Pub Date : 1999-01-01DOI: 10.1080/02571862.1999.10634854
A. Singels, C. Bezuidenhout
Information on the effects of El Nino on local climate and sugarcane production will assist planning and management. The objective of this study was to investigate the relationship between the southern oscillation index (SOI) and rainfall and sugarcane yields in South Africa. Probabilities of low rainfall more than doubled during summers with a consistently negative SOI phase during November. February rainfall was worst affected. Factors other than climate confounded the historical relationship between El Nino and sugarcane yields. Simulation studies to exclude non-climatic factors indicated that cane yields are reduced by significant margins following seven out of nine El Nino events. Results show that the phase of the SOI during spring is a reasonably reliable indicator of low rainfall during the subsequent midsummer and of low yields during the subsequent milling season.
{"title":"The relationship between ENSO and rainfall and yield in the South African sugar industry","authors":"A. Singels, C. Bezuidenhout","doi":"10.1080/02571862.1999.10634854","DOIUrl":"https://doi.org/10.1080/02571862.1999.10634854","url":null,"abstract":"Information on the effects of El Nino on local climate and sugarcane production will assist planning and management. The objective of this study was to investigate the relationship between the southern oscillation index (SOI) and rainfall and sugarcane yields in South Africa. Probabilities of low rainfall more than doubled during summers with a consistently negative SOI phase during November. February rainfall was worst affected. Factors other than climate confounded the historical relationship between El Nino and sugarcane yields. Simulation studies to exclude non-climatic factors indicated that cane yields are reduced by significant margins following seven out of nine El Nino events. Results show that the phase of the SOI during spring is a reasonably reliable indicator of low rainfall during the subsequent midsummer and of low yields during the subsequent milling season.","PeriodicalId":22913,"journal":{"name":"The South African Journal of Plant and Soil","volume":"79 1","pages":"96-101"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88057184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-01-01DOI: 10.1080/02571862.1999.10634839
P. Celliers, M. Labuschagne, C. S. Deventer
Yield losses due to high temperatures in the wheat growing season is a serious problem in South Africa. The aim of this study was to determine how the expression of general combining ability (GCA) and specific combining ability (SCA) was influenced by high temperatures in five commercial spring wheats. A full diallel cross was made with five spring wheat cultivars. One set of parents and their F1 hybrid progenies were grown under high temperatures and a second set under control temperatures. Additive gene action was predominant for all characteristics measured at both temperature levels. Additive gene action was significantly lower at the higher temperature conditions for most characteristics. Parents with the highest GCA effects at one set of temperatures tended to have the highest GCA effects for the other temperature level as well. SCA effects were expressed significantly different at the higher temperatures. High SCA effects for a characteristic at one temperature level were often paralleled by low or...
{"title":"Combining ability effects of some spring wheat cultivars at two different temperature levels","authors":"P. Celliers, M. Labuschagne, C. S. Deventer","doi":"10.1080/02571862.1999.10634839","DOIUrl":"https://doi.org/10.1080/02571862.1999.10634839","url":null,"abstract":"Yield losses due to high temperatures in the wheat growing season is a serious problem in South Africa. The aim of this study was to determine how the expression of general combining ability (GCA) and specific combining ability (SCA) was influenced by high temperatures in five commercial spring wheats. A full diallel cross was made with five spring wheat cultivars. One set of parents and their F1 hybrid progenies were grown under high temperatures and a second set under control temperatures. Additive gene action was predominant for all characteristics measured at both temperature levels. Additive gene action was significantly lower at the higher temperature conditions for most characteristics. Parents with the highest GCA effects at one set of temperatures tended to have the highest GCA effects for the other temperature level as well. SCA effects were expressed significantly different at the higher temperatures. High SCA effects for a characteristic at one temperature level were often paralleled by low or...","PeriodicalId":22913,"journal":{"name":"The South African Journal of Plant and Soil","volume":"23 1","pages":"15-17"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81684841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-01-01DOI: 10.1080/02571862.1999.10634841
P. L. Campbell, R. L. Kluge
Two integrated control strategies were developed for areas where wattle infestations could be utilized. Costing analyses were determined for initial control and four follow-up control operations using chemical control and fire. Efficacy of all treatments was high. Costs were significantly reduced during follow-up control operations. Rehabilitation of the cleared areas with pasture species stabilized the top soil and increased the carrying capacity of the land. The pastures could be maintained or allowed to revert to neighbouring veld (grassland) species, depending on the aims of the land manager. The financial returns from conversion of wattle infestations to pastures required 1 or 7 years utilization (grazing) to cover the costs of control, depending on the production system used. Control costs of these trials were compared with contract-based costs at the Kouga Work for Water project in the Eastern Cape.
{"title":"Development of integrated control strategies for wattle. 1. Utilization of wattle, control of stumps and rehabilitation with pastures","authors":"P. L. Campbell, R. L. Kluge","doi":"10.1080/02571862.1999.10634841","DOIUrl":"https://doi.org/10.1080/02571862.1999.10634841","url":null,"abstract":"Two integrated control strategies were developed for areas where wattle infestations could be utilized. Costing analyses were determined for initial control and four follow-up control operations using chemical control and fire. Efficacy of all treatments was high. Costs were significantly reduced during follow-up control operations. Rehabilitation of the cleared areas with pasture species stabilized the top soil and increased the carrying capacity of the land. The pastures could be maintained or allowed to revert to neighbouring veld (grassland) species, depending on the aims of the land manager. The financial returns from conversion of wattle infestations to pastures required 1 or 7 years utilization (grazing) to cover the costs of control, depending on the production system used. Control costs of these trials were compared with contract-based costs at the Kouga Work for Water project in the Eastern Cape.","PeriodicalId":22913,"journal":{"name":"The South African Journal of Plant and Soil","volume":"53 1","pages":"24-30"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77823976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-01-01DOI: 10.1080/02571862.1999.10634838
R. Prins, G. F. Marais
The Lr19 translocation is preferentially transmitted to the progeny of a heterozygote due to the actions of at least two genes, Sd1 and Sd2 (new designation). However, only Sd2 occurs in the recombinant, Lr19-149, and often causes self-elimination of the recombined translocated segment in heterozygotes. The degree of segregation distortion is determined by the interaction of the Sd genes with polygenes (responder genes) on various wheat chromosomes. In this study suspected responder alleles derived from ‘Inia 66’ or ‘Indis’ (chromosomes 2A, 2B, 3B, 5B, 5D and 6D) appeared mostly to be partially dominant to overdominant over the ‘Chinese Spring’ derived alleles. A specific allele may not necessarily hafe-tfoe same effect (suppression or enhancement) in different genetic backgrounds. Responder genes may not fully compensate for the absence of a homologue in a hemizygote which may then produce effects quite different from those of the homo- and heterozygotes.
{"title":"A genetic study of the gametocidal effect of the Lr19 translocation of common wheat","authors":"R. Prins, G. F. Marais","doi":"10.1080/02571862.1999.10634838","DOIUrl":"https://doi.org/10.1080/02571862.1999.10634838","url":null,"abstract":"The Lr19 translocation is preferentially transmitted to the progeny of a heterozygote due to the actions of at least two genes, Sd1 and Sd2 (new designation). However, only Sd2 occurs in the recombinant, Lr19-149, and often causes self-elimination of the recombined translocated segment in heterozygotes. The degree of segregation distortion is determined by the interaction of the Sd genes with polygenes (responder genes) on various wheat chromosomes. In this study suspected responder alleles derived from ‘Inia 66’ or ‘Indis’ (chromosomes 2A, 2B, 3B, 5B, 5D and 6D) appeared mostly to be partially dominant to overdominant over the ‘Chinese Spring’ derived alleles. A specific allele may not necessarily hafe-tfoe same effect (suppression or enhancement) in different genetic backgrounds. Responder genes may not fully compensate for the absence of a homologue in a hemizygote which may then produce effects quite different from those of the homo- and heterozygotes.","PeriodicalId":22913,"journal":{"name":"The South African Journal of Plant and Soil","volume":"6 1","pages":"10-14"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82360295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-01-01DOI: 10.1080/02571862.1999.10635012
L. Grobler, A. Bloem, A. Claassens
Sulphur is an essential nutrient for the production of the amino acids cysteine and methionine, which are important for protein syntheses. Previous studies showed that sulphur deficiencies are becoming common because of the tendency to use more concentrated and liquid fertilisers. The objective of this study was determining the threshold concentration values for sulphur in different soils, above which no yield increase can be expected with increased sulphur fertilisation. Four soils, low in sulphur, were selected and treated with five sulphur levels. After four to five weeks the first deficiency symptoms appeared at the lowest sulphur levels. The plants were harvested after ten weeks. It was found that sulphur had a definite effect on yields and 10 mg kg-1 in soil can be used as a threshold value.
{"title":"A critical soil sulphur level for maize (Zea mays L.) grown in a glasshouse","authors":"L. Grobler, A. Bloem, A. Claassens","doi":"10.1080/02571862.1999.10635012","DOIUrl":"https://doi.org/10.1080/02571862.1999.10635012","url":null,"abstract":"Sulphur is an essential nutrient for the production of the amino acids cysteine and methionine, which are important for protein syntheses. Previous studies showed that sulphur deficiencies are becoming common because of the tendency to use more concentrated and liquid fertilisers. The objective of this study was determining the threshold concentration values for sulphur in different soils, above which no yield increase can be expected with increased sulphur fertilisation. Four soils, low in sulphur, were selected and treated with five sulphur levels. After four to five weeks the first deficiency symptoms appeared at the lowest sulphur levels. The plants were harvested after ten weeks. It was found that sulphur had a definite effect on yields and 10 mg kg-1 in soil can be used as a threshold value.","PeriodicalId":22913,"journal":{"name":"The South African Journal of Plant and Soil","volume":"9 1","pages":"204-206"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80700151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-01-01DOI: 10.1080/02571862.1999.10634999
M. Manley, M. Nel
Due to a lack of electrical ovens, it is often found that in the households of the lower-income communities, a home-made steamed bread is prepared in a saucepan on a gas cooker or an open fire. The requirements of flour used to produce high-quality steamed bread are poorly defined. The suitability of Western and Southern Cape wheat for steamed bread production was, therefore, investigated. A marked increase in the nutritive value of steamed bread was reported compared to that of conventionally baked bread, mainly due to the loss of available lysine during conventional baking. Samples of three spring wheat cultivars that were produced during the 1995 and 1996 seasons in the Western and Southern Cape were selected. Flour protein content of these samples varied between 8 and 16%. Flour protein content, Falling Number determinations, gluten content, Mixograph, Alveograph and Rheofermentometer measurements and the 10 g baking test were performed on each of the flours. Steamed and conventionally baked breads we...
{"title":"Investigation of the suitability of Western and Southern Cape wheat flour for production of traditional South African steamed bread","authors":"M. Manley, M. Nel","doi":"10.1080/02571862.1999.10634999","DOIUrl":"https://doi.org/10.1080/02571862.1999.10634999","url":null,"abstract":"Due to a lack of electrical ovens, it is often found that in the households of the lower-income communities, a home-made steamed bread is prepared in a saucepan on a gas cooker or an open fire. The requirements of flour used to produce high-quality steamed bread are poorly defined. The suitability of Western and Southern Cape wheat for steamed bread production was, therefore, investigated. A marked increase in the nutritive value of steamed bread was reported compared to that of conventionally baked bread, mainly due to the loss of available lysine during conventional baking. Samples of three spring wheat cultivars that were produced during the 1995 and 1996 seasons in the Western and Southern Cape were selected. Flour protein content of these samples varied between 8 and 16%. Flour protein content, Falling Number determinations, gluten content, Mixograph, Alveograph and Rheofermentometer measurements and the 10 g baking test were performed on each of the flours. Steamed and conventionally baked breads we...","PeriodicalId":22913,"journal":{"name":"The South African Journal of Plant and Soil","volume":"48 1","pages":"135-142"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81510941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-01-01DOI: 10.1080/02571862.1999.10634996
G. A. Agenbag, R. Crous
Bromus diandrus Roth, is one of the most troublesome weeds in spring wheat crops of the western Cape wheat producing area of the Republic of South Africa and Australia. The selective control of this weed in wheat crops may, in future, be possible with MON 37532 (sulfosulfuron) a new herbicide developed by Monsanto SA. The effect of the relative density of B. diandrus in a wheat crop on the efficacy of this herbicide sprayed at either the 2- or6-leaf stage of the weed was studied in a pot experiment in a temperature-controlled glasshouse. A density of 3 plants pot-1 (170 plants rrr-2) was used for the wheat crop, while that of B. diandrus varied between 0 and 10 plants pot-1 (565 plants -2). At early applications (2-leaf stage), efficacy of MON 37532 improved with higher densities of B. diandrus. This was possibly due to stress conditions created by higher weed densities. This tendency was less evident when MON 37532 was applied at the 6-leaf stage. Reduced susceptibility in the older plants and less effic...
{"title":"Bromus diandrus Roth. control with MON 37532 in spring wheat (Triticum aestivum L.). 2. Effect of relative weed density and time of spraying","authors":"G. A. Agenbag, R. Crous","doi":"10.1080/02571862.1999.10634996","DOIUrl":"https://doi.org/10.1080/02571862.1999.10634996","url":null,"abstract":"Bromus diandrus Roth, is one of the most troublesome weeds in spring wheat crops of the western Cape wheat producing area of the Republic of South Africa and Australia. The selective control of this weed in wheat crops may, in future, be possible with MON 37532 (sulfosulfuron) a new herbicide developed by Monsanto SA. The effect of the relative density of B. diandrus in a wheat crop on the efficacy of this herbicide sprayed at either the 2- or6-leaf stage of the weed was studied in a pot experiment in a temperature-controlled glasshouse. A density of 3 plants pot-1 (170 plants rrr-2) was used for the wheat crop, while that of B. diandrus varied between 0 and 10 plants pot-1 (565 plants -2). At early applications (2-leaf stage), efficacy of MON 37532 improved with higher densities of B. diandrus. This was possibly due to stress conditions created by higher weed densities. This tendency was less evident when MON 37532 was applied at the 6-leaf stage. Reduced susceptibility in the older plants and less effic...","PeriodicalId":22913,"journal":{"name":"The South African Journal of Plant and Soil","volume":"4 1","pages":"123-126"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87573270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-01-01DOI: 10.1080/02571862.1999.10634995
G. A. Agenbag, R. Crous
MON 37532 (sulfosulfuron) is a new herbicide for the selective control of grasses and annual broadleaf weeds in wheat (Triticum aestivum L.). In this glasshouse study done in 2-litre pots filled with coarse sand, the product was evaluated for the selective control of Bromus diandrus Roth, in spring wheat. Dosage rates of MON 37532 varying between 0 and 45 g a.i ha-1 plus 0.25% of the surfactant, Agral 90, were applied at the 1-, 2-, 3- and 4-leaf stage of the weed plants. Although efficient control (> 85%) was only achieved when weeds were sprayed at the 1 -leaf stage, leaf growth of all B. diandrus plants ceased within 5 days after spraying, irrespective of time of spraying. Leaf area and dry mass determinations done at 6 weeks after spraying in this study confirmed that even if sprayed at the 4-leaf stage, MON 37532 stops B. diandrus from further growth and competition with the wheat plants. Higher dosage rates may be needed when sprayed at later growth stages. Growth of the spring wheat cultivar, SST 5...
{"title":"Bromus diandrus Roth. control with MON 37532 in spring wheat (Triticum aestivum L.). 1. Time of application and dosage rate","authors":"G. A. Agenbag, R. Crous","doi":"10.1080/02571862.1999.10634995","DOIUrl":"https://doi.org/10.1080/02571862.1999.10634995","url":null,"abstract":"MON 37532 (sulfosulfuron) is a new herbicide for the selective control of grasses and annual broadleaf weeds in wheat (Triticum aestivum L.). In this glasshouse study done in 2-litre pots filled with coarse sand, the product was evaluated for the selective control of Bromus diandrus Roth, in spring wheat. Dosage rates of MON 37532 varying between 0 and 45 g a.i ha-1 plus 0.25% of the surfactant, Agral 90, were applied at the 1-, 2-, 3- and 4-leaf stage of the weed plants. Although efficient control (> 85%) was only achieved when weeds were sprayed at the 1 -leaf stage, leaf growth of all B. diandrus plants ceased within 5 days after spraying, irrespective of time of spraying. Leaf area and dry mass determinations done at 6 weeks after spraying in this study confirmed that even if sprayed at the 4-leaf stage, MON 37532 stops B. diandrus from further growth and competition with the wheat plants. Higher dosage rates may be needed when sprayed at later growth stages. Growth of the spring wheat cultivar, SST 5...","PeriodicalId":22913,"journal":{"name":"The South African Journal of Plant and Soil","volume":"12 1","pages":"118-122"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89531236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-01-01DOI: 10.1080/02571862.1999.10634845
N. Bosque-Pérez, I. Buddenhagen
Studies have been conducted in Nigeria on biology of Cicadulina leafhopper vectors of maize streak virus (MSV), the role of indigenous grasses as reservoirs of virus and vectors, and on incidence and severity of MSV in relation to maize varietal susceptibility/resistance levels. Cicadulina populations peak before rains end in the savanna and after the rains in the forest zone. The proportion of viruliferous leafhoppers increases as the season progresses. C. mbila is the predominant vector species; four other species are less common. Off-season survival of MSV and vectors occurs in riverine areas in grasses and in areas with hydromorphic soils where maize is grown during the dry season. However, streak found in many grasses in Nigeria is not readily transmissible to susceptible field maize. Weeds most likely to perpetuate an epidemiologically-competent MSV maize strain are Axonopus compressus (an introduced perennial), Brachiaria lata and Setaria barbata (indigenous annuals). MSV epidemics occur only in ye...
{"title":"Biology of Cicadulina leafhoppers and epidemiology of maize streak virus disease in West Africa","authors":"N. Bosque-Pérez, I. Buddenhagen","doi":"10.1080/02571862.1999.10634845","DOIUrl":"https://doi.org/10.1080/02571862.1999.10634845","url":null,"abstract":"Studies have been conducted in Nigeria on biology of Cicadulina leafhopper vectors of maize streak virus (MSV), the role of indigenous grasses as reservoirs of virus and vectors, and on incidence and severity of MSV in relation to maize varietal susceptibility/resistance levels. Cicadulina populations peak before rains end in the savanna and after the rains in the forest zone. The proportion of viruliferous leafhoppers increases as the season progresses. C. mbila is the predominant vector species; four other species are less common. Off-season survival of MSV and vectors occurs in riverine areas in grasses and in areas with hydromorphic soils where maize is grown during the dry season. However, streak found in many grasses in Nigeria is not readily transmissible to susceptible field maize. Weeds most likely to perpetuate an epidemiologically-competent MSV maize strain are Axonopus compressus (an introduced perennial), Brachiaria lata and Setaria barbata (indigenous annuals). MSV epidemics occur only in ye...","PeriodicalId":22913,"journal":{"name":"The South African Journal of Plant and Soil","volume":"26 1","pages":"50-55"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79443573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1999-01-01DOI: 10.1080/02571862.1999.10634856
I. Buddenhagen, N. Bosque-Pérez
Maize streak virus (MSV) was first studied by Storey in Kenya in the 1920s and resistance transferred into East African maize in the 1960's. Yet the majority of farmers of East Africa are still growing streak-susceptible maize. At the International Institute of Tropical Agriculture (IITA) in Nigeria, an effort to incorporate streak resistance as an integral part of a holistic maize improvement program was begun in 1975. By 1979, usable resistance had been found and methods of large scale field challenge devised, and used routinely in the development of populations targeted at three major ecological zones in tropical Africa. Methods were continuously improved and resistant open pollinated varieties and hybrids produced that are now used on a large scale by farmers in West Africa. The strategy for success was based on: 1) Avoidance of virus strain specificity; 2) Large scale vector rearing and field infestation to ensure early infection; 3) Selection only for tolerance when infected; and 4) Not separating v...
{"title":"Historical overview of breeding for durable resistance to maize streak virus for tropical Africa","authors":"I. Buddenhagen, N. Bosque-Pérez","doi":"10.1080/02571862.1999.10634856","DOIUrl":"https://doi.org/10.1080/02571862.1999.10634856","url":null,"abstract":"Maize streak virus (MSV) was first studied by Storey in Kenya in the 1920s and resistance transferred into East African maize in the 1960's. Yet the majority of farmers of East Africa are still growing streak-susceptible maize. At the International Institute of Tropical Agriculture (IITA) in Nigeria, an effort to incorporate streak resistance as an integral part of a holistic maize improvement program was begun in 1975. By 1979, usable resistance had been found and methods of large scale field challenge devised, and used routinely in the development of populations targeted at three major ecological zones in tropical Africa. Methods were continuously improved and resistant open pollinated varieties and hybrids produced that are now used on a large scale by farmers in West Africa. The strategy for success was based on: 1) Avoidance of virus strain specificity; 2) Large scale vector rearing and field infestation to ensure early infection; 3) Selection only for tolerance when infected; and 4) Not separating v...","PeriodicalId":22913,"journal":{"name":"The South African Journal of Plant and Soil","volume":"35 1","pages":"106-111"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79003400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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