Excellence in Research: An investigation of the effects of Nicandra physalodes on the growth and development of weeds

Noxious weeds have been found to negatively impact crop production, which results in reduced yields. Physical management of weeds such as hoeing, and hand-pulling are usually time-consuming. Managing weeds using herbicides can lead to the weeds developing resistance to them. In addition to resistance, the herbicides can contaminate underground water. Thus, there is a need for an environmentally friendly, cost-effective integrated weed management approach. Studies on weed control using secondary compounds from plants are significant in plant productivity, hence, this proposed study will advance knowledge in plant biology and agriculture. The biological control approach to manage Pennisetum clandestinum (Kikuyu grass), Echinochloa crus-galli (barnyard grass), and Lolium multiflorum (Italian ryegrass) can be used. Faculty and students will conduct a detailed study in understanding how Nicandra physalodes affects the growth of weeds while crop growth remains unaffected. The proposed study will enhance research and training opportunities for undergraduate students at a Historically Black University and offer broader participation in STEM for minority students. Students will be mentored, with some aspects of the research used as course-based undergraduate research experience in plant anatomy, plant physiology, and ecology classes. The results from the proposed study will be presented at conferences and published in peer-reviewed journals. Local farmers might also benefit from the outcomes of this research project. According to the United States Department of Agriculture, P. clandestinum (Kikuyu grass) is a federally listed noxious weed that is competitive against legumes. It is a perennial grass whose seeds can lie dormant for a long time. It can also develop from rhizomes, easily colonize the soil surface, and grow fast. E. crus-galli (barnyard grass) is an annual, fast-growing weed competing against rice. L. multiflorum (Italian ryegrass) is an annual or biennial weed that competes with cereal crops. The authors of this proposed project have observed that Nicandra physalodes from the Solanaceae, a plant that contains alkaloids, can be used to manage monocotyledonous grasses. The hypothesis for the proposed study is that alkaloids found in Nicandra physalodes will inhibit the growth and development of P. clandestinum (Kikuyu grass), E. crus-galli (barnyard grass), and L. multiflorum (Italian ryegrass). The investigators, including the faculty and the students, will examine the morphological, observable, development, and growth effects of N. physalodes on the three noxious weeds under different environmental conditions such as changes in temperature and the soil pH. Also, cell division is expected to be affected when the three weeds display growth inhibition. The research team will also investigate any chromosome aberrations expressed when the weeds are growing in the presence of N. physalodes. The proposed study will also include the investigation of the compounds that will be extracted from the N. physalodes, which play an important role in the inhibition of the growth of these three weeds. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.