Phytosanitary Situation of <i>Maize streak virus</i>in the Main Maize Production Zones of Cameroon

Maize streak caused by the Maize streak virus (MSV, genus Mastrevirus) is transmitted by Cicadulina spp., and is responsible for considerable maize yield losses in all maize production zones in Africa, including Cameroon. A survey was conducted in 3 agro-ecological zones (AEZ) of Cameroon (Sudano-Sahelian: zone I, Western Highlands: zone III and Bimodal Rainforest: zone V) between November 2017 and November 2019 to determine the status of streak disease in maize farms. The incidence and severity were determined in 90 maize fields, 30 fields per AEZ;the effect of lightning on the disease was also assessed using 15 fields under shade and 15 opened fields per AEZ. The highest streak disease incidence (60%) was found in AEZ I, whereas the lowest incidence was 10% in AEZV. The highest disease incidence and severity (80% and 4.5 respectively) were observed in maize fields under shade as compared to open fields (70% and 4.5 respectively). The phylogenetic analysis of MSV sequences from symptomatic plants indicated it as MSV-A strain identical to be previously reported to determine the virus diversity in relation to the other characterization isolates. This information is important for the development of control strategies to limit yield losses due to MSV.

Inhibitory Activities of Sole Cow Urine and Combined Cow Dung/Cow Urine against the Blight Disease of Ribwort (<i>Plantago lanceolata</i>) at the Cistercian Monastery in Mbengwi, Cameroon

Ribwort (Plantago lanceolata) is a small glabrous to pubescent perennial plant that is native to Europe, America, North Africa and Asia. Nowadays, it is cultivated in many countries across the globe, including Cameroon due to its extensive use in livestock and medicine. Unfortunately in Cameroon, however, the plant has been highly infested by blight, reducing its yield and medicinal value. To reduce blight infestation of ribwort and improve plant yields, we aimed to compare the efficacy of sole cow urine and combine cow dung/cow urine to inhibit blight disease caused by Phyllosticta ophiopogonis on ribwort. At the Cistercian Monastery in Mbengwi, Momo Division, Cameroon, we used a Randomized Complete Block Design (RCBD) with 3 Blocks consisting of two treatments (cow dung mixed with cow urine (combine cow dung/urine) and sole cow urine) and one control. After spraying the different blocks of ribworts plants with combined cow dung/urine and sole cow urine at a dosage of 3% concentration, we found an incidence of blight disease of 32.8% and 35.0% on ribworts sprayed with combined cow dung/urine and sole cow urine, respectively, compared to 67.8% in the control. This implies that a mixture of cow dung/cow urine reduces the incidence of blight disease significantly. Furthermore, our pathogenicity test showed that Phyllosticta ophiopogonis (fungus) was responsible for the blight disease. Therefore, to increase ribwort growth, improve adaption and reduce Phyllosticta ophiopogonis fungal infestation in Cameroon, we recommend that the plant should be sprayed with a mixture of cow dung and cow urine at 3% concentration.