Six hypotheses for profitable apple production based on the economic work-package within the ISAFRUIT Project

Summary

As a result of an economic analysis of apple farms in Switzerland, Germany, The Netherlands, and France, we identified six factors that can be influenced by apple producers that might impact the economic success of their orchard. The critical factors identified were: yield; quality of the apples (as graded results); orchard size; number of cultivars; production costs; and specialisation in organic production and/or farmgate sales. Yield and graded results were the most important factors for the economic success of an orchard. Orchard size and production costs only affected the economics of an orchard under different conditions such as the size of the apple surface, or poor yield. The number of cultivars did influence the economic success of an orchard. Apple farms under organic production regimes and farmgate sales benefited from higher prices and, therefore, had a higher chance of economic success. The main condition for success was to maintain high product prices.     

The Relation Between Time of Picking and Storage Disorders in Cox’s Orange Pippin Apple Fruits

In four successive seasons. Cox’s Orange Pippin apples were picked at weekly intervals and stored under various conditions to assess the effect of time of picking on wastage from different causes.

Mean fruit weight increased by up to 20% over the 6 to 10 weeks of the picking periods.

The maturity of the fruit when picked was assessed by following the respiration pattern of samples kept at 12°C.

The results for successive pickings of fruit kept at 37°-38° F. (2.8°-3 ·3° C.) (normal cold storage temperature for Cox) and all removed from store at the same time, showed more core flush in early-picked apples, and more senescent breakdown and rotting in late-picked apples. There was no sudden change in liability to any of these disorders which could be associated with any particular stage of maturity. There were no consistent effects of time of picking on the amount of bitter pit or on weight loss during storage.

Storage at 32° F. (o° C.) (below the recommended temperature for the storage of Cox’s Orange Pippin) resulted in low temperature breakdown. This disorder tended to be less severe in apples picked just before the climacteric rise in respiration rate.

It is concluded that, for any particular orchard, picking date should be based not only on maturity as judged by colour and size, but on the expected liability of the fruit to disorders, such as core flush and rotting due to Gloeosporium, and on the type and period of storage required.     

Apple Mosaic Viruses Host Reactions and Strain Interference

The annual growth of an apple tree in the vegetative condition is distributed in a definite pattern between leaves, stems and roots ; when a crop is borne, this constitutes an additional end-point for growth materials. The disturbances in the pattern of vegetative growth caused by this additional region of utilization are described. Two-year-old apple trees were deblossomed at flowering or defruited on 30th May, and their growth was compared with that of cropping trees. The increments in weight were estimated by samples taken at treatment times.

After deblossoming, the trees made extra growth in terms of dry weight, more and larger leaves, and longer stems. The periods of greatest and least growth were the same as for cropping trees. Defruiting also resulted in extra growth, but this came later, and so was out of phase with the growth of fruiting trees. This extra vegetative growth (including more trunk thickening and root growth as well as leaves and new shoots) weighed more than the crop on the fruiting trees. Defruiting had slightly less effect than deblossoming.

The diversion of metabolites to the crop changed the pattern of growth in the rest of the tree. Cropping trees had 50% more leaf proportionate to total vegetative increment, and 50% less root, than deblossomed ones. The intervening regions varied roughly according to their position. Despite this greater leafiness of cropping trees, they produced significantly more total dry matter (vegetative growth plus crop) per unit area of leaf.

These results are attributed to the greater demanding power of the growing crop in diverting photosynthates from the lower parts of the tree and in increasing the rate of removal of photosynthates from the leaves.     

Variation in maturity traits within individual apples of cultivar Jonagold

Summary

Variation within individual apples of ‘Jonagold’ in firmness, soluble solids (sugar) content and starch conversion was strongly related to aspect. The south face of apples, relative to the north and east faces, had high firmness, low starch conversion and high soluble solids content. The Streif Index (a commonly-used composite measure of apple maturity) cancelled out the majority of the variation in the individual traits.     

An Approach to the Study of Yearly and other Variation in Crop Yields

The effects of deep ploughing, shallow ploughing-with-subsoiling, shallow ploughing, and shallow rotary cultivation combined factorially with three manurial treatments on the yields of vegetable crops are described. Each of the five crops in the rotation was grown in each year from i960 to 1962 on a sandy loam at Wellesbourne.

Where a high level of fertility bad been built up by the use of farmyard manure (FYM), yields were subsequently maintained at a high level for a three-year period by the use of NPK fertilizers alone.

Plots which had received either FYM with NPK fertilizers for each crop from 1954 to 1962 (FYM -j- NPK), or FYM with NPK fertilizers from 1954 to 1959 but with NPK only from i960 to 1962 (residual FYM + NPK), gave much higher yields than plots which had received only nitrogenous fertilizers from 1954 to 1959 and NPK fertilizers from 1960 to 1962. The increases in yields from FYM + NPK over those from residual FYM + NPK were small, and significant only for autumn lettuce and leeks.

Although, on average, the differences between the yields from the three ploughing treatments were small (the largest was 10%) some of the differences were significant.

The ploughing treatments gave significantly higher yields of early peas, autumn lettuce, leeks and Brussels sprouts than shallow rotary cultivation ; with early summer cauliflowers, however, only shallow ploughing-with- subsoiling gave a higher yield than shallow rotary cultivation.     

Biology of Some Predatory Insects and Mites Associated With the Fruit Tree Red Spider Mite (Metatetranychus Ulmi (Koch)) in South-Eastern England: I. The Biology of Blepharidopterus Angulatus (Fall.) (Hemiptera-Heteroptera,Miridae)

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.     

Response of the Cultivated Mushroom to Temperature at Various Stages of Crop Growth

The effect of temperature during the incubation stage of spawn manufacture and during the spawn-running, pre-cropping and cropping stages of crop production on the growth and yield of the cultivated mushroom was studied in controlled environment cabinets.

Temperature treatment during spawn manufacture and spawn-running affected the growth of mycelium during the spawn-running and pre-cropping stages, but had no effect on the number and weight of sporo-phores produced. Mycelium grew best during spawn-running when the temperature was kept at 75° F. (23·9° C.)

During pre-cropping a temperature of 65° F. (18·3° C.) resulted in less mycelial growth on the surface of the casing layer, an earlier start to cropping, a greater number and weight of sporophores and a lower average weight per sporophore than one of 75° F.

There was no difference in weight of crop when the cropping temperatures were 57° or 62° F. (13·9° or 16·7° C.) but 67° F. (1·5° C.) resulted in a reduced yield when compared with 62° F. The number of sporophores tended to increase as the cropping temperature was decreased. More sporophores were produced at 57° F. than at 62° F., and more were produced at 62° F. than at 67° F. Average weight per sporophore was lower at 57° F. than at 62° F. and was usually lower at 62° F. than at 67° F.

There were no significant interactions between the effects of temperature treatments applied at any of the stages on yield, but the temperature maintained during one stage influenced the development of the crop in up to two subsequent stages.     

Effects of different crop loads and thinning times on yield,fruit quality,and return bloom in Malus × domestica Borkh. ‘Elstar’

Summary

‘Elstar’ is the latest-maturing commercial apple cultivar grown in Norway, with high fruit quality when properly managed. In May 2006, an experiment with four different crop loads [2, 4 ,6, or 8 flowers or fruitlets cm^–2 trunk cross-sectional area (TCSA), respectively] was established at two different stages [first bloom (FB), or 20-mm diameter fruitlets] and compared to unthinned control trees. Fruit growth was measured on individual fruit for each treatment throughout the season at weekly intervals. Thinning at FB gave a significantly lower final percentage fruit set than thinning to the same cropping level at the 20-mm fruitlet stage. However, fruit weights and soluble solids contents (SSC) were significantly higher, and the background fruit colour improved when trees were thinned at FB. The final number of fruit at harvest was less than the amount established at FB, or at the 20-mm fruitlet stage. There were significant differences between treatments in final fruit numbers per TCSA, which reflected the different crop loads. Fruit weights and SSC values were highest with the lowest crop load, and decreased with increasing crop loads. There was also a strong crop-load effect on the extent of return bloom per tree in the subsequent year. Trees thinned at FB had significantly more flower clusters than those thinned at the 20-mm fruitlet stage of. Untreated control trees had the lowest number of flower clusters. The amount of return bloom declined with increasing crop load. Second year crop loads and fruit weights were highest when trees were thinned at FB to two or four apples cm^?2 TCSA in the previous year. Trees with the highest crop load had the lowest crop load in the following year. Fruit quality was generally high for all treatments.     

Foraging behavior of Osmia cornifrons in an apple orchard

An apple orchard consisting of a single commercial cultivar and of pollinizers such as Crab apples under the condition of natural pollination needs pollinators for stable fruit production. We investigated the foraging behavior of pollinators, especially Osmia cornifrons Radoszkowski, in order to evaluate their use instead of honeybees.     

The Effects of Formalin and Other Soil Treatments on the Replant Disease of Apple

Various biocidal and fungicidal treatments were applied to the soil of a 39-year-old apple orchard and their effects studied on the growth of replanted apples. With pot-grown apple seedlings as test plants, pre-planting soil treatments with chloropicrin, propylene oxide, steam or formalin increased growth on average by 123% and did not differ significantly from one another; the effect of furalaxyl* was small. With M.9 rootstocks as test plants and in situ soil treatments, formalin increased growth on average by 188%; furalaxyl and metalaxyl* did not cause significant growth increases.     

Effects of Time of Application of Inorganic Nitrogen Fertilizers on Apple Trees in a Grassed Orchard

Sulphate of ammonia, calcium nitrate or Nitrochalk was applied as a single annual dressing in October, December, February, April, June or August to Cox’s Orange Pippin apple trees on M.2 rootstock over a 14-year period, whilst control trees received no supplementary nitrogen.

The treatments affected the soil physical and chemical conditions, sward composition, and leaf and fruit mineral composition but, despite these effects, there were no long-term differences in tree growth or cropping between the kinds of fertilizer used or their times of application.

Nitrogen effects were progressive ; in the first four years there was a time X kind interaction on cropping; in the next five years only the time of application affected cropping and in the final five years neither time nor kind had differential effects on cropping, although N increased yield compared with the control. Growth was also increased by the N treatments but, again, only in the latter years of the experiment.

Leaf N was highly correlated with rainfall during March to August. In all but the first two and the last of the 14 years, rainfall was above the long-term average for the site.

February appeared to be the best month in which to apply sulphate of ammonia and calcium nitrate, and December for Nitrochalk application.     

Influence of a pre-harvest reflective orchard mulching film on lipid peroxidation and anti-oxidant activity in apple fruit during post-harvest storage

Summary

Studies have shown that applying a reflective film to the floor of an orchard enhances fruit colouration. Here we assessed whether this practice also prolonged the post-harvest storage life of apple (Malus domestica Borkh cv. Fuji and Malus prunifolia [Willd.]) fruit. Strips of reflective mulching film (RMF) were placed beneath the apple trees and RMF-treated fruit were compared with those from untreated control (CK) trees. Enzymes involved in reducing lipid peroxidation such as superoxide dismutase (SOD) and catalase (CAT) are associated with delaying fruit senescence. Their activities, as well as malondialdehyde (MDA) concentrations, were quantified as indicators of physiological changes related to lipid peroxidation and membrane damage in the peel and flesh of RMF-treated or control apple fruit during 50 d of post-harvest storage at 4ºC. SOD activities increased in the peel and flesh from RMF-treated fruit during the first 40 d post-harvest, but declined significantly during the final 10 d of storage. RMF treatment resulted in increases in CAT activities of 5 – 14% and 16 – 29% in the peel and flesh of RMF-treated apples, respectively, compared with untreated CK fruit. Conversely, MDA concentrations were 7 – 23% and 14 – 30% lower in the peel and flesh, respectively, of RMF-treated fruit than in CK fruit over the 50 d storage period. Similarly, RMF treatment resulted in reductions of 7 – 20% and 3 – 10% in saturated fatty acid (SFA) concentrations in the peel and flesh, respectively, compared to CK fruit, while the corresponding polyunsaturated fatty acid (PUFA) concentrations increased by 2 – 10% and 3 – 7%. In conclusion, the use of RMF in apple orchards appears to be an effective technique to delay post-harvest senescence in apple fruit.     

Differential utilization of nitrates by solanaceous species,crops (tomato and pepper) and weeds (black nightshade and thorn apple)

Summary

The capacity of nitrate absorption, accumulation and reduction was studied in four species of the Solanaceae. Two were cultivated species, tomato (Lycopersicon esculentum Mill.) and pepper (Capsicum annuum L.), and two weed species, black nightshade (Solanum nigrum L.) and thorn apple (Datura ferox L.), which often infest these crops. Black nightshade and thorn apple absorbed nitrates most rapidly. Maximum nitrate accumulation was observed earlier in tomato than in the other species, and as in pepper coincided with the flower bud stage. Maximum nitrate accumulation in black nightshade and thorn apple took place during flowering. Only in tomato and thorn apple did maximum nitrate reductase activity occur at the time of maximum nitrate accumulation. Growth and soil nitrate absorption was slowest in pepper, but nitrate accumulation by the plant and nitrate reductase activity was more sustained than in the other species. It was concluded that if these weeds emerge simultaneously with the crops, competition for nitrates by thorn apple, and especially black nightshade, would be greater than for the tomato crop and even more so for the pepper crop.     

The effect of gibberellins and cytokinins on fruit development of Bramley’s Seedling apple

Two applications of a 1 : 1 mixture of gibberellins A₄ and A₇ to either frost damaged or artificially decapitated Bramley's Seedling apple flowers resulted in increased fruit set and yield. It also increased the crop in an orchard without pollinators. Gibberellic acid was not effective. The addition of cytokinins had no beneficial effects and caused malformation.     

Comparison of methods for estimating the onset of the respiration climacteric in unpicked apples

The rate of deterioration of apples in storage is influenced by their maturity at harvest. Three methods based on the occurrence of the rise in ethylene production which is coincident with the climateric rise in respiration, have been used to assess the maturity of the crop for various apple cultivars.

In the first method internal ethylene concentrations (IEC) were measured in fruit samples soon after picking at weekly intervals. The onset of the climacteric was defined as the date when the internal concentration passed 0.1 μ l^-1. The other two methods were based on ethylene production by bulk samples picked at weekly intervals. In one, the mean delay between picking and the rise in ethylene production (DEP) was calculated, and the other recorded the first date on which at least half the replicate samples showed immediate ethylene production (IEP).

The dates determined by IEC and IEP were generally in agreement for each cultivar but there was little evidence of correlation in respect to site and season. Although low DEP values were loosely correlated with early IEP dates this relationship was not sustained over the full range of the data. Modifications to attain greater precision in estimating the progress of maturity in unpicked apples are suggested.     

Mini-review: The effects of apples on plasma cholesterol levels and cardiovascular risk – a review of the evidence

Summary

Evidence suggests that a high intake of fruits is associated with a reduced risk of cardiovascular disease (CVD) and lowered plasma cholesterol, but the specific effects of individual types of fruit, fruit fractions, and processed fruit are less well-studied. Apples are among the most frequently consumed fruits, and human and animal studies on apple may help to clarify the effect of this fruit on CVD risk markers. The aim of this mini-review is to summarise current evidence for a lowering effect of apple on the risk of CVD and plasma cholesterol levels, and to investigate whether such an effect is influenced by fruit processing or the form of intake. Possible mechanisms behind the cholesterol-lowering effect of apples are also considered. All relevant published experimental studies in humans and animals were identified within the open literature. Nine human studies were identified, of which four concerned the effects of whole apples, two the effects of dried apples, and three the effects of filtered apple juice. Additional studies considered specific apple components. In general, there was a cholesterol-lowering effect, in the range of 5 – 8%, after the intake of approx. three whole apples, whereas the consumption of apple juice (375 – 720 ml) had no effect on plasma cholesterol levels and may result in adverse effects on plasma triglyceride levels. Limitations in the study designs did not allow us to draw conclusions on the effect of the intake of whole, dried apples (15 – 52 g). We also identified a total of nine experimental studies in animal models. Feeding with apple products resulted in decreased levels of plasma (11 – 43%) and liver (23 – 67%) cholesterol in the majority of studies. There was an increased excretion of bile acids (3 – 56%) and cholesterol (5 – 41%) in rats fed with apple products. Based on the current evidence from human observational and intervention studies, it seems likely that a reduction in plasma total and LDL cholesterol occurs after a dietary intake of apples, which could lead to a decreased risk of CVD. On average, a daily intake of approx. three apples resulted in a decrease in total cholesterol of 5 – 8% (approx. 0.5 mmol l^?1). The consumption of filtered apple juice may result in adverse effects on plasma triglyceride levels. Evidence from animal studies suggests that the major mechanism behind the cholesterol-lowering effect of apples involves an increased clearance of plasma cholesterol due to enhanced faecal excretion of bile acids and cholesterol.     

The relationship between different spray combinations of certain fungicides with calcium nitrate and the incidence of bitter pit and fungal diseases of apple

Two apple cultivars, Cox’s Orange Pippin and Worcester Pearmain, were sprayed at high volume for scab control in two seasons with either captan or thiram, with dinocap to control mildew. On Worcester, it was confirmed that thiram reduced crop and increased fruit russet and bitter pit incidence; the proportion of misshapen fruits was also increased. On Cox, thiram reduced crop number, without any compensatory increase in weight, and provided inferior scab control as well as increasing fruit russet.

The application of commercial calcium nitrate (C.C.N.) four times between mid-June and mid-August led to a considerable reduction in the incidence of bitter pit and storage rots in fruits from trees sprayed with captan and dinocap; it also partially offset the greater incidence of bitter pit associated with thiram treatments. In contrast to this, the application of a similar total amount of calcium, either in the form of a standard lime sulphur programme or by adding C.C.N, to the organic fungicide programmes for scab control, i.e. from April to mid-July, failed to reduce the incidence of bitter pit on either cultivar. Neither C.C.N, programme affected cropping, fruit russeting or scab control on either cultivar.

The ratio of potassium to calcium was higher in leaves and fruits from Worcester trees receiving thiram than in those from trees receiving captan; the application of C.C.N, in the summer reduced this ratio in fruits from trees receiving captan but not in those from trees receiving thiram, although it reduced the incidence of bitter pit associated with both fungicide programmes.

Results on Cox show that fungicide deposition and control of scab were independent of fungicide formulation and of the presence or absence of C.C.N. ; mildew control was not affected when C.C.N, was applied as the recommended summer programme.     

Fruit and vegetable intake and serum cholesterol levels: a cross-sectional study in the Diet,Cancer and Health cohort

Summary

The aim of this study was to investigate, in a cross-sectional study, whether the intake of fruits and vegetables was associated with lower serum cholesterol levels. The groupings of interest for this study were apples, other fruits, and vegetables. A cross-sectional study was conducted among 42,972 men and women included in the Diet, Cancer and Health cohort (1993 – 1997). This population excluded persons with self-reported cardiovascular risk factors, in order to ensure a “heart-healthy” population. Among men, both apple and vegetable intake was found to be associated with significantly lower serum cholesterol levels. An increase in apple intake of 50 g d^?1 was associated with a 0.04 mmol l^?1 lower serum cholesterol level. Furthermore, analyses combining vegetable and alcohol intake showed lower serum cholesterol levels in men with a low alcohol intake (≤ 10 g d^?1). For women, the same pattern was seen for apples and vegetables, albeit to a lesser extent for apples. Analyses combining vegetable intake and waist circumference measurements showed that women with a smaller waist circumference had lower levels of serum cholesterol. Our findings thus provide some support for previous inverse associations found between higher apple intake and lower serum cholesterol levels.     

Laboratory Studies on the Toxicity of Hydrocarbon Oils and Similar Substances to the Eggs of Some Common Orchard Pests III. Experiments on the Eggs of the Green Apple Aphis (Aphis Pomi Deg.)

Four days after placing known amounts of a 20 p.p.m. aqueous solution of 1-naphthaleneacetic acid (NAA) (¹⁴C carboxyl-labelled) on the upper surface of detached apple leaves in a greenhouse, approximately 10% of the applied radioactivity was found within the leaves, 10% was still on the surface, and 80% was lost.

Apple leaves were found not to decarboxylate NAA, and the disappearance of carbon 14 from the leaf surface is attributed to the breakdown of NAA by ultraviolet radiation. The carboxyl group is lost, leaving a neutral compound, inactive in auxin tests, whose ultraviolet absorption spectrum is similar in general form to that of NAA.

When a 50 p.p.m. aqueous solution of NAA containing a non-ionic wetting agent is placed on the surface of an apple leaf held in darkness at 25° C., absorption proceeds at approximately 1% per minute until the surface deposit is dry. Thereafter, absorption continues much more slowly and at a rate depending on the relative humidity of the air and the temperature.

In experiments on translocation a 50 p.p.m. solution of radioactive NAA was applied to the basal leaves of fruiting spurs of Miller's Seedling. Over a period of 4 to 5 days, 17 to 28% of the carbon 14 which entered the leaves was translocated to the bourse and fruits, but between one half and three-quarters of this translocated radioactivity was in a form other than free NAA.

When radioactive NAA was fed into detached apple leaves through the transpiration stream, 80 to 90% was rapidly converted into a watersoluble addition compound (I), neutral in reaction and lacking auxin activity. Over the course of several days this compound was gradually replaced by a second addition compound (II), which is acidic in nature. Compound II built up more rapidly in Cox’s Orange Pippin than in Bramley’s Seedling.

The possible significance of these results is discussed, particularly in relation to the erratic performance of NAA in the field when it is used for the control of fruit drop or as a fruit-thinning agent. 1-NAPHTHALENEACETIC ACID (NAA) is a growth regulator employed in fruit-growing practice for reducing the pre-harvest drop of apples and pears, and as a fruit-thinning agent for apples. One of the chief disadvantages associated with the use of this compound is the variability in response shown by different varieties of apple, and by the same variety when treated under different conditions or in different seasons. These erratic responses make it difficult to predict the results of any particular application of NAA and offer a serious limitation to its use, particularly as a fruitthinning agent.

The aim of the experiments described in this paper was to obtain quantitative data relating to the behaviour of NAA when it is applied in aqueous solution to the surface of an apple leaf. By using NAA labelled with carbon 14 in the carboxyl group, the penetration of this compound into the leaf, its translocation from the spur leaves to the bourse, and its metabolism within the tree were studied. Attention was also devoted to the destruction of NAA by ultraviolet radiation, a discovery that was made during the course of the investigation and which, like the other factors studied, was thought to have a bearing on the variable performance of NAA in the field.     

苹果连作障碍研究进展

苹果连作障碍是制约苹果产业可持续发展的重要因素。苹果连作障碍的起因多而复杂,一些可能的因素在不同地区甚至同一地区不同果园也会不同,给苹果连作障碍的防控带来较大困难。概述了引起苹果连作障碍的主要原因,以及防治苹果连作障碍的主要方法,结合本课题组近10年来的相关研究,主要从连作苹果园土壤微生物群落结构变化、化感自毒作用(酚酸类物质)、土壤理化性质劣变等方面介绍了苹果连作障碍机制的研究进展;并从合理轮作、间套作和混作、深翻客土、施用有机物料等农艺措施,化学熏蒸、物理消毒等土壤消毒措施,抗性砧木选育等抗性育种措施,颉颃细菌、颉颃真菌、颉颃植物等生物防控措施方面介绍了苹果连作障碍防控的研究进展。对今后苹果连作障碍机理的进一步研究及防控技术的发展方向提出了展望。