Physico-chemical Properties of Soil and Petiole Length of Five Accessions of Vigna subterranea (L). Verdc Grown under Different Environmental Conditions
I. F. Effiong
Department of Plant Sciences, Akwa Ibom State University Ikot Akpaden, Mkpat Enin Local Government Area, Akwa Ibom State, Nigeria.
S. M. Sam
Department of Plant Sciences, Akwa Ibom State University Ikot Akpaden, Mkpat Enin Local Government Area, Akwa Ibom State, Nigeria.
J. E. Okon
Department of Plant Sciences, Akwa Ibom State University Ikot Akpaden, Mkpat Enin Local Government Area, Akwa Ibom State, Nigeria.
U. F. Ufot *
Department of Biochemistry, Akwa Ibom State University Ikot Akpaden, Mkpat Enin Local Government Area, Akwa Ibom State, Nigeria.
O. G. Okon
Department of Plant Sciences, Akwa Ibom State University Ikot Akpaden, Mkpat Enin Local Government Area, Akwa Ibom State, Nigeria.
S. C. Efiong
Department of Biological Sciences, Akwa Ibom State Polytechnic, Ikot Osurua, Ikot Ekpene Local Government Area, Akwa Ibom State, Nigeria.
I. J. Udo
Department of Biological Sciences, Akwa Ibom State Polytechnic, Ikot Osurua, Ikot Ekpene Local Government Area, Akwa Ibom State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Bambara groundnut (Vigna subterranea (L.) Verdc.) is an underexploited, drought-tolerant legume with considerable nutritional and agricultural importance, particularly in semi-arid regions. This study investigated the effects of drought stress, arbuscular mycorrhizal fungi (AMF), Calopogonium mucunoides, and their combined application on germination and petiole length of five V. subterranea accessions (TVSU1–TVSU5). The study was carried out using a randomised block design with three replicates. Plants were grown in sandy-loam soil characterised by moderate acidity (pH 5.30), low water-holding capacity (11.44 %), and relatively low fertility. Petiole length was measured weekly for 13 weeks, while germination was assessed under well-watered and drought conditions. Drought stress significantly affected germination and petiole development, with responses varying among accessions. Arbuscular mycorrhizal fungi (AMF) and C. mucunoides individually improved vegetative growth under drought, while their combined application produced the most pronounced beneficial effects. Under the combined treatment, TVSU4 and TVSU5 exhibited the greatest petiole elongation, reaching 21.86 cm at 13 weeks after planting, whereas TVSU2 showed limited responsiveness. C. mucunoides alone also promoted sustained petiole growth, with TVSU5 recording the highest value (23.43 cm). The combined treatment substantially improved drought-affected germination, approaching the well-watered control. These findings demonstrate significant accession-dependent variation in drought response and indicate that integrating Arbuscular mycorrhizal fungi (AMF) and C. mucunoides can enhance establishment and vegetative growth of Bambara groundnut under water-limited conditions. The approach offers potential as a sustainable strategy for improving drought resilience in Bambara groundnut production.
Keywords: Bambara groundnut, Vigna subterranea, drought stress, arbuscular mycorrhizal fungi, Calopogonium mucunoides, Petiole length, Drought tolerance