Composition of weed communities in seasonally flooded rice environments in East Africa is determined by altitude

Weeds are major biotic constraints to rice production worldwide. Compared other sub-regions, weed communities of not well described for East Africa and there is limited information on environmental factors affecting the distribution species. This study aimed address these knowledge gaps. Seasonally flooded fields 31 sites in Rwanda, Tanzania, Kenya Uganda, across three altitude classes (Low: <200 m; Medium 200–1,000 High: >1,000 m), were surveyed species using quadrats. Data analyses involved multivariate approaches, non-parametric Kruskal–Wallis tests logistic regressions, followed by calculation ranked abundance Shannon Wiener Index diversity analyses. A total 286 species, belonging 59 families, recorded with 42 previously reported as lowland sub-region. Twenty-four identified abundant altitudes. Weed was higher at medium altitudes compared high low Significant patterns floristic distinction between altitudinal observed, 80% dissimilarity. The dominated Echinochloa colona, Leptochloa squarrosa Sphaeranthus suaveolens, Crassula granvikii, Pycreus lanceolatus Ageratum conyzoides while E. Cyperus difformis esculentus. composition seasonally diverse. Identification a group (24) commonly articulation altitude-specific groups will facilitate development better tailored control programmes.