Abstract: Aim: To quantify current and predict future distribution of the citrus greening pathogens “Candidatus Liberibacter asiaticus” (Las) in Africa and “Candidatus Liberibacter africanus” (Laf) globally. Location: Africa. Methods: Three species distribution models (MaxEnt, BIOCLIM and Boosted Regression Trees) were used to predict the current and future potential distribution of Las in Africa, and the potential global distribution of Laf, using long-term bioclimatic variables. Tw...
Abstract: Intra- and interspecific interactions within communities of species that utilize the same resources are characterized by competition or facilitation. The noctuid stemborers, Busseola fusca and Sesamia calamistis, and the crambid stemborer, Chilo partellus were the most important pests of maize in sub-Saharan Africa before the recent “invasion” of fall armyworm (FAW), Spodoptera frugiperda, which currently seriously limits maize yields in Africa. This new pest is interacting wit...
Abstract: Maize lethal necrosis disease occur in major growing regions of Kenya, causing losses of up to 100% estimated at 50 million US$ in 2014/15. The study was undertaken to evaluate the efficiency of thrips and aphids in transmission of maize lethal necrosis viruses. Maize seedlings were inoculated with adults and nymphs of Western flower thrip (Franklinella occidentalis), corn leaf aphids (Rhapolosiphum maidis) and Russian wheat aphid (Diuraphis noxia) carrying maize lethal necrosis vi...
Abstract: The fall armyworm (FAW) has recently invaded and become an important pest of maizein Africa causing yield losses reaching up to a third of maize annual production. The present studyevaluated different aspects of resistance of six maize cultivars, cropped by farmers in Kenya, toFAW larvae feeding under laboratory and field conditions. We assessed the arrestment and feedingof FAW neonate larvae in no-choice and choice experiments, development of larvae-pupae, foodassimilation under l...
Abstract: Enset (Ensete ventricosum), is a perennial herbaceous plant belonging to the family Musaceae, along with banana and plantain. Despite wild populations occurring in eastern, central and southern Africa, it is only in Ethiopia that the crop has been domesticated, where it is culturally and agriculturally symbolic as a food security crop. Although an under-researched orphan crop, enset serves as a staple food for about 20% of the Ethiopian population, comprising more than 20 million p...
Abstract: Sweetpotato potyviruses [Sweet potato feathery mottle virus (SPFMV), Sweet potato virus G (SPVG) and Sweet potato virus 2 (SPV2)] commonly infect sweetpotato and weedy morning glories in the USA. These viruses are transmitted in a non-persistent manner by various aphid species and cause up to 15% yield loss. Sweetpotato is vegetatively propagated, and in the USA growers are supplied with virus tested propagation material to minimize impact of viruses. However the rapid re-infection...