The effect of planting dates on the incidence and population dynamics of the cassava root scale, Stictococcus vayssierei, in Cameroon

• Published in: International journal of pest management 1999-01, Vol.45 (2), p.125-130
• Main Authors: Ambe, J. T., Ntonifor, N. N., Awah, E. T., Yaninek, J. S.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Cameroon; Cassava; Coccidae; Control; Cultivars; Cultural control; Fundamental and applied biological sciences. Psychology; Manihot esculenta; Phytopathology. Animal pests. Plant and forest protection; Planting Dates; Population Dynamics; Protozoa. Invertebrates; Stictococcus Vayssierei
• ISSN: 0967-0874; 1366-5863
• DOI: 10.1080/096708799227914

A study on the influence of planting dates on the incidence of the cassava root scale, Stictococcus vayssierei, was conducted using an improved and a popular local cassava variety from each of two participating villages in the rain forest of Cameroon. Monthly planting of each variety from April to October of 1995 and S. vayssierei sampling from 1 month after each planting until 12 months after planting was done. S. vayssierei attacked both cassava varieties in each village. The pest usually occurred in clusters or aggregations on the subterranean parts of the plants. The highest root scale densities were ca 75 and 51 individuals per plant during the long dry and rainy seasons, respectively. Generally, higher S. vayssierei densities were recorded during the dry season irrespective of the village. Planting in August- September predisposes the early bulking stages of the crop to high root scale pressures in the dry season which can have serious repercussions on cassava storage root yield. The onset of the main rainy season (April/ May) was the most appropriate period for planting cassava to enable the more susceptible early growth stages of the crop to avoid the period of high root scale infestations. These results highlight the possibility of using cultural practices in managing S. vayssierei .