Compatibility of Rhizobium inoculant and water hyacinth compost formulations in Rosecoco bean and consequences on Aphis fabae and Colletotrichum lindemuthianum infestations

Belowground Influence of Rhizobium Inoculant and Water Hyacinth Composts on Yellow Bean Infested by Aphis fabae and Colletotrichum lindemuthianum under Field Conditions

“…Soils in this region have been classified as dystro-mollic Nitisols (FAO, 1974;Rota et al, 2006). Nutrient composition for the soil was; total phosphorus (18.9 ppm), total nitrogen (0.26 %), organic carbon (2.5 %), potassium (0.41 cmol c kg −1 ), sodium (0.1 cmol c kg ), zinc (1.9 ppm) and iron (0.37 ppm), with acidic pH of 4.2 (Naluyange et al, 2014 …”

“…For example, root colonization by Rhizobium has been found to promote plant resistance to insect pests (Thamer et al, 2011). However, Rhizobium colonization of roots has also been related to an increase in aphid and fungal incidences on leguminous shoots, which has been attributed to improved nutritive suitability of the host plant due to nitrogen fixation (Dean et al, 2009(Dean et al, , 2014Naluyange et al, 2014). Such effects of Rhizobium on legumes are modified by soil fertility amendments (El-Wakeil & El-Sebai, 2009;Dean et al, 2009).…”

“…In the Lake Victoria basin, combined application of water hyacinth compost and commercial Rhizobium inoculant had some positive effects on performance of the commercial Rosecoco bean cultivar, depending on the water hyacinth compost formulation (Naluyange et al, 2014). However, farmers in the Lake Victoria basin, especially in Western Kenya, mostly rely on local bean cultivars obtained from the market, including the yellow bean 'Mugasa' (David & Sperling, 1999;Otsyula et al, 2004).…”

“…Among the strategies, Rhizobium inoculants are being developed to enhance legume production by fixing nitrogen in the Lake Victoria basin (Bala et al, 2011). At the same time, nutrient-rich water hyacinth in the heavily eutrophied lake is being processed into compost, and transferred onto nutrient depleted farmlands for crop production (Naluyange et al, 2014). Removal of water hyacinth from Lake Victoria restores conditions that are favorable for fishing.…”

“…Removal of water hyacinth from Lake Victoria restores conditions that are favorable for fishing. Furthermore, water hyacinth compost contains phosphorus (Gunnarsson & Petersen, 2007;Naluyange et al, 2014), which is necessary for nodulation and nitrogen fixation in Rhizobium-inoculated bean seeds (Ssali & Keya, 1983), through processes such as enhancement of plant growth (Robson et al, 1981), improvement of shoot metabolism (Jakobsen, 1985) and specific roles in nodule initiation, growth and function (Israel, 1987). Such specific roles of phosphorus include ATP synthesis for nodule development and function (Ribet & Drevon, 1996), as well as for signal transduction and cell membrane biosynthesis (Graham & Vance, 2003).…”