Abundance and Partial Harmfulness Index (PHI) of Weeds in Plantain (Musa paradisiaca L., Musaceae) in Mé Region, South-East Côte d'Ivoire

Abstract

Poor weed management can result in additional costs that can be estimated at over 35%. Determining of the most troublesome weeds is becoming an essential part of effective weed control. A study was therefore carried out in the south-east of Côte d'Ivoire, in plantain plantations, to identify abundant weeds and assess their potential for causing damage. Two approaches were used. The first one consisted in carrying out a survey of plantain growers and the second in carrying out floristic surveys in plantain fields. To do this, the degree of infestation and the Partial Harmfulness Index of the major weeds in these works were analysed. Growers have identified 19 weeds that are difficult to control. In terms of weed flora, 152 species divided into 115 genera belonging to 47 families were recorded. The infestation diagram distinguished 20 major weeds, of which Panicum laxum is the most aggressive (FC = 80.28%; ADaverage= 1.55). The Partial Harmfulness Index (PHI) determined five (5) potentially harmful weeds (PHI ≥ 1000). After cross-referencing the two lists of constraining and major weeds (survey and floristic survey), there is floristic homogeneity, with 25 constraining and major weeds in this study. With a view to better weed control in banana cultivation in the Mé region, growers should take into account the most abundant and constraining weeds in order to reduce yield losses.