in storage time, the hull and kernel firmness (63% and 75%, respectively) and kernel lipid (55%) decreased in treated fruits. Still, the phenolic compounds (45%) and antioxidant activity (10%) of the kernel, hull malondialdehyde (66%), and kernel and hull anthocyanin (71%) increased. Fruits treated with CaO 1% (contained the most kernel lipids and flavonoids and the lowest hull), kernel anthocyanin, and kernel carotenoids. As a result, CaO + GABA pre-harvest treatment was recognized as the best treatment by maintaining antioxidant properties, better overall acceptance, and a higher percentage of healthy fruits during storage. However, applying the treatment before harvesting in the orchard takes a lot of time, but water does not accumulate in the pistachio hull, and the treatment is better absorbed.

Preharvest Application of Melatonin Affects the Color, Strength, and Antioxidant Capacity of Pear Peels by Regulating Phenylpropane Metabolism

Melatonin is an important regulator of fruit growth and development. To explore the physiological mechanism whereby preharvest melatonin application regulates the polyphenol content of ‘Yuluxiang’ pear peel, we sprayed 0.1 mM melatonin during the first fruit expansion and early color change periods, and the control group were sprinkled with fresh water. Then, we measured the contents of anthocyanin, lignin, and major monomeric phenolics and the activities of key enzymes associated with phenolic metabolism. The results showed that melatonin application significantly increased the content of total phenolics, total flavonoids, total anthocyanins, and lignin in the peel from the color change to mature development stages. Near maturity, the activities of all key enzymes, except dihydroflavonol-4-reductase, were higher than those in the control samples, but significant differences in enzyme activity occurred at different time points. Compared with the control group, the fruit peels of the melatonin-treated plants exhibited a higher antioxidant activity and accumulated more flavonols. Thus, preharvest spraying of melatonin can alter the activity of key enzymes associated with phenolic metabolism, increasing the total phenol, flavonoid, anthocyanin, and lignin contents, which in turn, affects the color, strength, and antioxidant capacity of pear peels.

Preharvest application of MeJA enhancing the quality of postharvest grape berries via regulating terpenes biosynthesis and phenylpropanoid metabolisms

Methyl jasmonate (MeJA) is an important phytohormone that regulates the development of grape, but the effect and underpin mechanism of its preharvest application on secondary metabolites accumulation in postharvest grape berries are still unclear. In this study, the transcriptome profiles combined with metabolic components analysis were used to determine the effect of preharvest MeJA application on the quality formation of postharvest rose-flavor table grape Shine Muscat. The results indicated that preharvest MeJA treatment had no significant effect on TSS content, but had a down-regulation effect on the accumulation of reducing sugar and titratable acid in the berries. The content of chlorophylls and carotenoids in treated berries was significantly higher than that of the control. Many phenolic components, such as trans-ferulic acid, resveratrol, quercetin, and kaempferol, were sensitive to MeJA and their contents were also significantly higher than that of the control under MeJA treatments during the shelf life. Compared with other volatile aroma components, terpenoid components were more sensitive to preharvest MeJA signals, the content of which presented an overall upward trend with increasing MeJA concentration and prolonging storage time. Furthermore, most of the differentially expressed genes in the general phenylpropanoid pathway and terpenoid biosynthesis pathway were up-regulated responding to MeJA signals. The most upregulated regulatory factors, such as VvWRKY72, VvMYB24, and VvWRI1, may be involved in MeJA signal transduction and regulation. Preharvest MeJA may be an effective technique for enhancing the quality of postharvest Shine Muscat grape berries, with its positive effect on enhancing the characteristic aroma and nutritional components.

Preharvest Application with Oxalic Acid and Calcium Nitrate Maintains the Quality of Cold-Stored 'Swelling' Peach Fruits

Preharvest Application with Oxalic Acid and Calcium Nitrate Maintains the Quality of Cold-Stored 'Swelling' Peach Fruits

Aminoethoxyvinylglycine Reduces Preharvest Fruit Drop and Fruit Ethylene Evolution in ‘Red Delicious’ Apple but Affects Fruit Size and Quality Inconsistently

Aminoethoxyvinylglycine (AVG) is widely used in commercial apple (Malus ×domestica Borkh.) production to reduce preharvest fruit drop (PFD) and delay ripening for harvest management. Recently, the maximum allowable concentration of AVG was doubled (up to 264 mg⋅L−1). Reports of the relationship between the AVG concentration and fruit growth, size, and quality have been contradictory. We evaluated the relationship between the AVG concentration and PFD, fruit size, fruit quality, and expression of ethylene signaling-related and cell wall modification-related genes. Experiments were conducted in 2019 and 2020 using mature ‘Red Delicious’ in western North Carolina. The AVG treatments [0 and 132 (AVG-1x) and 264 mg⋅L−1 (AVG-2x)] were applied 3 weeks before the expected harvest. The AVG treatments reduced fruit drop and internal ethylene concentration relative to the control in both years. There was no difference in drop between AVG-1x and AVG-2x applications. Only in 2020 did AVG treatments delay fruit softening and starch hydrolysis and reduce soluble solids concentration. There were no effects on red fruit color development. Fruit size was unaffected by AVG in 2019, but it was reduced in 2020 with the AVG-2x application. AVG reduced ethylene synthesis and altered signaling, evidenced by decreased relative expression of genes related to ethylene signaling (ARGOS1, ARGOS2). AVG applications also reduced the expression of EXPA8;1, suggesting that reduced cell wall disassembly was associated with a reduction in fruit softening. These results indicate that preharvest applications of 132 mg⋅L−1 AVG effectively reduced PFD via altering ethylene evolution and signaling. Use of a higher AVG concentration was of limited benefit.

Pre-Harvest Application of Strigolactone (GR24) Accelerates Strawberry Ripening and Improves Fruit Quality

GR24, a synthetic strigolactone analogue, plays a crucial role in a wide range of life processes. Studying the effects of the pre-harvest application of GR24 on strawberry ripening and fruit quality provides a scientific basis for the application of GR24 in horticultural crop production. GR24 solutions at concentrations of 0, 0.5, 1 and 2 µmol/L were applied to strawberries at the de-greening stage. The results showed that pre-harvest treatment with 1 µmol/L GR24 increased fruit weight and size; promoted fruit softening; increased the content of sugars, total flavonoids, total phenolics, and anthocyanins, and increased antioxidant activity. These results proved that GR24 effectively accelerated fruit ripening and improved fruit quality. In addition, to gain more insight into the biological mechanism of GR24 in fruit ripening, we conducted a combined transcriptomic and metabolomic analysis. It was found that the differences were related to sugar and flavonoid biosynthesis, particularly in the later stage of fruit ripening. qRT-PCR analysis revealed that GR24 increased gene expression activity and metabolite accumulation in the anthocyanin and sugar biosynthetic pathway, thereby promoting strawberry color and flavor.

Influence of Benzothiadiazole on the Accumulation and Metabolism of C6 Compounds in Cabernet Gernischt Grapes (Vitis vinifera L.).

Pre-harvest application of elicitors improves grape quality, specifically the phenolic compounds and color characteristics. Limited research has been conducted on the impact of elicitors on the C6 compounds found in grapes. This is due to lack of comprehensive studies examining the combined effects of bound aroma compounds, enzyme activity, and substrate availability. This study aimed to assess the impact of benzothiadiazole (BTH) on the physicochemical properties and C6 compounds of Cabernet Gernischt grapes during ripening. Compared with the control group (CK), BTH treatment significantly increased the 100-berry weight, skin/berry ratio, pH, total phenolic content, and total flavonoid content in ripe grapes. Additionally, BTH treatment led to significant reductions in reducing sugar, total soluble solids, titratable acidity, linoleic acid, linolenic acid, and free C6 aldehydes. Furthermore, BTH treatment significantly decreased the contents of free C6 alcohols and increased the levels of free and bound C6 esters. BTH treatment also increased the activities of lipoxygenase, alcohol dehydrogenase, and alcohol acetyltransferase enzymes, while it decreased the activity of hydroperoxide lyase enzyme. The application of BTH resulted in changes to the physicochemical properties and levels of C6 compounds in Cabernet Gernischt grapes by up-regulating enzyme activity and down-regulating precursors.