The King Fruit versus Lateral Fruit Thinning Effects on Yield and Fruit Quality in Apple

ABSTRACT

This research was conducted to determine the king versus lateral fruit thinning effects on yield and fruit quality of ‘Elstar’, ‘Granny Smith’, ‘Starkrimson Delicious’, ‘Ultra Red’, ‘Topred’, and ‘Jonagold’ apple (Malus domestica Borkh.) cultivars grafted on MM106 rootstock in 2002-2003. Removal of the king fruit (KFR) treatment partially increased the yield in ‘Jonagold’, ‘Elstar’, and ‘Granny Smith’ cultivars while the effects were different by years in “Starkrimson Delicious”. Leaving of the king fruit (KFL) treatment gave better results in the ‘Topred’ cultivar, and similar effects were obtained from both treatments in ‘Ultra Red’ cultivar. Non-significant differences were obtained from both treatments with respect to fruit weight in the ‘Topred’, ‘Starkrimson Delicious’, ‘Jonagold’ and ‘Granny Smith’ cultivars. Leaving of the king fruit treatment increased the fruit weight significantly in ‘Elstar’ and ‘Ultra Red’ cultivars in 2002. The values of fruit flesh firmness (lb), total soluble solids content (%), pH, titratable acidity (%), total and invert sugar quantity (g/100 g^?1) were not found to be significantly different between the treatments with a few exceptions. The ‘KFR’ treatment that removed the dominant effect of the king fruit can be recommended for the ‘Elstar’ and ‘Jonagold’ cultivars because this treatment increased the yield and did not decreased the fruit weight significantly in these cultivars except for ‘Elstar’ in 2002. On the other hand ‘KFL’ treatment can be recommended for the ‘Granny Smith’, Topred’ and ‘Ultra Red’ cultivars. Although this treatment decreased the yield of ‘Granny Smith’ it increased the mean fruit weight 45.6-62.7 g in the two experiment years. ‘Starkrimson Delicious’ did not show clear response to the treatments.     

苹果果实酶促褐变底物及多酚氧化酶活性的研究

 以5个苹果品种为试材，研究了果实的褐变度，绿原酸、儿茶素和表儿茶素含量及多酚氧化酶(PPO)对不同底物的活性。结果表明，‘富士’果实褐变度最高，其次为‘新红星’，‘金冠’最低。3种酚类物质总量新红星和富士最高，金冠最低。儿茶素仅在‘乔纳金’和金冠果实中检测到少量。富士果实绿原酸含量显著高于表儿茶素，新红星和‘王林’表儿茶素含量显著高于绿原酸。以绿原酸为底物，PPO活性新红星最高，其次是富士和金冠，王林最低。以表儿茶素为底物，富士、乔纳金和王林PP0活性显著高于金冠和新红星。以儿茶素为底物，王林PPO活性最高，其次是富士，新红星最低。     

In vitro germination of apple pollens

In order to characterize pollen viability and germinability by biochemical parameters, an introductory investigation was made of the germinability in vitro of pollen of 2 apple cultivars, ‘Golden Delicious’ and ‘Starkrimson’, partially self-incompatible and totally self-incompatible, respectively. Best results of percent germination were obtained for both cultivars after 120 min incubation in Petri dishes at 30°C in a medium containing 0.2 M sucrose, 20 μg/ml H₃BO₃, 300 μg/ml Ca(NO₃)₂ · 4H₂O. Optimum pH was 6.0 for ‘Starkrimson’ and 7.0 for ‘Golden Delicious’.     

Einfluss von Erntezeitpunkt und Lagerverfahren auf die Druckstellenempfindlichkeit von Äpfeln

The influence of harvest date and storage method on bruises sensitivity of apples was investigated. The cultivars ‘Braeburn’, ‘Jonagold’ and ‘Golden Delicious’ were harvested at three times in an interval of 10 days. Fruits have been stored at 2°C in normal atmosphere (cold storage) or in film bags (CA-/ULO-storage; CA?=?Controlled Atmosphere, ULO?=?Ultra Low Oxygen) for three months. Monthly fruits were bruised by a penetrometer applying a range of pressures. One day later the appearance of bruises were evaluated. Increasing pressures resulted in bruises of increasing severity. Early harvest led to less severe bruises. No differences were observed in storage conditions, but duration of storage increased bruise sensitivity of ‘Braeburn’. In comparison of the three cultivars ‘Braeburn’ was less sensitive than ‘Jonagold’ and ‘Golden Delicious’.     

Effects of selected fungicide treatments on the sugar content of ‘Golden Delicious’ and ‘Jonagold’ apples

Several fungicide treatment schemes were assayed on ‘Golden Delicious’ and ‘Jonagold’ apples. The free sugars (fructose, glucose, sorbitol, sucrose and their total) of freshly harvested apples were measured and compared to those obtained with the corresponding untreated apples (control). With ‘Golden Delicious’, the fungicide treatments generally increased the content of fructose, sucrose and total sugars, but had no effect on the glucose content. With ‘Jonagold’, similar effects were observed, but their intensities generally were lower than in ‘Golden Delicious’; in some cases, the treatments even decreased the sugar content.     

Application of five DNA marker techniques to distinguish between five apple (Malus × domestica Borkh.) cultivars and their sports

Summary

Genetic variation between five apple cultivars (‘Golden Delicious’, ‘Gala’, ‘Jonagold’, ‘?ampion’, and ‘Idared’) and ten of their sports (‘Golden Delicious Reinders’, ‘Goldrosio’, ‘Gala Must’, ‘Gala Schniga Schnitzer’, ‘Jonagored’, ‘Jonagold Excel’, ‘Szampion Arno’, ‘Szampion Reno Malinowy’, ‘Idaredest’, and ‘Red Idared’) was investigated using five types of DNA markers: Inter-Simple Sequence Repeats (ISSR), Simple Sequence Repeats (SSR), Amplified Fragment Length Polymorphism (AFLP), Sequence-Specific Amplified Polymorphism (S-SAP), and Inter-Primer Binding Site (iPBS) amplification. In total, 941 polymorphic amplified fragments were obtained using 12 ISSR, 12 SSR, ten AFLP, 19 iPBS, and 15 S-SAP primers or primer pairs. Four of the above-described techniques (except for SSRs with the primer pairs used in this study) were able to distinguish between the sports and their parental cultivar. The most effective technique to distinguish between the genotypes analysed was S-SAP, which detects variations in DNA regions flanking retrotransposon insertion sites.The combined use of ISSR,AFLP, iPBS, and S-SAP markers identified and distinguished all of the sports tested.     

The Growth of Apple Central Fruits as Affected by Thinning with NAA,BA and Naphthenic Acids

Plant growth regulators such as α?naphthylacetic acid (NAA) or 6?benzyladenine (BA) are commonly used for thinning apple fruits. NAs exhibits an auxin- and gibberellin-type biological activity, stimulate the uptake and translocation of auxins in plant tissue, as well as IAA synthesis and act as surfactants. It was assumed that NAs applied at the stadium of early fruit growth might cause fruit abscission in apple, similarly to NAA. The goal of the research was to test the presumed thinning effect of naphthenic acids on apple cultivars ‘Golden Delicious’ and ‘Red Delicious’. Three treatments were applied on both apple cultivars including 16.5?μL L^?1 NAA, 200?μL L^?1?BA and 2.63?mg L^?1?potassium salts of NAs. Cortical cell size and the number of cell layers were measured in order to determine the contribution of cell size and cell division in early fruit growth, as affected by chemical thinning treatments. The effects of plant growth regulators NAA, BA and NAs on fruit set, fruit size and the anatomy of the fruit cortex highly depend on varietal differences. In ‘Golden Delicious’ fruit set reduction by chemical thinning increases both the number of cell layers and cell size of apple fruit, while in ‘Red Delicious’ NAA inhibits fruit growth, while BA is ineffective. Cell growth promoting activity of NAA and NAs, accompanied by the decrease in fruit set and reduced competition among fruits within the canopy, results in a significant fruit weight increase at harvest. The research confirms the auxinic properties of NAs, and their assumed thinning activity.     

Effect of Different Treatments on Branching of Some Apple Trees in Nursery

This study was conducted to determine effect of different treatments on branching of one-year-old ‘Fuji’, ‘Granny Smith’ and ‘Red Delicious, Red Chief’ trees which grafted on M9 rootstock. Plant growth promoting rhizobacteria (Pseudomonas BA-8) strain, 6?Benzyl Adenin (BA) and pinching were used to promote branching. The BA (300?ppm) and BA-8 (10⁹CFU/ml) were applied to first twenty centimeters of the top part of trees. The BA, BA-8 and Pinching was applied to trees at 75?cm in length. According to our results, BA-8 and pinching increased number of branches compared to control and BA treatments for all cultivars. BA-8 increased number of branches in ‘Fuji’, ‘Red Delicious, Red Chief’ and ‘Granny Smith’ from 2.71, 1.70 to 4.25 branches/tree, respectively while pinching increased 1,95 branches/tree in ‘Red Delicious, Red Chief’ and 4,01 branches/tree. The highest branch’s angle was obtained from BA-8 bacteria in ‘Fuji’ (64.46°), and ‘Red Delicious, Red Chief’ (52.08°) and ‘Granny Smith’ (56.91°). BA-8 bacteria treatment was found alternative practice instead of pinching in terms of branching performance.     

苹果杂交后代经济性状的遗传变异分析

以富士、新红星等苹果品种为亲本组配11个杂交组合,获得482棵杂交单株.对杂交后代的开花株率、花量、果形、果实色泽、风味和果实综合品质等遗传变异进行了分析探讨.     

论我国苹果品种的更新问题

‘国光’、‘金冠’、‘红星’、‘倭巾’、‘青香蕉’、‘大国光’等是我国主要栽培的苹果品种:其中‘国光’在辽宁省占比重60%—70%,在山东及黄河故道地区占30%—40%,虽然‘国光’在辽东半岛和胶东半岛适应性强、产量高、耐贮藏,但果个小,着色差在国际市场上缺乏竞争力,而且在黄河故道地区裂果严重,急需进行更新,‘金冠’、‘红星’贮藏性差、‘倭巾’、‘青香蕉’、‘大国光’品质不良,作者根据苹果发展趋势和我国具体条件提出一套更新品种组合.认为‘红富士’、‘华冠’(‘金冠’ב富士’)和‘华帅’(‘富士’ב新红星’)应是我国今后主要更新的品种,三者在生产中所占比重应在80%—90%,后两个品种,一个可代替‘金冠’,一个则代替‘红星’.     

Varietal Reactions to Viruses Causing Star Crack and Russet Rings on Apple Fruits

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.     

Hormonal regulation of physiological leaf spot and premature leaf abscission in ‘Golden Delicious’ apple trees

Exogenous growth substances (GA₄₊₇, IAA, PBA, and ABA) alone and in combination were applied as leaf dips to young ‘Golden Delicious’ apple trees in a growth room at 21 °C. All treatments containing GA₄₊₇ accelerated the incidence of physiological leaf spot over treatments without GA₄₊₇, ABA alone delayed the appearance of leaf spot. PBA, PBA + GA₄₊₇, and PBA + GA₄₊₇ + IAA retarded the abscission of spotted leaves.GA₄₊₇ and GA₄₊₇ + PBA also accelerated leaf spot development in bearing ‘Golden Delicious’ trees in the orchard.Fumigation of apple trees with ethylene at 2, 10, and 20 ppm had no influence on the occurrence of leaf spot or premature abscission.     

Studies on the hawthorn (Crataegus azarolus L.): III. A potential rootstock for ‘Golden Delicious9 apple and ‘Williams’ pear

Seedlings of the hawthorn Crataegus azarolus L. were budded with ‘Williams’ pear and ‘Golden Delicious’ apple and followed for compatibility, growth control, precocity and suckering. Four years of observations indicated that the hawthorn is compatible with ‘Williams’ and ‘Golden Delicious’, conferring growth control and precocity; and producing suckers profusely. On the other hand, bud break in ‘Williams’ started 10 d earlier and gave longer shoots than ‘Golden Delicious’. Delayed symptoms of incompatibility and long-term reciprocal influences require further study.     

Anatomical and morphological study of apple (Malus × domesticaBorkh.) flower buds growing under inadequate winter chilling

Summary

Some apples cultivars produce low yields when grown in regions with inadequate winter chilling. Their unsatisfactory development is attributed to the lack of climatic adaptation which causes some abnormalities in bud differentiation. The development of reproductive spurs is erratic, leading to vegetative shoots, and the flower index is very low. The purpose of this work is to understand the flower differentiation problem. An assessment was made through morphological and histological studies, also an analysis of climatic data was performed in an attempt to identify the responsible factors. The number of chilling hours recorded was about 695. Defoliation was delayed and happened during the second week of January. Bud break was advanced by 10 d in comparison with the average period. The spurs density (12 and 23 spurs per m of twigs) was similar to the values observed in normal situation. The buds carried by these spurs evolved into vegetative shoots for all variety × rootstock combination used in this study. The average of this transformation was 47 and 50% for ‘Golden Delicious’ and ‘Starking Delicious’, respectively. A flowering index obtained was very low (1.3 kg per tree). Anatomical observations carried out on buds collected in October showed that differentiation was undertaken and the floral primordium was already formed with some abnormalities in flower development in later stage. At anthesis, internal structures of the buds showed primordia disorganized. Reproductive organs presented pistil abortion with low microsporogenesis. Xylem vessel elements were not observed at the base of the bud and vascular connection was not established. This problem in flower development occurred at this stage which was affected by external factors. The winter was characterized by periods of high temperatures which affect negatively the accumulation of chilling units. The mode of action of temperature, notably of chilling on the formation of flowering organs and vessels, remains to be determined.     

Effects of grafting height of MM106 rootstock on growth,lateral shoot formation and yield in apple trees

Summary

Between 2004 and 2008, the effects of different grafting heights on sylleptic shoots were tested in the apple (Malus domestica Borkh.) cultivars ‘Granny Smith’ and ‘Gloster’, and cumulative fruit yields were evaluated. MM106 apple rootstocks were grafted 10, 20, 40, or 60 cm above soil level in August 2004. The results showed that an increased grafting height significantly decreased tree height in both cultivars. The tallest and shortest trees were observed at grafting heights of 10 cm (153.0 and 170.0 cm) and 60 cm (141.3 and 143.5 cm) in ‘Granny Smith’ and ‘Gloster’, respectively.Among the various grafting heights tested, 60 cm in ‘Granny Smith’ and 20 cm in ‘Gloster’ gave the largest stem diameters (17.6 mm and 16.8 mm, respectively). The number of lateral shoots increased significantly with increased grafting height in both cultivars. The largest numbers of lateral shoots in ‘Granny Smith’ (10.75) and ‘Gloster’ (2.00) were obtained from a grafting height of 60 cm, while 2.55 and zero lateral shoots occurred at 10 cm grafting height in ‘Granny Smith’ and ‘Gloster’, respectively. Shoot lengths decreased significantly by increasing the grafting height. Grafting heights of 10 cm and 60 cm resulted in the tallest and shortest shoots in both cultivars. Cumulative fruit yields were significantly affected by grafting height in both cultivars. The highest yield was found for a 60 cm grafting height in both ‘Granny Smith’ (11.295 kg tree^–1) and ‘Gloster’ (4.818 kg tree^–1).The results of this study suggest that grafting heights of 40 cm and 60 cm have the potential to promote branching and early bearing for apple fruit production in sustainable and organic agricultural systems.     

Estimation of the Colour Properties of Apples Varieties Using Neural Network

The consumer acceptance and the quality standard of agricultural products such as apple are determined mostly by their colour. Colour is measured with a colorimeter and quantified using the C.I.E. L^*, a^*, b^* colour space system. It is used commonly by researchers for the classification and identification of apple fruit. To the best of our knowledge, the present study is the first study investigating the prediction of some colour properties of six apple varieties through artificial neural networks (ANN). The apple varieties are ‘Amasya’, ‘Starking’, ‘Granny Smith’, ‘Pink Lady’, ‘Golden Delicious’, ‘Arapk?z?’ and the colour properties are L^* (lightness), a^* (redness), b^* (yellowness), C^* (chroma), h^* (hue angle), CI (chroma index). General Regression Neural Networks (GRNN) and Adaptive Neuro Fuzzy Interface System (ANFIS) structures were employed to predict the colour properties. According to the experimental and simulation results, the proposed ANFIS predictor had a superior performance in prediction of these colour parameters.     

Photosynthetic acclimation of apple spur leaves to summer-pruning

A/C_i and photosynthetic light response curves for gas exchange characteristics were measured for spur leaves of 25-year-old ‘Golden Delicious’ and ‘Granny Smith’ apple trees (Malus domestica Borkh.) to investigate their acclimation capacity to a shade-to-sun transition in a commercial apple orchard. Spur leaves of both cultivars adapted to summer-pruning within 2 weeks, regardless of the time of the season at which pruning was conducted. There were no significant differences between the spur leaves of later pruned trees and corresponding leaves on trees that were continuously pruned during the summer period in terms of net photosynthetic rate and carboxylation efficiency, for both cultivars. The shape of the photosynthetic light response curves also proved the acclimation potential of both cultivars to shade-to-sun transitions. The rapid increase of the chlorophyll a/b ratio after pruning indicated that the acclimation of the photosynthetic system to avoid over-excitation of the photosynthetic reaction centers occurred within 1 week. Nevertheless, leaf dry mass per leaf area was intermediate between ‘continuous summer-pruning’ and ‘no-pruning’ treatments for leaves on later pruned trees, indicating that the acclimation to shade-to-sun transitions was not perfect in either cultivar. The present data also support the hypothesis that nitrogen, phosphorus, calcium, and magnesium are distributed to leaves growing under the highest photosynthetic photon flux density in order to maximize photosynthesis.     

Stärkeeinlagerung in die Blütenorgane beim Apfel vom Beginn der Blütenknospendifferenzierung bis zur Aufblüte

Starch as an important reserve carbohydrate plays in deciduous fruit species an important role in frost resistance of the wood during winter as well as of flowers during spring frosts. Also during development of flowers the deposition of starch, e.g. in the conducting tissue of the style and in pollen grains is evident. This starch accumulation in the reproductive flower parts seems to be important for fertilization and thus fruit set. The investigations presented should contribute to elucidate the dynamic of starch accumulation in the different organs of a flower bud in apple, from the beginning of bud differentiation until anthesis. The sampled buds were sectioned after embedding in plastic material. Starch accumulation was determined by image analysis. In the four apple cultivars ‘Boskoop’, ‘Elstar’, ‘Golden Delicious’ and ‘Pinova’ starch deposition could be observed already shortly after beginning of flower bud differentiation in July/August in the calyx, corolla, anthers and ovary. Until autumn, starch content increased considerably, it showed during winter some fluctuations according to flower organ, and decreased again towards the flowering season, presumately by conversion to sucrose, as shown in the wood in relation to frost resistance. This decrease seems to be related to the energy demand which is needed for flower development, fertilization and early fruit development.     

Across- and along-row pollen dispersal in high-density apple orchards: Insights from allozyme markers

Summary

The organization of most high-density orchards of apple (Malus x domestica Borkh.) into single-cultivar rows is often viewed as an impediment to effective pollen dispersal and pollination; however, few direct estimates of pollen dispersal are available to assess the extent of this problem. We estimated the magnitude of pollen dispersal across rows (pollinator cultivars: Idared, Vista Bella, Granny Smith), and along rows, (pollinator cultivars Fuji, Paulared, Golden Russet), in two high-density orchards in Ontario, Canada. Fruit were sampled from trees at regular intervals along transects that extended beyond (either across or along row) each pollinator cultivar and the percentage of seeds that were sired by the pollen donor was estimated using allozyme markers. Seeds sired by the pollinator cultivar were found from seven (‘Granny Smith’) to 18 rows (‘Idared’) from the nearest pollinator tree and from seven (‘Fuji’, ‘Paulared’) to five trees (‘Granny Smith’) down the same row. Measured in metres, the maximum pollen dispersal distance was greater across rows (62.4.m) than along rows (13.7.m). However, the average dispersal distance across rows, expressed in metres or trees, (17.4.±m.3.6, 3.6.±0.7 trees) did not differ from that along rows (5.8.m.±4.1, 2.7.±0.8 trees). These results are at odds with previous studies that indicate that honeybees move farther along rows than across, and have important implications for the design of commercial apple orchards.     

Induction of viable 2n pollen in sterile Oriental × Trumpet Lilium hybrids

In order to induce viable 2n pollen from highly sterile diploid Oriental × Trumpet (OT) (Lilium), N₂O was used to treat flower buds of four sterile diploid OT cultivars (‘Nymph’, ‘Gluhwein’, ‘Yelloween’, and ‘Shocking’) at different stages of meiosis. There was no pollen germination in the controls. However, after N₂O treatment at 600 kPa, three of the OT hybrids (‘Nymph’, ‘Gluhwein’, and ‘Yelloween’) not only exhibited fertile flower percentages (4.3–16%), but also higher rates of pollen germination (18.8–72.5%). In addition, both the fertile flower percentages and rates of pollen germination were higher following 48 h N₂O treatment at 600 kPa than the 24 h treatment. Following 72 h N₂O treatment at 600 kPa, most flower buds or plants were damaged and any undamaged flowers showed abnormal anthers at the time of flowering. This indicated that 48 h of N₂O treatment at 600 kPa was optimal to induce viable 2n pollen in three out of four sterile hybrid OT lily cultivars. These results also showed that prophase I – metaphase I was the optimum stage of meiosis at which to induce 2n pollen by N₂O treatment in lily hybrids.