During the period 1997-2000, while studying a commercial compost that originated from sewage slud... more During the period 1997-2000, while studying a commercial compost that originated from sewage sludge and refuse from the city of Barcelona, we encountered a compost that naturally suppressed Fusarium oxysporum. On analysing the biotic components involved in that suppressiveness, we discovered that it contained a wide variety of Trichoderma species. We isolated around 200 different Trichoderma strains from the suppressive compost. These were evaluated as detailed previously in Cotxarrera et al. (2002) and in the PhD Thesis of L. Cotxarrera (2006). The specific isolate T34 of the species T. asperellum (Fig. 18.1) was patented due to its efficacy in controlling Fusarium wilt of tomato. The Spanish patent ES 2188385 B1 was later extended to several EU countries (EP 1400586 B1) and the USA (US 7,553,657 B2). Almost simultaneously with our research, under Directive 91/414 EEC, the European Commission decided to evaluate all active substances (ASs) in plant protection products (PPPs) on the market. The aim was to (i) harmonise such products across the different Member States and (ii) exclude those pesticides that were deemed hazardous for human health or which had a negative environmental impact.
The composting of winery waste is an alternative to the traditional disposal of residues, and als... more The composting of winery waste is an alternative to the traditional disposal of residues, and also involves a commitment to reducing the production of waste products. We studied two residues (sludge and grape stalks), mixed in two proportions (1:1 and 1:2 sludge and grape stalks (v/v)), and we also examined the effects of grinding the grape stalks. Our results showed that composting the assayed materials was possible. Best results were obtained in the compost heap in which the residues were mixed in the proportion 1:2, and where the grape stalks had been previously ground. Optimum results required a moisture around 55% and a maximum temperature around 65°C and an oxygen concentration not lower than 5-10%. The resulting compost had a high agronomic value and is particularly suitable for the soils of the vineyards which have a very low organic matter content. The compost can be reintroduced into the production system, thereby closing the residual material cycle.
Physiological and Molecular Plant Pathology, Apr 1, 2013
ABSTRACT Compost is used as a peat substitute and soil amendment because of its suppressive prope... more ABSTRACT Compost is used as a peat substitute and soil amendment because of its suppressive properties against soilborne plant diseases. It is also effective in reducing foliar diseases, which suggests that compost systemically affects the plant. The improvement of plant nutrition due to the compost has been suggested as an important factor. In this study, we found higher resistance of Arabidopsis plants grown in an olive marc compost against Botrytis cinerea than in plants grown in perlite. There was no difference in the leaf nutrients of the plants grown in the two substrates. Hence, the compost does not have a nutritional effect on this system. In Col-0 plants, the incidence of diseased leaves was reduced by 30% and an equal reduction in disease was induced in jar1-1 mutants. However, there was no disease reduction in sid2-1. This suggests the need for SA signalling in compost-induced resistance. Furthermore, PR-1 expression was higher in compost-grown plants than in perlite-grown plants before and after pathogen inoculation. VSP2 expression in artificially wounded plants was lower in compost-grown plants than in perlite-grown plants, which suggests that there was negative crosstalk between compost-induced and wound-induced signals.
The soil/substrate that supports plant roots and provides water and nutrients to plants is often ... more The soil/substrate that supports plant roots and provides water and nutrients to plants is often considered a hostile environment that harbours plant pathogens. Moreover, the most common strategy used to control risk of disease from the soil is the eradication or minimization of soil pathogens regardless of the presence of other organisms. Consequently, the extensive use of physical/chemical biocides generates a soil/substrate microbiological vacuum which makes it more susceptible to reinfestation by pathogens, increases disease incidence and in some cases enhances fungal resistance. In Europe, legislation on plant protection products has been re-evaluated since 1991 (Directives 1991/414 and 2009/128), leading to a drastic reduction in the use of chemical compounds. A reduction in fungicides that effectively combat disease is achieved with the use of suppressive composts in pot plants. Suppressive composts similar to suppressive soils are examples of natural biological control of di...
Colonisation of plant roots by selected beneficial Trichoderma fungi or Pseudomonas bacteria can ... more Colonisation of plant roots by selected beneficial Trichoderma fungi or Pseudomonas bacteria can result in the activation of a systemic defence response that is effective against a broad spectrum of pathogens. In Arabidopsis thaliana, induced systemic resistance (ISR) triggered by the rhizobacterial strain Pseudomonas fluorescens WCS417r is regulated by a jasmonic acid-and ethylene-dependent defence signalling pathway. Jasmonic acid and ethylene also play a role in Trichoderma-induced resistance. To further investigate the similarities between rhizobacteria-and Trichoderma-induced resistance, we studied the response of Arabidopsis to root colonisation by Trichoderma asperellum T34. In many aspects T34-ISR was similar to WCS417r-ISR. First, colonisation of the roots by T34 rendered the leaves more resistant to the bacterial pathogen Pseudomonas syringae pv. tomato, the biotrophic oomycete Hyaloperonospora parasitica and the necrotrophic fungus Plectosphaerella cucumerina. Second, treatment of the roots with T34 primed the leaf tissue for enhanced jasmonic acid-responsive gene expression and increased formation of callose-containing papillae upon pathogen attack. Third, T34-ISR was fully expressed in the salicylic acid impaired mutant sid2, but blocked in the defence regulatory mutant npr1. Finally, we show that the root-specific transcription factor MYB72, which is essential in early signalling steps of WCS417r-ISR, is also required for T34-ISR. Together, these results indicate that the defence pathways triggered by beneficial Trichoderma and Pseudomonas spp. strains are highly similar and that MYB72 functions as an early node of convergence in the signalling pathways that are induced by these different beneficial microorganisms.
During the period 1997-2000, while studying a commercial compost that originated from sewage slud... more During the period 1997-2000, while studying a commercial compost that originated from sewage sludge and refuse from the city of Barcelona, we encountered a compost that naturally suppressed Fusarium oxysporum. On analysing the biotic components involved in that suppressiveness, we discovered that it contained a wide variety of Trichoderma species. We isolated around 200 different Trichoderma strains from the suppressive compost. These were evaluated as detailed previously in Cotxarrera et al. (2002) and in the PhD Thesis of L. Cotxarrera (2006). The specific isolate T34 of the species T. asperellum (Fig. 18.1) was patented due to its efficacy in controlling Fusarium wilt of tomato. The Spanish patent ES 2188385 B1 was later extended to several EU countries (EP 1400586 B1) and the USA (US 7,553,657 B2). Almost simultaneously with our research, under Directive 91/414 EEC, the European Commission decided to evaluate all active substances (ASs) in plant protection products (PPPs) on the market. The aim was to (i) harmonise such products across the different Member States and (ii) exclude those pesticides that were deemed hazardous for human health or which had a negative environmental impact.
The by-products of palm date (Phoenix dactylifera) contaminated by Fusarium oxysporum f.sp. albed... more The by-products of palm date (Phoenix dactylifera) contaminated by Fusarium oxysporum f.sp. albedinis (Fusarium) were composted with different rates of bovine manure, urea or ammonium nitrogen. Water was added to maintain optimum humidity at 60-70%. During the process of composting and whatever the ratio of the manure or nitrogen in the piles, the pH remained stable and relatively alkaline at values ranging from 8.2 to 8.7. By contrast, electrical conductivity decreased from 25 to 30%. The evolution of the internal temperatures in the piles depended on the volume of the manure added to the mixture, but was characterized by a mesophilic phase showing a fast increase in temperature, then a thermophilic phase, with high temperatures ranging from 50 to 70°C in the piles rich in bovine manure. However, internal temperatures remained unchanged in urea- or ammonium-containing piles. In the piles containing bovine manure, Fusarium was completely eliminated during the thermophilic phase. The...
Pepper (Capsicum annuum L.), one of the most widely grown vegetables worldwide, is susceptible to... more Pepper (Capsicum annuum L.), one of the most widely grown vegetables worldwide, is susceptible to root rot caused by Phytophthora capsici. Many biocides have recently been banned in Europe because of human health and environmental concerns. Integrated pest management is a European priority, where biological control together with other agronomic practices should replace pesticide management of plant diseases in the future. Application of different concentrations of the fungus Trichoderma asperellum strain T34 (the in T34 Biocontrol®) on incidence of disease caused by P. capsici in pepper was studied. Different methods of application of the microbial control agent and inoculation of the pathogen were examined. T34 and etridiazole (Terrazole®) were compared for their ability to suppress P. capsici. T34 reduced disease in most of the assayed situations (up to 71% disease reduction), while etridiazole was effective only when applied at the same time as the pathogen. The results obtained ...
The use of compost tea extracts to control leaf diseases is an alternative that enables the use o... more The use of compost tea extracts to control leaf diseases is an alternative that enables the use of chemicals in agriculture to be reduced. However, little is known about the mechanisms responsible. We examined an aerated compost tea prepared from composted market and garden wastes and tested its effect on naturally occurring powdery mildew disease produced by the foliar pathogen Erysiphe polygoni in tomato plants (Lycopersicon esculentum cv. Roma) grown in perlite in an unheated greenhouse. Untreated plants showed whitish patches of powdery mildew, while in the treated plants the mycelium could hardly be seen and leaves only showed localized yellow spots corresponding to former sites of infection. Tea compost reduced disease incidence by 19% when used as a preventive treatment and eradicated the pathogen on the leaves when applied as a curative treatment. Treatment was not associated with increased peroxidase or chitinase activity in the leaves and induction of local resistance is u...
Session 1. Advances in analytical techniques for growing media and composting Invited paper Europ... more Session 1. Advances in analytical techniques for growing media and composting Invited paper European standardisation of growing media A critical review. Andreas Baumgarten.
Verticillium Wilt of Olive, a disease caused by the hemibiotrophic vascular fungus Verticillium d... more Verticillium Wilt of Olive, a disease caused by the hemibiotrophic vascular fungus Verticillium dahliae Kleb. presents one of the most important constraints to olive production in the world, with an especially notable impact in Mediterranean agriculture. This study evaluates the use of RGB vegetation indexes in assessing the effects of this disease during the biotrophic phase of host-pathogen interaction, in which symptoms of wilt are not yet evident. While no differences were detected by measuring stomatal conductance and chlorophyll fluorescence, results obtained from RGB indexes showed significant differences between control and inoculated plants for indexes Saturation, a*, b*, green Area (GA), normalized green-red difference index (NGRDI) and triangular greenness index (TGI), presenting a reduction in plant growth as well as in green and yellow color components as an effect of inoculation. These results were contrasted across two scenarios of mineral fertilization in soil and so...
Fusarium tomato wilt is one of the most prevalent and damaging diseases wherever tomatoes are gro... more Fusarium tomato wilt is one of the most prevalent and damaging diseases wherever tomatoes are grown intensively. Progress in agriculture in the 21st century is set to be based on lowering agrochemical inputs (implementation of Directive 2009/128/EC on sustainable use of pesticides), which can be achieved to some extent through the use of beneficial microorganisms. This study aimed at comparing the effects of the mycorrhizal fungus Rhizophagus irregularis and the biological control agent Trichoderma asperellum strain T34 on the incidence of fusarium wilt and the growth of tomato plants. Both R. irregularis and T34 lowered disease incidence at similar rates, compared to control plants. R. irregularis added below the seedlings reduced disease incidence more than when it was mixed with the substrate. T34 and R. irregularis increased plant height to the same extent, compared to both control and diseased plants. R. irregularis gave the highest levels of chlorophyll, followed by T34 and control plants; however, the measures for infected plants were slightly better for T34 than for R. irregularis. T34 and R. irregularis had similar effects on Ca, Mg, S, Mn, B and Si uptake in tomato plants, but R. irregularis induced a greater P, K, Zn, Cu and Mo accumulation than T34. Interestingly, at the end of the experiment, the depletion of the substrate was lower on Ca, Mg and S for plants inoculated with either R. irregularis or T34 compared to control plants, while the substrate for T34-treated plants had the lowest levels of Fe, Mn, Zn and Cu.
During the period 1997-2000, while studying a commercial compost that originated from sewage slud... more During the period 1997-2000, while studying a commercial compost that originated from sewage sludge and refuse from the city of Barcelona, we encountered a compost that naturally suppressed Fusarium oxysporum. On analysing the biotic components involved in that suppressiveness, we discovered that it contained a wide variety of Trichoderma species. We isolated around 200 different Trichoderma strains from the suppressive compost. These were evaluated as detailed previously in Cotxarrera et al. (2002) and in the PhD Thesis of L. Cotxarrera (2006). The specific isolate T34 of the species T. asperellum (Fig. 18.1) was patented due to its efficacy in controlling Fusarium wilt of tomato. The Spanish patent ES 2188385 B1 was later extended to several EU countries (EP 1400586 B1) and the USA (US 7,553,657 B2). Almost simultaneously with our research, under Directive 91/414 EEC, the European Commission decided to evaluate all active substances (ASs) in plant protection products (PPPs) on the market. The aim was to (i) harmonise such products across the different Member States and (ii) exclude those pesticides that were deemed hazardous for human health or which had a negative environmental impact.
The composting of winery waste is an alternative to the traditional disposal of residues, and als... more The composting of winery waste is an alternative to the traditional disposal of residues, and also involves a commitment to reducing the production of waste products. We studied two residues (sludge and grape stalks), mixed in two proportions (1:1 and 1:2 sludge and grape stalks (v/v)), and we also examined the effects of grinding the grape stalks. Our results showed that composting the assayed materials was possible. Best results were obtained in the compost heap in which the residues were mixed in the proportion 1:2, and where the grape stalks had been previously ground. Optimum results required a moisture around 55% and a maximum temperature around 65°C and an oxygen concentration not lower than 5-10%. The resulting compost had a high agronomic value and is particularly suitable for the soils of the vineyards which have a very low organic matter content. The compost can be reintroduced into the production system, thereby closing the residual material cycle.
Physiological and Molecular Plant Pathology, Apr 1, 2013
ABSTRACT Compost is used as a peat substitute and soil amendment because of its suppressive prope... more ABSTRACT Compost is used as a peat substitute and soil amendment because of its suppressive properties against soilborne plant diseases. It is also effective in reducing foliar diseases, which suggests that compost systemically affects the plant. The improvement of plant nutrition due to the compost has been suggested as an important factor. In this study, we found higher resistance of Arabidopsis plants grown in an olive marc compost against Botrytis cinerea than in plants grown in perlite. There was no difference in the leaf nutrients of the plants grown in the two substrates. Hence, the compost does not have a nutritional effect on this system. In Col-0 plants, the incidence of diseased leaves was reduced by 30% and an equal reduction in disease was induced in jar1-1 mutants. However, there was no disease reduction in sid2-1. This suggests the need for SA signalling in compost-induced resistance. Furthermore, PR-1 expression was higher in compost-grown plants than in perlite-grown plants before and after pathogen inoculation. VSP2 expression in artificially wounded plants was lower in compost-grown plants than in perlite-grown plants, which suggests that there was negative crosstalk between compost-induced and wound-induced signals.
The soil/substrate that supports plant roots and provides water and nutrients to plants is often ... more The soil/substrate that supports plant roots and provides water and nutrients to plants is often considered a hostile environment that harbours plant pathogens. Moreover, the most common strategy used to control risk of disease from the soil is the eradication or minimization of soil pathogens regardless of the presence of other organisms. Consequently, the extensive use of physical/chemical biocides generates a soil/substrate microbiological vacuum which makes it more susceptible to reinfestation by pathogens, increases disease incidence and in some cases enhances fungal resistance. In Europe, legislation on plant protection products has been re-evaluated since 1991 (Directives 1991/414 and 2009/128), leading to a drastic reduction in the use of chemical compounds. A reduction in fungicides that effectively combat disease is achieved with the use of suppressive composts in pot plants. Suppressive composts similar to suppressive soils are examples of natural biological control of di...
Colonisation of plant roots by selected beneficial Trichoderma fungi or Pseudomonas bacteria can ... more Colonisation of plant roots by selected beneficial Trichoderma fungi or Pseudomonas bacteria can result in the activation of a systemic defence response that is effective against a broad spectrum of pathogens. In Arabidopsis thaliana, induced systemic resistance (ISR) triggered by the rhizobacterial strain Pseudomonas fluorescens WCS417r is regulated by a jasmonic acid-and ethylene-dependent defence signalling pathway. Jasmonic acid and ethylene also play a role in Trichoderma-induced resistance. To further investigate the similarities between rhizobacteria-and Trichoderma-induced resistance, we studied the response of Arabidopsis to root colonisation by Trichoderma asperellum T34. In many aspects T34-ISR was similar to WCS417r-ISR. First, colonisation of the roots by T34 rendered the leaves more resistant to the bacterial pathogen Pseudomonas syringae pv. tomato, the biotrophic oomycete Hyaloperonospora parasitica and the necrotrophic fungus Plectosphaerella cucumerina. Second, treatment of the roots with T34 primed the leaf tissue for enhanced jasmonic acid-responsive gene expression and increased formation of callose-containing papillae upon pathogen attack. Third, T34-ISR was fully expressed in the salicylic acid impaired mutant sid2, but blocked in the defence regulatory mutant npr1. Finally, we show that the root-specific transcription factor MYB72, which is essential in early signalling steps of WCS417r-ISR, is also required for T34-ISR. Together, these results indicate that the defence pathways triggered by beneficial Trichoderma and Pseudomonas spp. strains are highly similar and that MYB72 functions as an early node of convergence in the signalling pathways that are induced by these different beneficial microorganisms.
During the period 1997-2000, while studying a commercial compost that originated from sewage slud... more During the period 1997-2000, while studying a commercial compost that originated from sewage sludge and refuse from the city of Barcelona, we encountered a compost that naturally suppressed Fusarium oxysporum. On analysing the biotic components involved in that suppressiveness, we discovered that it contained a wide variety of Trichoderma species. We isolated around 200 different Trichoderma strains from the suppressive compost. These were evaluated as detailed previously in Cotxarrera et al. (2002) and in the PhD Thesis of L. Cotxarrera (2006). The specific isolate T34 of the species T. asperellum (Fig. 18.1) was patented due to its efficacy in controlling Fusarium wilt of tomato. The Spanish patent ES 2188385 B1 was later extended to several EU countries (EP 1400586 B1) and the USA (US 7,553,657 B2). Almost simultaneously with our research, under Directive 91/414 EEC, the European Commission decided to evaluate all active substances (ASs) in plant protection products (PPPs) on the market. The aim was to (i) harmonise such products across the different Member States and (ii) exclude those pesticides that were deemed hazardous for human health or which had a negative environmental impact.
The by-products of palm date (Phoenix dactylifera) contaminated by Fusarium oxysporum f.sp. albed... more The by-products of palm date (Phoenix dactylifera) contaminated by Fusarium oxysporum f.sp. albedinis (Fusarium) were composted with different rates of bovine manure, urea or ammonium nitrogen. Water was added to maintain optimum humidity at 60-70%. During the process of composting and whatever the ratio of the manure or nitrogen in the piles, the pH remained stable and relatively alkaline at values ranging from 8.2 to 8.7. By contrast, electrical conductivity decreased from 25 to 30%. The evolution of the internal temperatures in the piles depended on the volume of the manure added to the mixture, but was characterized by a mesophilic phase showing a fast increase in temperature, then a thermophilic phase, with high temperatures ranging from 50 to 70°C in the piles rich in bovine manure. However, internal temperatures remained unchanged in urea- or ammonium-containing piles. In the piles containing bovine manure, Fusarium was completely eliminated during the thermophilic phase. The...
Pepper (Capsicum annuum L.), one of the most widely grown vegetables worldwide, is susceptible to... more Pepper (Capsicum annuum L.), one of the most widely grown vegetables worldwide, is susceptible to root rot caused by Phytophthora capsici. Many biocides have recently been banned in Europe because of human health and environmental concerns. Integrated pest management is a European priority, where biological control together with other agronomic practices should replace pesticide management of plant diseases in the future. Application of different concentrations of the fungus Trichoderma asperellum strain T34 (the in T34 Biocontrol®) on incidence of disease caused by P. capsici in pepper was studied. Different methods of application of the microbial control agent and inoculation of the pathogen were examined. T34 and etridiazole (Terrazole®) were compared for their ability to suppress P. capsici. T34 reduced disease in most of the assayed situations (up to 71% disease reduction), while etridiazole was effective only when applied at the same time as the pathogen. The results obtained ...
The use of compost tea extracts to control leaf diseases is an alternative that enables the use o... more The use of compost tea extracts to control leaf diseases is an alternative that enables the use of chemicals in agriculture to be reduced. However, little is known about the mechanisms responsible. We examined an aerated compost tea prepared from composted market and garden wastes and tested its effect on naturally occurring powdery mildew disease produced by the foliar pathogen Erysiphe polygoni in tomato plants (Lycopersicon esculentum cv. Roma) grown in perlite in an unheated greenhouse. Untreated plants showed whitish patches of powdery mildew, while in the treated plants the mycelium could hardly be seen and leaves only showed localized yellow spots corresponding to former sites of infection. Tea compost reduced disease incidence by 19% when used as a preventive treatment and eradicated the pathogen on the leaves when applied as a curative treatment. Treatment was not associated with increased peroxidase or chitinase activity in the leaves and induction of local resistance is u...
Session 1. Advances in analytical techniques for growing media and composting Invited paper Europ... more Session 1. Advances in analytical techniques for growing media and composting Invited paper European standardisation of growing media A critical review. Andreas Baumgarten.
Verticillium Wilt of Olive, a disease caused by the hemibiotrophic vascular fungus Verticillium d... more Verticillium Wilt of Olive, a disease caused by the hemibiotrophic vascular fungus Verticillium dahliae Kleb. presents one of the most important constraints to olive production in the world, with an especially notable impact in Mediterranean agriculture. This study evaluates the use of RGB vegetation indexes in assessing the effects of this disease during the biotrophic phase of host-pathogen interaction, in which symptoms of wilt are not yet evident. While no differences were detected by measuring stomatal conductance and chlorophyll fluorescence, results obtained from RGB indexes showed significant differences between control and inoculated plants for indexes Saturation, a*, b*, green Area (GA), normalized green-red difference index (NGRDI) and triangular greenness index (TGI), presenting a reduction in plant growth as well as in green and yellow color components as an effect of inoculation. These results were contrasted across two scenarios of mineral fertilization in soil and so...
Fusarium tomato wilt is one of the most prevalent and damaging diseases wherever tomatoes are gro... more Fusarium tomato wilt is one of the most prevalent and damaging diseases wherever tomatoes are grown intensively. Progress in agriculture in the 21st century is set to be based on lowering agrochemical inputs (implementation of Directive 2009/128/EC on sustainable use of pesticides), which can be achieved to some extent through the use of beneficial microorganisms. This study aimed at comparing the effects of the mycorrhizal fungus Rhizophagus irregularis and the biological control agent Trichoderma asperellum strain T34 on the incidence of fusarium wilt and the growth of tomato plants. Both R. irregularis and T34 lowered disease incidence at similar rates, compared to control plants. R. irregularis added below the seedlings reduced disease incidence more than when it was mixed with the substrate. T34 and R. irregularis increased plant height to the same extent, compared to both control and diseased plants. R. irregularis gave the highest levels of chlorophyll, followed by T34 and control plants; however, the measures for infected plants were slightly better for T34 than for R. irregularis. T34 and R. irregularis had similar effects on Ca, Mg, S, Mn, B and Si uptake in tomato plants, but R. irregularis induced a greater P, K, Zn, Cu and Mo accumulation than T34. Interestingly, at the end of the experiment, the depletion of the substrate was lower on Ca, Mg and S for plants inoculated with either R. irregularis or T34 compared to control plants, while the substrate for T34-treated plants had the lowest levels of Fe, Mn, Zn and Cu.
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