TITLE:
Environmental and Management Factors That Influence Commelina Species in Selected Agro-Ecological Zones in Western Kenya
AUTHORS:
Runyambo Irakiza, Andika Darius, Watako Arnold, Mwonga Samuel, Musili Paul, Kirika Paul
KEYWORDS:
Commelina, Canonical Correspondence Analysis (CCA), Environment, Management, Weed Vegetation
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.13 No.6,
June
30,
2022
ABSTRACT: Commelina species are plant resources full of promise as future food and feed that thrive in diverse ecosystems. They are medicinal
plants, leafy vegetables, forage for ruminants, feed for cricket insects, crop protection, and fuel. However, information regarding factors driving Commelina in agro-ecological zones in Western Kenya is lacking. Therefore, we investigated
the diversity of Commelina species, the composition of associated weed species
as well as environmental and management factors affecting their diversity and distribution
based on 22 variables from 12 production sites. In the survey, 115 species belonging
to 30 families were recorded of which 11 Commelina species were identified.
Among Commelina species, Commelina diffusa and Commelina benghalensis var. benghalensis (non-hybrid variant) had higher relative density. Multiple
linear regressions revealed
that the environment (exchangeable sodium
percentage, magnesium, soil pH, and total
nitrogen) and management (agriculture system type) variables exert a stronger effect on the diversity
of Commelina species. Detrended Correspondence Analysis detected different
ecological conditions for Commelina species and the composition of associated weed species. The forward selection
based on Canonical Correspondence Analysis indicated that the distribution of Commelina species responded significantly to soil pH, available phosphorous, total nitrogen, fertility, and crop
spacing. Partitioning variation showed the great importance to the environment than management (10.57% versus 5.97%). The low shared variance (environment × management) was -0.4%, indicating that the two factors
have a more individualistic than interactive nature. However,
the 83.86% that remained unexplained was attributed to stochastic variation
or unmeasured variables. This study suggests that the identified five important
variables affecting the distribution of Commelina species will certainly
contribute to the prioritization of ecological aspects leading to the growth condition of Commelina species.