Concentration and mode-dependent effects of aqueous shoot extract of Euphorbia graminea (grassleaf spurge) on growth performance of Solanum lycopersicum L. var. Roman VF (tomato)

Title : Concentration and mode-dependent effects of aqueous shoot extract of Euphorbia graminea (grassleaf spurge) on growth performance of Solanum lycopersicum L. var. Roman VF (tomato)

Abstract:

Euphorbia graminea, a widely distributed weed, is known to accumulate diverse bioactive secondary metabolites. However, its potential allelopathic or stimulatory effects on crop species remain unexplored. This study investigated the effects of application mode (foliar vs. soil) and concentration of aqueous shoot extract of E. graminea on the vegetative growth of tomato (Solanum lycopersicum). Fresh shoots of E. graminea were collected at the vegetative stage. Aqueous extracts were prepared by blending 30, 60, or 90 g of fresh shoot material with distilled water (1:10 w/v), allowing maceration for 24 h, and filtering. The resulting extracts were applied to tomato plants via foliar spray or soil drench, with distilled water serving as the control. Growth parameters including shoot height, root length, number of branches, number of leaves, fresh weight, dry weight, net assimilation rate (NAR), and relative growth rate (RGR), were measured at harvest. Extract application significantly influenced tomato growth in a concentration- and modedependent manner. Foliar application of the 90 g extract concentration resulted in the greatest shoot height (101.82±2.50), branch number (14.67±0.67), and root length (16.95 ± 3.65). In contrast, soil application of the 30 g concentration maximized leaf number (102.00±16.23), NAR (0.020 ± 0.004), and RGR (0.220 ± 0.047), while soil application of the 60 g concentration produced the highest fresh biomass (34.01 ± 14.77). No single treatment uniformly enhanced all parameters, suggesting differential responsiveness of growth processes to extract composition and delivery route. In conclusion, aqueous shoot extract of E. graminea exhibits growth-promoting effects on tomato under controlled conditions, with optimal responses dependent on both concentration and mode of application. These findings highlight the potential of this underutilized weed as a source of plant biostimulants. Further studies are recommended to identify the active compounds and elucidate their mechanisms of action, as well as to validate these effects under field conditions. 

Biography:

Ejeoghene Rita Ogbimi is a Plant Physiologist and faculty member at Obafemi Awolowo University, Nigeria. She obtained her B.Sc., M.Sc., and Ph.D. degrees in Botany, with her doctoral degree awarded in 2018. She is a member of the Botanical Society of Nigeria, Botanical Society of America, Nigerian Conservation Foundation, and the Organization for Women in Science for the Developing World (OWSD). Her earlier research focused on the mass propagation of economically important crops and tree species using tissue culture techniques. She has also explored the use of organic fertilizers, particularly extracts from underutilized plants, as eco-friendly alternatives to inorganic fertilizers for sustainable and green agriculture. Driven by a passion to address global challenges such as food security, undernourishment, and climate change, her research interests have evolved into emerging areas of plant biotechnology. These include genome editing using CRISPR-Cas9 technology, as well as metagenomics and transcriptomics in relation to organic foods and sustainable agriculture. Through these advanced approaches, she aims to develop climate-resilient and nutritionally enhanced crops capable of meeting the demands of a changing environment. Her work incorporates cutting-edge genomic and molecular techniques such as CRISPR RNP, whole genome sequencing (WGS) to study rhizosphere microbiome interactions, and transcriptomic analyses to understand molecular mechanisms in organic crop systems. In addition to her research, she is deeply committed to academic mentorship and education. She strives to inspire young scientists, particularly in Nigeria, to engage in plant-based omics research and gene editing—fields that remain underexplored in her region. She actively promotes this through interactive teaching, outreach programs, and mentorship initiatives. Through her work, she seeks to contribute to innovative solutions for global food security while inspiring the next generation of African scientists to appreciate the complexity and potential of plant biology.