•Feathered trees have higher early yield and higher cumulative yield compared to the bench-grafted ones.•There was no difference in tree size between feathered and bench-grafted trees after 11 ...years.•‘G.11’ was the best rootstock for ‘Fuji’, ‘G.41’ for ‘Gala’, and ‘G.16’ for ‘Honeycrisp’ trees.•‘Gala’ orchard performance varied between sites due to differences between soil and climatic conditions.
In 2006, two 0.3 ha orchard trials were established at two sites (Dressel farm in Southeastern New York State and VandeWalle farm in Western New York State) to compare two tree types (feathered trees and bench-grafted trees) on five rootstocks three Geneva® rootstocks (G.11, G.16, G.41) with one Budagovsky rootstock (B.9) and one Malling rootstock (M.9T337) as controls. ‘Gala’ and ‘Fuji’ were used as scion cultivars at Dressel farm and ‘Gala’ and ‘Honeycrisp’ as the scions cultivars at VandeWalle farm. At each location, trees were planted at 3,262 trees ha−1and trained to a Tall Spindle (TS) system. Location, tree type and rootstock interacted to affect tree growth, production and fruit quality of each scion cultivar. ‘Gala’ trees from VandeWalle (Western NY State) were more productive (33% more production) than those from Dressel Farm (Southern NY State), because they produced more fruits per cm−2 and fruit size was bigger. When comparing the two tree types (feathered and bench-grafted) at both locations and across all rootstocks (B.9, G.11, G.16, G.41, and M.9T337), feathered trees were similar in tree size after 11 seasons as bench-grafted ones, except for ‘Fuji’ at Dressel farm where bench-grafted trees were 27% smaller than feathered trees. The bench-grafted trees had lower cumulative yield per hectare, cumulative yield efficiency, and cumulative crop load than the fully feathered trees. Finally, when comparing all 10 tree type × rootstock combinations, for ‘Fuji’, feathered trees with G.11, for ‘Gala’, feathered trees with G.41, and for ‘Honeycrisp’, feathered trees with G.16 were the combinations with the highest cumulative yield, high yield efficiency and crop loads, low biennial bearing, and with slightly significant larger fruits.
•‘Gala’ orchard performance varied between sites due to differences in soil and climatic conditions.•‘Fuji’ tress on TS with ‘G.11’ and ‘G.16’ were the most productive, with good fruit ...quality.•‘Gala’ trees on TS with ‘G.11’ and ‘G.41’ were the most productive, with good fruit quality.•‘Honeycrisp’ trees on TS with ‘G.16’ and ‘M.9’ were the most productive, with good fruit quality.
In 2006, two 1-ha orchard trials were established at each of two sites (Dressel farm in Southeastern New York State and VandeWalle farm in Western New York State) to compare seven Geneva® rootstocks (‘CG.4210’, ‘G.11’, ‘G.16’, ‘G.41’, ‘G.30’, ‘G.210’, and ‘G.935’) with one Budagovsky (‘B.9’) and three Malling rootstocks (‘M.9T337’, ‘M.26EMLA’ and ‘M.7EMLA’) as controls. ‘Gala’ and ‘Fuji’ were used as scion cultivars at Dressel farm and ‘Gala’ and ‘Honeycrisp’ as the scion cultivars at VandeWalle farm. At each location trees were trained to four high-density systems: Slender Pyramid (SP) (840 trees ha−1), Vertical Axis (VA) (1284 trees ha−1), Slender Axis (SA) (2244 trees ha−1), and Tall Spindle (TS) (3262 trees ha−1). Location, rootstock, and training system, interacted to affect growth, production and fruit quality of each scion cultivar. ‘Gala’ trees from VandeWalle farm were smaller but more productive than those from Dressel farm. In general, the largest trees (in trunk cross sectional area: TCSA) were SP on ‘M.7’ rootstock and the smallest were TS on ‘B.9’ and ‘G.11’. Cumulatively, yield was lowest for trees on SP with ‘M.7’. However, the highest values were on TS with ‘G.11’ for ‘Fuji’, TS with ‘G.41’ for ‘Gala’, and TS with ‘G.16’ and ‘M.9’ for ‘Honeycrisp’. Independent of the cultivar, trees on SP with ‘M.7’ had the highest number of root suckers. When comparing systems which had the same rootstocks, TS trees were the least vigorous ones, but much more productive although, fruit red color was slightly reduced compared to the lower density systems. When comparing dwarfing rootstocks common across several systems, generally, ‘G.16’ trees were the largest, however ‘G.11’, ‘G.41’ and ‘M.9’ were the most productive for ‘Fuji’, ‘Gala’ and ‘Honeycrisp’, respectively.
Rapid apple decline is a phenomenon characterized by a weakening of young apple trees in high density orchards, often followed by their quick collapse. The nature of this phenomenon remains unclear. ...In this work, we investigated the root system architecture (RSA) of declining and non-declining apple trees in two orchards in New York State. High-density orchard A consisted of 4-year-old 'Honeycrisp' on 'Malling 9 Nic29', and conventional orchard B consisted of 8-year-old 'Fuji' on 'Budagovsky 9'. In both orchards, a negative correlation (-0.4--0.6) was observed between RSA traits and decline symptoms, suggesting that declining trees have weaker root systems. Scion trunk diameter at the graft union, total root length, and the length of fine and coarse roots were significantly (
< 0.05) reduced in declining trees in both orchards. Additionally, internal trunk necrosis at, above, and below the graft union was observed in declining trees in orchard A but not in orchard B. Finally, latent viruses were not associated with decline, as their occurrence was documented in declining and non-declining trees in orchard A, but not in orchard B. Together, these results showed weakened root systems of declining trees, suggesting that these trees may experience deficiencies in water and nutrient uptake, although distinct RSA and trunk health traits between the two orchards were noticeable.
Precision crop load management of apple requires counting fruiting structures at various times during the year to guide management decisions. The objective of the current study was to evaluate the ...accuracy of and compare different commercial computer vision systems and computer applications to estimate trunk cross-sectional area (TCSA), flower cluster number, thinning efficacy, and yield estimation. These studies evaluated two companies that offer different vision systems in a series of trials across 23 orchards in four states. Orchard Robotics uses a proprietary camera system, and Pometa (previously Farm Vision) uses a cell phone camera system. The cultivars used in the trials were ‘NY1’, ‘NY2’, ‘Empire’, ‘Granny Smith’, ‘Gala’, ‘Fuji’, and ‘Honeycrisp’. TCSA and flowering were evaluated with the Orchard Robotics camera in full rows. Flowering, fruit set, and yield estimation were evaluated with Pometa. Both systems were compared with manual measurements. Our results showed a positive linear correlation between the TCSA with the Orchard Robotics vision system and manual measurements, but the vision system underestimated the TCSA in comparison with the manual measurements (R2s between 0.5 and 0.79). Both vision systems showed a positive linear correlation between nubers of flowers and manual counts (R2s between 0.5 and 0.95). Thinning efficacy predictions (in June) were evaluated using the fruit growth rate model, by comparing manual measurements and the MaluSim computer app with the computer vision system of Pometa. Both systems showed accurate predictions when the numbers of fruits at harvest were lower than 200 fruit/tree, but our results suggest that, when the numbers of fruits at harvest were higher than 200 fruit/tree, both methods overestimated final fruit numbers per tree when compared with final fruit numbers at harvest (R2s 0.67 with both systems). Yield estimation was evaluated just before harvest (August) with the Pometa system. Yield estimation was accurate when fruit numbers were fewer than 75 fruit per tree, but, when the numbers of fruit at harvest were higher than 75 fruit per tree, the Pometa vision system underestimated the final yield (R2 = 0.67). Our results concluded that the Pometa system using a smartphone offered advantages such as low cost, quick access, simple operation, and accurate precision. The Orchard Robotics vision system with an advanced camera system provided more detailed and accurate information in terms of geo-referenced information for individual trees. Both vision systems evaluated are still in early development and have the potential to provide important information for orchard managers to improve crop load management decisions.
Many viruses occur in apple (
(Borkh.)), but no information is available on their seed transmissibility. Here, we report that six viruses infecting apple trees, namely, apple chlorotic leaf spot ...virus (ACLSV), apple green crinkle-associated virus (AGCaV), apple rubbery wood virus 2 (ARWV2), apple stem grooving virus (ASGV), apple stem pitting virus (ASPV), and citrus concave gum-associated virus (CCGaV) occur in seeds extracted from apple fruits produced by infected maternal trees. Reverse transcription polymerase chain reaction (RT-PCR) and quantitative RT-PCR (RT-qPCR) assays revealed the presence of these six viruses in untreated apple seeds with incidence rates ranging from 20% to 96%. Furthermore, ASPV was detected by RT-PCR in the flesh and peel of fruits produced by infected maternal trees, as well as from seeds extracted from apple fruits sold for fresh consumption. Finally, a large-scale seedling grow-out experiment failed to detect ACLSV, ASGV, or ASPV in over 1000 progeny derived from sodium hypochlorite surface sterilized seeds extracted from fruits produced by infected maternal trees, suggesting no detectable transmission via embryonic tissue. This is the first report on the seedborne nature of apple-infecting viruses.
•Higher NPV values for ‘Honeycrisp’, followed by ‘Gala’ and, finally, for ‘Fuji’.•Feathered trees reached the break-even year faster than did bench-graft trees.•Fastest investment pay offs was ...achieved with ‘Honeycrisp’, followed by ‘Gala’ and ‘Fuji’.•The most important factors that influence orchard profitability are fruit price and yield.•Fruit price and yield showed a positive linear relationship with NPV while discount rate, tree price, land cost and labor cost showed negative relationship.
Planting a new orchard requires a complex management strategy that involves many factors including cultivar, rootstock, planting density, training system, tree type, climate, and economic conditions that affect orchard profitability. To evaluate the relative importance of each factor, data from long-term field studies is required to analyze their impact on lifetime profitability. Here, we conducted two long-term field studies at two locations in New York State (Dressel farm in South-eastern and VandeWalle farm in Western New York State). The trials were planted in 2006 at a planting density of 3,262 tree/ha and the trees were trained as Tall Spindles. The aim of this study was to compare the impact of tree type (newly bench-grafted trees and large 2-year feathered trees) and rootstock (B.9, M.9, G.11, G.16, G.41) on long-term profitability of three apple cultivars (‘Fuji’, ‘Gala’, and ‘Honeycrisp’). There were important differences in profitability between cultivars, with a higher Net Present Value (NPV) for ‘Honeycrisp’, followed by ‘Gala’ and, finally, for ‘Fuji’. For all the cultivars, the NPV of the feathered trees was substantially higher compared to bench-grafted trees. Furthermore, the highest cumulative NPV's for ‘Honeycrisp’ were on B.9, G.11 and G.16, whereas with ‘Fuji’ the highest NPV's were on G.16, G.11 and M.9 and with ‘Gala’ the highest NPV's were on G.16, G.41 and M.9. The break-even year of a positive NPV for each rootstock, tree type, and cultivar, showed that the fastest investment pay offs were achieved with ‘Honeycrisp’, followed by ‘Gala’ and ‘Fuji’. Feathered trees showed a faster break-even year of a positive NPV compared to bench grafted trees in all cultivars. Our results showed that the key variables that influence orchard profitability were, in descending order, fruit price and yield, followed by discount rate, labor cost, and finally tree price and land cost.
The adoption of mechanical thinning and pruning in commercial apple orchards has been limited largely by the risk of development and spread of fire blight. This devastating disease, caused by the ...bacterial pathogen
, may be transmitted by mechanical injury such as pruning, especially under warm, moist conditions conducive to bacterial growth, infection, and disease development. However, risk may be mitigated by avoiding highest-risk times and applying a bactericide, such as streptomycin, after mechanical thinning or pruning. In 'Gala' and 'Idared' orchards, we evaluated the risk of fire blight development and spread after mechanical thinning early in bloom (20% bloom), when seasonal temperatures are cooler and there are few open flowers available for infection. In both orchards, we also evaluated the spread and development of fire blight by mechanical pruning in July and in August, before and after terminal bud set, when shoot growth is slowed and the tree is less susceptible to infection. We also assessed the potential efficacy of a streptomycin or
biopesticide application after mechanical thinning and pruning to mitigate the spread of fire blight. In the 'Gala' orchard, disease never developed beyond the inoculated tree after thinning or pruning, which was unexpected for this highly susceptible cultivar. In the 'Idared' orchard, incidence of blossom or shoot blight from the point source, represented as relative area under the disease progress curve, was rarely different for trees that underwent mechanical thinning or mechanical pruning compared with untreated trees, and it was often reduced or eliminated when the antibiotic streptomycin or the
biopesticide was applied within 24 h of mechanical thinning or pruning. For both thinning and pruning, incidence of fire blight dropped off quickly beyond the inoculated tree in the 'Idared' orchard and generally was not observed in trees beyond 10 to 15 m from the inoculated point source or predicted beyond 10 m by exponential and power law models fit to the disease progress curves. The results of this work demonstrate the low risk for fire blight development and spread by mechanical thinning and pruning when practiced under low-risk conditions-early in bloom for mechanical thinning and after terminal bud set (in August) for mechanical pruning-especially when paired with a subsequent bactericide application. This study demonstrates the safe use of mechanical thinning and pruning in commercial apple production, corroborated by anecdotal evidence from apple growers in western New York State.
•The choice of cultivar has a very large effect on long-term profitability primarily because of the different prices assigned to different cultivars.•High-density plantings with a density of ...2500–3300 trees per hectare on dwarfing rootstocks are less risky investments because of the shorter breakeven time.•With cultivars that have high fruit price and with high density plantings, the investment to plant a new orchard is less risky because of the shorter breakeven time.•Labor cost had a significant effect on NPV but was of much less importance than fruit price, yield and discount rate.
An economic analysis of profitability using Net Present Value (NPV) was conducted using data from two long-term training system × rootstock field trials conducted in New York State from 2006 to 2016 (Dressel Farm in southeastern New York State and VandeWalle Farm in Western, New York State). We used trial data for the first 11 years and estimated values for years 12–20 using average data from the last 4 years of field data. The field trials compared four training systems with different planting densities (Slender Pyramid, 840 trees ha−1; Vertical Axis, 1282 trees ha−1; Slender Axis, 2244 trees ha−1; and Tall Spindle, 3262 trees ha−1) each evaluated with several rootstocks in an incomplete factorial treatment list and with two cultivars at each location. By the end of the trial (11 years) all combinations of planting density, rootstock and cultivar were profitable (NPV positive) at the VandeWalle site but at the Dressel site seven combinations of rootstock and planting density with ‘Fuji’ and two combinations with ‘Gala’ were not profitable. Projected profitability over 20 years using estimated yields and fruit quality for years 12–20 showed that all combinations would be profitable by year 20. Estimated 20-year NPV was greatest with the Tall Spindle system with the highest planting density compared to the other lower density systems. Economic performance was mostly driven by planting density, regardless of the rootstock selection. Among cultivars, ‘Honeycrisp’ had significantly higher profitability largely due to high fruit price). ‘Gala’ had intermediate profitability due to high yields and medium fruit price while ‘Fuji’ which had low fruit price had significantly lower profitability than ‘Gala’. Among rootstocks, there was a significant interaction with training system and cultivar, so the same rootstock was not the most profitable with every cultivar and system. With ‘Fuji’ the most profitable combination was on G.16 rootstock planted at the highest density, however, it was not significantly better than with G.11 or M.9. With ‘Gala’ at Dressel farm the most profitable combination was on G.11 in the Tall Spindle system (planted at the highest density) but it was not significantly better than with G.16, G.41, M.9 or B.9. With ‘Gala’ at VandeWalle farm the most profitable combination was on G.41 planted at the highest density but it was not significantly better than on G.11, G.16, M.9 or B.9. With ‘Honeycrisp’ the most profitable combination was on M.9 planted at the highest density but it was not significantly better than G.11, G.16, G.41 or B.9. A sensitivity analysis showed that among economic parameters affecting the long-term profitability of an orchard, fruit price and yield were vastly more important than other factors. Of intermediate importance were the discount rate and labor costs while of much lesser importance were tree costs and land costs.