Exploratory study of weed density, distribution and soil seed bank composition in a selected abaca (Musa textilis) plantation at Baybay City, Philippines

Abaca (Musa textilis), a major fiber crop in the Philippines, remains vulnerable to yield losses from weed competition and pathogen transmission. This study assessed the density, distribution, and persistence of weeds in abaca plantations in Baybay City, Philippines, with emphasis on their above-ground vegetation (ABV) and soil seed bank (SSB). Weed communities were surveyed using quadrats, while soil samples were analyzed through the seedling emergence method under greenhouse conditions. Phytosociological parameters, diversity indices, and Sørensen’s similarity index were employed to compare ABV and SSB composition. Results showed that broadleaf weeds dominated both ABV (70.1%) and SSB (83.8%), with grasses and sedges contributing minimally. Species diversity was higher in ABV (H′ = 0.73) than SSB (H′ = 0.56), suggesting stronger ecological dominance within the seed bank. Chromolaena odorata was most prevalent above ground, while Ageratum conyzoides dominated the seed bank, indicating a potential future shift in weed pressure. Both species are of concern as they can serve as alternate hosts of Pentalonia nigronervosa, the vector of Abaca bunchy top virus (ABTV), and reservoirs of plant pathogens. These findings highlight the dual role of weeds as competitors and disease reservoirs in abaca systems. Effective management should integrate timely control of broadleaf weeds, soil seed bank depletion strategies, and vector management to protect abaca yield and fiber quality.