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1.
Merton Worcester apple trees in pot culture were supplied for four consecutive years with N, P, Ca and K at two rates. Apples of this cultivar differed from those of cvs Cleopatra and Jonathan both in their response to nutrient supply variations and in the interrelationships among the levels of mineral elements in the fruit and bitter pit incidence at harvest. The association between fruit levels of N, P, K and Mg previously observed in the other two cultivars was absent in Merton. In two years a positive association appeared in Merton between K level and bitter pit incidence. Doubling the K supply reduced fruit Ca level and increased protein N level and bitter pit incidence. A threefold increase in the Ca supply had the opposite effect on each of these variables. Bitter pit incidence was not affected by doubling the P supply, but was increased by supplying extra N, some of which was in the form of ammonium ion. The differences found between Merton Worcester and the two cultivars studied previously under the same cultural conditions demonstrate that any conclusions in this area concerning apples in general are valid only if they are based on findings over a number of seasons in a wide range of cultivars.  相似文献   

2.
Summary

Various fungicides, gibberellins (A417) and their mixtures were tested for the control of russet of ‘Golden Delicious’ apple fruit in the major apple-growing area in Israel. Four foliar applications of captan, metiram, the strobilurins kresoxim-methyl, trifloxystrobin, azoxystrobin, or the polyoxin B compound Polar from the green tip stage to the end of the petal fall stage gave similar reductions in russeting, compared with the controls, but none eliminated it. Tank mixtures of the gibberellins (A417) Regulex and Perlan with captan, each at full rate, did not improve russet control, compared with each component alone at the same rate. Similarly, both captan and trifioxystrobin, and the gibberellin (A417) Cytolin or their mixtures at full rates provided similar significant level of control of russet on fruit. Fruit in the upper part of the tree had significantly more russet than fruit in the lower part of the tree, regardless of treatment applied. In addition, russet was more severe on fruits of trees grown in the west side of the row, than those of trees grown on the east side. Data suggest that factors other than fungicides, which may act by reducing russet-inducing microorganisms, may be involved in russet development.  相似文献   

3.
Pruning in late summer was compared with winter pruning on mature 23-year-old spur pruned trees of Cox’s Orange Pippin on M.2 rootstock. Two nitrogen treatments were superimposed, namely a standard dressing of 126 units N (sulphate of ammonia) applied in March as compared with 288 units N (nitrate of soda) applied in mid-August at the time of summer pruning. Summer pruning reduced trunk girth increment, advanced blossom development, increased the amount of red colour on the fruits and drastically reduced the incidence of bitter pit in stored fruit. The treatments did not affect cropping. Nitrogen treatments had no overall effect upon the incidence of bitter pit, but in the first season, when bitter pit was most prevalent, high levels of N applied in August reduced the amount, a similar trend being recorded the following year.  相似文献   

4.
Fruit-thinning treatments were applied in the three seasons 1963–65 to Cox trees to investigate the relationships between leaf : fruit ratio, fruit size, cell volume and cell number, and the incidence of rotting and disorders following air storage at 2·8° C. (37° F.) and o° C. (32° F.). Progressively more severe thinning was required, sis fruit development proceeded, to obtain a similar increase in fruit size. This declining response to thinning was accompanied by a progressively smaller increase in the cell numbers of fruits as the treatments were delayed. Thinning also caused an increase in cell-enlargement rate but the magnitude of the response varied between different experiments and did not appear to be related to the developmental stage at which the treatment was applied.

The larger fruits from thinned trees were more susceptible to bitter pit, breakdown, and rotting caused by Gloeosporium perennans, but were less susceptible to low-temperature injury than fruits from unthinned trees. Bitter-pit incidence was related to fruit size within each treatment and was more severe in fruit where the ratio between the potassium and calcium concentrations was high. Low-temperature injury was associated with fruit with low dry matter and potassium contents. Susceptibility to this disorder and to rotting was also influenced by fruit maturity as measured by the progress of the climacteric rise in respiration rate. There were no marked relationships between storage disorders and the numbers or size of cells in fruits produced by the various treatments included in these experiments.  相似文献   

5.
秋锦苹果苦痘病与果实矿质元素含量和品质相关性的研究   总被引：2，自引：0，他引：2  
以套袋秋锦苹果为试材,测定了苦痘病果与健果不同部位矿质含量及可溶性固形物的含量。结果表明:矿质元素含量果皮果肉,苦痘病果实的Ca含量低于健果,果皮中尤为明显;苦痘病果N、P、K、B含量及N/Ca、K/Ca、B/Ca、P/Ca均高于健果,N/K、N/P和K/P差异不明显;果皮不着色面Ca含量均低于着色面,而N含量均高于着色面。苦痘病果可溶性固形物含量显著高于健果。果皮各矿质元素之间以及各矿质元素与SSC间存在较密切的相关性。  相似文献   

6.
In a pot experiment with apple trees, cultivar ‘Cox's Orange’, Ca was omitted in the nutrient solution for periods of different length. Trees lacking Ca in the latest 23 of the growth period contained 42 mg kg?1 Ca in the fruits, which is 21% below control. In the bulked sample, average size of fruits was not considerably affected, but the distribution of small and large fruits changed toward more smaller fruits. Concommitantly, bitter pit was reduced compared to the control.Sufficient K supply (1.20–1.70% K in leaf dry matter) given to trees receiving high Ca supply depressed Ca concentration in the fruits to 41 mg kg?1, which is 23% below control. Average fruit size was not significantly changed, but the distribution was towards larger fruits. Under these circumstances bitter pit was increased. Ca deficiency, caused either by omission of Ca or competition between K and Ca, increased fruit rot, russeting and cracks on the fruits. Short term variations in Ca levels were not seen to produce any measurable response.  相似文献   

7.
In several commercial orchards the percentages of Ca and K in the leaves and fruit of the cultivar Cox’s Orange Pippin were determined at intervals during one or more years. The values for a series of untreated trees were continually compared with those of a comparable series of trees which were sprayed at about seven-day intervals with a Ca(NO3)2 solution. At the end of each experiment the fruit was placed in storage and later examined for the incidence of bitter pit.

The Ca contents of leaves and fruit and the quotient (K+Mg)/Ca in the leaves of untreated trees showed only a moderate relationship with the percentage of bitter pit. The K content of the fruit was more closely correlated, however.

The level above which much bitter pit was unlikely to occur was found to be approximately 7.5–8 mg Ca in a fruit of 140 g fresh weight.

The total amount of Ca in the untreated fruit increased in a rather regular and comparable fashion in the various experiments. The rate of increase was somewhat higher during the first period of development, until the fruit reached about 20–40 g in weight, than during its subsequent growth.

Spray treatments increased the Ca content of the leaves by 0.2–0.5% of the dry weight; a maximum of 4 mg Ca was added to the fruit, an increase of 47% on the basis of the amount already present. In general the Ca level increased progressively during the season with successive spray applications, and 9–15 sprays reduced bitter pit incidence to about 5%.

The permeability of the fruit tissue to ions diminished as a result of the sprays, and it is suggested that an increase in cell membrane permeability may be involved in the development of the disease.

For commercial orchards, more frequent sprays may need to be applied than are recommended at present to provide effective control of bitter pit.  相似文献   

8.
Covering apple orchards with nets protects them from hailstorms but this changes the amount and quality of the light supplied to the trees. This study was carried out to assess the effects of shade provided by white protection net on yield and fruit quality of apple orchards in Southern Brazil, along three growing seasons (2002/2003, 2003/2004, and 2004/2005). ‘Gala’ and ‘Fuji’ apple trees (on MM111 rootstock, raised as slender spindles, with a spacing of 5.5 m × 3 m) were left uncovered (control trees) or covered with white net. The white net reduced the photosynthetically active radiation (λ = 400–700 nm) accumulated over the trees’ canopy along a day by 18.4%, leading to a higher leaf chlorophyll content in both cultivars, and a higher specific leaf area in ‘Gala’. The shade provided by the net did not affect yield and increased fruit average weight in both cultivars. At harvest, the number of seeds per fruit and severity of russet were not affected by netting in both cultivars, as well as the incidence of watercore in ‘Fuji’. The main beneficial effects of the white net were the reduced incidence of sunburn on ‘Gala’, reduced incidence of bitter pit during cold storage in both cultivars, and reduced incidence of apple scab at harvest and of decay after cold storage in ‘Fuji’. Fruit fly damage in ‘Gala’ (assessed in one season) was reduced by netting. However, netting affected negatively some fruit quality attributes. ‘Gala’ and ‘Fuji’ apples from trees protected by the net had a poor skin color (pale blush and a more intense green background color) at harvest. The net reduced flesh firmness and SSC, and increased the starch index of ‘Gala’ apples at harvest, and reduced flesh firmness and SSC, assessed after cold storage and shelf life, in fruits of both cultivars.  相似文献   

9.
Severe hand thinning of fruitlets on Cox’s Orange Pippin trees five weeks after full blossom led to a doubling of fruit weight by harvest. Although the rate of cell division was stimulated slightly, the larger fruit size was due mainly to an increased rate of cell enlargement.

The respiration rate of whole fruits was slightly higher after thinning and the onset of the climacteric rise was advanced. Respiration per cell was correspondingly higher in the larger cells of the thinned fruit and respiration per unit protein was similar to that of fruit from unthinned trees.

Potassium, magnesium, and phosphorus contents, expressed on a fresh weight basis, were higher in the cortical tissue of the thinned fruits. Calcium per unit fresh weight was unaffected by thinning and the ratio of calcium to cell surface remained relatively constant throughout development in both types of fruit.

Senescent breakdown and bitter pit developed during storage only in the thinned fruit. Slight differences in the incidence of rotting and low temperature breakdown between the two types of fruit are attributed to the effects of maturity rather than of fruit size.  相似文献   

10.
国光苹果在碱性土壤中易发生缺钙,引起果实苦痘病的发生。本文通过两年的研究证实,果实苦痘病的发生是由于果实内钙素含量低,氮素含量高,氮、钙比值过大的原因。果实中钙素的积累主要是在盛花后的8周前,而果实发育中后期,钙素积累缓慢。树体喷洒钙盐以硝酸钙,氯化钙混同硼砂效果较好。预防苦痘病的发生,还应注意限制土壤氮肥的施用量。  相似文献   

11.
钙素营养与套袋苹果苦痘病的关系   总被引：9，自引：0，他引：9  
为了探讨苹果套袋后苦痘病加重的原因,以富士苹果为试材,对果实发育过程中钙、氮含量的变化规律,果实幼果期和成熟期钙总量,套袋后果实微环境湿度变化及不同有机质果园苦痘病发生率进行了测定。结果表明,未套袋苹果果实在幼果期吸收钙量占成熟果实总钙量30%左右,后期占70%左右,套袋影响了果实对钙的吸收;套袋使袋内湿度增加,果实表面蒸腾作用降低,使果实对钙的吸收受到影响;同时套袋果氮含量一直高于未套袋果,N/Ca增大,促成了苦痘病的发生。增加果园有机质含量,可以改善根际钙离子供应,降低苦痘病的发生。  相似文献   

12.
English sources of viruses causing star crack and russet ring were grafted to nine apple varieties. Only Golden Delicious reacted to all virus sources. This variety differentiated most clearly between different sources of star crack inoculum. Cox’s Orange Pippin and Spartan reacted to all star crack sources; Belle de Boskoop, Weisser Winterglocken, Lord Lambourne, Laxton’s Fortune and Worcester Pearmain reacted when inoculated with some sources but not others, while Granny Smith reacted to none. Golden Delicious developed leaf and fruit symptoms when inoculated with russet ring viruses, but Cox’s Orange Pippin, Spartan, Belle de Boskoop, Weisser Winterglocken and Granny Smith did not. Mailing II rootstocks developed characteristic leaf symptoms when infected with russet ring viruses. One inoculation source caused leaf mottling and necrosis and russeted warts on the fruits of Golden Delicious and Cox’s Orange Pippin. A rough-skin condition of Belle de Boskoop was perpetuated by buds and grafts but not transmitted. Some of the English viruses caused symptoms, in certain varieties, indistinguishable from diseases reported from Germany, Switzerland, the Netherlands, and North America.  相似文献   

13.
Summary

An experiment was carried out over a six year period to relate the storage quality of ‘Cox’s Orange Pippin’ apples to the mineral composition of leaves, fruitlets and fruits and to the climatic conditions during development. The apples were sampled from 24 orchards over a wide geographic area. The extent to which physiological disorders, bitter pit and low temperature breakdown (LTB), and quality attributes, greenness and firmness, of stored fruit could be predicted either before or at harvest was determined. For each response variable, a short-list of up to 12 potential explanatory variables was selected from an initial set of up to 54 possible explanatory variables, using stepwise regression techniques. Predictive models were generated by selecting variables from the initial short-list using a cross validation technique. The average incidence of bitter pit in controlled atmosphere (CA) storage at 1.2% O2 (<1% CO2) was 4% compared with 12% for similar samples stored in air. Predictive models accounted for up to 67% of the variance in bitter pit in air-stored fruit but the percentage was lower (39%) for fruit stored in CA. The concentrations of calcium and potassium in fruit were particularly important for predicting bitter pit in air-stored fruit but less so for fruit stored in CA where more explanatory variables were required for prediction. Fifty one per cent of the variance of LTB in fruit stored in CA was accounted for by a nine-variable model incorporating three climatic variables. A simple three-variable model (leaf nitrogen concentration, harvest firmness and fruit dry weight) accounted for 67% of the variance in ex-store firmness and the addition of other nutritional and climatic variables increased the percentage variance accounted for to 76%. Seventy-one per cent of the variance in the greenness of fruit after CA storage was accounted for by a six-variable model. The possible physiological significance of the explanatory variables in each model is discussed.  相似文献   

14.
Routine sprays applied at regular intervals against apple scab on open-centred bush Cox’s Orange Pippin trees on M.IX rootstock were compared with curative sprays promptly applied after infection periods, as defined in terms of the Mills chart from instrument readings. A total saving of ten applications resulted from curative treatment over seven consecutive seasons. Routine interpretation of instrument data failed in only one marginal instance to detect an infection period, which arose from discontinuous wetting, but thereby jeopardized curative control in one season (1963).

With the one exception, both methods gave a high degree of scab control every year, although infection on the unsprayed controls was often severe. Some spray damage occurred in the form of reduced cropping or fruit russeting, particularly from phenylmercury chloride and didecyldimethyl-ammonium bromide as curative sprays, and from lime-sulphur applied post-blossom, either curatively or as routine. Captan with DNOPC (“dinocap”), however, gave superior crops showing relatively light russeting, and dodine acetate proved generally safe.

Although curative spraying proved generally successful on these relatively small, open trees, its exclusive use on an extensive scale is problematic. A feasible compromise is to reinforce a basic routine with curative sprays when desirable.  相似文献   

15.
Fungicide programmes, designed to control both scab and mildew, have been compared for phytotoxicity in several seasons on apple and pear varieties. Dodine acetate was found to cause russeting of the fruits of several apple and pear varieties. In one year, frost at a spraying time seemed to interact with dodine acetate application to produce unusual russet on Sunset apples. Crops of Conference and of Doyenne du Cornice pears were reduced in some years when dodine was applied.

The fungicide based on nitrated octylphenols, DNOPC, caused no undesirable effects on the apple varieties, but tended to reduce cropping on pears; the effects of the unesterified mixture, DNOP, were more serious.

Both dodine acetate and DNOPC caused reductions of fruit bud formation on Cornice, an effect already reported for organomercurial fungicides on Conference and for didecyldimethylammonium bromide (DDAB) on both varieties. It is suggested that freedom from this effect should be a criterion to be satisfied in the evaluation of any new pesticide for pears.  相似文献   

16.
苹果苦痘病与果实内矿质养分平衡状况的相关性分析   总被引：2，自引：0，他引：2  
对大连瓦房店地区苹果苦痘病病害程度不同的红富士苹果果实进行了氮、磷、钾、钙、镁、铁、锰、铜、锌、硼、钼含量的测定。结果表明:苦痘病的病害程度与苹果果实内的含氮量呈极显著正相关关系,即苦痘病越严重,果实内的含氮量越高;苦痘病的病害程度与苹果果实内的氮/钙比呈极显著正相关关系,即果实内氮含量越高,钙含量越低,苦痘病越严重;病害程度与苹果果实内的钙/(钾+镁)比呈极显著负相关关系;病害程度与果实内的铜含量呈极显著正相关关系;病害程度与果实内的磷、钾含量无显著的相关关系。试验得出:苹果果实内氮含量过高,是导致苦痘病发生的重要因素。  相似文献   

17.
Ninety-seven trees of 25 seedling varieties of apple, propagated on Malus sikkimensis seedling rootstocks, were inoculated by bud-grafting from a tree of Emneth Early showing symptoms of bitter pit. A further 97 trees were kept as uninoculated controls. The incidence of bitter pit in the two groups of trees was 67% and 68% respectively, from which it is concluded that bitter pit is very unlikely to be a virus disease.  相似文献   

18.
The importance of the fungicide used for Apple Scab control in affecting the development of harmful populations of the Fruit Tree Red Spider Mite, Metatetranychus ulmi (Koch), has been noted by Gilliatt (1935), Cutright (1944) and Pickett et al. (1946). The advent of the relatively specific organic fungicide glyodin (Chandler and Thurston, 1949) offered a hope of scab control with a minimum of side-effects on arthropod populations and hence of assessing the role of predators in the control of M. ulmi. In a preliminary trial in Kent (Collyer and Kirby, 1955), on plots sprayed with one or another of four fungicides in 1951–3, higher populations of M. ulmi developed following lime sulphur sprays than after glyodin or captan ; wettable sulphur gave an intermediate result. Conversely, higher populations of predacious mites (Typhlo- dromus spp.) were present on glyodin- or captan-treated trees than on trees receiving lime sulphur. No apparent differences in populations of predatory insects resulted from the four fungicide treatments, and the tentative conclusion was drawn that in this experiment these insects were less likely than the predacious mites to be a cause of the markedly different M. ulmi populations. However, as the plots were small and the trees very close, any differences in insect numbers caused by the treatments would soon be adjusted. A second large-scale trial was made at a more suitable site at Mellow Purgess Farm, Stondon Massey, near Brentwood, Essex in 1952–6, where plots were much larger, allowing several guard rows, and the trees were much younger and smaller, facilitating thorough spraying and representative sampling. Also, this relatively isolated orchard had received very few spray applications in the past and had never suffered from mite infestations at an economic level; Typhlodromus mites and several insect predator species were already present.  相似文献   

19.
Summary

Bitter pit incidence in Bramley apples that were cooled prior to either slow (three weeks) or rapid (one day) establishment of controlled atmosphere (CA) conditions (9% CO2, 12% O2) was 14.7 and 3.2% respectively. Bruise susceptibility was also reduced by rapid CA establishment although the rate of fruit softening was unaffected. The control of bitter pit by pre-storage treatment with 15–25% CO2 for one to three weeks was no better than by rapid establishment of CA, although bruise susceptibility was further reduced by some treatments. Some pre-storage treatments caused injury to the apple skin and flesh (brownheart). The extent to which fruits were injured was dependent on CO2 concentration and the duration of CO2 treatment. There was some evidence that early picked fruit not cooled prior to CO2 treatment was more severely injured both internally and externally by CO2 than that harvested later and cooled prior to treatment.  相似文献   

20.
土壤有机质对"红富士"苹果产量和品质的影响   总被引：2，自引：1，他引：1  
测定了"红富士"苹果园0~40 cm土层的有机质含量,分析了相应果园苹果的产量和果实品质,为果园科学施肥提供依据。结果表明:土壤有机质含量在2%以上的果园苹果产量高、果实品质好,几乎不发生苦痘病;土壤有机质含量在2%以下的果园苹果产量低、果实品质差,苦痘病发生严重。  相似文献   

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