Response of improved Brachiaria (Urochloa) grass cultivars to foliar diseases and their agronomic performances in Rwanda

Abstract

This is the final version of the article that is published ahead of the print and online issue Brachiaria (Urochloa) grass is one of the most important tropical forages distributed in the tropical and subtropical regions of eastern and western hemispheres (Renvoize et al. 1996). Brachiaria grass possess several characteristics of agricultural and environmental significance, such as high biomass yield, nutritious to livestock, drought and shade tolerance, soil fertility improvement, high nutrient use efficiency, mitigation of the climate change adversity and effective bioagents for pests and parasitic weed management (Subbarao et al. 2009;Maass et al. 2015;Khan et al. 2016). The genus Brachiaria consists of approximately 100 species, of which seven perennial species of African origin have been exploited for fodder production, and they have been cultivated in Asia, Australia, the South Pacific, and South America at various scales (Stür et al. 1996;Jank et al. 2014). Brachiaria species are a common and valuable constituent of natural vegetation in East Africa (Boonman 1993), but their use as sown pasture for animal production is very recent in the region (Maass et al. 2015;Njarui et al. 2016). A broad adaptation, excellent animal performances and high biomass yields are among the major factors that promote a wider and rapid adoption of Brachiaria grass across the tropics and subtropics. However, the productivity of Brachiaria grass is affected by different abiotic and biotic factors, including diseases causing high yield losses (Nzioki et al. 2016; Hernandez et al. 2017). Diseases of Brachiaria grass, their symptoms, geographical distribution, and management options have been reviewed by Valerio et al. (1996). These diseases have negative impact on livestock productivity, because they reduce forage yields and quality.Brachiaria grass is one of the preferred forages by livestock keepers in Rwanda and in other East African countries (Mutimura and Everson 2012;Maass et al. 2015). As mentioned earlier, diseases are among the major biotic constraints of Brachiaria grass production, and diseases, such as leaf rust, leaf spot, and leaf blight are reported to cause economic loss (Lenné and Trutman 1994;Miles et al. 1996;Rao et al. 1996;Alvarez et al. 2014;Maass et al. 2015). For instance, leaf rust can cause up to 100% yield loss, reduces leaf crude protein content to between 49 and 53% and subsides availability of other nutrients (Lenné and Trutman 1994). Similarly, leaf blight reduces forage biomass yield by approximately 50% in the tropics (Alvarez et al. 2013). Recent studies have shown widespread distribution of leaf rust, leaf spot, and leaf blight diseases in Kenya and Rwanda (Nzioki et al. 2016;Uzayisenga et al. 2020). Therefore, sustainability of Brachiaria grass production in Africa relies on how well these diseases are managed.Many pastures including Brachiaria grass are considered low-value crops, often cultivated in large acreage and management of diseases using chemical is too costly and

Integrating multiple soil management practices: A system‐wide approach for restoring degraded soil and improvingBrachiariaproductivity

“…and contribution are limited mainly by poor and unsustainable production practices (Pereira et al, 2016;Uzayisenga et al, 2021;Yiberkew et al, 2020).…”

“…Brachiaria is a grass native to SSA with several desirable agricultural and environmental characteristics (Wassie et al., 2018). It is drought‐tolerant, has a high biomass, nutritional value, nutrient use efficiency, carbon sequestration capacity, pest biocontrol efficiency, and improves soil aggregation, water retention, and aeration (Uzayisenga et al., 2021; Wassie et al., 2018). Thus, Brachiaria plays imperative roles in soil productivity improvement and mitigating climate change adversity.…”

“…Thus, Brachiaria plays imperative roles in soil productivity improvement and mitigating climate change adversity. However, its productivity and contribution are limited mainly by poor and unsustainable production practices (Pereira et al., 2016; Uzayisenga et al., 2021; Yiberkew et al., 2020).…”