Impact of different types of green manure on pests and disease incidence and severity as well as growth and yield parameters of maize

The emergence of pests and diseases, including the maize streak virus, leaf blight, the African stem borer, and gray leaf spot, poses a persistent threat to maize production (Zea mays L. cv: DMR-ESR-Yellow) around the world. A field experiment was conducted at the School of Agriculture experimental site, Njala University, Sierra Leone, during a two-year period (2020–2021) to assess the effects of green manure on pest and disease incidence and severity as well as growth and yield parameters of maize. The experiment was laid out in a randomized complete block design (RCBD) with three replications and four treatments: Cal. 3 t.ha(−1), Cal. 6 t.h(−1), Pan. 3 t.h(−1), Pan 6 t.ha(−1) and a control plot amended with 200 kg ha(−1) of N (urea) and NPK 15:15:15 ha(−1) split application. The study showed that gray leaf spot damage was the most severe infection among all treatments. Therefore, the effects of the most severe disease and pest of maize in Sierra Leone can be minimized by applying green manure. Moreover, results reveal that Calopogonium- Pueraria mixture amended plots showed significant performance in the measured growth parameters viz. highest leaf number, large leaf area stem girth, superior plant height, best ear height (64.6–78.5 cm), higher cob yield (1.2–1.4 t.ha(−1)) ear (1.8–2.1 t.ha(−1)) and dry grain yield (0.5–0.7 ha(−1)). Panicum green manure results showed that prompt and adequate application, as well as decomposition of green manures, is imperative for the successful conservation and sustainability of maize farming systems. The findings of this research could improve the efficiency of green manure use in pest, disease, and crop management systems.