Sustainable rice production in African inland valleys: Seizing regional potentials through local approaches

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Rice-feeding insects and selected natural enemies in West Africa: biology, ecology and identification.

https://www.jstage.jst.go.jp/article/jsta1957/51/2/51_2_41/_pdf

Breeding and Dissemination Efforts of “NERICA”

Characterization of Novel Rice Germplasm from West Africa and Genetic Marker Associations with Rice Cooking Quality. (August 2005) Karim Traore, B.S., Institut Polytechnique Rural de Katibougou; M.S., University of Nebraska-Lincoln Co-Chairs of Advisory Committee: Dr. Anna M. McClung Dr. William L. Rooney Genetic resource enhancement is the foundation of any good breeding program. Landraces from West Africa, interspecifics between Oryza sativa and Oryza glaberrima and improved lines from the West African Rice Development Association and other research centers were introduced to the Beaumont Rice Research center for in situ evaluation and characterization. Beside the introduction of seeds, milled samples were also introduced for grain chemistry analysis. Field evaluation combined with physicochemical and molecular characterization revealed unique characteristics among African germplasm. New rice for Africa (NERICA) lines performed well in the USA environment. Varieties like Nerica 2, Nerica 3, Nerica 4, and Nerica 5 need more attention because of their superior performance in yield and grain quality. Landraces did not perform well due to their height and late maturity and their resulting problems with lodging. The rapid visco analyzer RVA profiles showed that the cultivar Jaya has unusually strong paste viscosity features. Comparing West Africa samples grown in Cote d’Ivoire with those grown in Texas, parameters like AA, ASV, Hot, Cool, and CT were not stongly affected by the environment. According to the Stbk value, cultivars

Characterization of novel rice germplasm from West Africa and genetic marker associations with rice cooking quality

African rice gall midge (AfRGM) is one of the most destructive pests of irrigated and lowland African ecologies. This study aimed to identify the quantitative trait loci (QTL) associated with AfRGM pest incidence and resistance in three independent bi-parental rice populations (ITA306xBW348-1, ITA306xTOG7106 and ITA306xTOS14519), and to conduct meta QTL (mQTL) analysis to explore whether any genomic regions are conserved across different genetic backgrounds. Composite interval mapping (CIM) conducted on the three populations independently uncovered a total of 28 QTLs associated with pest incidence (12) and pest severity (16). The number of QTLs per population associated with AfRGM resistance varied from three in the ITA306xBW348-1 population to eight in the ITA306xTOG7106 population. Each QTL individually explained 1.3 to 34.1% of the phenotypic variance. The major genomic region for AfRGM resistance had a LOD score and R2 of 60.0 and 34.1% respectively, and mapped at 111 cM on chromosome 4 (qAfrGM4) in the ITA306xTOS14519 population. The meta-analysis reduced the number of QTLs from 28 to 17 mQTLs, each explaining 1.3 to 24.5% of phenotypic variance, and narrowed the confidence intervals by 2.2 cM. There was only one minor effect mQTL on chromosome 1 that was common in the TOS14519 and TOG7106 genetic backgrounds; all other mQTLs were background specific. We are currently fine-mapping and validating the major effect genomic region on chromosome 4 (qAfRGM4). This is the first report in mapping the genomic regions associated with the AfRGM resistance, and will be highly useful for rice breeders.

/pdf/qtl-mapping-in-three-rice-populations-uncovers-major-genomic-3cfrhh64f8.pdf

QTL Mapping in Three Rice Populations Uncovers Major Genomic Regions Associated with African Rice Gall Midge Resistance.

The African rice gall midge, Orseolia oryzivora Harris and Gagne (Diptera: Cecidomyiidae), is an important pest of rice, Oryza sativa, in Burkina Faso as well as other countries in West and East Africa. In spite of its importance, little is known regarding the relationship between gall midge populations and grain yield losses. To determine yield losses the gall midge was reared in cages and adult midges were placed on caged plants of the rice variety ITA 123 at different population levels. The seven treatments consisted of different numbers of insects infested on the plants; 0 insect pairs (non‐infested check), and 1, 5, 10, 15, 20 or 25 midge pairs/cage. The loss in yield in relation to the non‐infested control was highly positively correlated (R2 = 0.81) with the percentage of gall midge damaged tillers. The infestation by the insect on the plants resulted in the compensatory production of tillers which developed in response to the gall midge damage but the compensation was not sufficient to ma...

/pdf/estimation-of-rice-yield-losses-due-to-the-african-rice-gall-10dmbnviao.pdf

Estimation of rice yield losses due to the African rice gall midge, Orseolia oryzivora Harris and Gagne

Populations of larvae and pupae of the African rice gall midge, Orseolia oryzivora Harris & Gagne (Diptera: Cecidomyiidae), and two parasitoids, Platygaster diplosisae Risbec and Aprostocetus procerae (Risbec)[= Tetrastichus pachy diplosisae Risbec], were recorded in replicated experiments on farmers' fields at Karfiguela, Burkina Faso in the 1992 wet season and the 1993 dry season. In each season, four plantings were made at 14-day intervals and samples taken at weekly intervals for 10 weeks. Gall midge populations in the wet season developed through three distinct phases: an initial slow increase, followed by a period of rapid increase coinciding with maximum tillering, and then a final decline. On average, the highest midge populations and highest levels of parasitism developed in the later plantings. During the dry season midge infestations were low and no parasites were detected.

Population Dynamics, Host Plant Damage and Parasitism Associated with the African Rice Gall Midge in Southern Burkina Faso

Lepidopteran stemborers (Chilo zacconius Bleszynski, Chilo diffusilineus de Joannis and Maliarpha separatella Ragonot) and diopsid flies (Diopsis spp.) are economically significant insect pests of rice in Burkina Faso. The objective of this study was to monitor damage trends and the pre-imaginal populations of these insects on two host plants, cultivated (Oryza sativa L.) and wild rice (Oryza longistaminata Chev and Roehr). The study was conducted over four consecutive rice crop seasons from 1999 to 2001 in three irrigated rice-growing locations in western Burkina Faso. Sampling of cultivated rice was conducted monthly in 1 m quadrates in 100 randomly selected farmers’ fields. Data on wild rice were collected monthly from each of the three locations using 500 tillers that were plucked at random and dissected. Results showed that in the absence of a rice crop lepidopteran stemborers and diopsid flies are able to survive on O. longistaminata, which can host the pre-imaginal populations of these insects throughout the year. Damage caused on cultivated rice varied across farmers’ fields, seasons and phenological stages of the plants. With 8% the highest average extent of ‘whiteheads’ was recorded during the dry season. These results are important elements in the design of a sustainable management strategy for these insect pests.

Seasonal abundance of lepidopteran stemborers and diopsid flies in irrigated fields of cultivated (Oryza sativa) and wild rice (Oryza longistaminata) in western Burkina Faso.

Aims: The study aimed at determining the periods of high pest population of the mango tree mealybug Rastrococcus invadens Williams with respect to biotic and abiotic factors. Study Design: Semiweekly observations were performed on the mango trees with a view of assessing the density of alive, dead or parasitized R. invadens. Original Research Article Nebie et al.; AJEA, 11(6): 1-11, 2016; Article no.AJEA.24819 2 Place and Duration of the Study: This study was conducted in Western Burkina Faso from May 2014 to April 2015. Methodology: A set of mango trees was selected in each of the following locations: Toussiana, Beregadougou and Orodara. The assessment was conducted on 20 leaves (five leaves per cardinal point) that were picked up from each mango tree at each observation date. The parasitized mealybugs were kept inside pill boxes for two weeks and the emerging parasitoids were collected and kept in alcohol 70°. Data were registered and processed with the Microsoft Excel 2010 and SPSS software. Results: Results showed that R. invadens’ populations were more abundant during the wet season (May-September 2014) than the dry season (November 2014-April 2015) in all study locations. In general, parasitism was low. Some peaks of abundance were recorded in both wet and dry seasons. The evolution of the mortality of the insect pest was the same in all locations and peaks were observed from December 2014 to April 2015. The density of living R. invadens was significantly correlated with temperature and relative humidity. Impact of the parasitism due to Anagyrus mangicola Noyes and Gyranusoidea tebygi Noyes were also assessed and discussed. Conclusion: Periods of R. invadens populations’ abundance are well known in Western Burkina Faso. The parasitoids A. mangicola and G. tebygi are well established. The level of parasitism could be improved by releasing of A. mangicola and G. tebygi to control R. invadens efficiently.

Population Dynamics of the Mango Mealybug Rastrococcus invadens Williams (Homoptera: Pseudococcidea) in Western Burkina Faso

This study was conducted on both station and farmers' fields during the 2010 dry cropping season in the Vallee du Kou rice scheme. We investigated the effect of three rice-transplanting periods (8–10 days) on the population dynamics, damage and parasitism associated with rice stem borers. The on-station experiment was designed as a randomized complete block with three treatments (planting dates) and four replications. Regular intervals of 14 days were observed between subsequent planting dates. Weekly agronomic and entomological assessments were performed from the 21st day after transplanting (DAT) to the 84th DAT. The on-farm experiment covered 1200 ha divided into two zones in which 48 farmers' fields were selected according to the periods of rice transplanting (resulting in 16 fields per period). On-station results indicated 10.1% of deadhearts and 7.5% of whiteheads due to stem borers in the first transplanting period, resulting in the lowest yield (2 metric tons/ha). In farmers' fields, the genus Chilo was found to be the most injurious rice stem borer in Vallee du Kou. The highest larval parasitism (38.5%) was recorded in the third treatment. These results provide important data that can be used in the development of an integrated management strategy for rice insect pests in Vallee du Kou.

Effect of transplanting period on the population dynamics, parasitism and damage of lepidopteran rice stem borers in irrigated rice scheme of Vallée du Kou, Burkina Faso

Dona Dakouo

Papers

Estimation of rice yield losses due to the African rice gall midge, Orseolia oryzivora Harris and Gagne

Population Dynamics, Host Plant Damage and Parasitism Associated with the African Rice Gall Midge in Southern Burkina Faso

Seasonal abundance of lepidopteran stemborers and diopsid flies in irrigated fields of cultivated (Oryza sativa) and wild rice (Oryza longistaminata) in western Burkina Faso.

Population Dynamics of the Mango Mealybug Rastrococcus invadens Williams (Homoptera: Pseudococcidea) in Western Burkina Faso

Effect of transplanting period on the population dynamics, parasitism and damage of lepidopteran rice stem borers in irrigated rice scheme of Vallée du Kou, Burkina Faso