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1.
Summary

The effect of 2,4-dichlorophenoxy-propionic acid (2,4-DP) on fruit ripening on the tree was investigated in `La France' pears (Pyrus communis L.). Forty-five ppm, 2,4-DP solution was applied at 159 d after full bloom (DAFB), which was optimum harvest date for `La France' pears. They were compared with fruit harvested at 159 DAFB and placed in a controlled room with a 208C and 90% r.h. After harvest, the fruit firmness decreased dramatically 13 d after harvest (DAH). In 2,4±DP treatment, the levels decreased gradually 13 d after treatment (172 DAFB). In the untreated control, the levels also showed a slight decrease with time. Final ethylene concentration was almost the same in harvested and 2,4-DP treated fruit, but lower in the untreated control. In each treatment, water-soluble polyuronide (WSP) concentrations increased with time and hexametaphosphate-soluble polyuronide (HMP) and HCl-soluble polyuronide (HP) concentrations decreased. WSP concentration increased rapidly 20 DAH in harvested fruit and 194 DAFB in 2,4-DP treatment. Harvested and 2,4-DP treated fruit reached the edible condition on 17 DAH and 194 DAFB, respectively. Pectinesterase (PE) activity increased slightly with time for all treatments, showing no significant difference between treatments. Polygalacturonase (PG) activity increased gradually in all cases, being higher in 2,4-DP treated fruit than in control fruit left on the tree. These results suggest that 2,4-DP treatment before harvest induces pear fruit softening. This implies that 2,4-DP may be used as a replacement for low-temperature storage to promote the ripening, and good quality ripe fruit with buttery and juicy texture may be harvested on the tree.  相似文献   

2.
Summary

Corky tissue (CT) is a major disorder affecting the fruit of sapota (Manilkara achras) ‘Cricket Ball’ in India. Affected fruit have a hard lump in the pulp and dry acidic flesh, but have no external symptoms. The main objective of the present study was to investigate the role of seed in the disorder. Treating fruit with 1.0 g l–1 gibberellic acid (GA3) at 50% maturity increased fruit fresh weight and presumably seed growth, and reduced the incidence of CT compared with that in untreated control fruit. In contrast, fruit treated with 3.0 g l–1 paclobutrazol (PBZ) showed the opposite response. Fruit treated at 70% or 90% maturity gave no response, suggesting that poor seed viability during the early stage of fruit development was associated with CT. Seed stored for 30 d under ambient conditions lost water and had lower viability. There were decreases in the moisture content and calcium concentration in seed and pulp as the severity of CT increased in fruit harvested in the field, indicating a “reverse flow” of water and nutrients from the fruit. It is proposed that the incidence of CT is related to reduced seed viability and the consequent losses of water and calcium from fruit due to competition for resources with the rest of the tree. Further studies are required to assess the potential of the application of GA3 to reduce the incidence of CT in commercial orchards.  相似文献   

3.
Summary

`Huangjin' peaches (Prunus persica Batsch) were harvested at commercial harvest time (commercial) and 20 d before (early) or after (later) commercial harvest. Fruit from each harvest were stored at three temperature regimes (0, 5 and 10°C) at 95% r.h. After four weeks of storage at 0 or 5°C, early harvested fruit developed more leatheriness but less mealiness and later harvested fruit did not develop leatheriness but developed more mealiness comparedwith fruit from commercial harvest. Overall, fruit stored at 5°C developed more mealiness but less leatheriness than fruitat 0°C for the same period of storage. When stored at 10°C for two weeks, after which fruit were senescent, fruit did not develop any leatheriness or mealiness regardless of harvest times. Fruit with leatheriness were firmer (>30 N) thanjuicy or mealy fruit (<10 N) after the same period of cold storage and 4 d at 20°C. Mealy fruit were as soft as juicy fruit. 1-Aminocyclopropane-1-carboxylate oxidase (ACO) activity, 1-aminocyclopropane-1-carboxylic acid (ACC) content, and polygalacturonase (PG) and galactosidase (GAL) activities were lower, and insoluble pectin content was higher in leathery fruit than that in juicy or mealy fruit. ACO, PG and GAL activity, ACC, and insoluble pectin content were similar between mealy and juicy fruit.  相似文献   

4.
Summary

Fresh ‘Patterson’ apricot was harvested at three fruit maturity levels and characterized with measurements of flesh colour, Brix, acidity and levels of specific sugars. Fruit from the three maturity classes were sun-dried under uniform conditions. Dry fruit was again analysed for the content of specific sugars before cold storage. Stored fruit were sampled periodically for colour coordinates L*, C* and H° during an eight-month period. The study was repeated for two harvest seasons. In each season, significant differences (P≤0.05) were observed between the three fruit maturity classes for Brix, acidity, C* and H8. Levels of specific sugars varied significantly (P≤0.01) with regard to fruit maturity class, tissue type and fruit status. Regression analysis of colour coordinate changes during the storage period indicated significant (P≤0.05) differences in rate of colour shift of L*, C* and H8 relative to fruit maturity class. While dried fruit of the immature class was of substandard quality after the storage period, both medium and most mature dry fruit were of sufficient quality to warrant marketing even after eight months of cold storage.  相似文献   

5.
Summary

The objectives of this study were to determine the efficacy of 1-methylcyclopropene (1-MCP) treatment on ripening of ‘Tsugaru’ fruit at different stages of maturity (early, mid-, and late harvest) and the responses of the early- to late-maturing apple cultivars,‘Tsugaru’,‘Hongro’ and ‘Fuji’, respectively, during storage at ambient temperature (20º ± 2ºC). Fruit at different stages of ripening were treated with 0.5, 1.0, or 2.0 µl l–1 1-MCP for different durations (e.g., 1.0 µl l–1 1-MCP for 8 h, 16 h, or 24 h) or with various delays before treatment (e.g., 1.0 µl l–1 1-MCP on the day of harvest, or 1 d, or 2 d later). Application of 1-MCP to unripe fruit inhibited ethylene production, lowered the rate of respiration and maintained titratable acidity (TA) more effectively than when more mature fruit was treated. However, the effects of 1-MCP on flesh firmness were similar for apples at mid- or late harvests. 1-MCP treatment of early-harvested fruit of the early-maturing ‘Tsugaru’, which had the highest level of ethylene production and respiration rate, inhibited softening and loss of TA to a greater extent than for late harvested fruit. The same pattern of softening was found for ‘Hongro’ and ‘Fuji’. Firmness of ‘Tsugaru’ and ‘Fuji’ apples was maintained after 8 h treatment with 1.0 µl l–1 1-MCP, while a 16 h treatment was required for ‘Hongro’. Treatment delays of ≤ 2 d before the application of 1-MCP had no negative impact on fruit firmness. Overall, these results indicate that 1-MCP can be used to maintain the quality of non-refrigerated apples.  相似文献   

6.
以软溶质水蜜桃清水白桃为试材,分别在树上完熟的前6、4和2d采样,贮藏于25℃,相对湿度90%的环境条件下至完熟,与树上完熟果实相比较,调查了果实的生理变化、色泽和果汁品质性状,并对完熟果实进行了风味评定。结果表明,贮藏期间的果实乙烯释放量以完熟前2d采收的果实增加最快并在果实完熟时达到最大,树上完熟的果实乙烯释放量最少。树上完熟前6d采收的果实,果皮亮度、果汁的蔗糖含量、“果香型”内酯类物质含量均低于后3次采收的果实,其中以树上完熟前2d采收的果实为最高。相反滴定酸、柠檬酸、天冬酰胺和“清香型”香气物质含量以树上完熟前6d采收的果实最高。完熟果实的风味评定也显示了树上完熟前2d采收的果实综合评价最高,早期采收的果实即使贮藏后达到完熟果肉硬度,甜度和香味少、酸味重。另外,树上完熟的果实肉质粗,酸度低,有怪香味,综合评价不高。  相似文献   

7.
Summary

In New Zealand, 6.2% soluble solids concentration (SSC) is the minimum maturity at which kiwifruit destined for export can be harvested. Ambient temperature during the fruit maturation period has been shown to affect the soluble solids accumulation rate. The purpose of the present study was to describe variation in the rate of fruit soluble solids accumulation in different regions and seasons and to develop a means of quantifying the effects of temperature on the rate of fruit maturation. Measurements of fruit SCC were made over a three year period on one orchard in each of six principal kiwifruit-growing regions across New Zealand. The date at which fruit reached 6.2% SSC varied by 34 d across all sites and years. There was an 18 d range in the average date across all sites, with Riwaka, the coolest site being the earliest, and Kerikeri, the warmest site, being the latest. The variation from year to year across all sites was 12 d. We formulated a non-linear, time-dependent model to predict the rate of change of SSC with time, given the temperature and the time since flowering. This model accounted for nearly 60% of the variation in the date that 6.2% SSC was reached and 70% of the variation in the date that 6.5% SSC was reached, if a common initial SSC was assumed across all sites and seasons. No improvement was obtained if the initial SSC was measured about three months after flowering, rather than assumed. A similar model which used the day of year rather than days since flowering was found to be slightly less accurate. However, all three versions of the model performed better than a linear regression model based on mean temperature for the fruit growth period and the date at which 5.0% SSC was reached.  相似文献   

8.
Summary

Mature boysenberries (Rubus hybrid) were harvested, heat-treated (45°C for 1 or 3 h or 47°C for 1 h) or exposed to UV-C light (2.3, 4.6 or 9.2 kJ m–2), and stored at 20°C for 2 d. Fruit treated with 9.2 kJ m–2 or 45°C for 1 h showed less damaged drupelets per fruit and/or remained firmer than untreated fruit after 2 d. Those treatments were selected for further analyses. In another experiment, boysenberries were either UV-C (9.2 kJ m–2) or heat-treated (45°C for 1 h) and stored either at 20°C for 1 d or at 0°C for 4 d before transfer to 20°C for 1 d. Both UV-C and heat treatments reduced softening and/or fruit damage. Treated fruit had lower respiration rates and anthocyanin leakage than control fruit suggesting greater tissue integrity. Titratable acidity, pH, total sugar content and antioxidant activity in treated fruit showed fewer changes than in control fruit when stored at 20°C for 1 d. Results suggest that heat or UV-C treatment, alone or in combination with refrigerated storage, may be a useful non-chemical mean of maintaining boysenberry fruit quality and extending postharvest life.  相似文献   

9.
Summary

Several pre-storage time (0, 1, 2, 4, and 6 d) and temperature (3.5º, 10º, 15º, 20º, 25º, and 30ºC) delayed cooling (DC) treatments were tested on harvested ‘Honeycrisp’TM apples to determine which combination was optimal for reducing soft scald and low temperature breakdown (LTB), while maintaining the highest fruit quality [i.e., firmness, minimal mass loss, titratable acidity (TA), soluble solids content (SSC), absence of rot, and minimal skin greasiness] after 4 months of refrigerated air (RA) storage. Fruit were harvested from three separate Annapolis Valley (Nova Scotia) orchard sites in 2006 and in 2007. Multiple linear regression and surface response curves showed that fruit firmness and SSC generally increased throughout the DC treatment, but were affected curvilinearly by temperature, reaching a maximum at approx. 15ºC, then declining. Loss of fruit mass was positively related to a (day temperature2) interaction, indicating that it increased synergistically the longer and the warmer the DC treatment. Fruit acidity was affected only by temperature, with the highest TA values at approx. 15ºC, then declining at higher DC temperatures. Multiple logistic regression and surface responses demonstrated that the incidence of soft scald declined curvilinearly the longer and the warmer the DC treatment, while LTB declined curvilinearly with increasing DC temperature only. A positive (day2 temperature2) interaction indicated that fruit greasiness increased non-linearly as the duration and temperature of DC increased. Collectively, these results show that both soft scald and LTB were suppressed or eliminated by a DC regime of 25ºC for 1 – 2 d, or 30ºC for 1 d, without incurring a major reduction in fruit quality.  相似文献   

10.
Summary

The effects of storage temperature on quality and physiological responses in Chinese bayberry fruit (Myrica rubra Sieb. and Zucc. cv. Wumei) were investigated. Freshly harvested bayberries were stored at 20°C, 10°C, or 1°C for 60 h, 5 d, or 14 d, respectively. The rates of respiration and ethylene production, fruit firmness, total sugars, organic acids, and total soluble solids (TSS) contents, total titratable acidity (TA), pH, relative electrical conductivity (REC), and polyphenol oxidase (PPO) activity of fruit were measured during storage. The results showed that the rates of respiration and ethylene production decreased during storage, and that their values were lowered significantly by decreasing the storage temperature. Low temperatures maintained higher TSS contents, TA, and fruit firmness and inhibited any increases in pH, REC, and PPO activity in bayberry fruit. There was a significant decline in citric acid and sucrose contents during storage, with a more rapid decrease occurring at higher temperatures. The data obtained indicate that cold storage is an effective way to maintain quality and chemical components in Chinese bayberry fruit.  相似文献   

11.
Summary

Tomato plants (Lycopersicon esculentum (L.) Mill. cv. F144) were irrigated with low concentrations of mixed salts; the highest level (E.C. 7 dS m–1) simulated conditions used to produce quality tomatoes in the Negev highlands. CO2 enrichment (to 1200.mmol mol–1, given during the daytime) increased plant growth at the early stage of development. However, later growth enhancement was maintained only when combined with salt stress. In the absence of CO2 supplementation, overall growth decreased with salt (7 dS m–1) to 58% and fresh biomass yields to 53% of the controls. However, under elevated CO2 concentrations total plant dry biomass was not reduced by salt stress. CO2 enrichment of plants grown with 7 dS m–1 salt increased total fresh fruit yields by 48% and maintained fruit quality in terms of total soluble salts, glucose and acidity. Fruit ripening was about 10.d earlier under CO2 enrichment, regardless of salinity treatment. It is suggested that a combined utilization of brackish water and CO2 supplementation may enable the production of high-quality fruits without incurring all the inevitable loss in yields associated with salt treatment.  相似文献   

12.
Summary

Single-truss tomato plants grown hydroponically (wet-sheet culture) were exposed to a salinity (EC) of 5.0 dS m21 or 8.0 dS m21 at two fruit ripening stages, the immature green stage and the decolouring stage. These salinities were achieved by adding NaCl to the standard solution, which had an EC of 2.4 dS m21. Increased salinity at the immature green stage improved fruit quality more than increased salinity at the decolouring stage but decreased fruit yield more. The reduction in fruit yield was due to a decrease in fruit weight but not in fruit number. Salinity increased the concentration of soluble solids, citrate, ascorbic acid, K, chlorophyll a, chlorophyll b, lycopene, and carotene in the fruit, but the absolute amount of these constituents per fruit was decreased or not affected. These results suggest that the improvement in fruit quality induced by the salinity is caused by the reduction of water import into the fruit. The effectiveness of both salinities was significantly bigger when it was applied at the earlier development stage, suggesting that mature fruit would be less sensitive to strength of the EC.  相似文献   

13.
Summary

The potential effect of a hydrodispersion of maltodextrin, carboxylmethylcellulose, propylene glycol and sorbitan esters, on the reduction or prevention of spoilage caused by the fungus Colletotrichum gloeosporioides which produces anthracnose and by the fruit fly Anastrepha oblicua, was investigated as a coating for mango (Mangifera indica cv. Manila) fruit from commercial orchards in Jalcomulco, Veracruz, México. Coated and control mangoes were stored at 15 and 25?C and 85±5% r.h. Every 3 d, the coating was removed by washing with water, to determine the time necessary to minimize the damage caused by the anthracnose and the fruit fly larvae. In uncoated mangoes, larval growth and anthracnose manifestation occurred within 6 d at both storage temperatures. In coated mangoes, fruit fly larvae proliferation was avoided and anthracnose incidence was reduced. The results suggested that coatings should be remained for 9 d to avoid fruit fly larvae proliferating and minimize anthracnose incidence by 70%. Applying coatings may be part of a set of superficial treatments to guarantee the phytosanitary certification of tropical fruits such as mangoes.  相似文献   

14.
Summary

The compound benzo-(1, 2, 3)-thiodiazole-7-carbothioic acid S-methyl ester (BTH) effectively induces a systemic acquired resistance (SAR) response in plants and increases plant resistance to disease. To learn how BTH may affect post-harvest quality and disease resistance in peach, (Prunus persica L. cv. ‘Jiubao’) peach fruit were treated with 200 mg l–1 BTH for 5 min immediately after harvest, then incubated for 60 h at 20°C, 85–95% RH. Sixty h after treatment, fruit were inoculated with spore suspensions of Penicillium expansum at 1.2 104 CFU ml–1. The incidence of disease and lesion areas on peach fruit were significantly reduced by BTH-treatment (P < 0.05). In addition, chitinase and -1,3-glucanase activities in peach fruit were significantly enhanced by BTH-treatment (P < 0.05). Moreover, the total levels of phenolic compounds and chlorogenic acid, and the lignin content of BTH-treated fruit were significant higher than in control fruit (P < 0.05). The effects of BTH on fruit quality were also analysed. Soluble solids content, soluble pectin, titratable acidity and ascorbic acid levels in peach fruit were not significantly affected by treatment with BTH. Our results suggest that the application of BTH may control post-harvest diseases in peach fruit during commercial production.  相似文献   

15.
Summary

The influence of growing season on some physiological and biochemical variates related to fruit yield and quality was investigated in melon (Cucumis melo L.) plants cultivated in nutrient film technique in a greenhouse located at Pisa, Central Italy, from mid-March to mid-June, or from mid-July to mid-September. Compared with spring, the plants grown in summer exhibited faster growth and development, but produced fewer fruits of larger size and poorer quality due to reduced sucrose content. Growing season did not affect total leaf area, but dry-matter production and partitioning to the fruits was significantly lower in summer than in spring. Summer fruit ripened within 30–35 d after anthesis, about 14 d fewer than in spring. Higher average temperature was presumably responsible for earlier fruit maturation in summer, as in both seasons all melons were harvested after 450–500 degree-days (base temperature of 12°C) from anthesis. Fruit swelling did not account for the reduction of sucrose content in summer-grown fruits, which instead was due to shortage of photoassimilate supply and inadequate sucrose synthesis, as suggested by the rate of leaf gas exchange and the activity of sucrose phosphate synthase in the fruit flesh, as determined during the final stages of fruit development. Lower solar radiation was presumably responsible for the reduced leaf carbon assimilation in summer, as growing season did not affect leaf turgor, stomatal conductance, mineral status and chlorophyll content.  相似文献   

16.
Summary

Studies were conducted to evaluate the effects of drought during flowering for both container- and field-grown trees, and during fruit development for container-grown trees, on subsequent growth, flowering, yield and quality of the custard apple ‘African Pride’ in subtropical Australia. Moderate drought (ψL=–1.5 MPa) reduced shoot growth by 20–30% and increased the number of flowers per lateral by about 40% compared with well-watered controls due to reduced apical dominance and increased lateral branching. Overall fruit set was not adversely affected by drought. Drought also increased the number of fruit harvested per tree by 47% compared with well-watered controls. This response was mainly due to the increase in flower number per tree. Drought reduced average fruit size by 11% possibly due to effects on cell division in the first 4–6 weeks after fruit set or on net carbon assimilation. In summary, mild to moderate drought during the flowering period and fruit set increased flowering without adversely affecting fruit set, but decreased fruit size.  相似文献   

17.
Summary

‘Anjou’ pears were harvested from the Mid-Columbia Experiment Station, Hood River, Oregon, at 67 N firmness, stored at –1° or 20°C for 85 d and periodically tested for sensitivity to 0 or 500 µl l?1 propylene for at least 14 d at 20°C. Climacteric ethylene of pears stored at 20°C remained at low levels and started rising on the 90th day. Pears chilled at –1°C required 70 d to ripen and produced climacteric ethylene immediately upon transfer to 20°C. The sensitivity of the fruit to exogenous propylene increased progressively with storage time at –1°C. However, the non-chilled fruit responded to propylene similarly to freshly harvested fruit during the first 55 d of storage, then similarly to –1°C-stored fruit up to 85 d. Anjou pear ripening events and the sensitivity of the fruit to exogenous propylene developed differently in storage at non-chilling temperature compared with chilling temperature.  相似文献   

18.
Summary

The roles of self- versus cross-pollination and honey bee (Apis mellifera L.) foraging behaviour in low nut yield of cashew (Anacardium occidentale L.) were studied in NE Brazil in 1997 and 1998. It was shown that both self- and cross-pollination can set fruits in cashew, but most of fruits originating from self-pollination are shed 9–15 d after pollination, and fruits harvested are primarily from cross-pollination. Honey bees display foraging behaviour in cashew orchards conducive to cross-pollination, but in plantations originating from clonal material they failed to increase fruit yield despite cashew's dependence on insect pollination. It is concluded that cashew has a mechanism of selective abortion through which it discards self-pollinated fruits and that honey bees can contribute to increased fruit yield only when cashew trees of genetically diverse origin are found in the same orchard.  相似文献   

19.
Summary

Kiwifruit vines (cv. Hayward) were shaded from early spring until fruit harvest at levels of 100% (control), 70% or 45% full sun. Although shoot growth during the early part of the season was not significantly affected by the shading, the percentage bud burst was reduced and the time of full bloom appeared to be slightly delayed. The mean fresh weight of individual fruits was significantly reduced by shading, and fruit on shaded vines reached commercial harvest maturity of 6.2% soluble solids two to three days later than those on unshaded vines. During cool storage, fruit from vines grown under 45% full sun were slightly but consistently less firm and had lower soluble solids concentrations than unshaded fruit. No differences in the starch or total sugar contents were found between shaded or unshaded fruit, either at harvest or after cool storage. Shading vines did not affect either the colour (HunterLab values) or the chlorophyll concentration of fruit. Possible implications of these results for commercial orchards are discussed.  相似文献   

20.
Summary

Changes in fruit weight, total soluble solids (TSS), sugar content and postharvest ethylene production during fruit development were compared on fruit of cherimoya (Annona cherimola Mill., cv. Big Sister) pollinated at different times (early, at the beginning of April, 1995 and late, at the end of May, 1994). Fruit weight increased by growth, independently of pollination times. Changes in TSS and sugar content were strongly affected by pollination time. In late pollinated fruits, both TSS and sugar content increased during the growth period, 110–160 d after pollination, while neither increased with fruit growth in early pollinated fruit. Moreover, changes in TSS and sugar content after ripening depended not only on pollination time but also on the growth period. With late pollination, fruit harvested after 140 d became edible after ripening. The TSS and total sugar contents, (the sum of fructose, glucose and sucrose contents) increased to about 20° Brix and above 16%, respectively. But early pollinated fruits were not edible after ripening, since total sugar content increased only to about 7%, even though they kept growing for 160 d on the tree. The maximum rate of ethylene production declined and the number of days to the ethylene peak from harvest is also reduced with growth in both cases. These changes were closely correlated with days after pollination (r>0.9) regardless of pollination time. Comparisons of accumulated temperature suggest that temperature at pollination time and during the resting period of growth affected fruit development. These results indicate that neither fruit weight nor number of days after pollination is a suitable index for harvesting time.  相似文献   

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