J. Afun | Kwame Nkrumah University of Science and Technology (original) (raw)
Papers by J. Afun
Journal of Essential Oil Bearing Plants, 2017
Abstract Many natural enemies of herbivorous insects are attracted to semiochemicals emitted by p... more Abstract Many natural enemies of herbivorous insects are attracted to semiochemicals emitted by plants. Semiochemicals emitted by host plants can prime neigbouring plants to adjust their defensive mechanism against future attack. Crop protection, using plant signal is recently gaining momentum due to health and environmental concerns about the use of synthetic pesticides. Semiochemicals have successfully been used to protect maize from the stem borer through the Push /Pull technology. Chromolaena odorata plant is known to support a large and varied insect fauna although the chemistry involved has not been fully established. To determine the volatiles emitted by the undamaged C. odorata plant that might be associated with the insect plant interaction, Dynamic headspace technique was used to collect volatiles from the plant under laboratory conditions and analysed using a Gas chromatography and Gas Chromatography coupled with Mass Spectrometer (GC-MS). Thirty three compounds were identified from the collected headspace volatile from the plant. (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), 4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT) and E-β-farnesene are three semiochemicals identified that had not been reported to be emitted by an intact C. odorata plant from Ghana.
Traditional shifting cultivatiOn appears to be sustainable if fallow periods are sufficient to re... more Traditional shifting cultivatiOn appears to be sustainable if fallow periods are sufficient to restore soil fertility, maintain soil structure and suppress pests. These traditional systems are threatened in West Africa because of increasing land pressure resulting in shorter fallow periods. Studies were conducted on farmers\u27 fields in Côte d’lvoire to determine how fallow length affects populations of insect pests and their natural enemies and weed growth and yield losses due to weeds. Length of fallow influenced the abundance of certain arthropod species as indicated by sweep-net sampling. Populations of the stalk-eyed flies Diopsis spp., leaf·feeding beetles, and leafhoppers/spittlebugs were significantly higher in the long fallow (5-13 years) fields than in the short fallow (\u3c3 years) fields. The natural enemy complex consisting of spiders, predaceous ladybird beetles and dragonflies/damselflies also increased with length of fallow, while fallow period had no effect on the ...
Asian Journal of Advances in Agricultural Research, 2021
This study was conducted to evaluate the efficacy of synthetic insecticides in managing Helicover... more This study was conducted to evaluate the efficacy of synthetic insecticides in managing Helicoverpa armigera Mill in tomato production. The experiment was conducted during the major and minor tomato growing seasons at the Sekyere Kumawu and Asante Akim North districts in Ghana. The experimental design was a 3 x 5 factorial randomized complete block with four replications. Four insect pest control regimes were evaluated for their effectiveness in controlling the tomato fruit borer. Three tomato varieties were used in this experiment. The results showed that, significantly, higher marketable fruit yields were obtained on the sprayed plots than the control plots. In general, the variety “pectomec” suffered the highest yield loss on the water sprayed field, followed by UC 82 and lastly, power rhino, although all the varieties suffered losses greater than 50%. This shows that none of the varieties used for this study is completely resistant to Helicoverpa armigera. Yields were generally ...
Volume 5,Issue 1, 2019, 2019
Journal of Experimental Agriculture International, 2017
A survey and exclusion study to establish the presence of D. bulbifera and its associated phytoph... more A survey and exclusion study to establish the presence of D. bulbifera and its associated phytophagous insect fauna was conducted in Ghana between 2004 and 2006. The purpose was to identify potential biological control agents for this plant invading natural and protected areas in Florida, USA. The survey covered five regions based on herbarium records from three academic institutions in Ghana. A total of 40 phytophagous insect species in 9 orders were encountered on the plant with 24 species attacking D. bulbifera in two feeding guilds foliage and bulbil in Ghana. The
Journal of Agricultural and Urban Entomology, 2009
During recent visits to Southeast Asia by scientists from Virginia Polytechnic Institute and Stat... more During recent visits to Southeast Asia by scientists from Virginia Polytechnic Institute and State University and Clemson University who were participating in a USAID-funded Integrated Pest Management Collaborative Research Support Program (IPM CRSP), heavy infestations ...
African Journal of Agricultural Research, 2008
Knowledge of the insect complex associated with any crop is essential for developing pest control... more Knowledge of the insect complex associated with any crop is essential for developing pest control strategies for the crop. Literature on cashew insects is lacking in Ghana. Field surveys were conducted from July 2003 to October 2005, to collect and identify the insect fauna on cashew. The surveys were conducted in 13 major cashew growing areas within ten districts of the Northern, Upper West, Brong-Ahafo and Eastern Regions of Ghana. Pyrethroids knock down and visual examination methods were used. A total of 170 insect species were collected. Eighty nine species of the total collection were identified to family level, 57 of which were identified to at least the generic level. Key words: Survey, insect species, distribution, cashew, Ghana.
Journal of Cell and Animal Biology, 2008
Cashew (Anacardium occidentale Linn.) has become a very important non-traditional tree crop in Gh... more Cashew (Anacardium occidentale Linn.) has become a very important non-traditional tree crop in Ghana. Several insect pests, however, have been recorded on cashew and prominent among which is the cashew mosquito, Helopeltis schoutedeni Reuter (Hemiptera: Miridae). The biology of H. schoutedeni was studied in the laboratory at 24.9 to 33oC and 72.4 to 88.5% Relative humidity (R.H.). Females pre-dominated males in the ratio of 0.7:0.3. The mean pre-oviposition, oviposition and post-oviposition periods were 3.6 ± 0.1, 10.2 ± 0.6 and 6.6 ± 0.4 days, respectively. The life cycle from egg to adult emergence lasted 24.0 days. There were five nymphal stages and the mean durations ranged from 2.7 ± 0.10 days for the 3rd instar to 3.5 ± 0.10 days for the 4th instar. The incubation averaged 8.2 ± 0.05 days. The mean pre-copulation period was 2.6 ± 0.1 days. Peak copulation activity occurred between 1400 H and 1700 H. Copulation did not take place until both sexes were at least 2 days old. Males...
Asian Journal of Advances in Agricultural Research, 2021
Tomato (Lycopersicon esculentum) is a popular and important crop as it is consumed worldwide. It ... more Tomato (Lycopersicon esculentum) is a popular and important crop as it is consumed worldwide. It serves as a source of nutrients such as vitamins A and C. In Ghana, tomato production contributes to agricultural GDP, employment creation and foreign exchange earnings. However, tomato production is faced with challenges that hamper productivity. This has been attributed mainly to attacks by pests such as fruit borers. Therefore, this study was conducted to ascertain the characteristics of tomato farmers in Sekyere Kumawu and Asante Akim North districts in Ghana and their knowledge on fruit borers. Structured questionnaires were administered to gather data from sixty respondents who were sampled through a multistage sampling technique. Results from the survey showed male dominance in commercial tomato production in both districts with an average age of 43 years, which falls within the active working age group. Majority of the farmers indicated that they were into tomato production for c...
Journal of Animal and Plant Sciences, 2011
1 SUMMARY This study was conducted to determine the resistance status of maize lines and varietie... more 1 SUMMARY This study was conducted to determine the resistance status of maize lines and varieties to Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae) attack. Ten maize lines; EVDTW99STRQPMCo, FU2090DYFP, TZEEY-PopSTRC4, DMLSRYQPM, GH90DYFP, FU2080DWF/DPop, TZE-Y-PopDTSTRC4, 2000SYNEEWQPM, GH90DWOP and Fu2090DWDPop, and three varieties; Dorke SR, Dodzi and Mamaba (flint maize) were subjected to Sitophilus zeamais attack in a completely randomized design set up. Ten females of S. zeamais were introduced into 50 grammes of shelled whole maize of each of the ten lines and three varieties to oviposit for three days. Based on knowledge of the life cycle of the pest, the set ups were checked for new emergences after 21 days. Emerged weevils were removed and counted daily without replacement, with the first batch of emergence occurring at 27 days after treatment from Fu2090DYFP and Fu2090DWDPop and the longest period of emergence observed in EVDTW99STRQPMCo, Dodzi, Dorke and GH...
African Journal of Agricultural Research, 2021
Positive selection technique (PST) involves physical examination of plants at vegetative stage fo... more Positive selection technique (PST) involves physical examination of plants at vegetative stage for viral disease symptoms and using tubers from apparently symptomless plants as planting materials in seed yam production. This study determined PST use among farmers in Atebubu-Amantin and Ejura-Sekyedumase Municipalities of Ghana. Viral diseases were observed on 63 PST and 63 non-PST farms within these Municipalities. PST farms (two in third season and two starters) were selected to assess the impact of continuous PST practice on plant establishment, disease incidence, severity and yield. Harvested seed yams from asymptomatic and symptomatic plants were sampled for virus detections using Double Antibody Sandwich-Enzyme Linked Immunosorbent Assay (DAS-ELISA). Viral disease incidence (35.70%) and severity (1.51) observed on PST farms were significantly lower than non-PST farms with 54.11% and 2.80, respectively (p< 0.05). PST farms in the third season had higher plant establishment (6...
Cashew (Anacardium occidentale Linn.) has become a very important tree crop in Ghana. It is, howe... more Cashew (Anacardium occidentale Linn.) has become a very important tree crop in Ghana. It is, however, attacked by several sap sucking insects, including the mosquito bug, Helopeltis schoutedeni Reuter. Both the nymph and adult of H. schoutedeni feeding on cashew by sucking the sap from flushing shoots, panicles and immature fruits. The present study investigated the comparative effects of these food sources on the development, survival and oviposition of the species. All the nymphal stages experienced faster rates of development and survival when fed on fruits compared with feeding on flushing shoots or panicles. The adults survived longer and produced higher numbers of viable eggs when fed on fruits or flushing shoots than when fed on panicles. Key words: Comparison, developmental rate, survival rate, longevity, Helopeltis schoutedeni, cashew
Journal of Science and Technology (Ghana), 2007
Bulletin of Entomological Research, 1999
Effects of five weed management regimes on abundance of weeds, insect pests, generalist predators... more Effects of five weed management regimes on abundance of weeds, insect pests, generalist predators and on pest damage and rice yield were investigated in upland rice in Côte d‘Ivoire over two years. In both years there was a highly significant negative correlation between weed biomass and grain yield across all treatments. Only two pest insect groups, Nephotettix spp. (Cicadellidae) and seed sucking Heteroptera, were consistently more abundant in unweeded plots and had a consistent significant positive correlation between abundance and weed biomass across all seven treatments. These polyphagous groups may have been more dependent on resources provided by weeds than the other pests studied. However, pest damage was not affected by presence or absence of weeds, suggesting that populations were below a damage threshold. Ants were the most abundant predators in the rice canopy and were most abundant in unweeded treatments. Abundance of both ants and spiders was significantly positively c...
Biological Agriculture & Horticulture, 1999
ABSTRACT The effects of weed residues on the abundance and activity of generalist arthropod preda... more ABSTRACT The effects of weed residues on the abundance and activity of generalist arthropod predators and insect pests and on rice yields in upland rice were studied. Weed residues were placed in the experimental plots in three ways: (1) residues left in situ where weeds are uprooted; or (2) placed in small piles throughout the field; or (3) removed from the field but heaped at the edges to be burnt when dry. The study investigated the effects of residue disposal in upland rice under research station conditions designed to simulate conditions in farmers' fields.Spider activity was significantly greater in plots with scattered residues and strips of residue and least in plots from which residues had been removed. Staphylinid beetle activity was significantly greater in plots with a supplementary weed mulch than in other treatments. By contrast, spider density was greater when residue was piled or used as mulch rather than when scattered but the smallest populations occurred in the no-residue plots. Carabid beetles were significantly more abundant in plots with strips or piles of weeds and staphylinid beetles were most abundant in the mulched plots. Ants were not affected by weed residue placement.Among the ten pest groups studied, the abundance of only Chaetocnema sp., was significantly greater in plots with strips and piles than in other treatments, populations of other pests being unaffected by weed residue placement. In 1994, mean percentage of deadhearts (stem-borer damage) was significantly greater in the residue-free plots than in other treatments but in 1995 the differences between treatments were not significant. In both years, grain yield was not affected significantly by weed residue placement but was lowest in the residue-free plots.
A survey and exclusion study to establish the presence of D. bulbifera and its associated phytoph... more A survey and exclusion study to establish the presence of D. bulbifera and its associated phytophagous insect fauna was conducted in Ghana between 2004 and 2006. The purpose was to identify potential biological control agents for this plant invading natural and protected areas in Florida, USA. The survey covered five regions based on herbarium records from three academic institutions in Ghana. A total of 40 phytophagous insect species in 9 orders were encountered on the plant with 24 species attacking D. bulbifera in two feeding guilds foliage and bulbil in Ghana. The Original Research Article
Journal of Essential Oil Bearing Plants, 2017
Abstract Many natural enemies of herbivorous insects are attracted to semiochemicals emitted by p... more Abstract Many natural enemies of herbivorous insects are attracted to semiochemicals emitted by plants. Semiochemicals emitted by host plants can prime neigbouring plants to adjust their defensive mechanism against future attack. Crop protection, using plant signal is recently gaining momentum due to health and environmental concerns about the use of synthetic pesticides. Semiochemicals have successfully been used to protect maize from the stem borer through the Push /Pull technology. Chromolaena odorata plant is known to support a large and varied insect fauna although the chemistry involved has not been fully established. To determine the volatiles emitted by the undamaged C. odorata plant that might be associated with the insect plant interaction, Dynamic headspace technique was used to collect volatiles from the plant under laboratory conditions and analysed using a Gas chromatography and Gas Chromatography coupled with Mass Spectrometer (GC-MS). Thirty three compounds were identified from the collected headspace volatile from the plant. (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), 4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT) and E-β-farnesene are three semiochemicals identified that had not been reported to be emitted by an intact C. odorata plant from Ghana.
Traditional shifting cultivatiOn appears to be sustainable if fallow periods are sufficient to re... more Traditional shifting cultivatiOn appears to be sustainable if fallow periods are sufficient to restore soil fertility, maintain soil structure and suppress pests. These traditional systems are threatened in West Africa because of increasing land pressure resulting in shorter fallow periods. Studies were conducted on farmers\u27 fields in Côte d’lvoire to determine how fallow length affects populations of insect pests and their natural enemies and weed growth and yield losses due to weeds. Length of fallow influenced the abundance of certain arthropod species as indicated by sweep-net sampling. Populations of the stalk-eyed flies Diopsis spp., leaf·feeding beetles, and leafhoppers/spittlebugs were significantly higher in the long fallow (5-13 years) fields than in the short fallow (\u3c3 years) fields. The natural enemy complex consisting of spiders, predaceous ladybird beetles and dragonflies/damselflies also increased with length of fallow, while fallow period had no effect on the ...
Asian Journal of Advances in Agricultural Research, 2021
This study was conducted to evaluate the efficacy of synthetic insecticides in managing Helicover... more This study was conducted to evaluate the efficacy of synthetic insecticides in managing Helicoverpa armigera Mill in tomato production. The experiment was conducted during the major and minor tomato growing seasons at the Sekyere Kumawu and Asante Akim North districts in Ghana. The experimental design was a 3 x 5 factorial randomized complete block with four replications. Four insect pest control regimes were evaluated for their effectiveness in controlling the tomato fruit borer. Three tomato varieties were used in this experiment. The results showed that, significantly, higher marketable fruit yields were obtained on the sprayed plots than the control plots. In general, the variety “pectomec” suffered the highest yield loss on the water sprayed field, followed by UC 82 and lastly, power rhino, although all the varieties suffered losses greater than 50%. This shows that none of the varieties used for this study is completely resistant to Helicoverpa armigera. Yields were generally ...
Volume 5,Issue 1, 2019, 2019
Journal of Experimental Agriculture International, 2017
A survey and exclusion study to establish the presence of D. bulbifera and its associated phytoph... more A survey and exclusion study to establish the presence of D. bulbifera and its associated phytophagous insect fauna was conducted in Ghana between 2004 and 2006. The purpose was to identify potential biological control agents for this plant invading natural and protected areas in Florida, USA. The survey covered five regions based on herbarium records from three academic institutions in Ghana. A total of 40 phytophagous insect species in 9 orders were encountered on the plant with 24 species attacking D. bulbifera in two feeding guilds foliage and bulbil in Ghana. The
Journal of Agricultural and Urban Entomology, 2009
During recent visits to Southeast Asia by scientists from Virginia Polytechnic Institute and Stat... more During recent visits to Southeast Asia by scientists from Virginia Polytechnic Institute and State University and Clemson University who were participating in a USAID-funded Integrated Pest Management Collaborative Research Support Program (IPM CRSP), heavy infestations ...
African Journal of Agricultural Research, 2008
Knowledge of the insect complex associated with any crop is essential for developing pest control... more Knowledge of the insect complex associated with any crop is essential for developing pest control strategies for the crop. Literature on cashew insects is lacking in Ghana. Field surveys were conducted from July 2003 to October 2005, to collect and identify the insect fauna on cashew. The surveys were conducted in 13 major cashew growing areas within ten districts of the Northern, Upper West, Brong-Ahafo and Eastern Regions of Ghana. Pyrethroids knock down and visual examination methods were used. A total of 170 insect species were collected. Eighty nine species of the total collection were identified to family level, 57 of which were identified to at least the generic level. Key words: Survey, insect species, distribution, cashew, Ghana.
Journal of Cell and Animal Biology, 2008
Cashew (Anacardium occidentale Linn.) has become a very important non-traditional tree crop in Gh... more Cashew (Anacardium occidentale Linn.) has become a very important non-traditional tree crop in Ghana. Several insect pests, however, have been recorded on cashew and prominent among which is the cashew mosquito, Helopeltis schoutedeni Reuter (Hemiptera: Miridae). The biology of H. schoutedeni was studied in the laboratory at 24.9 to 33oC and 72.4 to 88.5% Relative humidity (R.H.). Females pre-dominated males in the ratio of 0.7:0.3. The mean pre-oviposition, oviposition and post-oviposition periods were 3.6 ± 0.1, 10.2 ± 0.6 and 6.6 ± 0.4 days, respectively. The life cycle from egg to adult emergence lasted 24.0 days. There were five nymphal stages and the mean durations ranged from 2.7 ± 0.10 days for the 3rd instar to 3.5 ± 0.10 days for the 4th instar. The incubation averaged 8.2 ± 0.05 days. The mean pre-copulation period was 2.6 ± 0.1 days. Peak copulation activity occurred between 1400 H and 1700 H. Copulation did not take place until both sexes were at least 2 days old. Males...
Asian Journal of Advances in Agricultural Research, 2021
Tomato (Lycopersicon esculentum) is a popular and important crop as it is consumed worldwide. It ... more Tomato (Lycopersicon esculentum) is a popular and important crop as it is consumed worldwide. It serves as a source of nutrients such as vitamins A and C. In Ghana, tomato production contributes to agricultural GDP, employment creation and foreign exchange earnings. However, tomato production is faced with challenges that hamper productivity. This has been attributed mainly to attacks by pests such as fruit borers. Therefore, this study was conducted to ascertain the characteristics of tomato farmers in Sekyere Kumawu and Asante Akim North districts in Ghana and their knowledge on fruit borers. Structured questionnaires were administered to gather data from sixty respondents who were sampled through a multistage sampling technique. Results from the survey showed male dominance in commercial tomato production in both districts with an average age of 43 years, which falls within the active working age group. Majority of the farmers indicated that they were into tomato production for c...
Journal of Animal and Plant Sciences, 2011
1 SUMMARY This study was conducted to determine the resistance status of maize lines and varietie... more 1 SUMMARY This study was conducted to determine the resistance status of maize lines and varieties to Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae) attack. Ten maize lines; EVDTW99STRQPMCo, FU2090DYFP, TZEEY-PopSTRC4, DMLSRYQPM, GH90DYFP, FU2080DWF/DPop, TZE-Y-PopDTSTRC4, 2000SYNEEWQPM, GH90DWOP and Fu2090DWDPop, and three varieties; Dorke SR, Dodzi and Mamaba (flint maize) were subjected to Sitophilus zeamais attack in a completely randomized design set up. Ten females of S. zeamais were introduced into 50 grammes of shelled whole maize of each of the ten lines and three varieties to oviposit for three days. Based on knowledge of the life cycle of the pest, the set ups were checked for new emergences after 21 days. Emerged weevils were removed and counted daily without replacement, with the first batch of emergence occurring at 27 days after treatment from Fu2090DYFP and Fu2090DWDPop and the longest period of emergence observed in EVDTW99STRQPMCo, Dodzi, Dorke and GH...
African Journal of Agricultural Research, 2021
Positive selection technique (PST) involves physical examination of plants at vegetative stage fo... more Positive selection technique (PST) involves physical examination of plants at vegetative stage for viral disease symptoms and using tubers from apparently symptomless plants as planting materials in seed yam production. This study determined PST use among farmers in Atebubu-Amantin and Ejura-Sekyedumase Municipalities of Ghana. Viral diseases were observed on 63 PST and 63 non-PST farms within these Municipalities. PST farms (two in third season and two starters) were selected to assess the impact of continuous PST practice on plant establishment, disease incidence, severity and yield. Harvested seed yams from asymptomatic and symptomatic plants were sampled for virus detections using Double Antibody Sandwich-Enzyme Linked Immunosorbent Assay (DAS-ELISA). Viral disease incidence (35.70%) and severity (1.51) observed on PST farms were significantly lower than non-PST farms with 54.11% and 2.80, respectively (p< 0.05). PST farms in the third season had higher plant establishment (6...
Cashew (Anacardium occidentale Linn.) has become a very important tree crop in Ghana. It is, howe... more Cashew (Anacardium occidentale Linn.) has become a very important tree crop in Ghana. It is, however, attacked by several sap sucking insects, including the mosquito bug, Helopeltis schoutedeni Reuter. Both the nymph and adult of H. schoutedeni feeding on cashew by sucking the sap from flushing shoots, panicles and immature fruits. The present study investigated the comparative effects of these food sources on the development, survival and oviposition of the species. All the nymphal stages experienced faster rates of development and survival when fed on fruits compared with feeding on flushing shoots or panicles. The adults survived longer and produced higher numbers of viable eggs when fed on fruits or flushing shoots than when fed on panicles. Key words: Comparison, developmental rate, survival rate, longevity, Helopeltis schoutedeni, cashew
Journal of Science and Technology (Ghana), 2007
Bulletin of Entomological Research, 1999
Effects of five weed management regimes on abundance of weeds, insect pests, generalist predators... more Effects of five weed management regimes on abundance of weeds, insect pests, generalist predators and on pest damage and rice yield were investigated in upland rice in Côte d‘Ivoire over two years. In both years there was a highly significant negative correlation between weed biomass and grain yield across all treatments. Only two pest insect groups, Nephotettix spp. (Cicadellidae) and seed sucking Heteroptera, were consistently more abundant in unweeded plots and had a consistent significant positive correlation between abundance and weed biomass across all seven treatments. These polyphagous groups may have been more dependent on resources provided by weeds than the other pests studied. However, pest damage was not affected by presence or absence of weeds, suggesting that populations were below a damage threshold. Ants were the most abundant predators in the rice canopy and were most abundant in unweeded treatments. Abundance of both ants and spiders was significantly positively c...
Biological Agriculture & Horticulture, 1999
ABSTRACT The effects of weed residues on the abundance and activity of generalist arthropod preda... more ABSTRACT The effects of weed residues on the abundance and activity of generalist arthropod predators and insect pests and on rice yields in upland rice were studied. Weed residues were placed in the experimental plots in three ways: (1) residues left in situ where weeds are uprooted; or (2) placed in small piles throughout the field; or (3) removed from the field but heaped at the edges to be burnt when dry. The study investigated the effects of residue disposal in upland rice under research station conditions designed to simulate conditions in farmers' fields.Spider activity was significantly greater in plots with scattered residues and strips of residue and least in plots from which residues had been removed. Staphylinid beetle activity was significantly greater in plots with a supplementary weed mulch than in other treatments. By contrast, spider density was greater when residue was piled or used as mulch rather than when scattered but the smallest populations occurred in the no-residue plots. Carabid beetles were significantly more abundant in plots with strips or piles of weeds and staphylinid beetles were most abundant in the mulched plots. Ants were not affected by weed residue placement.Among the ten pest groups studied, the abundance of only Chaetocnema sp., was significantly greater in plots with strips and piles than in other treatments, populations of other pests being unaffected by weed residue placement. In 1994, mean percentage of deadhearts (stem-borer damage) was significantly greater in the residue-free plots than in other treatments but in 1995 the differences between treatments were not significant. In both years, grain yield was not affected significantly by weed residue placement but was lowest in the residue-free plots.
A survey and exclusion study to establish the presence of D. bulbifera and its associated phytoph... more A survey and exclusion study to establish the presence of D. bulbifera and its associated phytophagous insect fauna was conducted in Ghana between 2004 and 2006. The purpose was to identify potential biological control agents for this plant invading natural and protected areas in Florida, USA. The survey covered five regions based on herbarium records from three academic institutions in Ghana. A total of 40 phytophagous insect species in 9 orders were encountered on the plant with 24 species attacking D. bulbifera in two feeding guilds foliage and bulbil in Ghana. The Original Research Article