Nematoregulatory Effect in Industrial Banana Plantations of Service Plants, Crotalaria retusa, Cajanus cajan, Brachiaria decumbens and Panicum maximum in Fallow Land in the South Comoé Region of Côte d’Ivoire

Aims: In the context of promoting alternative cropping systems with less chemical inputs, studies on the introduction of service plants to reduce pesticide use are a major research effort. The pest caused by plant parasitic nematodes is a major constraint in banana cultivation. One of the main alternatives to the use of chemical nematicides is the rational use of service plants with nematoregulatory properties in crop rotation.

Study Design: The experiment was carried out following Complete randomized design (CRD) with three replications.

Place and Duration of Study: In industrial banana plantations located in the town of Ayamé, 40 km from the town of Aboisso in the forest area of southeast Côte d’Ivoire, between March to October 2016.

Methodology: Among the candidate species, Crotalaria retusa, cajanus cajanus, Brachiaria decumbens and Panicum maximum were evaluated because of their nematoregulatory ability, promoting better sanitation of banana plots infested with nematodes. The experiment tested the behaviour of four service plant species in the field over a period of 8 months during a banana fallow (Musa spp.) populated by nematodes (Radopholus similis, Pratylenchus coffeae, Helicotylenchus multicinctus and Meloidogyne spp.).

Results: The results obtained showed that all the service plants used had a purifying effect on nematodes except Cajanus cajan. Soil and root analyses of host plants show the nematoregulatory action of Crotalaria retusa, Cajanus cajan, Brachiaria decumbens and Panicum maximum by reducing the number of nematodes after 8 months of fallow. Fallows of poacea are the ones that reduce the most Radopholus similis and Pratylenchus coffeae rates. A reduction in the length of fallow time was also noted.

Conclusion: This research has made it possible to improve the management of banana fallow land. This will ultimately help to define, under Côte d'Ivoire environmental conditions, a permanent living cover in association and/or rotation with the banana tree, in order to sustainably improve banana cultivation.