Accumulation Of Total Soluble Solids Research Articles

Quality and shelf life of strawberry fruit as affected by edible coating by moringa leaf extract, aloe vera gel, oxalic acid, and ascorbic acid

ABSTRACT In the current study, the most effective concentrations of moringa leaf extract (MLE), aloe vera gel (AV gel), ascorbic acid (1 mM) and oxalic acid (5 mM) were used. Physically mature fruits harvested from a commercial orchard were dipped in aqueous solutions of different edible coatings and kept at ambient conditions (25±2ºC & 55-60% RH) for evaluation of the quality and enzymatic parameters on daily basis till marketability. Current results revealed that 5 mM ascorbic acid treatment resulted in 57% reduced fruit weight loss; while 20% AV gel coating increased firmness by 60% over a 5-day ambient storage period. Application 6% MLE exhibited 50.7% and 49.7% reduced respiration rate and ethylene production respectively. Fruit biochemical quality parameters were also improved with the lowest accumulation of total soluble solids as a result of slow respiration, higher titratable acidity, ascorbic acid contents, carotenoids and anthocyanin contents in all treated fruit. While, total phenolic contents and total antioxidants along with superoxide dismutase, catalase, peroxidase, and anthocyanins were higher in ascorbic acid treated fruits. The activity of poly phenol oxidase enzyme was lowest in fruits treated with 5 mM ascorbic acid solution. Conclusively, the application of different edible coatings was proved to be beneficial as numerous fruit biochemical and antioxidative attributes were improved by ascorbic acid treatment; furthermore, MLE, AV gel and oxalic acid treatments were also helpful in maintaining fruit quality of strawberry fruits over a 5-days ambient storage period.

Effect of Maleic Hydrazide and Waxing on Quality and Shelf-life of Mango (Mangifera indica L.) Fruits

The effect of post-harvest treatment of maleic hydrazide (MH)with and without waxing on the quality and shelf-life of ‘Kitchner’ and‘Abu-Samaka’ mango fruits at 18 ±1°C and 85% - 90% relative humiditywas studied. Maleic hydrazide and wax treatments delayed fruit ripening,reduced losses, maintained quality and extended shelf-life of mangofruits. MH at 500 and 1000 ppm significantly delayed fruit ripening bytwo and four days in both mango cultivars, respectively, compared withthe untreated fruits. The higher the concentration of MH, the more delayin fruit ripening. Waxing in addition to MH treatment resulted in ripeningdelay of six days in fruit ripening than treatment with MH alone. Theeffect of MH and waxing treatments in delaying mango fruit ripening,was indicated in retarded respiratory climacteric, reduced water loss,delayed peel colour development, fruit softening and total soluble solidsaccumulation and retained ascorbic acid content.

Post-Bloom CPPU Application Is Effective at Improving Fruit Set and Suppressing Coloration but Ineffective at Increasing Fruit Size in Litchi

This study aimed to provide a reference for the practical use of forchlorfenuron (CPPU) in the improvement of fruit set and quality (especially size) in litchi (Litchi chinensis Sonn.). CPPU at 5 mg/L was sprayed to fruit clusters of ‘Feizixiao’ at 2, 4, 6 and 8 weeks after female bloom (WAFB) in 2017 and at 2, 4, 6, 8, 9 or 10 WAFB in 2018, with spraying water as the control. The treatments were all effective at suppressing fruit abscission, resulting in higher fruit retention at harvest. Except for treatment at 2 WAFB, which caused stunted fruit and significantly reduced fruit weight, all the treatments had no significant influence on fruit weight and flesh (aril) weight, although CPPU tended to increase pericarp weight and strongly suppressed fruit coloration, and such effects were most significant in treatments at 4, 6 and 8 WAFB. Content of total soluble solids (TSS) in commercially ripe fruit (11WAFB) was not significantly influenced by CPPU applied at any of the stages. Ripe fruit continued to gain redness but lost TSS as it became overripe. CPPU suppressed redness gaining, the effect being stronger in later application. The treatments did not influence TSS loss, but treatments at 4, 6 and 8 WAFB significantly reduced the increase in fruit membrane leakage. In treatment at 6 WAFB, CPPU residue in the pericarp decreased sharply with time but relatively constant in the aril, where it maintained lower than 10 μg/kg, the maximal residue limitation in Australia and the United States. The results suggest that 5 mg/L CPPU is effective at improving fruit set and suppressing fruit pigmentation but has no significant effect on fruit size and TSS accumulation or maintenance in litchi.

Long-term response of dragon fruit (Hylocereus undatus) to transformed rooting zone of a shallow soil improving yield, storage quality and profitability in a drought prone semi-arid agro-ecosystem

Agricultural crops especially fruit trees are constrained by edaphic stresses in shallow soils with low water retention and poor fertility. Therefore, interventions of shifting to trench planting for better root anchorage and replacing the filling soil were evaluated for 8 years in dragon fruit (Hylocereus undatus) cultivated in Deccan Plateau of peninsular India. When averaged for last 5-years, 44 % higher fruit yield (18.2 ± 1.0 Mg ha−1) was harvested from trees planted in trenches filled with 1:1 mixture (T-mixed) of native soil (loamy sand with 26.7 % stones (>2mm), field capacity, FC 0.20 cm3 cm−3; organic carbon, OC 0.17 %; Av-N 54.6 kg ha−1) and a black soil (clay 54.4 %; FC 0.42 cm3 cm−3; OC 0.70 %; Av-N 157.1 kg ha−1) than the recommended pit planting (12.4 ± 1.2 Mg ha−1). Improvements in fruit yields with trenches filled with black (T-black) and native (T-native) soil were 32 and 13 %, respectively. Yield losses (total– marketable yield) were reduced by 40, 20 and 18 % over pit method with T-mixed, T-black and T-native soil, respectively. Marketable quality attributes like fruit weight, fruit size metrics and pulp/peel content were further improved under T-mixed soil. Accumulation of total soluble solids (TSS), sugar content, phenolic and flavonoid compounds were higher in fruits from T-native soil. During storage, fruits from T-native soil and pit planting exhibited minimum physiological weight loss and retained more firmness, TSS, sugars, titratable acidity, phenolic-flavonoids contents, FARP and DPPH activities. T-mixed soil provided better hydrozone and nutrients for resilience of fruit plants while protecting from aeration problems envisaged in poorly drained black soils. With B:C ratio (1.85) and lower payback period (4-years), T-mixed soil showed superior economic viability. Therefore, soil management module of planting in trenches filled-in with mixture of native and black soils can be recommended to boost productivity of fruits from shallow soils under water scarce degraded regions without penalising agro-ecosystem.

Grape berry transpiration influences ripening and must composition in cv. Tempranillo (Vitis vinifera L.).

The implications of grape berry transpiration for the ripening process and final grape composition were studied. An experiment was conducted, under controlled conditions, with fruit‐bearing cuttings of Vitis vinifera L. cv. Tempranillo. Three doses of the antitranspirant di‐1‐p‐menthene were applied directly to the bunch at the onset of veraison: 1%, 5%, and 10% (v/v) (D1, D5, and D10, respectively). A treatment with bunches sprayed with water (D0) was also included as a control. Grape and bunch transpiration, and total soluble solids (TSS) accumulation rate decreased as the dose of antitranspirant increased, thus resulting in the lengthening of the ripening period. Bunch transpiration rates were linearly correlated with the elapsed time between veraison and maturity, and with the TSS accumulation rate. The evolution of pH, malic acid and total skin anthocyanins during ripening did not show remarkable changes as a consequence of the artificially reduced bunch transpiration. However, a decoupling between TSS and anthocyanins was observed. At maturity, the bunches treated with D10 had significantly lower must acidity and higher pH and extractable anthocyanin levels, these differences being likely associated with the lengthening of the ripening period. The results show a clear implication of grape transpiration for the ripening process and final grape composition, and give new hints on the direct application of antitranspirants to the bunch as a way to regulate sugar accumulation while avoiding the concurrent delay of color development.

Effect of Natural Waxes on Quality and Shelf Life of Tomato (Solanum lycopersicum L.) Fruits

The effect of three natural waxes (bee, carnauba and jojoba) on quality and shelf-life of ‘Ergon’ tomato cultivar was evaluated.Tomato fruits were harvested at the mature-green stage from a greenhouse belonging to the College of Agricultural Studies, Sudan University of Science and Technology. Fruits were selected for uniformity of size, color and freedom from blemishes and defects, and transported in field boxes to the laboratory. The fruits were washed, treated with 0.1 % sodiumhypochlorite (Clorox, 5 %) as a disinfectant and air dried. The waxes were dissolved in olive oil (1:1) and applied by brushing over the surface of the fruits in a thin layer. The treatments were: bee wax, carnauba wax, jojoba wax and untreated (control).They were arranged in a completely randomized design with four replications. The treated and untreated fruitswere stored in carton boxes for 30 days at 18±1 ˚C and 80- 85 % relative humidity in a cold room at the Department of Horticulture, Faculty of Agriculture, University of Khartoum. Analysis of variance at significancelevel of P ≤ 0.05 was performed on the data using SBS (version 23) statistic. The results showed that the natural waxes significantly reduced losses, maintained quality and extended shelf-life of tomato fruits. The wax treatments significantly delayed fruit ripening (6, 4 and 2 days), reduced water loss (34.1, 19.4 and 9.7 %), decreased peel color (40, 20and 12 %), fruit softening (87.5, 45.0 and 27.5 %), and total soluble solids accumulation (23.2, 13.4 and 7.2 %), in fruits treated with jojoba wax, carnauba wax and bee wax, respectively, compared with un-waxed (control) fruits. Jojoba wax was most effective, followed by carnauba wax and the least was the bee wax. It is recommended that natural waxes,especially jojoba and carnauba waxes, can effectively be used to delay fruit ripening, reduce weight loss, maintain quality and extend shelf-life of tomato fruits.

Evolution of Bioactive Compounds during Storage of Poyo Bananas after Treatment with Calcium Chloride

Visually, the obvious characteristic of banana ripening is the progressive change of the epicarp from green to yellow according to several stages whose importance contributes to extend the total duration of the process. The present study was carried out with the aim of prolonging the ripening time of bananas while following the behavior of the physiological parameters related to this process. To achieve this objective, after treatment of bananas with calcium chloride, several parameters were evaluated. These were ripening rate, firmness, water content, soluble solids content and pigment content in the peel. Secondly, the evolution of antioxidant parameters such as: lycopenes and β-carotenes in the pulp; total phenols, flavonoids and ascorbic acid contents in the peel and pulp have been assessed. As a result of these analyses, it appeared that the best shelf life was obtained with bananas treated with tween 80 at 2 and 4% Cl2Ca. The lowest bananas shelf lives were recorded in 6 and 8% Cl2Ca and in the control. Similarly, the low loss of firmness, low accumulation of total soluble solids, low increase in water content in the pulp were found in the 2 and 4% Cl2Ca tween 80 treatments. The change in chlorophyll went in a decreasing direction during storage, but almost similarly in all treatments. The increase in lycopene content was effective during this time in a less rapid manner in the 2 and 4% calcium chloride treatments. Variations in β-carotenes, total phenols, and ascorbic acid were also increased throughout the storage period. However, at the end, it was difficult to correlate their evolution to any concentration of calcium chloride used for banana processing. It is also this lack of influence of calcium chloride as a treatment on the significant decrease of flavonoids in the pulp and not significant in the peel that was observed. Furthermore, the contents of the compounds measured in the peel and the pulp were lower in the pulp. It is thus with the bananas treated with tween 80 to 2 and 4% of calcium chloride that the majority of the parameters were influenced in favour of the preservation of bananas.

Identification of main factors affecting the within-field spatial variability of grapevine phenology and total soluble solids accumulation: towards the vineyard zoning using auxiliary information

Identification of main factors affecting the within-field spatial variability of grapevine phenology and total soluble solids accumulation: towards the vineyard zoning using auxiliary information

‘Frontenac’ Grape Response to Canopy Management in North Dakota

Experiments were conducted in 2013 and 2014 to evaluate the effects of training system and leaf removal treatments on yield and quality for ‘Frontenac’, an interspecific hybrid wine grape, at a research vineyard located near Absaraka, North Dakota. The experiment was structured as a randomized complete block design with a split-plot arrangement including four training system treatments (Geneva Double Curtain (GDC), High Cordon (HC), Vertical Shoot Positioned (VSP), Four-Arm Kniffin (4AK)), and four-leaf removal timing treatments (bloom, post-bloom, veraison, and a control, no removal) with eight replicates. In 2013, 1428 growing degree days (GDDs) accumulated in the 155 days between frost events. In 2014, 1156 GDDs accumulated in the 121 days between frost events, 272 GDDs less than the year prior. Even with the large GDD differences between years, there was no significant interaction between trellis type and leaf removal, and the main factor of leaf removal did not influence any of the fruit variables where data were collected. Combined data analysis showed no significant differences in fruit juice total soluble solids (TSS) or titratable acidity (TA). The fruit juice pH in 2013 was greater when grapes were grown in the VSP system compared to grapes grown in the other trellis systems. In 2014, live nodes and total shoots were greater for grapes grown on GDC and 4AK systems compared to grapes grown on the HC and VSP systems. Additionally, in 2014, grapes grown on the GDC system had a greater cluster number and yield when compared to grapes grown on the 4AK or VSP systems. These findings suggest that ‘Frontenac’ fruit TSS accumulation and TA were not affected by leaf removal or trellis system in North Dakota vineyards and that yield gains may be reached due to the training system without negatively affecting fruit quality.

Effects of the irrigation regimes on grapevine cv. Bobal in a Mediterranean climate: I. Water relations, vine performance and grape composition

Climate change scenarios are predicting an increase in temperature as well as more scarce and torrential rainfall episodes. Due to this, an imbalance between grape technological and phenolic maturity is being observed detrimentally affecting grapes composition. In semi-arid areas, irrigation management is a main field practice to influence grape ripening. The goal of the present study was to investigate in Vitis vinifera L. cv. Bobal grapevine responses to three watering regimes: (i) Rainfed, (ii) deficit irrigation (DI) replacing only 35% of the estimated crop evapotranspiration (ETc) and (iii) full irrigation (FI) replacing 100% ETc. In the mid-summer, rainfed grapevines showed different degrees of water stress determined by midday stem water potentials (Ψstem) ranging from −1.1 to −1.4 MPa depening on the season. Rainfed plants had in all seasons less vigor and production and, at harvest, higher concentrations of total soluble solids (TSS) and grape phenolics compounds, as well as lower pH, with respect to the other water regimes studied. DI grapevines, generally, had intermediate values between Rainfed and FI, which presented extreme values of the studied parameters respect to Rainfed. The effects observed on grape color parameters and phenolic compounds with the Rainfed regime were mainly due to a dehydration of the berry, which lowered the yield and the weight of the berry compared to the irrigated treatments. The lower TSS accumulation in the DI berries with respect to the Rainfed, will favor obtaining wines with lower alcohol content, currently more demanded by the consumers. Besides, despite the differences obtained between water regime treatments in the TSS accumulation, the extractability of the anthocyanins was similar, which is interesting since anthocyanin extraction from grapes is prerequisite to the formation of stable red wine pigments. Although the most convenient irrigation strategy might depend to the wine style to be obtained, DI is a strategy that can help to close the gap in the imbalance between the technological and phenolic maturity, positively affecting vine yield and performance with respect to the rainfed strategy.

High Carbon Dioxide Treatment Modulates Sugar Metabolism and Maintains the Quality of Fresh-Cut Pear Fruit.

The purpose of this study is to explore the effect of 10% carbon dioxide (CO2) on the fruit quality and sugar metabolism of fresh-cut pear during storage. The results indicated that carbon dioxide treatment maintained fruit quality by delaying the decline of firmness and promoting the accumulation of total soluble solids (TSS). Moreover, carbon dioxide enhanced activities of sucrose synthase (SS), and sucrose phosphate synthase (SPS). The activities of amylase, acid invertase (AI), neutral invertase (NI), SS-cleavage, fructokinase (FK), hexokinase (HK), sorbitol oxidase (SOX), NAD-dependent sorbitol dehydrogenase (NAD-SDH), and NADP-SDH in CO2-treated fruit were inhibited. Expression levels of key genes were found to correspond with the related enzyme activities. As a result, the accumulation of glucose, fructose, sorbitol, and sucrose were accelerated by CO2, which were 12.58%, 13.86%, 24.7%, and 13.9% higher than those of the control at the end of storage, respectively. The results showed that CO2 could maintain the quality of fresh-cut pears by regulating the conversion of various sugar components to enhance soluble sugars content.

The Effect of Elevated CO2 on Berry Development and Bunch Structure of Vitis vinifera L. cvs. Riesling and Cabernet Sauvignon

Carbon dioxide (CO2) as one of the main factors driving climate change is known to increase grapevine growth and yield and could, therefore, have an impact on the fruit quality of vines. This study reports the effects of elevated CO2 (eCO2) on berry development and bunch structure of two grapevine cultivars (Vitis vinifera L. cvs. Riesling and Cabernet Sauvignon) within the VineyardFACE (Free-Air Carbon Dioxide enrichment) experiment, using must analysis and non-invasive fluorescence sensor technology. Berry development was examined on five dates over three consecutive years by analyzing total soluble solids (TSS), pH, total acidity, organic acids, nutrition status, and non-invasive Multiplex measurements. Before harvest, secondary bunches were collected to examine bunch and berry parameters. Results showed that eCO2 had little impact on berry composition of Riesling and Cabernet Sauvignon during berry development, which could be related to bunch structure or single berry weight within single seasons. Elevated CO2 (eCO2) did not result in modified TSS accumulation during ripening but was directly related to the chlorophyll index SFR_R. Higher single berry weights (SBW), higher malic acid (MA), and lower tartaric acid (TAA) were examined at some stages during development of berries under eCO2 levels. Our study provides evidence that eCO2 did alter some bunch and berry parameters without a negative impact on fruit quality.

Identification of Nonhost Cover Crops of the Three-Cornered Alfalfa Hopper (Spissistilus festinus)

The three-cornered alfalfa hopper, Spissistilus festinus (Say) (Hemiptera: Membracidae) was identified as a vector of grapevine red blotch virus (GRBV) in a greenhouse study. GRBV impacts berry maturation, resulting in reduced accumulation of total soluble solids, increased titratable acidity, and altered levels of secondary metabolites that affect color, flavor, and aroma of finished wine made from infected grapes. S. festinus feeds and reproduces on a variety of plant species found in and around vineyards, including certain cover crops and weeds. The suitability of 15 commonly planted cover crops for S. festinus adult feeding and oviposition was determined. In no-choice tests, purple vetch, berseem clover, annual ryegrass, buckwheat, Trios triticale, and Zorro fescue supported survival of adult S. festinus, oviposition, and emergence of nymphs. In contrast, orchard grass, creeping red fescue, fawn tall fescue, hard fescue, and California poppy did not support survival of adult S. festinus, nor were nymphs observed. Relative preference for hosts that supported nymph emergence was determined in choice tests. The legume species (purple vetch and berseem clover) exhibited higher nymph emergence than the nonlegume cover crops (Zorro fescue, Trios triticale, buckwheat, and annual ryegrass). Cultivating cover crops that do not support S. festinus survival or oviposition may aid in reducing the risk of S. festinus moving into and establishing in vineyards.

Exogenous procyanidin treatment delays senescence of harvested banana fruit by enhancing antioxidant responses and in vivo procyanidin content

Banana fruit has high nutritional value and is consumed worldwide. However, rapid senescence shortens the storage time of harvested banana fruit after ripening. Procyanidins (PAs) are excellent antioxidants, but their effects on harvested fruit are obscure. Here, we explored the effects of exogenous PAs on senescence in banana fruit. Notably, a 1% PA solution delayed senescence of banana fruit, as demonstrated by reduced decrease in pulp firmness, peel color changes, and total soluble solids accumulation in pulp. Reactive oxygen species levels, malondialdehyde content, and relative conductivity rates in peels were significantly decreased, whereas superoxide dismutase, catalase, and peroxidase activity and expression were enhanced by PA treatment. The DPPH scavenging activity in peels of PA-treated fruit was also enhanced, and in vivo PA contents in the peel and pulp were induced by PA treatment. Overall, PA-dependent delayed senescence could help maintain the freshness of harvested banana fruit.

Effects of Variable Rate Nitrogen Application on cv. Barbera Performance: Yield and Grape Composition

This paper follows a first contribution on the long-term effects of variable rate nitrogen application on vegetative growth and leaf nutritional status of a small Barbera vineyard, where three vigor levels classified as low, medium, and high (L, M, H) were identified pretrial from normalized difference vegetation index (NDVI) values determined by remotely sensed imagery (5 megapixel resolution). Variable rate fertilization supplying no N (0 kg/ha; C), standard rate (60 kg/ha; S), and variable rate application (VRA) of 60 or 120 kg/ha to H, M, and L over four consecutive seasons showed that variability among vigor levels was significantly reduced in years three and four, while mean effects related to fertilization strategy were not significant. In this companion paper, L vines were most balanced, suggesting a change in fertilization strategy to no N application in M and H areas, and for maintenance supply in L plots. However, significant vigor level × year interactions indicated that within-vigor variability for total yield and berry weight was considerably reduced, while concomitant seasonal accumulations of sugar and color in 2014 and 2015 were much less variable within dates across vigor levels, suggesting the efficacy of the VRA approach. While the main effects of fertilization supply were mostly non-significant, seasonal accumulation of total soluble solids and anthocyanins in 2014 and 2015 showed that plots receiving 60 kg N/ha had lower within-date values than C (no N), suggesting increasing sensitivity over years. However, the L vines had an almost negligible response to increased N supply, and most observed responses were primarily due to reduced vine capacity.

The effect of 1-methylcyclopropene (1-MCP) on expression of ethylene receptor genes in durian pulp during ripening

Rapid fruit ripening is a significant problem that limits the shelf life of durian, with ethylene having a major impact on the regulation of this event. Durian treated with ethephon ripened 3 d after treatment with increased pulp total soluble solids, ethylene production of the whole fruit and decreased pulp firmness compared to the control fruit. 1-MCP treatment delayed ripening by up to 9 d with inhibited accumulation of total soluble solids, color change, softening and ethylene production. Genes related to ethylene perception (DzETR1 and DzETR2) and the signaling pathway (DzCTR1, DzEIL1 and DzEIL2) in the pulp were investigated during this process, using qPCR to quantify changes in gene transcription. All candidate genes were significantly up-regulated in ripening durian pulp. Ethephon treatment increased the expression of DzETR1 and DzETR2 genes, while expression of DzCTR1, DzEIL1 and DzEIL2 were slightly affected. 1-MCP treatment significantly inhibited the expression of the DzETR2 and DzEIL1 genes. The promoters of DzETR2 genes were isolated and their activation by fruit transcription factors studied using transient expression in tobacco leaves. It was found that members of the kiwifruit and apple EIL1, EIL2 and EIL3 genes strongly activated the DzETR2 promoter. These results suggest that ethylene-induced ripening of durian is via the regulation of DzETR2 by EIL transcription factors.

The Interactive Effect of Pruning Level and Irrigation Strategy on Grape Berry Ripening and Composition in Vitis vinifera L. cv. Shiraz

A partial rootzone drying (PRD) irrigation technique (0.5 ML/ha) was compared with a standard irrigation treatment (1 ML/ha) at three different pruning levels of 30, 60 and 120 nodes per grapevine in Vitis vinifera L. cv Shiraz. Berry size was found to decrease as node number per grapevine increased, but was not significantly altered by the PRD treatment. The influence of these treatments on the accumulation of total soluble solids per berry was investigated during berry ripening and was shown to be reduced at higher node number (120 nodes). There was no effect of PRD on the accumulation of total soluble solids. Juice titratable acidity and the concentration (per g) and content (per berry) of grape anthocyanins and phenolics were compared between treatments at harvest. In one season of the study, juice titratable acidity, anthocyanin and phenolic concentration was unaltered by the PRD treatment. In a further season, juice titratable acidity was decreased in response to the PRD treatment and was associated with increases in grape anthocyanin and phenolic concentration in response to PRD. Where there was a small increase in anthocyanin concentration in response to PRD, this was found to be independent of berry size. In addition, linear regression analysis showed a poor relationship between berry size and anthocyanin concentration, but a significant relationship was found between berry size and anthocyanins per berry.

Composite coating of alginate-olive oil enriched with antioxidants enhances postharvest quality and shelf life of Ber fruit (Ziziphus mauritiana Lamk. Var. Gola).

The present study has been carried out to evaluate the effect of a composite edible coating of 2% Sodium alginate and 0.2% Olive oil with combination of 1% ascorbic acid and 1% citric acid on the post harvest nutritional quality and shelf life of Ber fruit stored at 25±2°C and 65% R.H. The coatings reduced the decay occurrence, weight loss, accumulation of total soluble solids (TSS) and total sugars in Ber fruit and enhanced the level of antioxidants. The delayed activity of polygalacturonase (PG), Pectate lyase (PL) and Pectin methyl esterase (PME) was noticed in coated fruits than that of the control fruit indicating the reduced softening and ripening process. These findings suggest that the composite edible coating tested under the current study has the potential to control decaying incidence of Ber fruit, extends its storage life and also improves its valuable nutritional characteristics.

Influence of retained node number on Sauvignon Blanc grapevine phenology in a cool climate

Background and Aims In Marlborough's cool climate, slow ripening grapes often do not reach ripeness. This study determined the effect of crop load, achieved via different levels of retained node number, on Sauvignon Blanc phenology and ripening. Methods and Results Two to six canes, each single cane unit having 12 nodes, were laid down and from these vines phenological development was recorded and growth curves were calculated for budburst, flowering, veraison and ripening over 4 years, from 2007 to 2010. The different crop loads, obtained through these pruning treatments, had little influence on vine phenology until after veraison when the retained node number had a significant influence on the rate of accumulation of total soluble solids during the ripening period. Target ripeness was delayed by up to 41 days when 72 nodes were retained, compared with 24 nodes. Simple modelling with generalised logistic functions accurately described phenological changes in the plant and improved the reliability of statistical comparison of time courses between the different treatments. Conclusion For all 4 years of the study, differences in retained nodes per vine had little influence on the phenology of the vine up to veraison, but had a strong effect on the rate of ripening because of subsequent differences in crop load. After the first year of the trial, the influence of the retained nodes on yield gradually diminished and as a consequence so did the influence on the rate of ripening. Significance of the Study A clear demonstration of the strong influence of crop load on the rate of ripening of Marlborough Sauvignon Blanc, together with the capacity of the vines to adjust their source/sink balance over time, with the direction of the adjustment determined by the node number.

Manipulating the leaf area to fruit mass ratio alters the synchrony of total soluble solids accumulation and titratable acidity of grape berries

Background and Aims This study investigated: (i) the importance of changing the leaf area: fruit mass ratio (LA : FM) by crop removal and/or shoot trimming on total soluble solids (TSS) concentration and content, pH, titratable acidity (TA) and berry mass; (ii) the extent to which changes in LA : FM ratio altered the synchrony TSS : TA ratio; and (iii) whether the responses were consistent for Pinot Noir and Sauvignon Blanc. Methods and Results Vertical shoot positioned–trained vines were trimmed shortly after fruitset or at veraison to six or 12 main leaves per shoot and crop thinned by removing 0, 50 or 75% of the bunches. TSS and pH, TA and fresh berry mass were measured weekly from pre-veraison to harvest. TSS concentration accumulation in berries was slowed with shoot trimming and accelerated by crop removal, with crop removal having a greater effect. Trimming shoots at fruitset in combination with no crop removal resulted in the greatest delay in veraison (the start of TSS accumulation) and slowest rate of TSS accumulation. TSS content mirrored TSS concentration for LA : FM manipulations at fruitset but fewer differences were detected for LA : FM changes at veraison. In contrast, TA and pH were largely unaffected. Conclusions Changes to the LA : FM ratio via crop removal or shoot trimming modified berry TSS accumulation but not TA. Such desynchronisation was consistent for both cultivars. Significance of the Study Crop and/or leaf removal represent valuable means to manipulate the time to achieve target fruit TSS concentration and TA. The similar responses of the two cultivars indicate that LA : FM manipulation could potentially have common responses for different cultivars. The desynchronisation of berry components highlights the need to consider each berry component individually and in a dynamic manner by sampling throughout the ripening phase.