Performance Of Apple Trees Research Articles

Apple chlorotic leaf spot virus infection affects the physiology and biochemistry of leaves and the quality of fruits of Tuscany (Italy) autochthonous apple varieties

AbstractThe present study focused on three autochthonous varieties of apple trees belonging to the old Tuscany germplasm (central Italy), Chitignano, Mora and Ruggine, and aimed to (a) evaluate the presence of the four main latent viruses of apple trees (apple chlorotic leaf spot virus [ACLSV], apple mosaic virus [ApMV], apple stem grooving virus [ASGV] and apple stem pitting virus [ASPV]) and (b) elucidate the biochemical and physiological responses of apple leaves and fruits challenged by ACLSV (the only virus detected). Indeed, despite no visible symptoms being reported, more than half of the assayed trees tested positive for ACLSV, although it occurred only in Mora and Ruggine. ACLSV impaired the photosynthetic performance of apple trees, especially in Ruggine leaves, but variety‐specific responses in terms of reorganization of photosynthetic pigment and primary metabolites were reported. Mora showed a higher ability to trigger the de‐epoxidation state of xanthophylls and to accumulate α‐tocopherol, while d‐glucose and sucrose increased only in infected Ruggine leaves, probably as a signalling response and/or an osmotic adjustment of this variety under ACLSV infection. Unexpectedly, ACLSV infection slightly increased pome size, but it dramatically reduced their quality (i.e., soluble solids content), again especially in Ruggine, the only variety where reductions of d‐fructose, d‐glucose and malic acid contents were reported. Overall, the evidence here reported could offer valuable insights to effectively cope with the detrimental viral diseases affecting this species and to protect the production of one of the most consumed and appreciated fruits in the world.

Assessing and Quantifying the Carbon, Nitrogen, and Enzyme Dynamics Effects of Inter-row Cover Cropping on Soils and Apple Tree Development in Orchards

Cover crops between rows in orchards can improve the development of soil resources and increase agricultural productivity. However, there have been few reports of cover crops that can act as a “green manure” in apple orchards across arid and semiarid zones. This study investigated the effects of planting interrow vegetation on soil properties and apple tree performance during a 32-month experiment. There were six treatments: clean cultivation as a control; natural grass planting; planting with ryegrass; planting with alfalfa; planting with tall fescue; and planting with villous wild pea cover crops. The treatments primarily affected the 0- to 20-cm surface soil layer. Soil carbon, nitrogen, and enzyme levels initially decreased (during the first 12–24 months); then, they increased (24–32 months). The cover crops significantly increased nutrient contents (soluble organic carbon, microbial carbon and nitrogen, alkaline dissolved nitrogen, nitrate nitrogen, and ammonium nitrogen) in the 0- to 20-cm soil layer by more than 19.6% and increased the related enzyme activities by more than 25.2%. The alfalfa and wild pea alleys had a stronger effect on the soil environment than the control, natural grass, ryegrass, and tall fescue alley treatments; however, after 32 months, the alfalfa treatment inhibited fruit tree growth and development. This was unexpected because alfalfa seemed to have a positive effect on soil fertility characteristics. Under local ecological conditions, villous wild pea had the greatest effect on apple orchard productivity and significantly increased short branching by 15.9%, fruit weight per fruit by 12.6%, yield per plant by 8.6%, and soluble sugar content by 10.5% compared with clean cultivation. The correlation analysis showed that there were significant or highly significant positive correlations between fruit tree performance and soil carbon, nitrogen, and enzyme activity levels as the soil layer depth increased. Therefore, under local ecological conditions, cover crops have a greater effect on orchard surface soil fertility than on deeper soils, and intercropping with villous wild pea potentially produces the greatest improvement in apple orchard productivity.

Orchard floor management strategy to maintain performance of apple trees in replant soils

Orchard floor management strategy to maintain performance of apple trees in replant soils

Development and productivity of ‘Maxi Gala’ apple trees at different planting depths

The influence of planting depth on apple trees is a discussion theme between growers, technicians and researchers, about what is the influence on vigor, uniformity and even longevity of the orchard. The aim of this work was to evaluate the vegetative and productive performance of apple trees planted at different depths. The experiment was carried out in Vacaria-RS, Brazil (latitude 28°30’44”S; longitude 50°56’02”W) in 2010 with the cultivar ‘Maxi Gala’ grafted on M.9 rootstock. The treatments consisted of three different planting depths, with the graft union 5 cm above the ground, 10 and 20 cm. Trees planted with the graft union 5 cm above the ground were more vigorous and yielded less. Trees planted with the graft union 20 cm above the ground showed less vigor in the canopy but did not increase yield. Trees with the graft union 10 cm from the ground presented an intermediate vigor and the highest yield. Fruit quality was not influenced by the different planting depths.

Relationship between soil alteration index three (AI3), soil organic matter and tree performance in a ‘Cripps Pink’/M7 apple orchard

Alteration index three (AI3), which calculates the balances between three microbially-secreted enzymes, potentially enables differences between soils due to contrasting management practices to be quantified in relative terms. The ability of AI3 to distinguish between apple orchard soils under conventional and organic production protocols, and to reflect tree performance, were tested in a maturing ‘Cripps Pink’/M7 apple orchard. Activities of β-glucosidase, phosphatase and urease were determined colourimetrically in extracts of tree-row top-soils (0–15 cm) taken during September and January over five consecutive seasons. Soil organic matter content was determined by dichromate oxidation. Stem circumference and yield were measured manually. AI3 correlated significantly (p = 0.05) with soil organic matter, yield and yield efficiency. AI3 may thus be a useful indicator of relative apple tree performance under organic and conventional soil surface management practices.

(312) Replant Apple Tree Performance, and Rhizotron Observations of Root Development, Distribution, and Survival for Three Rootstock Clones in a New York Orchard

Rhizotron observations enabled us to compare the performance of three apple (Malu ×domestica) rootstock clones following different pre-plant soil treatments in an apple replant study at Ithaca, NY. Trees were planted in Nov. 2001, with one minirhizotron tube per tree in three replicate plots of three rootstocks (M7, CG30, and CG6210), three pre-plant soil treatments (fumigation, compost amendment, and untreated controls), and two planting positions (within the old tree rows, or in the old grass lanes). Monthly root observations were conducted during the 2003 and 2004 growing seasons. There were substantially fewer new roots observed in the first bearing year (2004) than the previous nonbearing year (2003), for all three rootstocks. A root-growth peak in early July accounted for more than 50% of all new roots in 2003, but there was no midsummer root growth peak in 2004. Neither pre-plant soil treatments nor old row or grass-lane planting positions had much influence on root growth. The median lifespan for roots of CG6210 was twice as long as that of CG30 and M7 in 2004. Also, CG6210 had more roots below 30-cm depth, while M7 had more roots from 11–20 cm. Trees grafted on CG6210 were bigger and yielded more fruit in the third year after planting, compared with trees on CG30 and M7 rootstocks. Crop load severely inhibited new root development and changed root-growth dynamics during the first cropping year, with a surge in root growth after fruit harvest in Oct. 2004. Rootstock genotype was the dominant influence on root lifespan and distribution, compared with pre-plant soil fumigation, compost amendments, or replanting positions within the previous orchard rows or grass lanes.

USE OF ORGANIC APPLICATIONS TO INCREASE PRODUCTIVITY OF HIGH DENSITY APPLE ORCHARDS

USE OF ORGANIC APPLICATIONS TO INCREASE PRODUCTIVITY OF HIGH DENSITY APPLE ORCHARDS

597 Rootstock and Scion Interact to Affect Apple Tree Performance: Results from a 10-year Trial by the NC-140 Technical Committee

In 1990, trials were established at 13 sites including `Golden Delicious', `Jonagold', `Empire', and `Rome' apple cultivars in all combinations on M.9 EMLA, B.9, Mark, O.3, and M.26 EMLA rootstocks. After 10 growing seasons, rootstock and cultivar interacted significantly to affect trunk cross-sectional area and yield efficiency but not yield per tree or survival. Generally, trunk cross-sectional area was greatest for M.26 EMLA, followed by O.3, M.9 EMLA, B.9, and Mark. However, differences between B.9 and Mark and between M.9 EMLA and O.3 varied with cultivar. B.9 was 34% to 46% larger than Mark with `Golden Delicious' and `Empire,' but they were similar for `Jonagold' and `Rome.' O.3 was 27% larger than M.9 EMLA with `Golden Delicious' and `Empire,' they were similar for `Rome', and O.3 was 12% smaller than M.9 EMLA with `Jonagold'. M.26 EMLA resulted in the greatest cumulative yield per tree, followed by O.3, M.9 EMLA, B.9, and Mark. Generally, cumulative yield efficiency (1992–99) was greatest B.9 and Mark and least for M.26 EMLA. M.9 EMLA and O.3 were similar and intermediately efficient. However, differences between B.9 and Mark and between M.9 EMLA and O.3 varied with cultivar. M.9 EMLA and O.3 were similarly efficient with `Golden Delicious', `Jonagold', and `Rome,' but M.9 EMLA was 11% more efficient than O.3 with `Empire'. B.9 and Mark were similarly efficient with `Golden Delicious' and `Jonagold', but Mark was 15% more efficient and 25% less efficient than B.9 trees with `Empire' and `Rome', respectively. Site played an important role, but survival was best for B.9 and poorest for O.3. Cooperators included: J.L. Anderson, W. Autio, J. Barden, G. Brown, R. Crassweller, P. Domoto, A. Erb, D. Ferree, A. Gaus, R. Hayden, P. Hirst, F. Morrison, C. Mullins, J. Schupp, and L. Tukey.

Effect of nitrogen dressings to Jonathan apple trees in a long-term experiment

During the last three decades, diverse effects of nitrogen application on the performance of apple trees were studied in field and pot experiments at the Experimental Station of University of Horticulture and Food Industry. The basic experiment, using different rates of nitrogen in kg/ha (check, N-50; N-100; N-200; N-400; and N-800), was carried out for a period of 13 years, thus including almost the whole bearing period of Jonathan apple trees on M.9 rootstocks.
 The need of nitrogen in apple orchards on M.9 rootstock and soils with moderate humus content can be decreased considerably. Nitrogen application significantly increased leaf nitrogen and magnesium, but depressed leaf phosphorus and potassium content. With increasing doses of nitrogen fruit nitrogen content significantly increased and parallelly phosphorus and potassium content decreased. Even the lowest rate of nitrogen application decreased the red colouration of fruits. A direct negative correlation between nitrogen fertilzation and fruit firmness was not proved. No close and significant correlation between fruit quality parameters and the nitrogen content in leaves, sampled at different dates, was revealed.

Discrimination against 13CO 2 in the leaves of water stressed apple

During CO2 fixation, C3 plants discriminate against the naturally occurring stable isotope 13CO2. The extent of discrimination may be a useful screening tool to evaluate the extent of stress, as compared to gas exchange measurements, as it is an integrated measure of internal physiological and environmental parameters influencing the performance of the plant throughout the season. Twelve four-year-old <Braeburn> apple trees (Malus domestica Borkh.) were used in this study. The three treatments, each randomly assigned to four trees, were: control (C) which received sufficient irrigation to initiate drainage, early deficit (ED) which was deficit irrigated from 55 days after full bloom (DAFB) to 10000 DAFB and then irrigated as for C, and late deficit (LD) which was deficit irrigated from 105 DAFB until final Harvest at 177 DAFB. Leaf water potential was reduced in ED and LD treatments during the stress period as was photosynthesis and stomatal conductance. A significant reduction in the discrimination against 13CO2 occurred in the ED and LD trees when evaluated at the end of the stress period. This manuscript highlights the usefulness of 13CO2 discrimination in the evaluation of the impact of water deficit on the physiological performance of apple trees.

Rootstock and Scion Interact to Affect Apple Tree Performance: A 5-year Summary of the 1990 NC-140 Trial

In 1990, a trial was established at 17 locations in the United States and Canada including the scions `Golden Delicious', `Jonagold', `Empire', and `Rome” and the rootstocks M.9 EMLA, B.9, Mark, O.3, and M.26 EMLA. In 1994, trees on M.26 EMLA were the largest and trees on B.9 and those on Mark were the smallest, regardless of scion. Trees on M.9 EMLA were intermediate. `Golden Delicious' and `Empire” trees on O.3 were larger than those on M.9 EMLA. `Jonagold' and `Rome' trees on O.3 were similar in size to those on M.9 EMLA. With all scions, B.9 and Mark resulted in the lowest cumulative yields. With `Jonagold', `Empire', or `Rome' as the scion, O.3, M.26 EMLA, and M.9 EMLA resulted in the greatest and similar yields. With `Golden Delicious' as the scion, however, trees on M.9 EMLA yielded only as much as those on B.9 or Mark. Trees on B.9 and those on Mark were the most yield-efficient, regardless of scion. `Golden Delicious' and `Rome' trees on O.3 were similar to those on B.9 and those on Mark, but `Jonagold' and `Empire' trees on O.3 were less efficient than those on B.9 or on Mark. Overall, M.26 EMLA resulted in the lowest efficiency; however, M.9 EMLA resulted in more efficient trees only with `Empire' as the scion. Participants include: J.L. Anderson (Utah), W.R. Autio (Mass.), J.A. Barden (Va.), G.R. Brown (Ky.), P.A. Domoto (Iowa), D.C. Ferree (Ohio), A. Gaus (Colo.), R.L. Granger (Quebec), R.A. Hayden (Ind.), F. Morrison (Kan.), C.A. Mullins (Tenn.), S.C. Myers (Ga.), R.L. Perry (Mich.), C.R. Rom (Ark.), J.R. Schupp (Maine), and L.D. Tukey (Pa.).

SPRING Vs. AUTUMN FERTILIZER APPLICATION EFFECTS ON APPLE TREES IN THE MID-SOUTH

Three studies were established to compare spring (S) vs. autumn (F) N fertilizer applications on apple tree performance. The studies used newly planted trees, 4-yr-old trees, and 8-yr-old trees, fertilized with either ammonium nitrate or urea at 2 weeks after harvest (F) or at bud break (S). In the first 3 years growth in a newly planted orchard, time of fertilizer did not significantly affect tree height or TCSA. In the first cropping year, F fertilized trees had the greatest flower cluster number and bloom density but similar % set and yield compared to S fertilized trees. F fertilized trees in mature orchards studies tended to be shorter and have smaller TCSA increment after 3 yrs. Treatments did not affect bloom density, % set or total yield although spring fertilized trees had a greater % drop. Although spur leaves of F fertilized trees had greater N content at bloom, shoot leaves typically had lower N and Mn, and higher P, K, and Ca at 90 days after bloom compared to S treatment trees.

Apple Tree Performance with Mechanical Hedging or Root Pruning in Intensive Orchards

Annual mechanical hedging in August or root pruning at bloom was used to control the growth of four apple (Malus domestica Borkh.) cultivars in two orchard systems planted at half the recommended in-row spacing. Trunk cross-sectional area (TCA) per hectare on the trellis system was 30% higher, a result that correlated (r = 0.80) to a 40% higher cumulative yield per hectare over 10 years compared to the central leader system. Over 10 years, the cumulative yield and TCA per hectare of `Smoothee Golden Delicious', `Empire', and `Redchief Delicious' were higher in the trellis than the central leader system, while these characteristics of `Lawspur Rome Beauty' were not influenced by orchard system. `Lawspur' had the highest TCA per hectare, cumulative yield per hectare, and greatest tendency toward biennial bearing of the four cultivars. Root pruning reduced all tree-size measurements, while hedging did not influence tree height or average shoot length. Yield and yield per TCA were reduced by hedging and root pruning, with the greatest reduction in yield caused by root pruning. Hedging increased cumulative yield per hectare with root-pruned trees intermediate between hedged standard-spaced trees. Trellis trees had a higher density of spurs and shoots and a higher leaf area index than trees on the central leader system. An evaluation of the treatment combinations using net present value analysis indicated that none of the treatments was a profitable investment. Of the top twelve treatments, as evaluated for 10 years, nine were the central leader and three the trellis system, with none of the trellis and only four of the central leader treatments being hedged or root-pruned. Results of this study indicate that orchard intensification is accomplished best by choosing appropriate planting distances and not by attempting to control growth mechanically on trees planted too close for optimum performance.

Controlling Apple Replant Disease in `McIntosh' Apple Trees on Various Rootstock

Apple replant disease (ARD) adversely affects development and performance of apple trees planted in old orchard soils; it is characterized by stunted tree growth, which reduces orchard profitability (Hoestra and Oostenbrink, 1962; Mai and Parker, 1967). The probable cause of ARD is a complex of soil-borne microorganisms, including parasitic nematodes. The lesion nematode Pratylenchus penetrans is a component of ARD in some soils. Preplant soil fumigation improves root system development, tree growth, and cropping in some orchard sites (Hoestra and Oostenbrink, 1962; Jaffee and Mali, 1979; Mai and Parker, 1970). We examined the effects on tree performance of preplant soil fumigation, a postplant nematicide treatment, and rootstock at the Univ. of Vermont Horticultural Research Center in 1983. Results for 1983–1985 were reported by Costante et al. (1987). We now present results for the final 4 years of the experiment (1986-1989). Trees were on a well-drained Adams loamy sand (pH 6.2) on a 20-year-old orchard site infested with P. penetrans and with a diagnosed replant” disease problem (Costante et al., 1987). Eighty ‘Rogers Red McIntosh’ trees each on semi-dwarfing MM.111, MM. 106, M.7a, or dwarfing M.26 rootstock were planted on 2 May 1984 at 2.4 x 5.5 m spacing, including appropriate buffer areas.

INFLUENCE OF SOURCES, RATES AND TIMES OF SOIL APPLICATION OF NITROGEN ON APPLE TREE PERFORMANCE AND FRUIT QUALITY IN ONTARIO, CANADA

ISHS Symposium on Mineral Nutrition and Fruit Quality of Temperate Zone Fruit Trees INFLUENCE OF SOURCES, RATES AND TIMES OF SOIL APPLICATION OF NITROGEN ON APPLE TREE PERFORMANCE AND FRUIT QUALITY IN ONTARIO, CANADA

Effects of Deep Planting on Anchorage and Performance of Apple Trees

SummaryTrees of Cox’s Orange Pippin budded at 12 inches height on M.VII rootstocks were planted 6 inches deeper than usual and compared over a six-year period with similar trees budded at 6 inches and planted at normal depth, all without staking. The deep-planted trees all remained firmly anchored and required no staking while more than half the controls leaned over. There was a slight temporary check to growth with deep planting, and some reduction in early cropping. Suckering from roots was greatly reduced. The effects of deep planting were influenced by soil variation.