Tsafack N, Menozzi P, Brevault T, Soti V, Deconchat M & Ouin A.
Effects of landscape context and agricultural practices on the abundance of cotton bollworm Helicoverpa armigera in cotton fields : A case study in northern Benin. International Journal of Pest Management, 59 (4): 294-302. 2013. http://dx.doi.org/10.1080/09670874.2013.852270 IF=1.09
Abstract
Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a polyphagous pest of global importance, threatening several key crops, including cotton. This study analysed the influence of landscape composition and agricultural practices on (i) the abundance of H. armigera larvae, and (ii) the proportion of infested plants (infestation) in cotton fields in northern Benin. In 2011 and 2012, the abundance of H. armigera was monitored during the rainy period, with weekly observations of 50 cotton plants in 20 fields selected each year. We selected cotton fields based upon the composition of the surrounding landscape (cotton, tomato and maize fields, and areas of natural vegetation) within 500 metres radius buffers. We also recorded agricultural practices, included sowing date, crop rotation, and frequencies of weeding and of treatment with insecticides. In testing for a relationship between the pest problem and landscape and management, we fitted logistic multiple regression models and compared all the possible models using an information-theoretic approach. Cotton fields surrounded by cotton crops were found to have significantly higher infestation rates. Natural vegetation was positively correlated with the level of infestation. This study highlights the importance of considering both landscape variables and agricultural practices to improve strategies management of H. armigera.