New subdivision of cotton production area of Côte d’Ivoire based on the infestation of main arthropod pests

Abstract

Variations in populations of arthropod pests, under the influence of climate change, compromise the effectiveness of the cotton phytosanitary protection strategy in Côte d'Ivoire. This study aims to establish a new classification of cotton production areas, on the basis of predominant pests. A monitoring was therefore carried out from 2016 to 2019 in 400 farmers' fields. In these fields, surveys were conducted weekly, from the 30th to the 122nd day after emergence. Data analysis, through Principal Component Analysis, identified four groups of localities. The first group includes the northeastern localities (4°W to 5°W: 8°N to 10.5°N) such as Kong, Ouangolodougou, Sordi, Tiékpè, Kaouara. This area is characterized by high infestations of most pests (jassid, white flies, exocarpic lepidoptera, endocarpic lepidoptera, phyllophagous lepidoptera and mites). The second group is intermediate between northeast and central (5.5°W to 6.2°W: 8.3°N to 10.5°N). This area is characterized by infestations of jassid, white flies and exocarpic lepidoptera (H. armigera and D. watersi). It remains less infested by endocarpic lepidoptera (T. leucotreta and P. gossypiella). The third area is located in the South (4.5°W to 8.5°W: 6°N to 8.5°N). It is essentially infested by endocarpic lepidoptera T. leucotreta and P. gossypiella. Jassid and whitefly infestations are less important in this part, compared to the northern part. The fourth and last area extends from the center to the west (6°W to 8°W: 8°N to 10.5°N). Pest infestations are lower in this area compared to other areas.