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Lise Korsten - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of pre-harvest Bacillus licheniformis sprays to control mango Fruit Diseases
Crop Protection, 2007Co-Authors: M. Silimela, Lise KorstenAbstract:Abstract Bacillus licheniformis was evaluated as a pre-harvest spray treatment either on its own or alternated with copper oxychloride to control mango Fruit Diseases. Prior to initiating the spray trials, in vitro and in vivo studies were done to determine the effect of stickers, spreaders, a biostimulant and a copper fungicide on the biocontrol agent's ability to effectively attach to and colonise the mango leaf surface. Bioboost, Nufilm-P, Biofilm and Agral 90 did not affect antagonist growth in vitro . However, copper oxychloride and Supafilm inhibited the in vitro growth of B. licheniformis , more pronouncedly after 8 h. The in vivo study showed that stickers and spreaders did not improve the ability of B. licheniformis to attach to and colonise the leaf surface. Pre-harvest B. licheniformis applications alone and alternated with copper sprays applied at 3-weekly intervals from flowering until harvest controlled moderate levels of anthracnose, bacterial black spot and soft rot.
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Biological control in Africa: can it provide a sustainable solution for control of Fruit Diseases?
South African Journal of Botany, 2004Co-Authors: Lise Korsten, C.h. BornmanAbstract:Biological control has evolved from an obscure science to a well-established field of study. Biological control systems for citrus and subtropical Fruit crops have been studied at the University of Pretoria for more than 20 years. Various Bacillus spp. originally isolated from leaf and Fruit surfaces effectively controlled Cercospora spot of avocado, anthracnose of mango and avocado, Dothiorella/Colletotrichum Fruit rot complex and stem end rot of avocado and mango, soft brown rot on mango and postharvest decay and secondary infections on litchi and citrus. Control was achieved through semi-commercial preharvest sprays or postharvest pack-house dip and spray applications. Integrated treatments involving antagonists combined with quarter-strength or recommended dosage of fungicides, disinfectants or natural plant extracts also effectively suppressed postharvest Diseases of avocado, citrus and mango. Antagonist attachment, colonisation and survival were studied using several techniques including viable counts, electron microscopy and monoclonal antibodies. Modes of action of these different antagonist-pathogen-host combinations indicated several levels of interactions that were time and density-dependent and included secondary metabolites, nutrient competition volatiles and competitive colonisation. Innovative alternatives to apply the antagonists in the field were evaluated and included the use of foraging bees to disseminate the antagonists to flowers and woolly-based plastic caps to provide a slow release effect for the antagonist under field conditions. Commercialising the antagonists proved to be difficult due to limitations in local registration guidelines. The South African Fruit industries and the University of Pretoria currently hold the patent with regard to the formulation and application of these biocontrol products. One of these products, Avogreen (B. subtilis), a control agent against Cercospora spot on avocado, has been commercialised. This review discusses the problems, opportunities and challenges in developing and commercialising biocontrol agents in the African context. Only once these complex antagonist–pathogen–host interactions, microbial dynamic systems and environmental impact on product performance are fully understood, can biocontrol be truly regarded as a viable alternative to pesticides and will it provide some solution to Africa's critical crop protection needs.
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biological control of postharvest Diseases of Fruits
Annual Review of Phytopathology, 2002Co-Authors: Wojciech J Janisiewicz, Lise KorstenAbstract:▪ Abstract Losses from postharvest Fruit Diseases range from 1 to 20 percent in the United States, depending on the commodity. The application of fungicides to Fruits after harvest to reduce decay has been increasingly curtailed by the development of pathogen resistance to many key fungicides, the lack of replacement fungicides, negative public perception regarding the safety of pesticides and consequent restrictions on fungicide use. Biological control of postharvest Diseases (BCPD) has emerged as an effective alternative. Because wound-invading necrotrophic pathogens are vulnerable to biocontrol, antagonists can be applied directly to the targeted area (Fruit wounds), and a single application using existing delivery systems (drenches, line sprayers, on-line dips) can significantly reduce Fruit decays. The pioneering biocontrol products BioSave and Aspire were registered by EPA in 1995 for control of postharvest rots of pome and citrus Fruit, respectively, and are commercially available. The limitations ...
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field sprays of bacillus subtilis and fungicides for control of preharvest Fruit Diseases of avocado in south africa
Plant Disease, 1997Co-Authors: Lise Korsten, E E De Villiers, F C Wehner, Jm KotzéAbstract:In 3 consecutive years, preharvest applications of Bacillus subtilis field sprays integrated with copper oxychloride or benomyl consistently reduced severity of avocado black spot (BS), caused by Pseudocercospora purpurea at Omega, Republic of South Africa. Control was equal to that obtained with copper oxychloride or benomyl-copper oxychloride in the first and third years of spraying at Omega. In the second year, only the integrated treatment controlled BS, while copper oxychloride proved ineffective. The antagonist was applied on its own or integrated with copper oxychloride sprays at two other geographically distinct locations, Westfalia Estate and Waterval. The integrated and biological treatments at these localities were less effective than copper oxychloride sprays in controlling BS disease. Integrated control was more effective than B. subtilis sprays at Westfalia. On continuation of the biological spray program at Waterval for an additional three seasons, control was as effective as copper oxychloride in the last 2 years of spraying. Sooty blotch (SB), caused by an Akaropeltopsis sp., was reduced by the integrated treatment at Omega during the second season and at Westfalia during the first season. Although the two fungicide treatments reduced SB at Omega in the first season, copper oxychloride increased it above that of the control in the third season. Only the copper oxychloride treatment reduced SB at Waterval in the third season, while the B. subtilis treatment increased disease above that of the control in the fourth season.
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POSTHARVEST BIOLOGICAL CONTROL OF AVOCADO Fruit Diseases
1993Co-Authors: Lise KorstenAbstract:SUMMARY Bacillus subtilis on its own or integrated with prochloraz Tag-wax application was evaluated for control of avocado postharvest Diseases anthracnose, Dothiorella/ Colletotrichum Fruit rot complex (DCC) and stem-end rot (SE). Tag-waxed Fruit and/ or Fruit treated with prochloraz incorporated into Tag-wax, served as controls. The biological and integrated treatments were as effective as the prochloraz Tag-wax treatment in controlling DCC on Fuerte, and anthracnose and SE on Mass. In addition, the integrated treatment also effectively controlled SE on Fuerte and Ryan, at Westfalia Estate packhouse. Comparing a B. subtilis application at H.L. Hall & Sons, anthracnose and SE could effectively be controlled in two separate experiments. OPSOMMING Bacillus subtilis opsyeie ofge'inkorporeerin 'nprochloraz Tag-waks toediening was geevalueer vir beheer van avokado na-oes siektes antraknose, Dothiorella/ Colletotrichum vrugte vrot kompleks (DCK) en stingelendbederf (SE). Tag-waks behandelde vrugte of vrugte behandel met prochloraz ge'inkorporeer in Tag-waks, net gedien as kontroles. Die biologiese en ge'integreerde behandelings was net so effektief as die prochloraz Tag-waks behandelings en kon DCK op Fuerte en antracnose en SE op Hass beheer. Verderhet die ge'integreerde behandeling ook SE by Fuerte en Ryan beheer soos geevalueer by Westfalia Landgoed pakhuis.
Jm Kotzé - One of the best experts on this subject based on the ideXlab platform.
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field sprays of bacillus subtilis and fungicides for control of preharvest Fruit Diseases of avocado in south africa
Plant Disease, 1997Co-Authors: Lise Korsten, E E De Villiers, F C Wehner, Jm KotzéAbstract:In 3 consecutive years, preharvest applications of Bacillus subtilis field sprays integrated with copper oxychloride or benomyl consistently reduced severity of avocado black spot (BS), caused by Pseudocercospora purpurea at Omega, Republic of South Africa. Control was equal to that obtained with copper oxychloride or benomyl-copper oxychloride in the first and third years of spraying at Omega. In the second year, only the integrated treatment controlled BS, while copper oxychloride proved ineffective. The antagonist was applied on its own or integrated with copper oxychloride sprays at two other geographically distinct locations, Westfalia Estate and Waterval. The integrated and biological treatments at these localities were less effective than copper oxychloride sprays in controlling BS disease. Integrated control was more effective than B. subtilis sprays at Westfalia. On continuation of the biological spray program at Waterval for an additional three seasons, control was as effective as copper oxychloride in the last 2 years of spraying. Sooty blotch (SB), caused by an Akaropeltopsis sp., was reduced by the integrated treatment at Omega during the second season and at Westfalia during the first season. Although the two fungicide treatments reduced SB at Omega in the first season, copper oxychloride increased it above that of the control in the third season. Only the copper oxychloride treatment reduced SB at Waterval in the third season, while the B. subtilis treatment increased disease above that of the control in the fourth season.
I Donati - One of the best experts on this subject based on the ideXlab platform.
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postharvest control of monilinia laxa and rhizopus stolonifer in stone Fruit by peracetic acid
Postharvest Biology and Technology, 2004Co-Authors: Marta Mari, R Gregori, I DonatiAbstract:Abstract Peracetic acid (PAA) treatment of stone Fruit (sweet cherry, apricot, peach and nectarine) reduced the incidence of brown rot caused by Monilinia laxa and soft rot caused by Rhizopus stolonifer . The efficacy of the treatment depended on the length of time. Fruit, neither wounded nor inoculated and dipped for 1 min in a 125 mg L −1 PAA solution, showed a significant reduction of Monilinia rots with respect to control. Significant inhibition was also observed on Fruit wounded and inoculated with R. stolonifer and treated for 1 min with 250 mg L −1 PAA solution. Sodium bicarbonate (SBC), sodium propionate (Na-Pro) and potassium sorbate (K-Sorb), substances generally regarded as safe (GRAS), were also evaluated. Phytotoxic effects appeared on Fruit treated with SBC at the minimum effective concentration (3%). Any rot reduction was observed in Na-Pro Fruit treated, only K-Sorb at 1.5% was able to significantly reduce Monilinia infections in sweet cherries (61.6%), apricots (78%) and nectarines (31.8%) with respect to the controls, without any visible damage on the skin. Similar results were obtained on apricot wounded and inoculated with R. stolonifer . Fruit hydro-refrigeration significantly reduced the incidence of brown rot in Nero I and Van sweet cherries; disease control was improved by addition of PAA (125 mg L −1 ) in cold water. PAA efficacy on pre-existing infections can be very useful to control stone Fruit Diseases that can spread during shipping and marketing.
Esmaeil Chamani - One of the best experts on this subject based on the ideXlab platform.
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Control of nectarine Fruits postharvest fungal rots caused by Botrytis Cinerea and Rhizopus Stolonifer via some essential oils
Journal of Food Science and Technology, 2019Co-Authors: Mohammad Tahmasebi, Abdollah Golmohammadi, Ali Nematollahzadeh, Mahdi Davari, Esmaeil ChamaniAbstract:Nectarines ( Prunus persica L. Bath) are very sensitive Fruit to fungal infection. Today, the control of postharvest Fruit Diseases with essential oils (EOs) has been significantly noticed as a novel trend in biological preservation. In this study, volatile compounds of Cinnamon zeylanicum (CEO), Zataria multiflora (ZEO) , and Satureja khuzestanica (SEO) were analyzed by Gas Chromatography–Mass spectroscopy. Also, the in vitro antifungal activities of EOs against Botrytis cinerea and Rhizopus stolonifer were evaluated at different concentrations. The in vivo antifungal activity of these EOs on artificially infected nectarine Fruits was also considered. The major components were Thymol (32.68%) and Carvacrol (30.57%) for ZEO, cinnamaldehyde (80.82%) for CEO, and carvacrol (38.43%) for SEO. The application of different concentrations showed a decreasing trend in the fungus radial growth in all EOs. In the in vitro experiments, ZEO and CEO exhibited more significant mycelial inhibition results and reduction of the IC_50, MIC and MFC values against Botrytis cinerea and Rhizopus stolonifer , respectively. However, in the in vitro experiments, none of the treatments were capable of completely inhibiting the growth of the fungi. According to the results of this study, ZEO and CEO could reduce the damage caused by these fungi.
Francisco J Fernandezacero - One of the best experts on this subject based on the ideXlab platform.
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infection strategies deployed by botrytis cinerea fusarium acuminatum and rhizopus stolonifer as a function of tomato Fruit ripening stage
Frontiers in Plant Science, 2019Co-Authors: Stefan Petrasch, Christian J Silva, Saskia D Mesquidapesci, Karina Gallegos, Casper Van Den Abeele, Victor Papin, Francisco J FernandezaceroAbstract:Worldwide, 20-25% of all harvested Fruit and vegetables are lost annually in the field and throughout the postharvest supply chain due to rotting by fungal pathogens. Most postharvest pathogens exhibit necrotrophic or saprotrophic lifestyles, resulting in decomposition of the host tissues and loss of marketable commodities. Necrotrophic fungi can readily infect ripe Fruit leading to the rapid establishment of disease symptoms. However, these pathogens generally fail to infect unripe Fruit or remain quiescent until host conditions stimulate a successful infection. Previous research on infections of Fruit has mainly been focused on the host’s genetic and physicochemical factors that inhibit or promote disease. Here, we investigated if Fruit pathogens can modify their own infection strategies in response to the ripening stage of the host. To test this hypothesis, we profiled global gene expression of three fungal pathogens that display necrotrophic behavior - Botrytis cinerea, Fusarium acuminatum, and Rhizopus stolonifer - during interactions with unripe and ripe tomato Fruit. We assembled and functionally annotated the transcriptomes of F. acuminatum and R. stolonifer as no genomic resources were available. Then, we conducted differential gene expression analysis to compare each pathogen during inoculations versus in vitro conditions. Through characterizing patterns of overrepresented pathogenicity and virulence functions (e.g., phytotoxin production, cell wall degradation, and proteolysis) among the differentially expressed genes, we were able to determine shared strategies among the three fungi during infections of compatible (ripe) and incompatible (unripe) Fruit tissues. Though each pathogen’s strategy differed in the details, interactions with unripe Fruit were commonly characterized by an emphasis on the degradation of cell wall components, particularly pectin, while colonization of ripe Fruit featured more heavily redox processes, proteolysis, metabolism of simple sugars, and chitin biosynthesis. Furthermore, we determined that the three fungi were unable to infect Fruit from the non-ripening (nor) tomato mutant, confirming that to cause disease, these pathogens require the host tissues to undergo specific ripening processes. By enabling a better understanding of fungal necrotrophic infection strategies, we move closer to generating accurate models of Fruit Diseases and the development of early detection tools and effective management strategies.
