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1.
There were 6 treatments in each of 2 series covering the range from 1–6 fruit trusses per plant. The terminal growing-points were removed 2 leaves above the last inflorescence of each treatment in the “limited-stem” series, and 2 leaves above inflorescence 6 with inflorescences removed as necessary in the “full-stem” series.The yield of trusses 2–5 in the “full-stem” and of truss 2 in the “limited-stem” series was reduced by the presence of subsequent trusses. Similar trends were apparent with trusses 3–5 of the “limited-stem” series. It was suggested that the reduction in yield was due to competition between trusses for assimilates resulting in smaller and/or fewer fruit per truss.Data is presented to suggest that the net assimilation rate in the tomato plant can be reduced due to lack of fruit load and that fruit yield can be limited simultaneously by lack of both source and sink strength.  相似文献   

2.
The responses of January-sown cucumber cvs Farbio and Sandra to day and night temperature during the early post-planting stage (late February to mid-April) were examined in a glasshouse experiment. Three day temperatures (15°, 20° and 25°C) were combined factorially with three night temperatures (10°, 15° and 20°C). Comparisons were also made between two temperature regimes (21°C day: 19°C night and 24°C day: 17°C night) applied during the pre-planting stage (late January to late February) and between two mainstem cropping methods (restriction or retention of mainstem fruits). In the pre-planting stage the 24°C day: 17°C night temperature combination produced plants which were taller, heavier and leafier than those grown at 21°C day: 19°C night. During the first 12 weeks of harvesting the larger plants produced significantly more fruit and higher gross monetary returns than did their smaller counterparts. The difference then diminished and after 20 weeks of harvesting plants from the two pre-planting temperature treatments had produced similar weights of marketable fruit of equivalent value. In the early post-planting period increases in total leaf area and stem length were closely correlated with 24-h mean temperature. Earliness (first harvest) and total weight of fruit after four weeks of harvesting were also linearly related to mean post-planting temperature. Raising the 24-h mean air temperature (within the range 15.2° to 22.6°C) by 1°C during the early post-planting stage increased early (4 week) yield by 0.82 kg m-2 and total (20 week) yield by 1.17 kg m-2. There was no effect of day/night temperature amplitude. After 20 weeks of harvest, gross monetary returns and profitability were generally highest when mean temperature in the early post-planting period was high and fell progressively with reduced mean temperature. Restricting stem fruits to oné per leaf node produced no significant difference in either the yield or quality of fruit from plants of any of the temperature treatments. The results are discussed from physiological and practical viewpoints and a cost-benefit comparison of temperature treatments is presented.  相似文献   

3.
Fruit set was increased by removing all shoots 5 days after full bloom and at weekly intervals thereafter from trees of Sunset and Laxton’s Fortune, but removing shoots from Fortune trees 25 days after full bloom produced no beneficial effect on fruit retention. All treatments resulted in a heavier rate of fruit shedding during the ‘June drop’ period than occurred from control trees, and at harvest the trees without shoots had fewer fruits, and lower yields, than the controls. In a comparison of shoot removal and shoot tip removal starting 15 days after full bloom on Fortune trees, both treatments improved set, but whereas shoot removal caused a heavier ‘June drop’ compared with untreated trees, shoot tip removal increased the number of fruits retained to harvest and produced a yield increase. The difference between the two treatments in their influence on fruit retention, during and after the ‘June drop’, is accounted for by the beneficial effect of a relatively small number of leaves on each tipped shoot. Studies on the pattern of distribution of photosynthates, using 14CO2 and autoradiography, produced results supporting the concept of competition between fruits and shoots and also showed changes in the pattern of assimilate movement brought about by shoot tip removal. It is concluded that competition between fruits and shoots, occurring during blossoming and the following 2–3 weeks, may limit fruit set, but the presence of shoot leaves is beneficial to fruit retention in the later part of the season, particularly during the ‘June drop’ period.  相似文献   

4.
Summary

Young tomato plants were transferred to heated glasshouse compartments on 9 December at a density of 2.04 plants m-2 and grown as a conventional long-season tomato crop. Beginning in either the third, fifth, seventh or ninth week of the year, every other plant was allowed to retain one side shoot so as to increase the effective plant density to 3.06 plants m-2. Control crops were grown throughout at both the initial and the final densities. Two different patterns of taking the side shoots were tested in two sub-treatments: taking the required number of side shoots in four tranches over a period of six weeks was neither significantly better nor worse than taking them in two equal tranches, four weeks apart. The main effect of adding side shoots was to increase the number of fruit harvested per m-2, as compared with a control crop grown throughout at the initial density of 2.04 plants m-2. However, these additional fruit were not harvested until at least 80.d after the first side shoots had been allowed to grow. When side shoots were taken as early as week 3, a high proportion of the marketable fruit were in the preferred size (viz.47to57.mm in diameter, 50 to 90.g in weight, UK grade D) in all harvest periods. Thus, the additional side shoots enabled the crop to bear extra fruit and when the side shoots were taken early, the production of additional fruit coincided with the time when both the quantity of solar radiation incident per day and the concomitant assimilate production were increasing rapidly. Consequently, the supply of assimilates and the numbers of fruit available per m-2 were better matched for the purpose of continually producing fruit of one size. However, the presence of side shoots tended to reduce the number of marketable fruit carried on each truss. The addition of side shoots increased leaf area index and also significantly increased total fruit yield. The increased area of foliage served to shade more fruit from the heating effects of incident solar radiation and a smaller proportion of marketable fruit was downgraded to Class II in all side-shoot treatments. In general, the means of the four successive side-shoot treatments provided a graded series between those of the fixed low-density and the fixed high-density control treatments.  相似文献   

5.
The use of glass-sided boxes and trenches for observing the growth of the roots of glasshouse tomatoes has been investigated. Marked seasonal trends have been found with two varieties in two years. There was a rise to a peak followed by a rapid fall in total root length, due to death and disappearance of the roots, with a subsequent recovery. This trend occurred in all horizons of soil.

Growth of the stem and leaves was relatively steady from planting-out (March) until mid-May, when there was a slight decrease with subsequent recovery until the main stem and laterals were “stopped” in July.

The number of flowers per truss was high in the bottom five or six trusses, in which fruit set was high, fell in the median trusses which had low set, and rose in the uppermost trusses accompanied by increased set. The resulting production of fruit weight was high in the bottom trusses and low in the top.

The peak of root length development coincided with the swelling of the fruit in the bottom trusses; a trough occurred when the number of flowers per truss and the number set were low, and root length recovered when the first trusses were picked.  相似文献   

6.
The individual growth rates of the first five tomato fruits on 25 trusses of similar age within a crop grown in commercial glasshouse conditions were assessed from anthesis to ripening during April and May. Final size of fruit at ripening was proportional to the maximum rate of increase in fresh weight, about 40 d after anthesis, and related to the maximum rate of increase in diameter, between 15 and 20 d after anthesis, even though ripe fruit fresh weight varied from 20 g to over 100 g. On any one truss these fruit ripened within the same week, regardless of fruit size and prevailing growth rate. These findings suggest that final size was related to the peak fruit growth rate rather than the duration of development. A high growth rate late in development did not delay fruit ripening. The implications for recent continuous measurements of the diameter growth rate in young fruit are discussed.  相似文献   

7.
A schedule was devised to produce glasshouse strawberries from December to March, which is a period when few English strawberries are on the market. In an experimental test, fruit of good quality was obtained at the times planned. Gross yields from ‘Red Gauntlet’ were approximately 50 % greater than those from ‘Glasa’ and the respective marketable yields were 67 % and 60 % of gross yields. Total crop weight increased linearly with the lateness of the season, while average fruit size decreased, also linearly. Yields per plant were variable, the greatest being more than double the average, and were correlated with the number of flowers and number of trusses.  相似文献   

8.
Summary

The effect of leaf area index (LAI) on canopy growth, light interception, yield, fruit growth and quality and return bloom of kiwifruit were examined in 1990 and 1991. Different LAIs were obtained in the 1990 season with defoliation treatment made precociously at different intensities, in a diffuse way, uniformly in the whole canopy. At the end of canopy development LAIs of 3.6,3.3,3.1,2.6 and 1.8 were obtained and evaluated. The kiwifruit vines with a bud load of 680?700 and LAIs of 3.3 and 3.6 in 1990, showed an optimum and constant yield (>90 kg per vine), good average fruit weight (>100 g) and high fruit quality in both years, and also good return bloom the following season. The reduction of LAI to 2.6 and 1.8 drastically reduced, in the year of LAI imposition, both yield (?18.5% and ?30%, respectively) and mean fruit weight (?18.6% and ?29.1%, respectively) compared with vines with an LAI higher than 3.1. In the same treatments, the soluble solids concentration in the fruit was significantly decreased and a great reduction in numbers of fruiting shoots and numbers of fruits per fruiting shoot were observed in the year following the LAI imposition. In vines with the same bud load, fruit number and an LAI of 3.1, small variations in yield and fruit weight in the year of defoliation treatments were recorded, but in the following season the yield was significantly reduced (?14 kg per vine) due mainly to a decrease in the number of fruiting shoots (?14%). In kiwifruit vines with low LAI (2.6 and 1.8) nearly all fruits present in the canopy ripen, with no significant fruit drop. At low LAI, the sink strength of the fruit was greater and more extended so that vine growth and the plants reserves were restricted. Under the conditions of this experiment, an LAI higher than 3.3, corresponding to a leaf area-fruit ratio higher than 600 cm2 per fruit, is necessary to obtain regular vine growth and yield, optimum fruit size and quality and return bloom the following season.  相似文献   

9.
Summary

Relationships between the occurrence of russeting (cuticle cracking) and fruit diameter, relative growth rate (RGR) and the period from fruit set to harvest were investigated in a glasshouse experiment. Fruits were visually and microscopically examined for the presence of cracks and graded from 0 (no symptoms) to 4 (severe symptoms). Cracks occurred on fruits six to seven weeks after fruit set in the last phase of fruit growth. The extent of russeting increased with increase in the period from occurrence to harvest. Russeting was most marked at higher RGR and long periods from fruit set to harvest. The percentage of russeted fruits varied from 10 to 80% over the total production period. More russeting was apparent in plants carrying a low fruit load. It is suggested that this variation is the result of a complex of factors related both to fruit growth and fruit load and to the tensile strength and extensibility of the epidermis.  相似文献   

10.
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   

11.
Summary

The response of glasshouse grown tomatoes, cv. Counter, to day/night temperature regimes was examined in two consecutive years. In both years three day/night temperature regimes, with the same average 24-hour temperature, were applied in duplicate, i.e. high/low, equal, and low/high. Differences in temperature were maintained from three days after planting (4 December 1984 and 3 February 1986) until 13 May 1985 and 1 May 1986, respectively. Plant development (increase in number of trusses) was not affected.by the temperature regime. Growth in length of the stem was strongly reduced by a lower day temperature. In the first experiment the crop at the low day temperature treatment was damaged by leaf scorch, most likely caused by low transpiration. Consequently, early yield was lower for this treatment. In the second experiment no leaf scorch occurred and no significant differences in early yield were found. Final yield and average fruit weight, until 1 July for both experiments, were higher at the higher night temperature. Shelf life of the fruits and internal quality was not influenced by the temperature regime. Thus, the length of a tomato plant can be manipulated by the difference between day and night temperature, while development and early yield depend greatly on the average 24-hour temperature. Final yield can be higher at higher night temperature and the same average temperature because the crop is more robust. Temperature control based on average 24-hour temperat-ure can be used to minimize energy. consumption and, together with other growth factors, to optimize financial yield.  相似文献   

12.
Summary

To study the effects of prohexadione-calcium (Pro-Ca) on fruit quality, an experiment was performed in 2002 in which trees were treated with two different concentrations of Pro-Ca and left with different crop-loads. Increasing levels of thinning resulted in smaller yields, but greater fruit sizes, which followed a curvilinear pattern when plotted against crop-load. The soluble solids content and titratable acidity of fruits decreased linearly with increasing crop-load. Fruit skin chromaticity values also changed. Luminescence increased, while a* values decreased linearly with increasing crop-load, indicating more reddish and darker coloured fruits on trees subjected to very heavy thinning. In addition, the concentrations of soluble sugars in fruits changed with the level of cropping; fructose and glucose concentrations increased with crop-load, while sorbitol and sucrose decreased. The application of Pro-Ca shortly after full-bloom inhibited shoot elongation growth, but did not result in changes in yield or in any of the fruit quality parameters analysed.  相似文献   

13.
In a factorial experiment to investigate the combined effects of plant density and time of split application of fertilizer, 4 spacings and 3 fertilizer treatments were employed. Plant populations were varied between 24,000 and 54,000 per ha. Equal amounts of NPK were applied in different split applications and at specific physiological stages.Time to 50% flowering was delayed by fertilizer application as well as by wide within-row spacing. Total leaf N and P content declined with all treatments between flowering and mature-green stage of fruits, but increased again at table-ripe stage. Leaf K content remained constant throughout the growth period.Two-split applications of NPK, one at 2 weeks after transplanting to the field and the other at fruit set, were more beneficial than either no fertilizer or 3-split applications of equal amount of fertilizer, when the third application was at mature-green stage. This was indicated by higher fruit yields with 2-split applications.Highest fruit yields were obtained when tomatoes were planted either at 30.5 cm × 91 cm single-row spacing, or at 45.5 cm × 122.0 cm, double-row spacing, both giving 36,000 plants per hectare. Fruit yields were reduced at lower and higher population densities.  相似文献   

14.
Summary

Hail nets protect orchards from storm damage, but also offer potential water savings for fruit trees grown in arid areas. We investigated the effects of black nets on water use, growth, yield, and fruit quality in peach trees growing in Catalonia, Spain, over 2 years (2006 and 2007). Water savings were quantified by irrigating the netted trees to a similar midday stem water potential (Ψstem) as the control trees. This method was only partially successful in 2006, with the netted trees being over-watered early in the season (i.e., higher Ψstem than the controls), and under-watered (i.e., lower Ψstem than the controls) later in the season. A combination of water stress and a hail net resulted in lower yields because of a smaller fruit size. Skin colour was more enhanced in control fruit. In 2007, Ψstem values were similar between treatments. Any difference in tree performance was therefore due to the hail net per se. Fruit size was similar between treatments, and the lower yields of netted trees were due to decreased fruit number. There were no treatment differences in fruit skin colour or flesh firmness. Soluble solids concentrations were higher in nonnetted fruit. In both years, water savings amounted to approx. 25%, if irrigation replaced the potential evapotranspiration that was measured. Hail nets are therefore recommended for their effects on water saving in arid areas, despite lower fruit yields.  相似文献   

15.
Summary

Tomato plants (Lycopersicon esculentum Mill. `DRK') were grown hydroponically in two experiments to determine the effects of nutrient concentration and distribution in the root zone on yield, quality and blossom end rot (BER). The plants were grown in rockwool with their root systems divided into two portions. Each portion was irrigated with nutrient solutions with either the same or different electrical conductivity (EC) in the range 0 to 6.dS m±1. In both experiments, fruit yields decreased as EC increased from moderate to high when solutions of equal concentration were applied to both portions of the root system. However, higher yields were obtained when a solution with high EC was applied to one portion of the root system and a solution of low EC to the other portion. For example, the fresh weight of mature fruits in the 6/6 treatment was only 20% that of the 3/3 treatment but the 6/0 treatment had a yield that was 40% higher. The reduction in yield in the high EC treatments was due to an increase in the number of fruits with BER and smaller fruit size. BER increased from 12% to 88% of total fruits as EC increased from 6/0 to 6/6 and fruit length decreased from 67.mm to 52.mm. Fruit quality (expressed as titratable acidity and soluble solids) increased as EC increased. In summary, high yields of high quality tomatoes with minimal incidence of BER were obtained when one portion of the root system was supplied with a solution of high EC and the other portion with a solution of moderate or zero EC.  相似文献   

16.
Summary

Postharvest heat treatments have been used for many years as alternatives to chemical control of fungal diseases and insect infestation of fruits and vegetables. In this study, the effects of a new hot-water brushing (HWB) treatment on the resistance of red grapefruit (C. paradisi cv. Star Ruby) to green mould decay caused by Penicillium digitatum (Pers.: Fr.) Sacc. and on the development of chilling injury (CI) symptoms during cold storage were examined. The HWB treatment comprises rinsing hot water on the fruits as they move along a belt of brush rollers. A twenty second HWB treatment at 59 or 62° reduced decay, after arti®cial inoculation of wounded fruit, by 52 or 70%, respectively, compared with control unwashed fruit, whereas rinsing and brushing the fruit with tap water (~20°) or with hot water at 53 or 56°, were ineffective. HWB treatments applied 1–3 d prior to inoculation were most effective in enhancing the disease resistance of fruit, but were much less effective when the fruit were inoculated on the same day or 7.d later. HWB treatments at 59 or 62° for 20.s also significantly reduced the CI index and the percentage of fruit displaying CI symptoms by 42 and 58%, respectively, after six weeks’ storage at 2° and an additional week at 20°. Furthermore, HWB treatments cleaned the fruit and improved its general appearance without causing any surface damage, and did not influence fruit weight loss, percentage of total soluble solids (TSS) in the juice, juice acidity or fruit colour.  相似文献   

17.
We investigated the hypothesis that manipulating water out-flow of a plant through the shoot environment (potential transpiration, ET0) in a glasshouse could modulate the effect of salinity/osmotic potential in the root environment upon yield of tomatoes. Contrasting root-zone salinity treatments were combined with two climate treatments — a reference (high transpiration, HET0) and a “depressed” transpiration (low transpiration, LET0). The salinity treatments, characterised by their electrical conductivity (EC) were 6.5, 8 and 9.5 dS m−1, were always coupled with a reference treatment of EC=2 dS m−1. In another experiment, concentrated nutrients (Nutrients) and nutrients with sodium chloride (NaCl) at the same EC of 9 dS m−1 were compared.Marketable fresh-yield production efficiency decreased by 5.1% for each dS m−1 in excess of 2 dS m−1. The number of harvested fruits was not affected; yield loss resulted from reduced fruit weight (3.8% per dS m−1) and an increased fraction of unmarketable harvest. At the LET0 treatments, yield loss was only 3.4% per dS m−1 in accordance with the reduction in fruit weight. Low transpiration did increase fruit fresh yield by 8% in both NaCl and Nutrients treatments at an EC=9 dS m−1. Neither EC nor ET0 affected individual fruit dry weight. Accordingly, fruit dry matter content was significantly higher at high EC than in the reference (4% per each EC unit in excess of 2 dS m−1) and responded to ET0 to a minor extent. Control of the shoot environment in a greenhouse to manipulate the fresh weight of the product may mitigate the effects of poor quality irrigation water without affecting product quality.  相似文献   

18.
A spring and an autumn crop of eggplant (Solanum melongena) were grown under natural light conditions in a glasshouse at different day and night humidities. A high or low humidity by day was combined with either a high or low humidity by night. Vapour pressure deficits (VPD) achieved over the period in which the treatments were applied ranged from 0.44 to 1.18 kPa by day, from 0.24 to 0.91 kPa by night, with a 24 h mean from 0.34 to 0.99 kPa. The rate of plant development was unaffected by humidity. Fruit yields were reduced by continuously low VPD compared with the other treatments. The yield reduction could be attributed to fewer fruits being picked. Mean fruit weight was higher at high humidity by day. Continuously high VPD increased calyx withering, low VPD had no detrimental quality effects but promoted the incidence of Botrytis cinerea.  相似文献   

19.
陈学森  吴燕  孙永华  刘文  梁青 《园艺学报》2006,33(3):477-480
 以5～6年生的‘凯特’ ב新世纪’F1 代群体52个株系为试材, 对株系的自交坐果率、有效花比率、平均单果质量及单株坐果数等性状的变异及其与单株产量的相关性进行了研究, 结果表明, ①杏自交坐果率、有效花比率、平均单果质量、单株坐果数及单株产量等性状在F1 代广泛变异, 其中单株坐果数及自交坐果率的变异系数最大, 分别为102.0%和99.5% , 说明这两个性状的选择潜力较大; ②单株坐果数、自交坐果率及有效花比率均与单株产量极显著正相关, 相关系数( r) 分别为0.945、0.541和0.439, 且自交坐果率、有效花比率与单株坐果数的相关性亦达到极显著水平, 说明自交坐果率及有效花比率均是株系产量形成的主要因素; ③平均单果质量与单株产量的相关系数虽然为负值( r = - 0.176) , 但相关性不显著, 出现这种结果主要是由于在多因素相关分析系统中, 其他因素相互影响造成的。因此, 在本试验体系中, 果实大小不是产量形成的主要因素; ④依据上述相关性的研究结果, 初步提出并讨论了丰产选择与品质选择的“二次选择法”。  相似文献   

20.
The weekly rates of shoot extension and total growth in leaf length of the glasshouse tomato variety Potentate increased from germination until soon after the start of ovary swelling. It is postulated that when, or soon after, the first flower primordia were initiated, an internal reaction was stimulated that eventually resulted in the cessation of the progressive increase in the rates of shoot extension and growth in leaf length. Increase in the rate of vegetative growth ceased soon after the start of ovary swelling, but this occurred even when no ovaries were allowed to swell.

The diameter of the shoot was unaffected by removal of leaves but increased when no fruits were allowed to develop. Conversely, shoot extension growth was unaffected by removal of fruit but decreased when alternate immature leaves were removed, although the removal of mature leaves had no effect on shoot extension growth.

Removal of leaves was associated with a reduction in total fruit volume and an increase in total leaf length.

Removal of immature fruit was associated with an increase in total leaf length. Removal of alternate immature fruits had little effect on total fruit . volume ; the difference between normally fruiting plants and plants from which alternate fruits had been removed was less than 0?5%.  相似文献   

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