Determining the commercial viability of an exclusionary production system using disease-resistant columnar apple and sweet cherry cultivars

2006 Annual Report for LNE03-182

Project Type: Research and Education
Funds awarded in 2003: $137,169.00
Projected End Date: 12/31/2007
Region: Northeast
State: New York
Project Leader:
Peter Jentsch
Poma Tech Inc.

Determining the commercial viability of an exclusionary production system using disease-resistant columnar apple and sweet cherry cultivars

Summary

The project manager continued to develop the 5 ‘exclusion’ sites (including 1 CSA farm (Community sponsored agriculture), 2 commercial farms, 1 historic farm, and one research site at Cornell's Hudson Valley Lab.). The disease-resistant columnar apple and dwarfing sweet cherry trees planted in a v-trellis high-density system was maintained for optimum growth in preparation for 2006 fruit production. The addition of wood chip mulches, weed removal, use of the drip irrigation, and development of the fixed-canopy spray system (HVL site only) are being used to familiarize fruit growers with an integrated pest management system to protect against insect and vertebrate pests, hail and in the case of cherry, rainfall, without the use of synthetic and in some cases, organic pesticides.

The winter of 2005-06 was relatively mild compared to the previous years, causing no apparent fruit tree injury or reduction of fruiting buds on apple and cherry throughout the Hudson Valley. Commercial crop estimates throughout the region were very high. The project trees being in their 4th leaf should have produced an abundant crop this year, yet they did not produce a significant fruit quantity in 2006 to be economically viable. This seems to be a varietal response in the columnar trees we have chosen for the project. Pollination and fruit related evaluations were conducted in 2006 and initial estimates were optimum. Given the lack of fruiting potential and cost of exclusion netting, the placement of netting to reduce insect and vertebrate damage to the cherry planting will be added in spring 2007 and data to determine the efficacy of netting relative to non-netted plots will be evaluated.

We evaluated growth of the apple varieties used in the trial. For a second year we evaluated the degree of insect and disease pressure and efficacy of netting versus the non-netted plots as well as efficacy of organic pest management efficacy of the fixed spray system within the netting versus the non-netted plots. We conducted spray drift trials using the fixed spray system comparisons in the netted, un-netted compared to a conventional airblast application. We evaluated weed presence using mulch treatments in the netted and un-netted plots in which we evaluated weed species and density. We also collected weather data to determine the environmental factors related to the netting versus the non-netted plots.

A new pomologist was added to the staff of Cornell’s Hudson Valley Lab as of September 2006. Steve Hoying, the new Horticultural Extension Associate has shown some interest in the project but due to staffing and grape responsibilities will not be able to assist in the project.

Objectives/Performance Targets

Spring 2006

The exclusion production system is to be developed on each of the 5 farms and research sites. Evaluation of insect and disease will be made. Weather stations will be established and maintained to record environmental data throughout the growing season.

1. Overhead fixed spray system continued to be developed for canopy applications at the HVL site.

2. Continuation of weed management through the application of weed barrier of composted chipped hardwood for optimum tree growth.

3. Continuation of use of the mason / blue orchard bee for pollination within plots for optimum tree growth.

4. Maintenance of plots including pruning for optimum fruit establishment was continued.

5. Weather stations were established to monitor two collection sites to determine environmental conditions within exclusion plots compared to that in an un-netted plot.

6. Incidence of insect fruit damage and foliar presence was determined through pre-June drop and harvest data collection. Data was analyzed and presented in this report.

7. Incidence of disease to fruit and foliage was determined through early-mid season data collection. Data was analyzed and presented in this report.

Summer 2005
Growers and researchers will begin management protocols while making evaluations throughout the growing season.

1. Researchers to maintain detailed records and costs of inputs to conventional, IPM, and organic blocks while following exclusion management protocols.

2. Pomology team was to conduct fruit tree trunk and canopy volume measurements for growth baseline initiated (Previous Pomologist committed to the project no longer resides at the HVL and a substitute department will conduct horticultural data in 2006).

3. Entomology team to continue ground cover management.

Fall 2006
Year-end report to be sent to researchers, growers and NESARE.

1. Write–up and analysis of data in each area of applicable study for year three.

2. Expenditures for establishment and management of each system compiled.

3. Foliar analysis for nutritional analysis.

4. Fixed spray system evaluation for nutrient, irrigation and organic pesticide delivery.

Accomplishments/Milestones

Spring:
A total of 104 cubic yards of composted wood chip was added to the 5 sites to maintain weed control. No additional nitrogen was required in 2006 as manure at planting and organic matter decomposition provided adequate supplies for the third growing season.

A fixed nutrient, irrigation and spray system was completed. Organic pesticide programs were initiated in both covered and un-netted plots in a complete replicated block design. Complete evaluation of the four treatments was conducted.

Summer:
Technical time spent on weed removal was maintained from the previous year as reduction in weed composition was accomplished through the use of yearly mulch applications. Application of mulch for weed management continues to be the greatest expenditure of time and consequently capital resources.

Insect, disease and weather data was collected and analyzed to evaluate the efficacy of the exclusion production system. Efficacy of the exclusion system for disease and insect management was significantly superior, producing a higher level of marketable fruit than the un-netted plots with no pesticide inputs. Highest quality and number of marketable fruit were observed in the organically treated netted plots.

The fixed spray system was evaluated for spray drift using spray sensitive cards. The system demonstrated significantly reduced drift on pesticide in both the netted and un-netted plots than the conventional orchard airblast applications. The netted spray system showing the least amount of pesticide drift.

Fall:
Soil and foliar analysis was taken and evaluation confirmed adequate nutritional status in production plots with higher levels of both available nitrogen and organic matter compared to the commercial plots as well as neutral pH levels.

The exclusion production system was well maintained on each of the 5 farms and research site. Growers and researchers began management protocols while making evaluations throughout the growing season.

Impacts and Contributions/Outcomes

The development of the exclusion system and education of growers to become involved with function of the exclusion system continued in 2006.

Elimination in the use of herbicides to manage weed competition through the use of wood chip mulch and elimination of fungicide applications for disease management through the use of disease resistant cultivars has dramatically reduced the number of chemical applications required for this system of fruit production. Elimination of chemical drift and worker exposure are apparent consequences using this method of pest management. Labor in weed management continue to have offset any monetary savings that might have been realized in chemical and application reduction in 2006.

Poster kiosks describing the project are established on farm sites and in retail markets affiliated with individual project farms and will continue in the spring to broaden the community awareness of the project and its implication on fruit production, as well as benefits to apple and cherry consumers. Grower and community interest in non-spray apple production in commercial, historical / visitor based site, and pick you own sites where projects are visible, continue to develop.

Data from all plot evaluations in the following pages were taken to evaluated the efficacy of the fruiting varieties, insect exclusion system, organic applications within a fixed spray system and represent field means. The mean separation was performed by Fishers Protected LSD (P=<0.05). Treatment means followed by the same letter are not significantly different.

In 2006 weed presence within the plots was abundant in both diversity and density, differing numerically between the netted and un-netted plots. The differences in part may be due to the presence of birds roosting on the wire and defecating seed into the un-netted plots. Quack grass, Elytrigia repens, was prevalent through all the plots with netted plots averaging 13.6 plants/sq.ft.and un-netted plots averaging 11.8 plants/sq.ft. Red Sorrel, Rumex acetosella, was not found in the netted plots but averaged 4.3 plants/sq.ft in the un-netted. Wild Buckwheat, Polygonum convolvus, was also not found in the netted plots but averaged low numbers throughout at 0.1 plants/sq.ft in the un-netted. Dandelion, Taraxacum officinale, was prevalent in low numbers through all the plots with netted plots averaging 0.08 plants/sq.ft.and un-netted plots averaging 0.13 plants/sq.ft. Wild Black Cherry, Prunus serotina, was also prevalent in low numbers through all the plots with netted plots averaging 0.08 plants/sq.ft.and un-netted plots averaging 0.25 plants/sq.ft. Yellow Toadflax, Lunaria vulgaris, was not found in the netted plots but averaged 0.3 plants/sq.ft in the un-netted plots. Poison Ivy, Rhus radicans, was also prevalent in low numbers through all the plots with netted plots averaging 0.04 plants/sq.ft.and un-netted plots averaging 0.25 plants/sq.ft. Virginia Creeper, Parthenocissus quiquefolia, and Wild Grape, Vitis rotundifolia, was not found in the netted plots but averaged 0.5 and 0.08 plants/sq.ft in the un-netted plots respectively.

The fixed spray system was completed using both above and below ground delivery systems. Overhead sprays delivering organic nutrient and pesticide to both apple and sweet cherry varieties were initiated with herbicide delivery to begin in 2007. The system consists of ½” pvc tubing, overhead misting nozzles delivering 0.16 gpm (29.73 gpm per 6 treated plots in 371’ of linear row). Organic pesticide programs were initiated in both netted and un-netted plots in a complete replicated block design and consisted of 10 separate applications for control of plum curculio, leafroller complex, codling moth and the internal lep. Complex, stink bug complex, cherry and apple aphid complex, leafhopper complex, apple maggot. Treatment schedule: Surround WP at 50 lbs./A, 80% Sulfur at 18.0 lbs./A, Aza-Direct at 48.0 oz./A, Entrust at 2.5 oz./A on 25 May; Surround WP at 50 lbs./A, 80% Sulfur at 18.0 lbs./A, Aza-Direct at 48.0 oz./A on 31 May; Sulfur at 18.0 lbs./A on 14 June, 7 July; Sulfur at 18.0 lbs./A, Entrust at 2.5 oz./A on 21 and 30 June; 14, 21 July and 4 August.

Significant reductions in pesticide drift were recorded this season in comparison trials between a fixed spray system (FSS) within the netted exclusion and un-netted system and the conventional airblast spray system. No significant differences between drift in the netted and un-netted FSS were observed yet netted plots were observed having <50% of overall drift compared to the un-netted. Both netted and un-netted fixed system exhibited significantly less surface area drift than the conventional airblast application using a three-point hitch mounted sprayer delivering 100 gal./A at 300 psi. The netted FSS demonstrated 0.7 cm2 density of spray drift on water sensitive cards compared to 4.2 cm2 overall drift using the airblast application. Netted FSS having 0.7 cm2 vs 2.0 cm2 in un-netted FSS application. Both netted and un-netted fixed spray system demonstrated significantly less percent surface area drift (cards laying horizontal/parallel to the ground and vertical) than conventional airblast application. The netted fixed spray system, the un-netted fixed spray system, and the airblast applications having 3.9%, 11.6%, 25.4% overall drift respectively in all distances (5', 10', 20', 40') from the spray source. The greatest difference in the percent drift category was observed in drift occurring in the 5’ distance from each spray system. In the 5’ from source category the netted FSS covered 11.4% of the card, the un-netted FSS covered 34.5%, and the conventional airblast application covered 36.8% of the card. In the 10’ from source category the netted FSS covered 0.2% of the card, the un-netted FSS covered 0.2%, the conventional airblast application covered 29.9% of the card. The airblast application had drift in both the 20’ and 40’ range with 12.2% and 3.2% card coverage respectively compared to no visible drift in either the netted or un-netted fixed spray system in those ranges.

Substantial reductions in pest damage were observed to foliage and fruit of sweet cherry plots treated with organic fungicide and insecticide programs this season compared to untreated trees (see treatment schedule). The two early harvest varieties were evaluated prior to the heavy rains that caused complete harvest loss of our two later varieties (Regina and Sweetheart) No significant differences between cherry varieties were observed with regards to average number of fruit harvested (Attica: 32.5/tree; , Benton: 37.0/tree), bird damage (Attica: 3.6/tree; , Benton: 15.6/tree), rotted fruit on the tree (Attica: 2.7/tree; , Benton: 17.9/tree),, and harvested fruit weight. Cherry treated with an organic pest management program had more fruit at harvest (Treated: 46.7 fruit/tree totaling 456.9 grams , Untreated 16.8 / tree totaling 175.8 grams) and fewer rotten fruit on the tree (Treated: 9.6 fruit/tree, Untreated 11.3 / tree). The two late season sweet cherry varieties were lost due to heavy rains just prior to harvest leading to severe cracking and 100% loss of fruit.

Three of the four apple varieties we’ve chosen within the study parameters that are disease resistant dwarfing columnar varieties commercially available through Stark Brothers. These include the Stark ‘Ultra’, ‘Crimson’ and ‘Emerald’. The ‘Wijick’ variety is a ‘standard’ dwarfing columnar variety we used as a comparison. As stated earlier we found relatively high levels of flowers / tree. Fruit within and outside the exclusion cages were comparable in number using the blue orchard bee as a pollinator within the cages compared to the native pollinators outside the exclusion system. The number of fruit per tree of each variety was lower than expected during year three. We observed mean fruit numbers of 4.8, 4.2, and 7.7 fruit per tree in Stark ‘Ultra’, ‘Crimson’ and ‘Emerald’ respectively with too fruit to measure of the Wijick’ variety. The spacing of these trees on two spacing dimensions (12” and 18” tree spacing) with 16’ drive rows, represent 2722.5 and 1850 trees per acre respectively. Using our 2006 harvest data (and assuming 100% clean fruit within the exclusion system) we calculate a harvest of 130.7, 115.2, 210.5 bushel on 12” spacing, and 87.1, 76.8, 140.4 bushel on 18” spacing of ‘Ultra’, ‘Crimson’ and ‘Emerald’ respectively. The volume of high-density commercially grown fruit grown throughout the Hudson Valley will range from 500 to 1200 bushels per acre on any given orchard in any given year. The dwarfing disease resistant varieties used in this project appear to fall well below the range of acceptable per acre harvest volume of apple when grown at either spacing within a insect exclusion system during year three of this study. Yet most varieties using dwarfing systems require a minimum of five years to achieve a significant fruit potential. The price of orchard run fruit (Empire or McIntosh) averages $8.00 per bushel. If we apply this value to the exclusion system we estimate gross returns at $1217.10 in 12” tree spacing and $811.40 in 18” spacing. The establishment costs for an exclusion growing system (excluding labor) is $35,594.00 and $44,170.00 for the 18” and 12” spacing systems respectively. Excluding labor costs and organic pest management costs, the pay off of a 0% finance of establishment costs would not be possible given the low production yields demonstrated in year three. Pricing for organically grown or pesticide free fruit should be considerably higher than the $8.00/bu price, reducing the period of payoff. However, labor and organic spray materials are a considerable expense if one is to hire out the work and use organic pest management to augment the exclusion system using an over-head fixed spray system for insect and disease pest management.

We have conducted various entomological and disease studies over the past three years to discern their use in an insect exclusion. Terminal growth of the trees within the system was observed this year with Ultra exhibiting statistically reduced growth (11.38cm) compared to the other three varieties (Emerald 13.1cm, Crimson 13.3cm, Wijick 13.7cm). The netting had a statistically significant increase on the growth of all varieties with the mean growth within netting of 13.8cm compared to un-netted growth of 12.2cm. Sprayed plots had statistically significant greater growth with unsprayed plots achieving 12.2 cm of growth compared to 13.7cm in the sprayed plots. Overall, the greatest growth was achieved in the sprayed/netted plots (14.8cm) followed by unsprayed/netted plots (12.6cm), sprayed/unnetted plots (12.5cm), and unsprayed/un-netted plots (11.8cm).

Significant reductions in pest damage were again observed to foliage and fruit of apple within the exclusion plots this season. Significant differences between apple varieties for foliar damage were observed this season. Varietal differences in leaf yellowing due to potato leafhopper damage was observed to be significantly higher in Crimson exhibiting 8.7% compared to Emerald, Ultra and Wijick 3.3%, 3.9% and 5.2% respectively. Varietal differences were observed in leaf curl from potato leafhopper, significantly higher across all varieties with Emerald exhibiting the least damage at 36.2% Wijick, Crimson and Ultra and exhibiting 42.5%, 48.4% and 54.8% respectively. White apple and rose leafhopper feeding damage expressed in ‘stippling’ or cell content removal leaving a whitening of the leaf also were observed to show varietal differences with Ultra and Wijick exhibiting lowest damage levels (in a 0-4 rating) of 4.4a and 4.7a respectively, significantly different from Emerald at 8.1b and Crimson at 9.3c. Wijick had the highest incidence of Japanese beetle feeding, significantly different from the other three varieties at 12.5b% damage compared to Ultra, Crimson and Emerald at 6.4a, 6.7a, and 7.8a percent damage respectively. Leafroller damage to foliage was observed to be greatest in the Crimson at 43.0b %, with Emerald, Ultra and Wijick damage at 34.0a, 37.9ab, 38.0ab percent respectively.

Significant differences in foliar damage were observed between the netted and un-netted plots for all insects, with netted plots showing significantly less damage of all insects feeding on apple foliage. We also observed significant differences in foliar damage between sprayed and unsprayed plots for all insects, with sprayed plots showing significantly less damage of all insects feeding on apple foliage compared to unsprayed plots. In all cases the netted / sprayed plots (N/S) demonstrated lowest levels of foliar feeding by leafhopper complex, leafroller complex and the Japanese beetle compared to netted / unsprayed plots (N/US), un-netted / sprayed plots (UN/S), and un-netted / unsprayed plots (UN/US). Leaf yellowing caused by PLH was 2.5% (N/S), 5.2% (N/US), 4.8% (UN/S), 8.8% (UN/US); leaf curl caused by PLH was 24.5% (N/S), 39.5% (N/US), 58.3% (UN/S), 60.0% (UN/US); feeding damage caused by Japanese beetle was 3.0% (N/S), 10.6% (N/US), 7.3% (UN/S), 12.3% (UN/US); feeding damage caused by the leafroller complex was 20.3% (N/S), 28.7% (N/US), 50.6% (UN/S), 53.5% (UN/US); and feeding caused by the LH complex (in a 0-4 rating) was 0.05 (N/S), 0.12 (N/US), 1.54 (UN/S), 0.95 (UN/US).

Foliar evaluations were conducted of the mite complex on all varieties throughout the netted/un-netted and sprayed/unsprayed matrix. A Log10 (X+1) transformation was applied to all mite data. The mean separation was performed by Fishers Protected LSD (P= 18x magnification. ERM = European red mite Panonychus ulmi; TSM = Two spotted spider mite Tetranychus urticae ; ZM = Zetzellia mali; (AMB): Neoseiulus (=Amblyseius) fallacies (Garman), ARM = apple rust mite Aculus schlechtendali. There were no significant differences of mite found between the four varieties or between the netted and un-netted plots. There was one significant difference between the sprayed and unsprayed plots of the predatory mite ZM and its egg (sprayed 1.3 / leaf, unsprayed 12.1 / leaf). The ERM and TSSM motiles and their eggs had highest numbers in sprayed plots, 3x greater in the netted/sprayed plots than in the un-netted unsprayed plots. The phytoseiid mite predator AMB was present in equal numbers throughout the plots with slightly higher numbers in the unsprayed plots. The greatest difference was observed in the ZM in which equally high numbers were observed in the netted and un-netted unsprayed plots with very low numbers in the netted and un-netted sprayed plots. Sulfur appears to have greater negative impact on this biological control agent than on the phytoseiid population.

Fruit evaluations were conducted of the insect complex on all varieties throughout the netted/un-netted and sprayed/unsprayed matrix. The mean separation was performed by Fishers Protected LSD (P=<0.05). Treatment means followed by the same letter are not significantly different. All data represents field means. Fruit were sampled by examining all fruit per variety per plot. Insects sampled were apple maggot (AM) Rhagoletis pomonella (Walsh), codling moth (CM) Cydia pomonella (Linnaeus), European apple sawfly (EAS) Hoplocampa testudinea (Klug), obliquebanded leafroller (OBLR) Choristoneura rosaceana (Harris), plum curculio (PC) Conotrachelus nenuphar (Herbst), San Jose scale (SJS) Quadraspidiotus perniciosus (Comstock), tarnished plant bug (TPB) Lygus lineolaris (P. de B.) and internal lepidopteran including the redbanded Leafroller (RBLR) Argyrotaenia velutinana (Walker).

No significant difference in fruit damage was observed between the three varieties examined. Wijick had too few fruit to evaluate in 2006. Stark ‘Ultra’ had the greatest pressure from TPB (2.2%), early lepidopteran complex (3.3%), SJS (17.8%), and AM punctures (4.5%). Stark ‘Crimson’ had the greatest pressure from external lepidopteran complex (30.3%), internal lepidopteran complex (20.9%), and Stark ‘Emerald’ had the greatest pressure from EAS (3.5%), PC (95.3%), and AM tunneling (1.0%).

The greatest differences in insect pest management occurred between the netted and un-netted plots in which we observed 8.2% clean fruit in the netted plots compared to 1.8% clean in the un-netted plots.