SSA) participated as observers. Opening Statements Mr. Stefan Helming, Head of Planning and Devel... more SSA) participated as observers. Opening Statements Mr. Stefan Helming, Head of Planning and Development Department, GTZ welcomed the meeting participants. Acknowledging the similarities of concerns and goals between GTZ and the CGIAR particularly in SSA, he expressed interest in the work of the task forces and wished the participants a successful meeting.
Cowpea is one of the most important crops in West Africa and is essential for the region's food a... more Cowpea is one of the most important crops in West Africa and is essential for the region's food and nutrition security and economic development. Consequently, improving its agronomic performance and yield is a desirable goal. Brown blotch disease, caused by the fungal pathogen Colletotrichum capsici, is an important constraint of cowpea productivity, and at present, only limited genetic resources are available for breeding improved brown blotch-resistant varieties. The current study has characterized the genetic basis for brown blotch resistance conferred by the cowpea cultivar KN1 and identified a major dominant quantitative trait locus (QTL) for resistance on chromosome Vu02. A segregating F 2 population (n = 200), derived from a cross between KN1 and brown blotch-susceptible Tiligre (KVx775-33-2G), was developed and scored for disease severity following controlled inoculation. A subset of the population (n = 94) was genotyped with 99 newly developed allele-specific polymerase chain reaction (AS-PCR) markers, and multiple interval mapping was performed. One major and three minor QTL were identified. This is the first reported mapping of QTL conferring resistance to C. capsici in cowpea, and it is expected that the markers identified here will be a valuable resource for developing elite cowpea cultivars with resistance to brown blotch.
Archives of Phytopathology and Plant Protection, Dec 1, 2012
ABSTRACT The effect of aqueous extract of Cymbopogon citratus on sorghum seed germination and its... more ABSTRACT The effect of aqueous extract of Cymbopogon citratus on sorghum seed germination and its efficacy against Phoma sorghina transmission to sorghum vegetative organs and seed were studied in field conditions in 2008–2010. During these years, we also examined the effect of panicle protection on the reduction of P. sorghina infection. The aqueous extract of C. citratus lowers sorghum seed germination compared to untreated seeds, seeds treated with water and those treated with fungicide calthio C. P. sorghina is transmitted to the whole vegetative organs and seed of all the treatments. However, the aqueous extract of C. citratus significantly reduces the transmission of P. sorghina compared to untreated seeds, to seeds treated with water and those treated with fungicide. The protection of sorghum panicles before flowering limits the infection by P. sorghina compared to the panicles not protected.
ABSTRACT The aim of the study was to evaluate the potential of essential of from local plant in c... more ABSTRACT The aim of the study was to evaluate the potential of essential of from local plant in controlling some major seed-borne fungi of sorghum grow in Burkina Faso. Essential oils from Cymbopogon citratus (Lemongrass) Eucalyptus camaldulensis , (Eucalyptus) and crude oil from Azadirachta indica (Neem) were tested in vitro for inhibitory activity against Colletotrichum graminicola , Phoma sorghina and Fusarium moniliforme . Plant extracts were also tested on naturally infected sorghum seeds for controlling the fungi above mentioned. Essential oil from C. citratus significantly inhibited the in vitro radial growth of C. graminicola (76.2% inhibition), compared to the fungicide Dithane M-45. The mycelial growth of P. sorghina and F. moniliforme was slightly affected by this oil at the concentrations used. The extent of inhibition of the fungal growth was dependent on the concentration of essential oil used. Neem crude oil and Eucalyptus essential oil presented low inhibitory activity against test fungi. Concentrations of Eucalyptus essential oil were not harmful to sorghum seedling growth, while neem crude oil was highly phytotoxic. Essential oil of lemongrass at the concentration of 6% was effective in controlling seed-borne infection and seed-to-seedling transmission of C. graminicola and P. sorghina without affecting seedling development. Lemongrass has the potential to be used as sorghum seed treatment for controlling C. graminicola , P. sorghina and F. moniliforme .
ABSTRACT Soil moisture deficit frequently occurs at the onset of the growing season and may cause... more ABSTRACT Soil moisture deficit frequently occurs at the onset of the growing season and may cause crop failure. Resowing with early maturing varieties has often been the only alternative, besides transplanting. To assess the relative efficiency of the two rescue methods two sorghum (Sorghum bicolor [L.] Moench) cultivars, 'IRAT204' (day-neutral) and 'Nazongala' (photoperiod-sensitive), were grown in seven drought-prone environments in Western Africa. Grain yield of both cultivars was reduced by delayed sowing or transplanting at all environments. However, transplanting had less depressive effects than late sowing for both cultivars. Yield reduction was lowest when transplanting or resowing was done not later than two weeks from normal sowing time. Compensation levels were higher with the cultivar 'IRAT204' than with 'Nazongala'. While transplanting could contribute to partial yield loss recovery under erratic rainfall environments, it should not be considered as an option beyond four weeks from the normal sowing dates with day-neutral cultivars, due to their lack of phenological plasticity.
The location of P. sorghina on the different parts of sorghum seed and the efficacy of plant aque... more The location of P. sorghina on the different parts of sorghum seed and the efficacy of plant aqueous extract of C. citratus and A. indica were studied using blotter method. The identification of different parts of sorghum seed under a compound microscope shows that P. sorghina is present on all the parts of sorghum seed. There is a positive correlation between the infection of pericarp and the other parts of sorghum seed. The results reveal that 63% of endosperm infection by P. sorghina is explained by the infection of pericarp and 58% of embryo infection by P. sorghina is explained by the infection of pericarp and endosperm. The use of plant aqueous extracts in seed treatment lowers the infection rate of P. sorghina in all the components of sorghum seed. In comparison with the fungicide calthio C., plant aqueous extracts of lemon grass and A. indica have a tendency to lower the infection rate of P. sorghina.
ABSTRACT Poor seed quality is a major constraint to the adoption of improved sorghum cultivars in... more ABSTRACT Poor seed quality is a major constraint to the adoption of improved sorghum cultivars in West Africa because it results in poor stands. While genetic enhancement of this trait should not be overlooked, more immediate improvement of seed quality could result from better exploitation of the production environment. Under this postulate, seeds of thirty sorghum cultivars grown under normal rainfed (RS) conditions and under irrigation during the post-rainy (PR)season were compared for seed quality and seedling emergence and growth (grain quality affects products). Season effects accounted for a greater proportion of variance in phenotypic expression of cultivars than did genetic effects. Seeds from the PR harvest were less weathered and displayed greater grain weight, density and seedling emergence percentage compared to RS seeds. Furthermore, PR seeds produced more vigorous and faster growing seedlings than RS seeds. This work indicates that the post-rainy season, where possible, could be used to produce high quality seeds at reduced cost, since only supplemental irrigation is needed. Seed production in the post-rainy season would offer the added advantage of assuring isolation and reducing the risks of uncontrolled pollination.
Summary The use of phytosanitary products is becoming increasingly restricted, due to their high ... more Summary The use of phytosanitary products is becoming increasingly restricted, due to their high cost, as well as the unavailability of certain products on the local market and their damaging effects on the environment and health. These different reasons motivated the search for alternative solutions to the use of synthetic pesticides. On this basis, we took on the task of evaluating the anti-fungal effectiveness of aqueous plant extracts from Balanites aegyptiaca, Cymbopogon citratus, Cassia occidentalis and Portulaca oleracea. These extracts, at 30% concentration, were obtained after different maceration periods (6, 12, 24 and 48 hours) and tested in vitro against Colletotrichum graminicola and Phoma sorghina. The effect of the extracts on the mycelium growth of various fungi, when evaluated 10 days after incubation (DAI), shows that extracts of C. citratus, B. aegyptiaca, P. oleracea and C. occidentalis inhibit the growth of C. graminicola by 100%, 65%, 43% and 38%, respectively....
Background: Soaking of sorghum seeds for six hours in an aqueous extract of Eclipta alba has been... more Background: Soaking of sorghum seeds for six hours in an aqueous extract of Eclipta alba has been shown to increase the yield of sorghum in field experiments. The effect on yield is known to depend on field location and a mechanism involving pathogen suppression has been proposed. However, it has not been clear to which extent the same effect can be obtained by soaking of seeds in pure water (hydropriming). To address this question, fifty eight field tests were conducted comparing no treatment of seeds, hydropriming and treatment with plant extract. Experiments were distributed over three years in Burkina Faso on three locations previously showing a positive yield response to the plant extract. Results: Despite strong variation across locations and years, a mean yield increase of 19.6% was found for hydropriming compared to no treatment (p < .018). For the plant extract, an additional yield increase of 32.1% was found (p < .016) corresponding to a total increase of 51.7%. In a subset of 15 experiments, a positive, but non-significant correlation was observed between the additional effect of the plant extract and the effect of a binary pesticide, Calthio C. Significantly, however, the E. alba extract reduced the number of seedlings infected by seed-borne filamentous fungi (p < .05). A reduction of infection by more than five-fold was found for the E. alba extract compared to hydropriming and included potential pathogens of sorghum: Epicoccum sorghinum and Curvularia spp. Conclusion: Using 6-hours of soaking, hydropriming was an inherent component of seed treatment with the E. alba extract and contributed significantly to the overall observed increase of yield and emergence. An additional yield increase was caused by factor(s) derived from the plant, E. alba, and may involve suppression of pathogenic fungi.
Sorghum [Sorghum bicolor (L.) Moench] is a major subsistence crop throughout the region of Sahel.... more Sorghum [Sorghum bicolor (L.) Moench] is a major subsistence crop throughout the region of Sahel. With the exception of seeds and labour, no agricultural inputs are in general used in sorghum production since the grain is of a relatively low commercial value and the risk of losing the crop to drought, flooding, etc. is substantial. A meta-analysis of 118 field experiments was carried out to identify conditions in which two protective seed treatments could support a yield increase of sorghum in Burkina Faso. The two treatments were: i) treatment with the pesticide Calthio C (thiram and chlorpyrifos) and ii) treatment with an aqueous extract from the plant Eclipta alba. Both treatments were found to produce a yield increase (Medians: Calthio C +199 kg ha-1 , P<2x10-9 ; E. alba +90.5 kg ha-1 P<4x10-4). A strong relative effect of Calthio C on yield (+36%) was found for field experiments with a low baseline yield. A strong relative effect of E. alba extract on yield (+22%) was found for experiments with a low baseline of emergence. ANOVA of the 118 field tests showed that baseline crop performance (yield and emergence) and the effect of seed treatments were strongly linked to geographical location (twelve different villages included). Roots from sorghum in the village showing the strongest effect of both seed treatments (>40% yield increase) were found to carry a comparatively high load of the infectious ascomycetes: Fusarium equiseti, Macrophomina phaseolina and Curvularia lunata.
Soybean root rot is a worldwide soil-borne fungal disease threatening soybean production, causing... more Soybean root rot is a worldwide soil-borne fungal disease threatening soybean production, causing large loss in yield and quality of soybean. Fusarium species are well recognized as the important causal agent of Fusarium root rot, which are often distinct with respect to various factors in different soybean-producing regions
SSA) participated as observers. Opening Statements Mr. Stefan Helming, Head of Planning and Devel... more SSA) participated as observers. Opening Statements Mr. Stefan Helming, Head of Planning and Development Department, GTZ welcomed the meeting participants. Acknowledging the similarities of concerns and goals between GTZ and the CGIAR particularly in SSA, he expressed interest in the work of the task forces and wished the participants a successful meeting.
Cowpea is one of the most important crops in West Africa and is essential for the region's food a... more Cowpea is one of the most important crops in West Africa and is essential for the region's food and nutrition security and economic development. Consequently, improving its agronomic performance and yield is a desirable goal. Brown blotch disease, caused by the fungal pathogen Colletotrichum capsici, is an important constraint of cowpea productivity, and at present, only limited genetic resources are available for breeding improved brown blotch-resistant varieties. The current study has characterized the genetic basis for brown blotch resistance conferred by the cowpea cultivar KN1 and identified a major dominant quantitative trait locus (QTL) for resistance on chromosome Vu02. A segregating F 2 population (n = 200), derived from a cross between KN1 and brown blotch-susceptible Tiligre (KVx775-33-2G), was developed and scored for disease severity following controlled inoculation. A subset of the population (n = 94) was genotyped with 99 newly developed allele-specific polymerase chain reaction (AS-PCR) markers, and multiple interval mapping was performed. One major and three minor QTL were identified. This is the first reported mapping of QTL conferring resistance to C. capsici in cowpea, and it is expected that the markers identified here will be a valuable resource for developing elite cowpea cultivars with resistance to brown blotch.
Archives of Phytopathology and Plant Protection, Dec 1, 2012
ABSTRACT The effect of aqueous extract of Cymbopogon citratus on sorghum seed germination and its... more ABSTRACT The effect of aqueous extract of Cymbopogon citratus on sorghum seed germination and its efficacy against Phoma sorghina transmission to sorghum vegetative organs and seed were studied in field conditions in 2008–2010. During these years, we also examined the effect of panicle protection on the reduction of P. sorghina infection. The aqueous extract of C. citratus lowers sorghum seed germination compared to untreated seeds, seeds treated with water and those treated with fungicide calthio C. P. sorghina is transmitted to the whole vegetative organs and seed of all the treatments. However, the aqueous extract of C. citratus significantly reduces the transmission of P. sorghina compared to untreated seeds, to seeds treated with water and those treated with fungicide. The protection of sorghum panicles before flowering limits the infection by P. sorghina compared to the panicles not protected.
ABSTRACT The aim of the study was to evaluate the potential of essential of from local plant in c... more ABSTRACT The aim of the study was to evaluate the potential of essential of from local plant in controlling some major seed-borne fungi of sorghum grow in Burkina Faso. Essential oils from Cymbopogon citratus (Lemongrass) Eucalyptus camaldulensis , (Eucalyptus) and crude oil from Azadirachta indica (Neem) were tested in vitro for inhibitory activity against Colletotrichum graminicola , Phoma sorghina and Fusarium moniliforme . Plant extracts were also tested on naturally infected sorghum seeds for controlling the fungi above mentioned. Essential oil from C. citratus significantly inhibited the in vitro radial growth of C. graminicola (76.2% inhibition), compared to the fungicide Dithane M-45. The mycelial growth of P. sorghina and F. moniliforme was slightly affected by this oil at the concentrations used. The extent of inhibition of the fungal growth was dependent on the concentration of essential oil used. Neem crude oil and Eucalyptus essential oil presented low inhibitory activity against test fungi. Concentrations of Eucalyptus essential oil were not harmful to sorghum seedling growth, while neem crude oil was highly phytotoxic. Essential oil of lemongrass at the concentration of 6% was effective in controlling seed-borne infection and seed-to-seedling transmission of C. graminicola and P. sorghina without affecting seedling development. Lemongrass has the potential to be used as sorghum seed treatment for controlling C. graminicola , P. sorghina and F. moniliforme .
ABSTRACT Soil moisture deficit frequently occurs at the onset of the growing season and may cause... more ABSTRACT Soil moisture deficit frequently occurs at the onset of the growing season and may cause crop failure. Resowing with early maturing varieties has often been the only alternative, besides transplanting. To assess the relative efficiency of the two rescue methods two sorghum (Sorghum bicolor [L.] Moench) cultivars, &#39;IRAT204&#39; (day-neutral) and &#39;Nazongala&#39; (photoperiod-sensitive), were grown in seven drought-prone environments in Western Africa. Grain yield of both cultivars was reduced by delayed sowing or transplanting at all environments. However, transplanting had less depressive effects than late sowing for both cultivars. Yield reduction was lowest when transplanting or resowing was done not later than two weeks from normal sowing time. Compensation levels were higher with the cultivar &#39;IRAT204&#39; than with &#39;Nazongala&#39;. While transplanting could contribute to partial yield loss recovery under erratic rainfall environments, it should not be considered as an option beyond four weeks from the normal sowing dates with day-neutral cultivars, due to their lack of phenological plasticity.
The location of P. sorghina on the different parts of sorghum seed and the efficacy of plant aque... more The location of P. sorghina on the different parts of sorghum seed and the efficacy of plant aqueous extract of C. citratus and A. indica were studied using blotter method. The identification of different parts of sorghum seed under a compound microscope shows that P. sorghina is present on all the parts of sorghum seed. There is a positive correlation between the infection of pericarp and the other parts of sorghum seed. The results reveal that 63% of endosperm infection by P. sorghina is explained by the infection of pericarp and 58% of embryo infection by P. sorghina is explained by the infection of pericarp and endosperm. The use of plant aqueous extracts in seed treatment lowers the infection rate of P. sorghina in all the components of sorghum seed. In comparison with the fungicide calthio C., plant aqueous extracts of lemon grass and A. indica have a tendency to lower the infection rate of P. sorghina.
ABSTRACT Poor seed quality is a major constraint to the adoption of improved sorghum cultivars in... more ABSTRACT Poor seed quality is a major constraint to the adoption of improved sorghum cultivars in West Africa because it results in poor stands. While genetic enhancement of this trait should not be overlooked, more immediate improvement of seed quality could result from better exploitation of the production environment. Under this postulate, seeds of thirty sorghum cultivars grown under normal rainfed (RS) conditions and under irrigation during the post-rainy (PR)season were compared for seed quality and seedling emergence and growth (grain quality affects products). Season effects accounted for a greater proportion of variance in phenotypic expression of cultivars than did genetic effects. Seeds from the PR harvest were less weathered and displayed greater grain weight, density and seedling emergence percentage compared to RS seeds. Furthermore, PR seeds produced more vigorous and faster growing seedlings than RS seeds. This work indicates that the post-rainy season, where possible, could be used to produce high quality seeds at reduced cost, since only supplemental irrigation is needed. Seed production in the post-rainy season would offer the added advantage of assuring isolation and reducing the risks of uncontrolled pollination.
Summary The use of phytosanitary products is becoming increasingly restricted, due to their high ... more Summary The use of phytosanitary products is becoming increasingly restricted, due to their high cost, as well as the unavailability of certain products on the local market and their damaging effects on the environment and health. These different reasons motivated the search for alternative solutions to the use of synthetic pesticides. On this basis, we took on the task of evaluating the anti-fungal effectiveness of aqueous plant extracts from Balanites aegyptiaca, Cymbopogon citratus, Cassia occidentalis and Portulaca oleracea. These extracts, at 30% concentration, were obtained after different maceration periods (6, 12, 24 and 48 hours) and tested in vitro against Colletotrichum graminicola and Phoma sorghina. The effect of the extracts on the mycelium growth of various fungi, when evaluated 10 days after incubation (DAI), shows that extracts of C. citratus, B. aegyptiaca, P. oleracea and C. occidentalis inhibit the growth of C. graminicola by 100%, 65%, 43% and 38%, respectively....
Background: Soaking of sorghum seeds for six hours in an aqueous extract of Eclipta alba has been... more Background: Soaking of sorghum seeds for six hours in an aqueous extract of Eclipta alba has been shown to increase the yield of sorghum in field experiments. The effect on yield is known to depend on field location and a mechanism involving pathogen suppression has been proposed. However, it has not been clear to which extent the same effect can be obtained by soaking of seeds in pure water (hydropriming). To address this question, fifty eight field tests were conducted comparing no treatment of seeds, hydropriming and treatment with plant extract. Experiments were distributed over three years in Burkina Faso on three locations previously showing a positive yield response to the plant extract. Results: Despite strong variation across locations and years, a mean yield increase of 19.6% was found for hydropriming compared to no treatment (p < .018). For the plant extract, an additional yield increase of 32.1% was found (p < .016) corresponding to a total increase of 51.7%. In a subset of 15 experiments, a positive, but non-significant correlation was observed between the additional effect of the plant extract and the effect of a binary pesticide, Calthio C. Significantly, however, the E. alba extract reduced the number of seedlings infected by seed-borne filamentous fungi (p < .05). A reduction of infection by more than five-fold was found for the E. alba extract compared to hydropriming and included potential pathogens of sorghum: Epicoccum sorghinum and Curvularia spp. Conclusion: Using 6-hours of soaking, hydropriming was an inherent component of seed treatment with the E. alba extract and contributed significantly to the overall observed increase of yield and emergence. An additional yield increase was caused by factor(s) derived from the plant, E. alba, and may involve suppression of pathogenic fungi.
Sorghum [Sorghum bicolor (L.) Moench] is a major subsistence crop throughout the region of Sahel.... more Sorghum [Sorghum bicolor (L.) Moench] is a major subsistence crop throughout the region of Sahel. With the exception of seeds and labour, no agricultural inputs are in general used in sorghum production since the grain is of a relatively low commercial value and the risk of losing the crop to drought, flooding, etc. is substantial. A meta-analysis of 118 field experiments was carried out to identify conditions in which two protective seed treatments could support a yield increase of sorghum in Burkina Faso. The two treatments were: i) treatment with the pesticide Calthio C (thiram and chlorpyrifos) and ii) treatment with an aqueous extract from the plant Eclipta alba. Both treatments were found to produce a yield increase (Medians: Calthio C +199 kg ha-1 , P<2x10-9 ; E. alba +90.5 kg ha-1 P<4x10-4). A strong relative effect of Calthio C on yield (+36%) was found for field experiments with a low baseline yield. A strong relative effect of E. alba extract on yield (+22%) was found for experiments with a low baseline of emergence. ANOVA of the 118 field tests showed that baseline crop performance (yield and emergence) and the effect of seed treatments were strongly linked to geographical location (twelve different villages included). Roots from sorghum in the village showing the strongest effect of both seed treatments (>40% yield increase) were found to carry a comparatively high load of the infectious ascomycetes: Fusarium equiseti, Macrophomina phaseolina and Curvularia lunata.
Soybean root rot is a worldwide soil-borne fungal disease threatening soybean production, causing... more Soybean root rot is a worldwide soil-borne fungal disease threatening soybean production, causing large loss in yield and quality of soybean. Fusarium species are well recognized as the important causal agent of Fusarium root rot, which are often distinct with respect to various factors in different soybean-producing regions
Uploads
Papers by Paco SEREME