Serenade Max Research Articles

CONTROL OF WHITE CABBAGE DISEASES USING BIOLOGICALS

Purpose. To investigate effects of biologicals on disease-induced damage to white cabbage plants during the growing period and on yield. Methods. Informational/analytical (collection and review of publications), field research (planning and conducting experiments, records of plant damage, harvesting and accounting of yields), phytopathological (isolation and identification of pathogens), mathematical/statistical (processing of data). The following biologicals were used in he experiments: Azotobacterin liq. (Azotobacter chroococcum IMV B-7171), Ecophosphorin liq. (Bacillus megaterium IMV B-7168, Azotobacter chroococcum IMV B7171, Agrobacterium radiobacter IMV B-7246), Planrhiz liq. (Pseudomonas fluorescens), Haupsin liq. (Pseudomonas auerofaciens), Serenade ASO SC, Serenade MAX WP (Bacillus subtilis QST 713), and Trichodermin liq. (Trichoderma lignorum TD 93). Biologicals were sprayed on plants 3-4 times during the cabbage growing period. Antifungal potentials of mixtures of biologicals with fungicides were also investigated on white cabbage. Results. During the study years, Alternaria leaf spot, Fusarium wilt, black and soft rots were dominating diseases on plantations with different varieties of white cabbage. Biologicals effectively restrained the development of both fungal and bacterial diseases of white cabbage. The protective effect of the biologicals against fungal diseases averaged 45-62%, against bacterial diseases – 65-79%. The effectiveness of mixtures of biologicals and chemicals, in which fungicides were applied at minimally permissible doses, was similar to that of fungicides applied at full doses. Biologicals, due to their protective and growthstimulating properties, significantly increased the crop yield. Conclusions. The potentials of biologicals to control fungal and bacterial diseases of white cabbage during the growing period were evaluated. The biologicals effectively limited infection-inflicted damage to cabbage. The protective effect of the biologicas against various diseases of white cabbage during the growing period of different varieties averaged 45-79%. The biologicals increased the yields of late-ripening white cabbage varieties on average by 14.5–92%.

Efficacy of OMRI-certified fungicides and chitosan for managing early blight caused by Alternaria solani and Septoria leaf spot in tomato

Field studies to evaluate the efficacy of OMRI-certified fungicides and other materials for control of early blight caused by Alternaria solani and Septoria leaf spot of tomato were conducted in Lexington, Kentucky during 2009 and 2010. Nine fungicides as well as ammonium bicarbonate and chitosan were evaluated in an organic production system. The most effective fungicides for managing Septoria leaf spot and early blight of tomato were copper based. None of the biological-based products (Sonata® and Serenade Max®), plant-based extracts (Trilogy® and Regalia® SC), chitosan, ammonium bicarbonate nor horticultural lime sulfur provided a significant (P>0.05) reduction in disease severity. However, despite significant (P<0.05) disease control in plots treated with copper-based products, no significant (P>0.05) improvement in yield over the untreated control was observed during the first two experiments in which the initial symptoms of foliar disease were observed after fruits were set. In the third field trial, in which initial symptoms were observed before fruit set, Serenade Max®, Bordeaux mixture, Regalia® SC, water-soluble chitosan and lime sulfur improved yield, although none provided significant disease control. These results suggest that, when necrotrophic foliar disease develops after fruit set, fungicides may have no effect on yield. In addition, some OMRI-certified fungicides may improve tomato yields by unknown mechanisms that do not involve disease control.

Bacillus-based products for management of kiwifruit bacterial canker

Pseudomonas syringae pv. actinidiae is an important pathogen of kiwifruit (Actinidia deliciosa), and bacterial canker of this host is managed by monitoring and chemical control strategies. The efficacy of the bio-pesticides Amylo-X® (based on Bacillus amyloliquefaciens subsp. plantarum strain D747) and Serenade Max® (strain QST713 of B. subtilis) was evaluated by in vitro and in vivo experiments. Both antagonists inhibited different biovars of the pathogen in in vitro assays; QST713 was more efficient than D747. The two Bacillus strains also colonized A. deliciosa flowers (c. 105-7 cfu per flower) up to 96 h after inoculation. D747 persisted on leaves (c. 104-6 cfu cm-2) up to 4 weeks after inoculation, during 2 years in Emilia Romagna and Latium regions of Italy. On flowers, the antagonists reduced pathogen populations, compared to untreated (control) flowers. On A. deliciosa and A. chinensis plants under controlled conditions, Amylo-X® reduced severity of bacterial canker, providing ca. 50% relative protection on A. deliciosa and 70% on A. chinensis. Serenade Max® was less effective, giving 0% relative protection on A. deliciosa and 40% on A. chinensis. In a field trial, on A. deliciosa plants, Amylo-X® reduced the severity of bacterial canker on leaves, providing ca. 40% relative protection. The sensitivity of both antagonistic strains to streptomycin sulphate was confirmed by testing the most used concentration where antibiotics are approved for management of bacterial pathogens.

Comparison of efficacy and modes of action of two high-potential biocontrol <i>Bacillus</i> strains and commercial biocontrol products against <i>Botrytis cinerea</i> in table grapes

In table grapes (cv. Thomson Seedless), the antifungal activity against Botrytis cinerea was further analysed and compared between two high potential bacterial biological control agent (BCA) strains, Bacillus velezensis BUZ-14 and B. ginsengihumi S38. Two commercial biocontrol products (BPs), served as standards of comparison, Amylo-X® and Serenade Max®, also based on Bacillus BCA strains. The main mode of action quantified for all the strains was antibiosis due to hydrosoluble and volatile metabolites and their combinations. The BUZ-14 strain was the most active BCA strain, demonstrating significant disease reduction exceeding 60 % when used in the culture form grown in 863 medium, including living cells (LCs) and cell-free supernatant (CFS). Both BPs exhibited significantly reduced efficacy of their CFS fraction (< 10 %) compared with that of the two BCA strains, confirming their high antibiosis potential. The novel methodology allowed us to demonstrate the significant effect of the BCA culture medium on volatilome (VOC) antagonist efficacy. The S38 strain achieved the highest disease reduction (90 %) owing to the greatest production of VOCs in the richest MOLP (Medium Optimum Lipopetide Production) culture medium, whereas grape juice was the least favourable medium for VOC efficacy for both bacterial strains (BUZ14 and S38). The overall poor activity of living Bacillus cells in all the BCA and BPs tested is discussed based on the low capacity of the BCA strains to grow in the berry. Then, the presence of living cells is also discussed with the possibility that these cells are not required in field applications of such BCA strains in this genus. Moreover, different environmental suboptimal conditions, including temperature (22 and 27 °C) and relative humidity (RH) (100 and 85–95 %), were tested, and BUZ-14 exhibited the highest Botrytis reduction at both temperatures and RH values. However, no significant differences were observed between temperatures or RH values for the same BCA. Further studies in vineyard conditions and applications, such as biofumigation or active packaging, will be performed to confirm the new findings reported in this investigation.

Potential use of biofungicides and conventional fungicide for the management of Botrytis blossom blight in lowbush blueberries

ABSTRACT Botrytis blight is an economically important disease of lowbush blueberry that causes significant yield loss annually. In this study, the biofungicides, Diplomat 5SC; (polyoxin D), Timorex Gold; (tea tree oil), Fracture; (BLAD) and Serenade MAX; (Bacillus subtilis) were evaluated for their disease suppression potential against B. cinerea individually and in rotation with Switch® (cyprodinil and fludioxonil) under field conditions. Three applications of each biofungicide were made for the stand-alone treatments at 7–10 day intervals, with Switch® replacing the biofungicides during the second applications in the combined treatment. Results indicated that the products have the potential for use as a biofungicide in lowbush blueberries. All the stand-alone and rotational applications brought about a significant reduction in disease development, especially in 2019. The application of Diplomat 5SC; and Fracture®-Switch® rotation decreased disease development by over 63% in 2018. In 2019, all stand-alone treatments reduced disease development by more than 42%, whereas their rotation with Switch® reduced disease by over 69% at one site and at least 30% at another site. Stand-alone Diplomat 5SC® and Timorex Gold® along with Fracture®, Timorex Gold® and Serenade MAX; rotation resulted in over 20% more berries. This study suggests that the biofungicides and their integration with chemical fungicides have the potential as an alternative management strategy against Botrytis blossom blight to reduce the use of conventional fungicides and produce fruit with no detectable fungicide residues.

Management of Botrytis blossom blight in wild blueberries by biological control agents under field conditions

Botrytis blossom blight is an important disease of wild blueberries in Canada that causes over 20% yield losses annually. Four trials (2 in each year) were set up in 2015 and 2016 to investigate the efficacy of biofungicides against Botrytis blossom blight in wild blueberry. Botector®, Fracture® and Serenade MAX® were evaluated alone and in rotation with Switch® and compared with a standard control program (Fontelis®, Switch®, and Pristine®). Three applications of each biofungicide were done for stand-alone treatment, and each rotated with Switch® as combined treatment. Fungicides were applied at 7-10-day intervals starting from pre-anthesis, white tip stage. Botector®, Fracture® and Serenade MAX® rotation with Switch® suppressed Botrytis blossom blight by over 65% and 60% less disease incidence and severity compared to the untreated control. Significant disease suppression was observed in stand-alone application of Botector®, Fracture® and Serenade MAX® in 2016 whereas they were not effective in 2015. The rotation of Fracture® and Serenade MAX® with Switch®, and stand-alone Serenade MAX® resulted in increased harvestable berry yield. The results suggest that the use of biofungicides in tandem with conventional fungicides in an integrated disease management program, can adequately suppress Botrytis blossom blights.

Effective Biopesticides and Biostimulants to Reduce Aflatoxins in Maize Fields.

The presence of ear rots in maize caused by Aspergillus flavus that are also associated with the production of aflatoxins has evolved into an increasing problem over the last few years. Since no commercial biological control products are still available to control A. flavus in maize in Europe, this study targets to the evaluation of six biopesticides/biostimulants (Botector®, Mycostop®, Serenade Max®, Trianum®, Vacciplant®, and zeolite) for the control of A. flavus and the derived aflatoxins in in vitro and maize field bioassays. Mycostop®, Serenade Max®, Vacciplant®, and zeolite reduced significantly A. flavus conidia production by 38.8–63.1%, and most of them were able to reduce aflatoxin B1 (AFB1) production in laboratory studies. Mycostop®, Trianum®, and Botector® were effective in reducing AFB1, in vitro. In the field, Mycostop® and Botector® treatments resulted in significant reduction of the disease severity (16.5 and 21.9%, respectively) and decreased significantly AFB1 content in maize kernels by 43.05 and 43.09%, respectively. For the first time, these results demonstrated the potential of commercial non-chemical products to suppress disease symptoms and aflatoxin content caused by A. flavus in maize under laboratory and field conditions.

Integration of biological and chemical control of brown rot of stone fruits to reduce disease incidence on fruits and minimize fungicide residues in juice

Brown rot is a major disease of stone fruits caused by Monilinia spp. It can reach high incidence that leads to considerable losses during storage. Our work aimed at the evaluation of innovative biological and integrated approaches to control brown rot of apricots and peaches, and of their influence on the presence of fungicide residues both in the harvested fruits and derived peach juices. In this work, we report the results of a two-year field investigation carried out in 5 different farms in Southern Italy. Plant health management strategy was based on two treatments performed in the last thirty days before harvest. Two biocontrol agents (BCAs), the yeast Rhodotorula kratochvilovae strain LS11 and the commercial biofungicide Serenade Max® (based on Bacillus subtilis strain QST 713), were applied alone (biocontrol) or in combination with low doses of the fungicides (25% of full dosage, integrated control) cyprodinil (30 days before harvest), and boscalid (7 days before harvest). The highest protection was recorded in conventional (fungicides applied at full dosage) and integrated control treatments, both on apricots and peaches. In the integrated control, residues of fungicides in fruits and in peach juice were significantly lower compared to those of the conventional control in both fruit species. Our data show that biological and integrated control based on two key treatments at thirty and seven days before harvest can be considered as effective and safer control strategies of brown rot of stone fruits. Furthermore, the applied strategies can dramatically reduce and even set to zero the level of fungicide residues in derived fruit juices.

Acibenzolar-S-methyl is associated with yield reduction when used for managing bacterial wilt (Erwinia tracheiphila) in cantaloupe

Bacterial wilt, caused by Erwinia tracheiphila (Smith), can result in serious yield loss of cantaloupe in the Midwest United States. Although neonicotinoid insecticides are an effective means of managing the cucumber beetles that vector E. tracheiphila, this management regime may cause toxicity to pollinators. An alternative method of managing this disease is to use products that induce resistance. Over four years, we have compared disease severity of bacterial wilt, cucumber beetle numbers, feeding damage and yield as influenced by products purported to induce Systemic Acquired Resistance (SAR) or Induced Systemic Resistance (ISR). Acibenzolar-S-methyl (Actigard®) effectively lowered disease severity of bacterial wilt in years when disease pressure was moderate or high. Actigard® was also associated with lower levels of cucumber beetle feeding in some years. However, when disease pressure was low, Actigard® at some rates and timings, caused yield loss. The other products, Regalia® and Serenade Max®, are purported to elicit ISR and did not consistently lower disease levels or influence beetle feeding in the current study. The standard insecticide regime, imidacloprid used as a drench at planting and permethrin applications at weeks 3–6, was the most consistent method of lowering beetle feeding and thus managing bacterial wilt. Since Actigard® could be associated with yield loss, its use for the management of bacterial wilt in cantaloupe cannot be recommended.

Evaluation of Serenade Max to Control Fruit Rot of Grapes

<p>The effectiveness of the biopesticide Serenade Max to control fruit rot in grape was investigated. The experiments were conducted in commercial vineyard (cv Xinomavro Naousa). The results showed that this product was relatively effective to control fruit rots on grapes. No significant difference was observed between Serenade Max and Switch25/37.5 WG in both years of experiment. It was found that the fungus <em>Botrytis cinerea</em> commonly caused fruit rots (at a percentage of 96%) on the control grape fruits.<strong></strong></p><p>Generally, Serenade Max could be an alternative method against fruit rots of grape in biological fruit production system.</p>

Bacillus subtilis QST 713, copper hydroxide, and their tank mixes for control of bacterial citrus canker in Saudi Arabia

Citrus Bacterial Canker (CBC) is a serious disease that affects production of almost all commercial citrus cultivars in subtropical citrus growing regions worldwide. In this study, the effectiveness of monthly foliar sprays of wettable powder formulation Serenade MAX of Bacillus subtilis QST 713, alone or as tank mixes with copper hydroxide on CBC disease development was evaluated under greenhouse and uncovered nursery conditions. The QST 713 as a tank mix with copper hydroxide reduced significantly the disease severity and incidence, followed by the copper hydroxide treatment, compared to the control. The disease incidence on leaves of inoculated trees treated with a combination of copper with QST 713 was never higher than 19%, whereas, the disease incidence reached 43% for non-sprayed trees. It was possible to reduce the number of copper sprays up to 6 sprays per season when it was mixed with the bio-fungicide QST 713 to effectively control CBC compared with 8 sprays of copper hydroxide alone per season. Based on our results, the application of QST 713 not only may have potential for CBC management in conjunction with copper hydroxide or other disease control but also may reduce the frequency or rate of copper sprays in citrus groves.

A TaqMan-based qPCR assay for quantitative detection of the biocontrol agents Bacillus subtilis strain QST713 and Bacillus amyloliquefaciens subsp. plantarum strain D747

Biological control agents (BCAs) play an important role in crop protection. They can improve sustainability, prevent resistance to fungicides in target pathogens and reduce fungicide residues on produce. Bacillus subtilis strain QST713 (Serenade Max; Bayer CropScience, Leverkusen, Germany) and Bacillus amyloliquefaciens subsp. plantarum strain D747 [Amylo-X; CBC Europe S.r.l.—Biogard Division, Nova Milanese (MB), Italy] are two commercially available BCAs that are used against grey mould on table grape and other crops. TaqMan-based quantitative (q)PCR assays were developed and validated for quantitative and specific detection of the two BCAs on grape bunches following field sprays. Specific molecular markers were developed for each BCA, and TaqMan probes were designed and tested in qPCR on DNA extracted from washing water of grape berries. The assay proved specific and sensitive for both BCAs allowing detection at density as low as three colony-forming units (CFU) per gram of berries. The method will be useful to investigate the population dynamics of the two BCAs following their applications in vineyards.

Efficacy of Bacillus subtilis QST 713 formulations, copper hydroxide, and their tank mixes on bacterial spot of tomato

This study was conducted to investigate the effects of foliar sprays of wettable powder formulation (Serenade MAX or QRD 141) and aqueous suspension (Serenade ASO or QRD 145) of Bacillus subtilis QST 713, alone or as tank mixes with copper hydroxide, on bacterial spot disease and fruit yields of tomato. Field plots were established in London, Ontario Canada during the 2007–2010 growing seasons and disease conditions were created artificially by inoculations with cell suspension of bacterial spot pathogen. The aqueous suspension of biofungicide alone reduced the severity of bacterial spot on tomato foliage relative to water control in 3 of 4 years but in tank mix with copper hydroxide reduced disease severity on foliage in all 4 years. The wettable powder formulation of biofungicide alone did not consistently reduce bacterial spot severity on tomato foliage but in tank mix with copper hydroxide reduced disease severity on foliage in 3 of 4 years. Copper hydroxide alone also reduced the severity of bacterial spot on tomato foliage in 3 of 4 years. A consistent reduction in the percentage of diseased fruit was not seen with any of the biofungicide of copper hydroxide spray treatments. There was no consistent effect on marketable yield with any of the treatments. The wettable powder formulation of biofungicide in a tank mix with copper hydroxide increased total fruit yield during the first 2 years only, but the reason for this yield increase is not clear.The results suggest a moderate effect of biofungicide or copper hydroxide alone or in combination in reducing bacterial spot disease.

Performance of Natural Antagonists and Commercial Microbiocides towards <i>in Vitro</i> Suppression of Flower Bed Soil-Borne <i>Fusarium oxysporum</i>

Fusarium oxysporum is the causal agent for wilt diseases of many major ornamental and horticultural crops. In this study, we plated a local cut flower grower’s soil, with a persistent history of Fusarium wilt of scented stock, Matthiola incana but not the lettuce rotational crop. This yielded culture plates with characteristic pink to carmine red fungi, together with a mixed bacterial population, a percentage of which was visibly antagonistic to the Fusarium. Using molecular analyses via Polymerase Chain Reaction (PCR) assays, we identified that Fusarium oxysporum, Fusarium culmorum, Fusarium equiseti and Fusarium venenatum were prevalent in the soil. The co-habiting bacterial colonies that exhibited strong antagonistic activity (zone of clearance) towards the soil fungi corresponded to Bacillus subtilis, Bacillus amyloliquefaciens and Paenibacillus polymyxa species. Our results arising from an in vitro study involving Kirby-Bauer disc-diffusion agar assays, coupled with bio-imaging software techniques demonstrated that the three native soil bacteria were effective inhibitors of all Fusarium species tested, while Bacillus subtilis exhibited the highest antagonism towards the Fusarium oxysporum. Bioassay tests of micro-biocides Prestop (Gliocadium catenulatum), Serenade Max (Bacillus subtilis QST713) and commercial seaweed extract, AlgiVyt suppressed in vitro growth of Fusarium oxysporum infecting the scented stock flower to a greater extent, whilst fresh aqueous extracts of garlic (Allium sativum) and meadowsweet (Filipendula ulmaria) flowers were ineffective towards soil pathogen suppression. This scoping study offers cut flower growers additional options of tapping into populations of antagonistic bacteria found in soil persistently infected with the opportunistic soil phytopathogen Fusarium oxysporum, affecting cut flower crops, such as M. incana.

Sensitivity of Erwinia amylovora in Illinois Apple Orchards to Streptomycin, Oxytetracyline, Kasugamycin, and Copper.

In 2008 and 2009, severe fire blight (Erwinia amylovora) occurred in Illinois apple orchards, leading to speculation that streptomycin-resistant strains of E. amylovora might be present in some orchards. Statewide surveys were conducted in 2010, 2011, and 2012, and 117, 129, and 170, E. amylovora isolates were collected, respectively, from 20 counties. None of the 416 E. amylovora isolates tested were resistant to streptomycin (Agri-Mycin 17WP) at 50 mg/liter. Seven non-E. amylovora bacterial isolates were collected from E. amylovora-infected shoots that contained both a strA-strB streptomycin resistance gene and IS1133 on transposon Tn5393, which could be a potential source of streptomycin resistance for E. amylovora in Illinois in the future. Colony development of all 84 E. amylovora isolates tested was inhibited on Luria-Bertani medium amended with oxytetracycline at 50 mg/liter and kasugamycin (Kasumin 2L) at 100 mg/liter. Similarly, colony development of the 84 E. amylovora isolates was inhibited on casitone-yeast extract medium amended with copper sulfate at 0.16 mM. In 2011 and 2012, field trials were conducted to evaluate the efficacy of oxytetracycline (Mycoshield 17WP), kasugamycin (Kasumin 2L and ARY-4016-06), copper hydroxide (Kocide-3000 41.6DF), Bacillus subtilis (Serenade Max, QST713), and Pseudomonas fluorescens (Blight Ban A506) for management of fire blight in an apple orchard. Only kasugamycin (Kasumin 2L and ARY-4016-06) reduced blossom infection significantly. There was a significant interaction of kasugamycin (Kasumin 2L) with prohexadione calcium (Apogee 27.5DF) in reducing shoot blight incidence in the field in 2012.

Biological control of peach brown rot (Monilinia spp.) by Bacillus subtilis CPA-8 is based on production of fengycin-like lipopeptides

Bacillus subtilis CPA-8, a strain with demonstrated ability to control Monilinia spp. in peaches, was studied to elucidate its mechanisms of antifungal activity. Growth inhibition assays using cell-free supernatants and butanolic extracts showed strong antifungal activities against Monilinia laxa and Monilinia fructicola. By comparison with the reference B. subtilis strains UMAF6614 and UMAF6639, fengycin, iturin and surfactin lipopeptides were identified by thin layer chromatography in butanolic extracts from cell-free supernatants, indicating that antibiosis could be a major factor involved in the biological control ability of CPA-8. TLC-bioautography analysis confirmed the presence of fengycin, iturin and surfactin lipopeptides but strong antifungal activity could be associated only with fengycin lipopeptides. These results were definitively supported by mutagenesis analysis targeted to suppress fengycin biosynthesis by disruption of the B. subtilis fenB gene. By TLC-bioautography analysis it was possible to identify transformants from CPA-8 with reduced or suppressed antifungal activity, and this phenotype was associated with the lack of fengycin bands. Fruit trials confirmed that fengycin-defective mutants and their cell-free supernatants lost their ability to control peach brown rot disease in comparison with CPA-8 wild type strain or Serenade Max®, a commercial formulation based on B. subtilis. Furthermore, population dynamics studies determined that CPA-8 fengycin-deficient mutants survived in wounds in peach fruit equally well as the CPA-8 wild type. Taken together our data indicate that fengycin-like lipopeptides play a major role in the biological control potential of B. subtilis CPA-8 against peach brown rot.

Alternative Organic Fungicides for Apple Scab Management and Their Non-target Effects

A major challenge in organic apple production in humid production regions is the available fungicide options for apple scab [Venturia inaequalis (Cooke) Wint.] management. The standard sulfur/lime sulfur fungicide program can be injurious to the applicator, the apple ecosystem, and the apple tree itself. The objectives of this study were to compare the efficacy of three potential alternative fungicides [potassium bicarbonate (PB), neem oil (NO), and Bacillus subtilis (Bs)] with a standard organic sulfur/lime sulfur (SLS) fungicide program and a non-treated control (NTC) for management of apple scab and to evaluate potential non-target impacts on pest and beneficial arthropod populations. The five treatments were applied to ‘Empire’ trees arranged in a completely randomized design with five single-tree replications at the University of Vermont Horticultural Research Center in South Burlington, VT. Fungicides were applied with a handgun to drip using maximum label rates. Applications began on 26 Apr. 2007 and 23 Apr. 2008 and continued on approximately a weekly schedule through the end of June and then every 2 weeks through 23 July 2007 and 17 July 2008, respectively. The standard SLS treatment resulted in the best scab control in both years. The NO treatment reduced foliar and fruit scab compared with the NTC and the other alternatives at the end of the 2008 growing season and had insecticidal activity. However, both the SLS and NO treatments had disadvantages, including phytotoxic burning on the fruit and/or significantly more russeting on the fruit at harvest. In each year of the study, one or more of the alternative treatments, particularly Bs, resulted in higher insect damage than the non-fungicide-treated control. This research showed that PB, Bs, and NO do not offer advantages over the standard SLS fungicide program in organic apple production and in some cases offer distinct disadvantages in terms of non-target impacts. Chemical names used: potassium bicarbonate (Armicarb “O”), Bacillus subtilis (Serenade MAX), neem oil (Trilogy), sulfur (Microthiol Sulfur)/lime sulfur (Miller Lime Sulfur)

GRAS (GENERALLY RECOGNIZED AS SAVE) METHODS AS A POSSIBLE CONTROL OF POSTHARVEST FUNGAL DISEASES IN SWEET CHERRY

Sweet cherry is a fruit with a very limited storage life and fungal decay during shelf-life can often result in serious fruit loss. In Germany, there are no postharvest treatments allowed to control fungal diseases on sweet cherries. However, internationally interest is increasing in alternative methods that are harmless to consumer health. We tested different GRAS (Generally Recognized As Safe) methods to control Penicillium expansum (blue mould rot), Botrytis cinerea (gray mould rot) and Monilinia fructigena (brown rot) on sweet cherry in 2007 and 2008. Comparing the different GRAS methods, a combination of sodium bicarbonate (NaHC0 3 ) and yeast (Aurebasidium pullulans), a product marketed as Antinfek ™ 10H (polyhexamethylene biguanidine hydrochloride 3.2% w/w) a combination of Antinfek ™ with Serenade Max (Bacillus subtilis), and Antinfek ™ with calcium hydroxide, all showed good results in reducing postharvest fungal diseases. Other GRAS methods, such as citric acid, calcium formate, Na-metasilicate, chitosan, or yeast separately did not show adequate control against the tested fungi. Further GRAS research to control post-harvest diseases in sweet cherry is planned.

Annual Meeting, Winnipeg, Manitoba, 2009

Annual Meeting, Winnipeg, Manitoba, 2009

Evaluation of spray programs containing famoxadone plus cymoxanil, acibenzolar- S-methyl, and Bacillus subtilis compared to copper sprays for management of bacterial spot on tomato

Bacterial spot caused by Xanthomonas euvesicatoria Jones et al. and Xanthomonas perforans Jones et al. is a major disease on fresh market commercial tomato in Florida. Fourteen field trials were conducted between 1999 and 2005 (10 in south Florida and four in north Florida) testing famoxadone plus cymoxanil (Tanos 50DF ®, E.I. du Pont de Nemours and Company, Wilmington, DE), Bacillus subtilis strain QST 713 ( B. subtilis) (Serenade WPO ® or Serenade Max ®, AgraQuest, Inc., Davis, CA), and acibenzolar- S-methyl (ASM) (Actigard 50WG ®, Syngenta Crop Protection, Greensboro, NC) at different rates and in various application programs that were combined and rotated with copper hydroxide and mancozeb for management of bacterial spot. In field applied spray treatments containing famoxadone as a component, all of the programs significantly reduced bacterial spot severity on plants compared to the untreated control plants (UTC) and 97% of the programs were equal for disease suppression conferred by the copper-mancozeb standard. In spray programs containing ASM or B. subtilis plus copper hydroxide, treated plants had significantly reduced disease compared to the UTC plants and were not different from the plants treated with the copper-mancozeb standard. Yield data from small plots was unaffected. Several of the programs which used these compounds in rotation with copper-mancozeb provided similar levels of reduction in the disease severity for bacterial spot while reducing by 50% the amount of copper applied to plants. The effect of famoxadone plus cymoxanil on the survival of Xanthomonas in vitro did not cause a significant reduction in the bacterial population and was not determined to be directly bactericidal. However, greenhouse and field testing supports disease reduction of bacterial spot on plants treated with these compounds. The products tested in these trials may be useful, alternative tools for use in an integrated management program for bacterial spot on tomato.