Progress 04/01/16 to 03/31/21
Outputs
Target Audience:The main target audience reached during the full reporting periodof this project consisted of colleagues working in academia, government agencies, and private industry. Commercial growers, cooperative agents, and IPM scouts were initiallycontacted on a limited basis, but more frequently as the final, overall results were being communicated. Changes/Problems:The above report summarizes the first four years (2016-2019) of the project. Results from the fifth growing season (2020) were not available. A university-wide shutdown of all research occurred in 2020 due to the Covid-19 pandemic. What opportunities for training and professional development has the project provided?Throughout the five year project, the majority of the research was conducted by a technician. Techniques for working with biorational compounds were learned along with standard procedures for application and evaluation of the efficacy of conventional fungicides and bactericides. A graduate student assisted the technician in the initial growing season, 2016. This individual was exposed to biological methods for field evaluations of test materials, including the statistical approaches necessary to obtain valid data and meaningful results. How have the results been disseminated to communities of interest?Results were initiallydisseminated to colleagues through oral and poster presentations at regional and national professional meetings. Subsequent to these presentations, results were published in bothnon-referred and refereed journals. Commercial growers and agents were informed through presentations at local, state-wide, regional, and national grower meetings. Growers also learned of the results through articles published in commercial agricultural newsletters. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Integration of Biorational Materials. Throughout the five growing seasons of the project, a variety of newly released biorational materials, all of which were labeled for "organic" production, were observed to reduce incidence of blossom blight, rusty spot, and bacterial spot of peach. Although these reductions were statistically significant, the level of control was often low relative to conventional fungicides and bactericides. Thus, incorporation of these materials into current disease control programs will be limited. However, the use of biorationals in conjunction with partial cultivar resistance appears to be an effective strategy for management of peach bacterial spot; this is the topic of the upcoming hatch project. Goal 1. When applied alone, peach blossom blight was significantly reduced by the following materials (% control): Fracture (45%, 75%); Double Nickel (43%); Serenade Optimum (59%); Kumulus (43%); Armicarb (47%); Trilogy (43%); Oso (47%, 49%, 80%); and Stargus (64%). Of these materials, only Fracture and Oso provided a high level of control (75% & 80%, respectively), albeit in just one of the years. Peach rusty spot was significantly reduced by the following materials, but all levels of control were low: Oso (55%); Fracture (17%); Double Nickel (18%); Kumulus (19%) and Microthiol Disperss (28%). Serenade Optimum, Armicarb, and Triology failed to significantly reduce rusty spot. The ability of biorational bactericides to control peach bacterial spot was dependent on the susceptibility of the peach cultivar. On highly susceptible O'Henry peach, the biorational materials Stargus and Regalia were not as effective as the Kocide and FireLine conventional standards. However, when these same biorational materials were applied to partially resistant Suncrest peach, they were as effective as the two standards. Thus, when applied to cultivars with a low level of disease resistance, biorational bactericides can provide an effective program for management of peach bacterial spot. Goal 2. All biorational products examined for control of peach rusty spot yielded low levels of control when used alone. When alternated with the conventional standard fungicide, Rally, the biorationals Armicarb and Microthiol Disperss provided significant disease control (43% and 66%, respectively). However, these integrated programs were still not as effective as the Rally standard applied alone (86% control). Integrated management of peach blossom blight yielded results similar to those observed with rusty spot. When the biorational materials Oso and Vacciplant were applied in alternation with the conventional standards Rovral or Meteor, blossom blight disease levels were significantly reduced. However, the level of disease control observed, 53% and 62%, respectively, were well below the standards, which typically achieve > 85% control. Refinement of Cover Spray Usage. Brown rot disease, caused by the fungal plant pathogen Monilinia fructicola, is the most important fungal disease of stone fruit crops such as peach and nectarine. If not properly controlled, 100% of the crop can be lost when weather conditions are favorable for disease development. Typically, to control brown rot, three fungicide sprays are applied during the fruit maturation period just prior to harvest. The fungicide materials used at this time are highly effective, but are also prone to resistance development in the pathogen population. Also, control can be reduced if a significant amount of rainfall occurs during the ripening period when fruit become increasingly susceptible. Results from this study discovered that the final two late season "cover spray" fungicide applications, when consisting of the protectant fungicide captan, can provide 50 to 69% control of brown rot before the typical preharvest fungicide materials are applied. A bioassay test, developed to estimate fungicide residue on fruit, confirmed that control was due to the presence of an effective residue. Furthermore, since the protectant captan is not prone to resistance development, use of it in the final two cover sprays would be an effective strategy for reducing resistance development in the subsequent at-risk fungicide materials. The captan would reduce the pathogen population prior to use of these at-risk materials, thereby reducing the frequency of resistant strains and therefore selection for resistance. In addition, since significant rainfall did not reduce efficacy of the two captan cover sprays, use of this approach would provide more consistent brown rot control from year to year, regardless of the weather conditions. In summary, use of captan in the final two cover sprays prior to the preharvest period, should help growers maintain consistent yields and profitability. Goal 1. The minimum Captan 80WDG cover spray rate that provided a significant reduction in brown rot at harvest was 3.125 lb/A. Goal 2. Early (shuck split, first cover, and second cover) sprays and mid-season (third and fourth covers) failed to provide effective control of brown rot at harvest. The bioassay confirmed that insufficient residue was present on the fruit to provide effective control. However, the final two late season cover sprays (fifth and sixth covers) had an effective residue, based on the bioassay results, and significantly reduced brown rot at harvest. Goal 3. A comparison of the efficacy of a single final cover spray vs two final cover sprays was not conducted due to the 2020 research shut-down from the covid-19 pandemic (see below). Goal 4. Increasing the rate of sulfur (and ziram) in the cover spray program did not improve control of brown rot at harvest.
Publications
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Progress 10/01/19 to 09/30/20
Outputs
Target Audience:The main target audience reached during the reporting period consisted of colleagues working in academia, government agencies, and private industry (primarily Dec 2019, Jan 2020). Commercial growers, cooperative extension agents, and IPM scouts were contacted on a limited basis. Changes/Problems:The covid-19 pandemic of 2020+ resulted in significant changes in the planned research program. Fortunately, the early bloom sprays were applied at normal timing. This allowed evaluation of the integrated and organic programs for management of peach blossom blight. On April 10, 2020, as a result of the pandemic, a university-wide stoppage of all research was instituted. Fungicide application of test materials for each of the various treatments could not be performed at their proper timing. Thus, the peach bacterial spot and rusty spot studies had to be cancelled for the season. Various supplemental treatments for the cover spray study, as proposed in the 2018 and 2019 progress reports, could also not be examined. These treatments would have required fruit at harvest. Two post-bloom frosts on 17 and 19 April reduced fruit load, but sufficient fruit still remained. However, on 4 and 7 August, high winds from Tropical Storm Isaias and a local storm resulted in complete loss of all fruit. So, even though the research stoppage was lifted in time for application of brown rot sprays, the lack of fruit prevented execution of the study. Although treatment applications for the various studies were halted, application of standard fungicides (and insecticides, herbicides), pruning, fruit thinning, etc... were still required to preserve the health of all the research orchards. Maintenance of tree health was deemed an essential service. Thus, participant work load was similar, even though specific treatments were not being applied. What opportunities for training and professional development has the project provided?A tree fruit pathology technician conducted the majority of the field and laboratory research studies during the project period. Unfortunately, some of the novel techniques planned for evaluating bacterial spot disease progression could not be employed due to unforeseen problems. See the Changes / Problems section for details. How have the results been disseminated to communities of interest?Integration of Biorational Materials. Plans are to present the results of the integrated and organic programs for control of peach blossom blight after additional validation data are obtained (after 2021 season). Findings will be presented to colleagues at scientific meetings as well as commercial tree fruit growers. Plans were to present the 2020 results of the integrated peach bacterial spot control study at the Cumberland-Shenandoah Fruit Workers Conference and at the Southeastern Professional Fruit Workers Conference. Similarly, results from integrated control programs for peach rusty spot were also planned to be presented at these meetings. Unfortunately, unforeseen problems prevented execution of these studies. See the Changes / Problems section for details. Nevertheless, plans are to conduct these studies during the 2021 growing season, allowing dissemination of information at these meetings in fall / winter 2021-2022. Refinement of Cover Spray Usage. The final refereed paper, titled "Refinement of peach cover spray programs for management of brown rot at harvest" was published in Plant Disease. This publication marks the end of a series of studies that significantly improved management of peach brown rot. All of the major objectives for this component of the project were accomplished by 2018. What do you plan to do during the next reporting period to accomplish the goals?The project is ending in March, 2021. Nevertheless, evaluation of integrated programs for control of peach blossom blight, bacterial spot, and rusty spot will continue until sufficient data and results are obtained to allow proper dissemination and publication. Funding for continuance of the bacterial spot study has already been procured.
Impacts
What was accomplished under these goals?
Integration of Biorational Materials. At the beginning of the peach growing season, the three bloom sprays applied at pink, full bloom, and petal fall stages are for management of blossom blight. Typically, all three sprays consist of conventional fungicides, while integrated programs substitute biorational fungicides for one or two of the three applications. In full organic programs, one or more biorational materials are employed for all three sprays. In either case, the goal is to reduce the amount of conventional fungicide while maintaining the same level of disease control. Fewer sprays of conventional fungicide reduces (i) pesticide residues on fruit, (ii) exposure to the grower and public, and (iii) pesticide in the environment. In 2020, two integrated programs were examined for control of blossom blight. The first consisted of the biorational Vacciplant applied once at full bloom, with the conventional fungicide, iprodione, applied at pink and petal fall. The active ingredient in Vacciplant is Laminarin, an extract of the plant Laminaria digitata, which induces systemic acquired resistance. The second integrated program consisted of the biorational Oso applied twice, at pink and petal fall, with iprodione applied once at full bloom. The active ingredient in Oso, polyoxin D zinc salt, is an antibiotic that inhibits the growth of phytopathogenic fungal cell wall chitin. Results of the statistical analysis showed that the two integrated programs were as effective as two conventional programs consisting of the fungicides Luna Sensation or Miravis. Thus, these results showed that the amount of conventional fungicide used for controlling blossom blight can be reduced by 33% (Vacciplant program) to 66% (Oso program) when using integrated programs. Two full-season organic programs were also examined. The first program employed Oso for all three bloom applications, while the second program used the biorational Stargus. The active ingredient in Stargus, Bacillus amyloliquefaciens strain F727 cells and spent fermentation media, is a beneficial rhizobacterium that colonizes plant surfaces; inhibition of spore germination and mycelial growth prevents establishment of plant pathogens. Results showed that Stargus was as effective as both conventional fungicide programs at controlling blossom blight canker formation, thereby providing a 100% reduction in conventional fungicide usage. However, Oso was only as effective as Miravis, but not as effective as Luna Sensation. Additional data are needed to corroborate these findings. For results on peach rusty spot and peach bacterial spot, see Changes / Problems section. Refinement of Cover Spray Usage. All of the major objectives for this component of the project were accomplished by 2018. Orchard plot space and funding were not available in 2019 or 2020 to examine some of the remaining nuances / benefits of the newly derived cover spray program. Dissemination of the results to groups of interest was accomplished in 2019 (see prior report).
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Lalancette, N., Blaus, L.L., and Engel, P. 2020. Refinement of peach cover spray programs for management of brown rot at harvest. Plant Dis. 104:1527-1533.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Lalancette, N. and Blaus, L. 2019. Management of peach bacterial spot: Integration of biorational bactericides and cultivar resistance. The Cumberland-Shenandoah Fruit Workers Conference, 95th Annual Meeting, Dec 5-6, Winchester, VA.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Lalancette, N., and Blaus, L. 2019. Management of peach bacterial spot: Integration of biorational bactericides and cultivar resistance. The Southeastern Professional Fruit Workers Conference, Nov 5-7, Tifton, GA.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Lalancette, N. and Blaus, L. 2020. Evaluation of experimental, systemic, and biorational fungicides for management of peach diseases, 2019. Plant Disease Management Reports 14:PF027. Online publication doi:10.1094/PDMR14.
|
Progress 10/01/18 to 09/30/19
Outputs
Target Audience:The primary target audience reached during this reporting period consisted of commercial peach growers located in New Jersey and the mid-Atlantic region. The secondary audience consisted of cooperative extension agents, state-supported IPM scouts, and commercial consultants. The final audience was comprised of colleagues working in academia, government agencies, and private industry throughout the United States. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?A tree fruit pathology technician conducted the majority of the field and laboratory research studies during the project period. Although the technician was well versed in most techniques, some new approaches were learned. Of particular interest were some of the novel approaches used for evaluating the progression of peach bacterial spot epidemics. How have the results been disseminated to communities of interest?Integration of Biorational Materials. Given that only one year of data was available, the results of the 2018 study on control of peach bacterial spot with biorational materials was disseminated only to colleagues in the public and prifvate scientific community. A presentation was made at the fall 2018 Cumberland Shenandoah Fruit Workers Conference, Winchester, VA, which serves academic and industry scientists. Refinement of Cover Spray Usage. After multiple growing seasons of effective and confirming results for the new cover spray approach, a major effort was performed during the reporting period to disseminate the newly recommended approach for managment of peach brown rot at harvest. A "captstone" presentation was presented to colleagues in the academic and private sectors at the Fall 2018 Cumberland Shenandoah Fruit Workers Conference, Winchester, Virginia, and at the Fall 2018 Southeastern Professional Fruit Workers Conference, Manchester, Tennessee. Commercial growers in New Jersey learned about the new approach in presentations given at the 2019 north (Flemington) and south (Bridgeton) Commercial Tree Fruit Growers Meetings. Finally, a presentation was given to commercial growers and industry representatives in the mid-Atlantic region (NJ, PA, MD, DE, VA, WV) at the 2019 Mid-Atlantic Fruit and Vegetable Growers Conference, Hershey, PA. Current plans are to also present these results as an invited speaker at the 2019 Great Lakes Expo, Grand Rapids, MI in Dec, 2019 (see next years report). What do you plan to do during the next reporting period to accomplish the goals?Integration of Biofungicides / Biorational Bactericides. Given that the 2018 and 2019 results of the integrated peach bacterial spot control study do not agree with each other, plans are to repeat the study to verify one or the other year's results. Additional biorational treatments / materials for control of peach blossom blight and rusty spot, as well as bacterial spot, may also be investigated. Refinement of Cover Spray Usage. See prior 2018 report for further treatments to investigate various nuances of the novel approach. Results from these treatments are not necessary for use of the method, but do add to background information. Availability of cultivar, treatment space, and funding may limit extent of one or more aspects of either project component.
Impacts
What was accomplished under these goals?
Integration of Biorational Materials. In the 2018 growing season, the biorational bactericides Stargus and Regalia were shown to provide commercially acceptable amounts of saleable fruit (90% and 81%) when combined with cultivar resistance for management of peach bacterial spot (see prior report). Given this success, the study was broadened for the 2019 season by including two additional biorational materials, Double Nickel and LifeGard. Double Nickel's active ingredient is the bacterium Bacillus amyloliquefaciens strain D747; LifeGard's active ingredient is Bacillus mycoides isolate J. As in 2018, all materials in 2019, including the copper and antibiotic standards, were applied to highly susceptible O'Henry peach and susceptible Suncrest peach. Unfortunately, none of the biorational bactericides, as well as the two standards, were shown to significantly increase the amount of marketable fruit on either highly susceptible O'Henry or the somewhat more resistant Suncrest. Unlike the "normal severity' epidemic in 2018, the 2019 epidemic was very severe, with 79% and 98% of non-treated (control) fruit infected for Suncrest and O'Henry, respectively. This level of disease had not been observed since 1997. Assumming that the 2019 epidemic was a once in 23-year occurrence, plans are to repeat the 2019 study in 2020 in order to verify the 2018 results. If most years have epidemics of normal intensity, then combining biorational control with cultivar resistance may still be a viable option for commerical growers. However, data are needed to show that this integrated approach is effective for most years. In a separate study, the biorational material "Vacciplant" was examined for control of peach brown rot blossom blight. Vacciplant, an extract from the plant Laminaria digitata, contains biologically active compounds that induce systemic disease resistance in plants. Two identical experimental treatments were examined in which Vacciplant replaced one of the three standard conventional fungicide sprays applied during bloom (pink, bloom, petal fall). Both treatments were observed to significantly reduce blossom blight incidence and severity. One treatment provided control statistically equivalent to the full standard fungicide program; both yielded 72% control. These results show that the amount of conventional fungicide used for controlling brown rot blossom blight can be reduced by one-third (33%) without any loss in disease control. Further data are needed for verification. Refinement of Cover Spray Usage. All of the major objectives for this component of the project were accomplished by 2018 (see prior report). Unfortunately, no orchard plot space with a desired cultivar was available in 2019 to examine some of the remaining nuances / benefits of the newly derived cover spray program. Also, after six years of continuous funding, monies were no longer available for additional field work. Thus, the majority of effort for this project component was in extension of results to groups of interest (see dissemination of results section below).
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Lalancette, N. 2019. Contribution of cover sprays to effective management of peach brown rot. National Peach Council Program, Mid-Atlantic Fruit & Vegetable Convention, 28-31Jan, Hershey, PA.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Lalancette, N. 2019. Contribution of cover sprays to effective management of peach brown rot. South Jersey Commercial Tree Fruit Grower Meeting, Mar 6, RAREC, Bridgeton, NJ.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Lalancette, N. 2019. Contribution of cover sprays to effective management of peach brown rot. North Jersey Commercial Fruit Growers Meeting, Mar 7, Hunterdon County Complex, Flemington, NJ.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Lalancette, N. and Blaus, L. 2018. Evaluation of biorational bactericides for management of peach bacterial spot. Pages 77-89 in: Proceedings of the Cumberland-Shenandoah Fruit Workers Conference, 94th Annual Meeting, Winchester, VA.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2018
Citation:
Lalancette, N., and Blaus, L. 2018. Refinement of peach cover spray programs for sustainable management of brown rot. The Southeastern Professional Fruit Workers Conference, Oct 23-25, Manchester, TN.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2018
Citation:
Lalancette, N. and Blaus, L. 2018. Refinement of peach cover spray programs for sustainable management of brown rot. The Cumberland-Shenandoah Fruit Workers Conference, 94th Annual Meeting, Nov 29-30, Winchester, VA.
|
Progress 10/01/17 to 09/30/18
Outputs
Target Audience:The primary target audience reached during the reporting period consisted of commercial tree fruit growers, particularly peach growers, located within New Jersey, within the mid-Atlantic region, and within the nation. Secondary target audiences were cooperative extension agricultural agents, state-supported IPM scouts, and commercial consultants. The final audience was comprised of colleagues working in academia, government agencies, and private industry. Changes/Problems:Significant funding was available for determining the efficacy of two biorational bactericides / fungicides, Stargus and Regalia, at controlling peach bacterial spot. Thus, the disease focus of the "Integration of Biofungicides" portion of the project has been modified from peach rusty spot / blossom blight to also include peach bacterial spot. As mentioned in the Hatch project's introduction, bacterial spot is a major disease of peach that can cause 100% crop loss. Although the disease focus has been modified, the main goal of this portion of the project has remained the same, namely the integration of biorational materials into peach disease management programs. What opportunities for training and professional development has the project provided?A tree fruit pathology technician conducted the majority of the field and laboratory research studies during the project period. Athough the technician was well versed in most techniques, some new approaches were learned. How have the results been disseminated to communities of interest?Colleagues in the scientific community were updated on research results with poster and oral presentations at national and regional meetings of plant pathologists and professional fruit workers. Dissemination of results also occurred via publications in conference proceedings and Plant Disease Managment Reports. Since multiple years of results are now available from the research, a formal grower presentation is being planned for the 2019 Mid-Atlantic Fruit and Vegetable Convention in Hershey, PA. What do you plan to do during the next reporting period to accomplish the goals?Integation of Biofungicides / Biorational Bactericides. Replication of the integrated treatments in the field studies are needed to provide a second year of data. Focus of this work will be either peach bacterial spot, blossom blight, or rusty spot, depending on availability of funding and availability of an acceptable cultivar / orchard for the study. Refinement of Cover Spray Usage. A variety of treatments can be performed to further investigate the various nuances / benefits of the newly derived cover spray program. The optimum captan rate and timing results need to be examined in a combined treatment to provide final confirmation of the program approach. In addition, different programs utilizing both captan and sulfur can be examined for efficacy at reducing preharvest brown rot as well as seasonal control of peach scab. Late season captan cover sprays can be combined with "good" to "very good' rated preaharvest fungicides to determine if these combined programs can be highly effective. Finally, a comparison of different captan formulations may be performed to insure that all commercially available products provide equal protection.
Impacts
What was accomplished under these goals?
Integration of Biorational Bactericides. Two recently introduced biorational materials, Stargus and Regalia, were examined for their effective integration into peach bacterial spot managment programs.The active ingredient in Stargus consists of Bacillus amyloliquefaciens strain 727 cells and spent fermentation media. This rhizobacterium protects plants by colonizing the surface of plant tissues, thereby preventing the establishment of fungal and bacterial plant pathogens. In contrast, the active ingredient in Regalia, an extract of Reynoutria sachalinensis (giant knotweed), protects plants by inducing systemic resistance. The bioactive compounds in this extract stimulates the plant to increase phenolics, antioxidants, and strengthen cell walls. Both materials were compared to the current standards, copper bactericides and the antibiotic oxytetracyline, on both highly susceptible O'Henry peach and susceptible Suncrest peach. Results showed that neither compound provided adequate control of bacterial spot on highly susceptible O'Henry fruit. However, both biorational materials significantly reduced bacterial spot on susceptible Suncrest, providing control that was equivalant to the copper and antiobiotic standards. Total saleable fruit (market grades 1 + 2) for Stargus and Regalia were 90% and 81%, while the copper and antibiotic standards had 95% and 90% saleable fruit, respectively. These results demonstrated that an effective peach bacterial spot control program can be achieved when the biorational materials are used in conjunction with cultivar resistance, and that the level of resistance in the cultivar need not be high. On a scale of 1 to 6, with 1 = highly susceptible and 6 = highly resistant, O'Henry is rated at 1 while the "less" susceptible Suncrest is rated at 2. Most cultivars grown in the eastern U.S. are rated ≥ 2. Highly susceptible cultivars, such as O'Henry, are not recommended to growers. Refinement of Cover Spray Usage. Effect of Captan Rate. All three captan rate treatments significantly reduced brown rot at harvest. A rate response was also evident. The low, medium, and high rates, respectively, provided 34%, 51%, and 55% control. These results suggested that a significant contribution in brown rot control can be obtained from cover spray programs that employ lower captan rates of 2.0 to 2.5 lb active ingredient / acre. Relative to the higher 3.0 lb a.i./A "standard" rate used in prior studies, these lower rates represent a 17% to 33% cost savings in fungicide usage. Effect of Application Timing. The late season treatment, with captan applications at only 5th and 6th cover sprays (5C, 6C), significantly controlled brown rot at harvest, providing 52% control. Results of the bioassay strongly supported this outcome. Spore germination was reduced at both 7- and 21-days after 6C by 85% and 56%, respectively. Furthermore, as would be expected, the level of control exerted by the late season treatment was statistically equivalent to the full season program at the high rate. Thus, two cover sprays at 5C and 6C can provide the same benefit in brown rot control as seven sprays in the full program, a 71% reduction in number of sprays. As hypothesized, the mid-season treatment with applications at 3C and 4C did not provide significant control of brown rot at harvest. Fruit rot levels were not significantly different from the non-treated control and provided only 12% control. Green fruit at mid-season are not susceptible to brown rot. The early-season treatment was also not expected to provide brown rot control. However, fruit rot levels on trees receiving this treatment were significantly lower than on non-treated trees, resulting in 40% disease control. Results of the bioassay showed that spore germination on treated fruit was equivalent to that observed on non-treated fruit. Thus, an effective fungicide residue was not present to control rot development during the preharvest period. Given these results, disease control was most likely exerted earlier in the growing season by the shuck-split, 1C, and 2C sprays. Previous studies have shown that young green fruit can become infected during this period prior to pit hardening, resulting in the formation of very small quiescent infections. These infections remain latent until fruit ripening begins, at which time normal rot lesions form. The sprays applied at SS, 1C, and 2C prevented those early quiescent infections, resulting in the 40% control observed at harvest. Effect of Fungicide Chemistry. In the prior cover spray study, a low rate of sulfur and medium rate of ziram applied as cover sprays failed to contribute to brown rot control at harvest. In the current study, higher rates of these two materials, near the top of the labeled rate range, were examined to see if brown rot control could be garnered. Higher application rates sometimes translates into higher efficacy. Unfortunately, employing a higher application rate of sulfur was not an effective approach. The amount of brown rot at harvest for the Microthiol Disperss treatment was not significantly different from the amount observed for the non-treated control, resulting in only 13% control. The first bioassay did indicate presence of a moderately effective sulfur residue at 7-days after the final 6C spray; however, by 21-days, an effective residue was no longer present. Cover sprays employing the maximum labeled rate of ziram yielded mixed results for providing brown rot control at harvest. Significant control was observed in 2017, albeit the level of control was only 34%, while no control was observed in 2018. Bioassay results in both years showed a significant reduction in spore germination, thereby indicating the presence of an effective ziram residue on the fruit surface throughout the preharvest period. The level of disease control was statistically equivalent to control by captan at the low rate. However, ziram provided significantly less control than that observed with captan at either the medium or high rates. Thus, even at its highest labeled rate, ziram was not an equivalent substitute for captan for use in the cover sprays.
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2018
Citation:
Lalancette, N. and Blaus, L. 2017. Refinement of peach cover spray programs for sustainable management of brown rot. 11th International Congress of Plant Pathology and Annual Meeting of The American Phytopathological Society, 29Jul-3Aug, Boston, USA
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2018
Citation:
Lalancette, N. and Blaus, L. 2017. Integrated management of peach rusty spot epidemics. Cumberland Shenandoah Fruit Workers Conference, 29Nov-1Dec, Winchester, VA
|
Progress 10/01/16 to 09/30/17
Outputs
Target Audience:The main target audience reached during the reporting period consisted of commercial tree fruit growers, particularly peach growers, located within New Jersey, within the mid-Atlantic region, and within the nation. Secondary target audiences were cooperative extension agricultural agents, state-supported IPM scouts, and commercial crop consultants. The final audience was comprised of colleagues working in academia, government agencies, and private industry. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?A tree fruit pathology technician conducted the majority of the field and laboratory research studies during the project period. Although this technician was well versed in most techniques, some new approaches were learned. How have the results been disseminated to communities of interest?Colleagues in the scientific community were updated on research results published Plant Disease, Plant Disease Management Reports, and Proceedings to the 92nd Annual Cumberland-Shenandoah Fruit Workers Conference. In addition, presentations were given at this latter conference in Winchester, VA and at the Southeastern Professional Fruit Workers Conference in Mills River, NC. An early season frost in 2016 caused fruit loss which limited research / results in the first year. The current 2017 season, therefore, represents the first year of complete data. Thus, except for personal discussions, no results have been formally disseminated yet to commercial growers, agricultural agents, or other industry personnel. What do you plan to do during the next reporting period to accomplish the goals?The rusty spot study for objective #1 will be repeated in 2018. A minimum of two-years of data are needed to confirm findings and examine treatment activity under varying conditions. Any new biorational materials may be included or examined in other field studies. The cover spray study for objective #2 will be repeated. Since only partial data are available for the 2016 season, the 2017 season results are essentially the first replication.
Impacts
What was accomplished under these goals?
Integration of Biofungicides. A field study was conducted that incorporated two OMRI-listed fungicides, Microthiol Disperss (sulfur) and Carb-O-Nator (potassium bicarbonate), into standard fungicide programs for management of peach rusty spot epidemics. The integrated treatments consisted of two applications of the organic fungicide alternating with two applications of the conventional fungicide, Rally (myclobutanil). The standard program for comparison consisted of four applications of Rally, while full biorational programs consisted of four applications of each organic fungicide. Each of these treatments were examined on highly susceptible 'Autumnglo' peach and moderately susceptible 'Suncrest' peach. When applied alone, both biorational materials significantly reduce rusty spot, but control was inadequate for commercial acceptance. However, the Microthiol / Rally integrated program provided control equivalent to the standard Rally program on Suncrest, but not Autumnglo. Thus, the integration of biorational and conventional fungicides with host resistance was an effective strategy. This approach allows a 50% reduction in conventional fungicide usage without any loss in disease control. Further data are needed, particularly at shorter spray intervals, to determine if non-residual potassium bicarbonate products can be as effective as sulfur in integrated programs. Refinement of Cover Spray Usage. All three application rates of captan used in the peach cover spray programs provided significant control of brown rot at harvest. Furthermore, the level of disease control observed was proportional or related to the captan rate. The low, moderate, and high rates yielded 51, 69, and 78% control of brown rot, respectively. Disease and bioassay results from the application timing treatments indicated that captan cover sprays need to be applied during the late season (final two cover sprays) to create a residue that provides significant control during the preharvest period. In contrast, the mid-season cover sprays did not contribute to brown rot control at harvest. However, the early season sprays, which were also hypothesized to be ineffective, instead yielded 40% control. Since the bioassay indicated lack of fungicide residue during the preharvest period, the mechanism for control was thought to be protection of young, green fruit by the early sprays. Infection at this time results in very small quiescent lesions that do not enlarge until ripening during the preharvest period. This phenomena, which occurs in California and Australia, has not been observed in the eastern U.S., so further data are needed to confirm. Of the four protectant fungicides currently available for peach (captan, sulfur, ziram, thiram), only captan cover sprays provide the most effective brown rot control at harvest. Sulfur cover sprays, even at a near maximum rate, did not contribute to brown rot control. Ziram at its highest labeled rate did significantly reduce brown rot at harvest, but the level of control was significantly less than that provide by captan (at much lower rates). In the initial study, thiram was also not shown to provide any benefit. Results of this year's study revealed that relatively low rates of captan cover sprays can provide control of brown rot, and that the late season sprays are most critical. Furthermore, early season sprays may also be critical to prevent possible formation of quiescent lesions. Additional data are needed to confirm these findings. Once the final cover spray program is created, implementation by growers should (i) reduce selection for resistance to the at-risk preharvest fungicides and (ii) make brown rot control more reliable, particularly in wet years. And since the cover spray materials are multi-site protectants, resistance to them is unlikely, thereby making the approach sustainable.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2017
Citation:
Lalancette, N., Blaus, L.L., Gager, J.D., and McFarland, K.A. 2017. Contribution of mid-season cover sprays to management of peach brown rot at harvest. Plant Dis. 101:794-799.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2017
Citation:
Lalancette, N., and Blaus, L. 2017. Integrated management of peach rusty spot epidemics. The Southeastern Professional Fruit Workers Conference, Oct 3-5, Mills River, NC.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Lalancette, N., Blaus, L., and Feldman, P. 2016. Management of peach diseases with biorational and conventional fungicides. The Cumberland-Shenandoah Fruit Workers Conference, 92nd Annual Meeting, Dec 1-2, Winchester, VA.
- Type:
Journal Articles
Status:
Published
Year Published:
2017
Citation:
Lalancette, N. and Blaus, L. 2017. Management of peach blossom blight and rusty spot, 2016. Plant Disease Management Reports 11:STF016. Online publication 10.1094/PDMR11.
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Progress 04/01/16 to 09/30/16
Outputs
Target Audience:The main target audience reached during the reporting period consisted of commercial tree fruit growers, particularly peach growers, located within New Jersey, within the mid-Atlantic region, and within the nation. Secondary target audiences were cooperative extension agricultural agents, state-supported IPM scouts, and commercial crop consultants. The final audience was comprised of colleagues working in academia, government agencies, and private industry. Changes/Problems:The cold temperature injury to flowers and subsequent yield loss delayed results for objective #2 by one year. However, the goals can still be accomplished within the time span of the study. What opportunities for training and professional development has the project provided?A graduate student was hired for the summer to assist in various field studies, including those related to this project. The student learned the methodology for disease assessments, care of the trees, as well as associated laboratory techniques. The student also conducted the study to determine in vitro efficacy (EC50) for captan, ziram, and sulfur. A tree fruit pathology technician was involved in conducting all of the field and laboratory research studies during the project period. Although this technician was well versed in most techniques, some new approaches were learned. How have the results been disseminated to communities of interest?Colleagues in the scientific community were updated on research results published in Proceedings to the 92nd Annual Cumberland-Shenandoah Fruit Workers Conference. In addition, presentations were given at this latter conference in Winchester, VA; the Southeastern Professional Fruit Workers Conference in Gainesville, FL; and the annual meeting of The American Phytopathological Society in Tampa, FL. Given that the project has just started (1st year), no results have been disseminated yet to commercial growers, agricultural agents, or other industry personnel. What do you plan to do during the next reporting period to accomplish the goals?The study for objective #1 will be repeated in 2017. A minimum of two-years of data are needed to confirm findings and examine treatment activity under varying conditions. Any new biorational materials may be included or examined in other field studies. The cover spray study for objective #2 will be repeated. Since only partial data are available for the 2016 season, the 2017 season results will essentially be the first replication.
Impacts
What was accomplished under these goals?
On April 6, 2016, sub-zero temperatures caused substantial flower kill on those experimental peach blocks that were at full bloom. Only 50% of available test blocks had sufficient fruit for experimentation. As a result, the study for objective one proceeded normally, while only partial results were available for objective 2. Integration of Biofungicides. A field study was conducted that examined the efficacy of the biorational, OMRI-listed fungicides Fracture (BLAD protein), Double Nickel 55 (Bacillus amyloliquefaciens), Serenade Optimum (Bacillus subtilis), Kumulus (sulfur), Armicarb (potassium bicarbonate), and Trilogy (neem oil extract) for early season management of brown rot blossom blight and rusty spot. For comparison, the standard conventional fungicide treatment used Rovral (iprodione) and Rally (myclobutanil) for control of blossom blight and rusty spot, respectively. Disease pressure for blossom blight was very high. On non-treated control trees, 63.8% of shoots were infected with an average of 1.2 cankers per shoot. Results showed that Serenade Optimum provided control equivalent to the standard. The remaining biorational fungicides provided an intermediate level of management: treated trees had significantly less blossom blight canker incidence and severity than on non-treated trees, but disease levels were significantly greater than on trees receiving the Rovral standard. These results suggest that Serenade Optimum may be able to directly replace Rovral for blossom blight control, while the remaining biorational materials might be candidates for use in integrated programs with Rovral. Refinement of Cover Spray Usage. As indicated above, there were insufficient fruit in the test block used for the cover spray study. Thus, the harvest brown rot assessment could not be conducted in a satisfactory manner (low and variable fruit numbers). However, the bioassay, which only requires a few fruit per tree, was still conducted. Results from the bioassay indicated that only late season application timing provided sufficient residue for brown rot control during the preharvest period. Early and mid-season application timings yielded inadequate residues. Results from the rate study indicated that the concentration of captan could be reduced to the medium rate level (2.5 lb ai/A) without sacrificing brown rot control. The final test involved examination of other protectant fungicides at higher rates to determine if they could be used in place of captan. Ziram and sulfur at near-maximum labeled rates failed to provide acceptable fruit residue for brown rot control. An in vitro estimation of EC50 values confirmed that ziram and sulfur were only 25% and 10% as effective as captan, respectively. The above results are only tentative since they could not be confirmed with a brown rot assessment at harvest.
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2016
Citation:
Lalancette, N., Blaus, L., and Feldman, P. 2016. Peach disease management with early season biorational and late season conventional fungicide programs. Proceedings of The Cumberland-Shenandoah Fruit Workers Conference, 92nd Annual Meeting, Dec 1-2, Winchester, VA.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2016
Citation:
Lalancette, N., Feldman, P., and Blaus, L. 2016. Contribution of cover sprays to brown rot control: Effect of fungicide, rate, and timing. The Southeastern Professional Fruit Workers Conference, Oct 4-6, Gainesville, FL.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2016
Citation:
Lalancette, N., Blaus, L., Gager, J., and McFarland, K. 2016. Contribution of protectant fungicides applied as mid-season cover sprays to management of peach brown rot at harvest. Annual Meeting of The American Phytopathological Society, 31Jul-3Aug, Tampa, FL
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