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1.
Summary

For maximum yield of processing tomato by once-over mechanical harvesting, an optimum date for harvest has to be selected at the time when the factory-graded fruit yield is at its maximum. By recording the proportion of green, ripe (i.e. turning and red) and rotten (i.e. over-ripe and damaged) fruit over a period of about 20 d, the optimal harvest date can be identified. Based on observations taken from crops at four sites in the Mediterranean region over three years (1997-1999), the proportional change of fruit types (i.e. percentage total fruit weight) has been found closely related to the accumulation of daily maximum temperature (x, °Cd) during crop maturation. The change of percentage green fruit was y = 6172 l0–8 x2 – 768 l0–4 x + 25 (R2 = 0.882). Over the same period, the change in percentage ripe fruit was described less satisfactorily by y = – 12588 l0–8 x2 + 867 l0–4 x + 65.7 (R2 = 0.568). When heat units were calculated based on the daily maximum and minimum temperatures by six well-known methods, it was found that the reduction in percentage green fruit was significantly related to the sum of heat units calculated by all methods. The maximum percentage ripe fruit, about 80% of the total fruit weight, occurred soon after the percentage green fruit was equal to the percentage rotten fruit, both around 10% of total fruit weight.Therefore, the heat units required to reduce the green fruit from 25% to 10% of total fruit weight, calculated by different methods, can be used to predict accurately the optimal harvest date based on the accumulation of ambient temperature. In a range of likely temperature regimes, 7–9 days prediction for optimal harvest date can be made. However, the simplest method based on daily maximum temperature alone is as accurate as all the more complex methods and is likely to find wider application in the processing tomato industry.  相似文献   

2.
Fruit pigmentation in ripening cv. Gala, Schniga’ apples was monitored under the influence of fertigation weekly during 21 July–31 August 2009, i.e. 34 days before and 7 days after the optimal harvest date in Slovenia. The soil was a heavy loam clay with high humus content (2.8 %) and high acidity (low pH 4.9). The spectral indices NDVI (Normalized Difference Vegetation Index) and NAI (Normalized Anthocyanin Index) were obtained by a PA 1101 on attached fruit on the transition between the ground and blush colour of the fruit surface. NAI increased slowly from 0.25 to 0.6 two weeks prior to optimum maturity. NDVI values fell from 0.9 to 0.2 before and during ripening, with significant changes starting ca. 3 weeks before and during the week after the optimum harvest date. Fertigation delayed fruit ripening viz harvest date by ca. 4 days. Fertigation delayed changes in the intensity of the fruit’s epidermal pigments, expressed as NDVI for 1 week and NAI for 4 weeks, respectively, but had no significant effect on fruit colour or NDVI and NAI values at the optimal harvest date. At this time, those fruits from the fertigated trees were firmer with a lower starch index compared with the un-fertigated control. Statistically, highly significant correlations were found (p?≤?0.01) (r?=?0.35 to r?=?0.91, R2?=?0.11–0.83) between all the studied spectral and standard parameters i.e. fruit fresh firmness, soluble solids content and starch index.  相似文献   

3.
The influence of nectarine cultivar and the harvest date on fruit colour, fruit size, fruit quality parameters, and consumer acceptance were assessed. The analyses were carried on cultivars with different fruit taste (acidity and sweetness), from 5-years-old trees at the IRTA-Experimental Station of Lleida (Spain). The six cultivars were grouped in three pairs in which each had a similar commercial harvest date. Each pair comprised by a non-acid cultivar and an acid cultivar, except the pair of ‘Big Top®’ and ‘Mesembrine®’, which included two non-acid cultivars. The nectarines were harvested at 8 days intervals on five harvest dates, three of which were before the commercial harvest date, one at commercial harvest and another 1 week after commercial harvest.  相似文献   

4.
Summary

To determine the anatomical basis for differences in fruit size in Japanese persimmon (Diospyros kaki Thunb.), the number and sizes of parenchymal cells were measured in four astringent cultivars and in wild D. lotus over a single season in Japan. Fruit weight at harvest correlated with the final number of parenchymal cells (r = 0.95*) and their size (r = 0.92*). There was also a correlation between fruit diameter and the number of cell layers at full bloom (r = 0.93*), which increased 1.7 – 1.9-fold during fruit development.The duration of cell division and the sizes of the cells at full bloom were similar among the cultivars, whereas mean parenchymal cell lengths increased by 7.7-, 6.7-, 5.4-, 5.0- and 3.8-fold from full bloom to harvest in ‘Otanenashi’ (average fruit diameter = 96 mm), ‘Hiratanenashi’ (77 mm), ‘Saijo’ (54 mm), ‘Tsurunoko’ (44 mm), and D. lotus (20 mm), respectively. The final size of tannin cells was larger in ‘Otanenashi’ and ‘Hiratanenashi’ than in the other cultivars, including the wild species.These results indicate that the size of fruit at harvest was determined by the number of cells at full bloom, and their expansion during fruit development.  相似文献   

5.
Abstract

1-Methylcyclopropene (1-MCP), an ethylene action inhibitor, was applied to ‘d’Anjou' pears (Pyrus communis L.) at 20°C between 2 and 5 days after harvest. Scald of ‘d’Anjou' pears was completely controlled by 1-MCP at a concentration between 0.05 and 0.3 µl l1 after a prolonged cold storage plus 7 days of exposure to an environment with or without 500 µl l1 ethylene at a temperature of 20°C or 25°C. 1-MCP inhibited the biosyntheses of α-farnesene and its oxidative products (conjugated trienes) and thus controlled scald. However, fruit treated with the above concentrations of 1-MCP did not ripen normally in an environment with or without ethylene. Ethylene production and fruit softening of 1-MCP-treated ‘d’Anjou' pears were inhibited during 7 and 15 days at 20°C. ‘d’Anjou' fruit treated with 0.01 and 0.02 µl l1 1-MCP ripened normally on day 7 at 20°C after 3 months of cold storage at ? 1°C, and ripened fruit did not develop any incidence of scald. Untreated fruit developed substantial scald. After 4 months of storage or longer, both untreated fruit and fruit treated with 0.01 and 0.02 µl l 1 1-MCP developed an unacceptable incidence of scald upon ripening. Thus, use of other scald control methods may be necessary in addition to treatment with a low dosage of 1-MCP to insure both normal ripening and scald control for d'Anjou pear fruit from the Mid-Columbia district.  相似文献   

6.
Summary

Pears (Pyrus communis L. cv. Conference) were picked 7 d before (27 d), during (0) or 7 d (+7 d) after the estimated ideal time for commercial harvest. Changes in antioxidant content (ascorbate and glutathione) and in the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), total peroxidase (POX), ascorbate peroxidase (APX) and glutathione reductase (GR) were estimated immediately after harvest for each picking time. Ascorbate and non-protein thiols (glutathione) content significantly decreased with increasing maturity. Concommitantly, the activity of SOD and CAT fell about five-fold and two-fold, respectively, when the fruit was picked more mature, indicating a higher potential for the accumulation of cytotoxic O2.2 and H2O2 respectively. POX activity remained relatively constant until the optimal harvest date but increased later. APX activity increased 2.5-fold in the more mature fruit but GR remained stable. Collectively, these results provide evidence that harvest date is accompanied by a decline in the non-enzymic and enzymic systems responsible for catabolism of active oxygen species. This may contribute to explain the widely described influence of harvest date on the occurrence of physiological disorders in pears.  相似文献   

7.
Cucumber fruits (Cucumis sativus L., cv. Trópico F1) grown on perlite substrate and NFT (Nutrient Film Technique) were harvested during two seasons (winter and spring) to monitor the effects of climatic conditions and hydroponic growth systems on fruit quality at harvest. The best fruit quality at harvest, as measured by lightness and hue angle parameters, was obtained during the 3 weeks following the first winter picking. When values of a parameter of preharvest climate value called G* were lower than 0.4 MJ m−2 °C day−1 interval−1, the cucumber achieved its optimum quality at harvest, as measured by the dark green color of the skin. NFT-grown fruits showed darker and greener skin color (higher hue angle and lower lightness) compared with perlite-grown fruit, irrespective of the season considered. During the winter season, the plant transpiration rate was 30% higher in perlite than in NFT culture, which correlates with higher differences in G* and 40% additional yield in perlite. However, in spring G* was not sensitive enough to discriminate between the two hydroponic systems. In general, fruit quality at harvest in spring was lower than during the winter, due to flesh whitening, higher longitudinal and equatorial calibers, and slightly higher pH, as well as worse epidermal color coordinates (ranging from the dark and dull green color typical of winter fruit to light and a vivid green-yellow color). During the spring season, NFT-grown fruit were less acid than perlite-grown fruit with no apparent correlation with the climatic conditions or fruit nutrition.  相似文献   

8.
Information available on the role of site and fruit maturity in the quality of European plums in organic production has not been studied to date. European plum cv. ‘Green Gage’ grown in organic production was harvested in order to study the effect of site and fruit maturity on fruit quality. At harvest, significant differences were found in fruit weight, colour, firmness and TSS between harvest dates, whereas significant differences were found in fruit weight, colour, firmness and fruit Ca content between sites. Differences remained during storage. Fruit weight loss during storage was affected by site. Fruit with high Ca content showed higher firmness both at harvest and during storage. Harvest moment should not be chosen according to date, since differences between sites at the same date have been found. Firmness and colour parameters a* and h° would be useful to distinguish maturity at harvest between different sites and harvest dates. Linear regression between h° and firmness at harvest would allow the use of the h° colour parameter as a non-destructive measurement to distinguish maturity. Organic orchards should keep a minimum level of Ca in order to assure a slower fruit softening during storage.  相似文献   

9.
The present study was conducted to investigate the effects of pre-harvest aminoethoxyvinylglycine (AVG) treatments on fruit quality parameters and bioactive compounds of sweet cherry fruits (Prunus avium L. cvs. ’0900 Ziraat’, ‘Regina’ and ’Sweetheart’). Whole trees were sprayed once with an aqueous solution containing AVG (0, 100 and 200?mg L?1) three weeks before the anticipated commercial harvest. Measurements were performed a week before anticipated harvest date, at anticipated harvest date and a week after anticipated harvest date. AVG treatments significantly maintained flesh firmness of all three sweet cherry cultivars. Harvest was delayed at least for a week through the keeping of flesh firmness with AVG treatments. The treatments slowed down the red skin color development in all three cultivars. The measurements performed over fruits collected at different ripening stages revealed that AVG resulted in decreased total phenolics and total anthocyanin and ultimately decreased antioxidant capacity in sweet cherry fruits. AVG treatments also decreased soluble solids content and increased titratable acidity of the fruits. This study revealed that pre-harvest AVG treatments were more effective in delaying sweet cherry fruit softening. The main advantage is to maintain the firmness of late-harvested fruit by retaining fruit quality attributes of sweet cherry fruit.  相似文献   

10.
14 C distribution patterns were studied on small potted trees under glasshouse conditions by supplying 14 CO2 to selected source leaves for 24 hours and then preparing autoradiographs of the entire shoots. Experiments covered the period from the emergence of new growth, through flowering and fruit-set, up to the stage of fruit maturity.

Newly emerged growth drew 14 C assimilates from both current photosynthesis and stored substrate. Developing leaves represented strong sinks and did not become contributing organs until fully mature. Flowers also represented uniformly strong sinks for assimilates although after fruit-set some discrimination existed between adjacent fruitlets with respect to their ability to import assimilates. The developing fruit continued to act as sinks for assimilates up to the time of harvest.

14 C assimilate turnover in mature leaves following a brief exposure to 14 CO2 was sluggish, despite the presence of developing shoots in the leaf axils. The removal of 14 C photosynthate was still incomplete after 38 days in the glasshouse.  相似文献   

11.
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   

12.
Summary

Experiments were conducted on lychee (Litchi chinensis Sonn.) in subtropical Australia (lat. 27° –29°S) to evaluate the role of assimilates on fruit retention. All the leaves of the last flush, all the leaves of the previous flush (about eight leaves per terminal shoot), or all the old leaves were removed from trees. Medium (3–5.cm diameter) or large branches (5–10.cm diameter) were girdled and defoliated after fruit set, and fruit retention compared with ungirdled and undefoliated branches. Other branches were girdled and defoliated between anthesis and fruit harvest. Finally, 20, 50 or 80% of the flowering panicles were defruited on large trees. Defoliated trees had 35 to 45% lower yields than the controls. This was despite the treatment with all the old leaves removed having a much lower leaf area index than the other defoliation treatments (1.7 vs. 2.3 and 2.8). Leaves next to the inflorescences are more important for yield than the older leaves. Fruit retention was very low on girdled branches that had been defoliated, especially when the leaves were removed in the first 20.d after anthesis. This suggests that the yields of girdled branches were determined by the availability of assimilates soon after fruit set. In contrast, the number of fruit retained on ungirdled branches was unrelated to the number of leaves, with defoliation having no effect on yield. Fruit on these branches were supported by resources from elsewhere in the tree. Thinned trees had similar yields to those of unthinned plots (65–82.kg tree–1). Thinning apparently increased fruit retention in the remaining clusters, under a higher leaf:fruit ratio. There were large differences in the concentrations of starch in the tree, and seasonal changes, with starch declining from flowering to fruit harvest. In contrast, there were only small responses to the treatments, suggesting that the fruit were mainly dependent on current photosynthesis. Photosynthesis in the leaves behind the fruit clusters was more important than photosynthesis in the older shaded leaves.  相似文献   

13.
《Scientia Horticulturae》1986,28(3):271-279
The post-harvest development and senescence of cut waratah inflorescences (Telopea speciosissima R.Br.) held at 20° C is described. Individual flowers of the raceme opened and after 4 or more days the perianth abscised, wilted and changed color from bright red to blue-red. The end of vase life was defined as a readily discernible wilting and blueing of either flowers or of the bracts which subtend the inflorescence. During vase life the fresh weight, water content and anthocyanin concentration of both flowers and bracts decreased. Water uptake by the whole inflorescence decreased, the cumulative nett water loss increased and the fresh weight of the inflorescence decreased. Ethylene production by flowers increased to a maximum and then declined, while the low ethylene production by bracts slowly decreased. Vase life was extended from 7.9 to 11.7 days when the vase water was treated with chlorine bactericide (sodium dichloroisocyanurate, 25 mg l−1 available Cl). This increased vase life was accompanied by increased water uptake, decreased nett water loss, and a slower rate of decrease in flower and bract fresh weight and water content. Vase life was also extended by early harvest, when 6% of individual flowers were open rather than 48%. It was concluded that decreased water uptake and flower abscission were the major physiological factors which limited vase life.  相似文献   

14.
晋萍  程斐  刘荣  刘伟  孙修堂 《中国蔬菜》2010,1(12):80-82
奥林618是用耐贮硬肉型番茄自交系61-3-18-15为母本,68-5-3-1为父本配制成的耐贮型番茄一代杂种。早熟性好,始花节位第8节左右。坐果率高,定植后60~65 d(天)收获,可连续采收7~14穗果实,以留7穗果计算,平均露地产量7 000~8 000 kg·(667 m2-1,保护地可达10 000 kg·(667 m2-1以上;果面光滑,大红色,亮度好,平均单果质量200 g左右,果形指数0.78,果肉厚0.9 cm,无绿肩,转色快且均匀;耐低温弱光、耐高湿;高抗晚疫病,中抗青枯病;耐贮运,常温下货架期达20~25 d(天)。适宜北方地区日光温室春提前、秋延后栽培以及南方地区露地越冬栽培和部分地区高山越夏栽培。  相似文献   

15.
The fig tree (Ficus carica L.) is widely cultivated in the Mediterranean region under warm climates. Fig yield is governed by the previous crop load and is strongly dependent on shoot length. Special cultural practices are required to stimulate new vegetative growth that will ensure regular and high productivity. The present study focused on the use of the rest breaking agent hydrogen cyanamide (HC) as Dormex to enhance vegetative growth, which influences the yield. A field trial was held in northern Tunisia (36° 49′ N; 9° 48′ E) on mature fig trees cv. Zidi. In reference to untreated trees as control, two hydrogen cyanamide treatments at 1% and 1.5% HC were considered. Bud break rate, vegetative growth, starch content of shoots, yield, and fruit characteristics were assessed. Results indicated that 1.5% HC significantly increased shoot length, fruit number per shoot, and yield. It advanced bud break by 10 days and fruit ripening by 7 days compared to the control. However, leaf number, leaf area, and starch content seem to be unaffected by hydrogen cyanamide treatments. Regarding fruit quality, a 1.5% HC dose significantly increased dry matter content, while fruit diameter and total soluble solids remain unaffected. In conclusion, hydrogen cyanamide could be used under warm conditions to improve vegetative growth of fig trees cv. Zidi and consequently fig productivity. Application of 1.5% HC 40 days before bud break was the most effective in increasing shoot length and yield.  相似文献   

16.
Summary

Spurs of ‘Nijisseiki’ pear (Pyrus pyriflora Nakai) were allowed to assimilate 10033;CO2 at 87.d after anthesis (DAA) and at 108 DAA during the period of rapid fruit growth. Then the spurs were sampled periodically until fruit harvest time to trace the time course and amount of movement of assimilates from spur leaves to individual organs in the spur. The amount of 10033;C absorbed by fruit within 3.d after labelling was constant until harvest, regardless of the labelling date. However, the total amount of 10033;C in the spur decreased continually until harvest.Of the total amount of 10033;C recovered in the spur labelled at 87 DAA, by harvest, 43.2% of 13C was found in the fruit flesh (cortex of receptacle), 5% in the core (pith of receptacle 1 pericarp 1 seeds), 5.6% in spur stem, 5.4% in the source leaves, and 40.8% was respired and exported from the spur. Of total amount of initial 10033;C labelled at 108 DAA, at harvest, the proportion of 10033;C translocated to flesh, core, stem, respired, and remaining in leaves was 61%, 6.1%, 3.0%, 24% and 5.4%, respectively. Photosynthates fixed by the spur early in the rapid growth stage of the fruit contribute more to the formation of starch and structural materials and less to solublecarbohydrates in fruit than do those fixed later.  相似文献   

17.
Nitrogen supply can improve crop growth and yield. An over-use of nitrogen fertilizer in greenhouse crop productions, however, causes many environmental problems. The aim of this study was to quantify the effects of nitrogen on fruit growth and yield so as to facilitate the optimization of nitrogen management for cucumber (Cucumis sativus) crop in greenhouses. Four experiments with different levels of nitrogen treatments, substrates and planting dates on cucumber (cv. Deltastar) were conducted in greenhouses located at Shanghai during 2005 and 2007. Using data of one experiment, seasonal time courses of leaf nitrogen content (NL), leaf area per plant (LA), and the number of fruits growing per plant (nFG), as well as time course of the length of individual fruit growing on the plant (LF(i)) under different levels of nitrogen supply conditions were, respectively, determined as functions of a photo-thermal index (PTI). The impact of NL on LA was determined by curve fitting to the experimental data. The source/sink ratio (LA/nFG), an indicative of the source size per fruit, was then derived from the seasonal time courses of LA and nFG. The impact of NL on LF(i) was indirectly quantified by the relationship between source/sink ratio (LA/nFG) and the elongation rate of individual fruit (RFL(i)). Both the harvest date and fresh weight (WF(i)) of individual fruit growing at different node, and number of harvested fruits (nFH) were then calculated as functions of the fruit length. These quantitative relationships were assembled to form a model for predicting the effects of nitrogen on fruit growth and yield (fruit fresh weight per plant). Independent data from other experiments were used to validate the model. Our model gives satisfactory predictions of cucumber fruit growth and yield under different levels of nitrogen supply and growing season conditions. The coefficient of determination (r2) and the relative root mean squared error (rRMSE) between the predicted and measured values are, respectively, 0.92 and 0.22 (r2, rRMSE) for leaf area per plant, 0.90 and 0.24 for the number of fruits growing on the plant, 0.91 and 0.22, 0.90 and 0.23, and 0.92 and 0.21, respectively, for the length, harvest date and fresh weight of individual fruit growing on the plant, 0.94 and 0.20 for yield. The model may be used for the optimization of nitrogen management for cucumber production in greenhouses. Further model calibration and test would be needed when applying this model to a wider range of conditions.  相似文献   

18.
Summary

A factorial combination of three cultural factors (± hand-pollination, ± growth retardant, ± fruit thinning) were evaluated for their effects on fruit set and fruit size of ‘Fuyu’ persimmon (Diospyros kaki L.) in subtropical Australia (Lat. 27° S). Treatments were applied to individual shoots on mature seven year old trees. Fruit set of pollinated flowers was high compared with non-pollinated flowers (91% vs. 47%). Pollinated fruit also grew faster at all stages of fruit development and, at harvest, fresh weights were 25% heavier. Palcobutrazol significantly (P<0.05) increased fruit weight by 7% compared with controls but did not increase fruit set. Irrespective of treatment, fruit weight was not correlated (r<0.3, n.s.) with shoot length, number of nodes per shoot, fruit nodal position, shoot dry weight, leaf area per shoot, and number of leaves per shoot. Fruit fresh weight was only poorly correlated with shoot base diameter (r = 0.41*). Pollinated fruit had significantly (P<0.05) higher concentrations of nutrients (N, K, Ca, and Zn).  相似文献   

19.
Plants of ‘Glasa’ were forced early in growth rooms at 14°C under a 16-hour day consisting of 8 hours of mercury light, light intensities 12, 24 or 36 W m?2, supplemented by 8 hours of incandescent light, intensity 0.8 W m?2. Light intensity affected the flowering-date, the number of inflorescences, the number of flowers per inflorescence, stamen development and fruit set. For successful forcing, a light intensity of at least 24 W m?2 is necessary.  相似文献   

20.
Summary

The effect of Pichia membranefaciens on reducing post-harvest anthracnose rot caused by Colletotrichum acutatum in loquat fruit was investigated. Fruit were treated with different suspensions of P. membranefaciens before challenge with 1.0 105 spores ml–1 of C. acutatum, then incubated at 20°C for 6 d. The results showed that 1 108 colony-forming units (CFU) ml–1 of washed cell suspensions of the yeast provided better control of anthracnose rot than yeast in culture broth at the same concentration. Treatment with autoclaved cell cultures or culture filtrates did not prevent the incidence of disease. The concentration of a washed cell suspension of P. membranefaciens had a significant effect on the efficacy of controlling anthracnose rot in loquat fruit. At a concentration range from 1 106 to 1 109 CFU ml–1, the higher the concentration of the antagonist, the lower the incidence of the disease and the smaller the diameter of the lesions. In inoculated wounds of loquat fruit, populations of P. membranefaciens increased approx. 34-fold after 6 d of incubation at 20°C.Washed cell suspensions of P. membranefaciens also significantly inhibited spore germination and germ-tube growth of C. acutatum, in vitro. These results suggest that P. membranefaciens has potential as a biocontrol agent to reduce post-harvest decay caused by C. acutatum in loquat fruit.  相似文献   

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