Modelling pest dynamics of new crop cultivars: The FB920 banana with the Helicotylenchus multicinctus–Radopholus similis nematode complex in Martinique P. Tixier a, * , F. Salmon b , C. Chabrier a , P. Que ´ ne ´ herve ´ c a CIRAD, UPR 26, PRAM - BP 214 - 97285 Lamentin Cedex 2 - Martinique, French West Indies, France b CIRAD, UPR 75, PRAM - BP 214 - 97285 Lamentin Cedex 2 - Martinique, French West Indies, France c IRD, UMR RPB, PRAM - BP 214 - 97285 Lamentin Cedex 2 - Martinique, French West Indies, France article info Article history: Received 22 October 2007 Received in revised form 9 June 2008 Accepted 11 June 2008 Keywords: Population model Banana hybrids Musa SIMBA Martinique abstract The synthetic banana hybrid FB920 (Musa spp., AAA group) has been designed to be resistant to Sigatoka and Black Leaf Streak Diseases, caused respectively by Mycosphaerella musicola and Mycosphaerella fijiensis. In addition to these features, the hybrids seem less susceptible to plant-parasitic nematodes, especially the burrowing nematodes (Radopholus similis) and the lesion nematode (Pratylenchus coffeae) than classic Cavendish cultivars, such as Williams, Grande Naine, or Poyo. This genetic modification drastically reduces pesticide use. Herein, we used the SIMBA model (a model to simulate phenology, growth, and plant-parasitic nematode/banana interactions) to examine the population dynamics of plant-parasitic nematodes in cropping systems with hybrid FB920 in various initial conditions. Results from field observations and simulations show that in the long-term, the spiral nematodes (Heli- cotylenchus multicinctus) can overtake the burrowing nematodes and that nematode populations are smaller than in Cavendish banana fields. This reduced capacity of FB920 to support multiplication of R. similis reduces the use of pesticides and thus re-creates favourable conditions for fauna, thereby increasing the global sustainability and resilience of banana agro-ecosystems. Ó 2008 Elsevier Ltd. All rights reserved. 1. Introduction The early assessment of pest dynamics for a new cultivar (cv) is a major issue for plant-breeders and agronomists. Because of time and financial constraints, and the large number of hybrids to be tested, there are generally few measures on each cv and few studies on the long-term trends of the genotypes. Shorter et al. (1991) and Barbottin et al. (2006) proposed crop models to help breeders identify the best cvs for various practices, mostly on the basis of yield. Pest dynamics models initially developed to predict and manage pest populations can then be used to ex-ante evaluate new cvs in the long-term. The model should also be able to answer the main questions of the growers. So well-tested simulation approaches may offer a time- and cost-effective alternative to experiments for cv evaluation and management. Nevertheless, this evaluation step is rarely performed (Welch et al., 2002). Plant-parasitic nematodes limit banana production for the export market, in which the Cavendish cv prevails (Musa spp., AAA group, cv. Cavendish). Export bananas cover nearly one million hectare worldwide (FAOSTAT, 2007) and yield improvement in the absence of nematodes varies from 15 to 275% (Gowen and Que ´- ne ´ herve ´, 1990). The burrowing nematode Radopholus similis (Rs) which generates extensive root lesions and results in toppling over of the plants, is considered the most detrimental pathogen of banana roots. The spiral nematode Helicotylenchus multicinctus (Hm) is widely distributed in all banana production areas; root lesions are much less damaging as they remain mostly superficial and thus disturb plant nutrition less and never cause toppling over (Que ´ne ´ herve ´, 2008). Among banana cvs, tolerance against parasitic nematodes varies widely and the capacity to multiply species of nematodes varies from one cv to another (Que ´ ne ´ herve ´ et al., 2006). The variability of tolerance against plant-parasitic nematodes is partly explained by the level of condensed tannins in banana roots (Collingborn et al., 2000). New synthetic hybrids are mostly designed for their properties of high yield and pest resistance. Here, we study the new synthetic banana hybrid FB920 (Musa spp., AAA group), which is resistant to Mycosphaerella leaf spot diseases of bananas caused by Mycos- phaerella musicola (Sigatoka Disease) and M. fijiensis (Black Leaf Streak Disease). Such triploids are issued from conventional breeding techniques (Jenny et al., 2003), including diploid resistant genitors previously doubled with colchicine (Bakry et al., 2007). * Corresponding author. Tel.: þ596 (0) 596 42 30 17; fax: þ596 (0) 596 42 30 01. E-mail address: tixier@cirad.fr (P. Tixier). Contents lists available at ScienceDirect Crop Protection journal homepage: www.elsevier.com/locate/cropro 0261-2194/$ – see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.cropro.2008.06.004 Crop Protection 27 (2008) 1427–1431