WEED CONTROL WITH A COVER CROP (NEONOTONIA WIGHTII) IN MANDARIN ORCHARDS IN GUADELOUPE (FWI)
Weed management is an important point of citrus production in Guadeloupe (French West Indies). Orchards are traditionally planted on sloping ground, and the use of herbicides regularly sprayed on the whole farm is the most common practice. Such a practice impacts the environment and the production benefits. Introduction of cover crops on these orchards is an interesting alternative. The very first aim of cover crops is to control weeds, but benefits in terms of erosion and other services are also expected. This study consists in quantifying the effects of cover crop introduction on mandarin orchards (Citrus reticulate Frémont). The cover crop system is designed in order to obtain a perennial association and to limit chemical intervention as much as possible. Over the 3 years course of the study, two different modalities were compared: (i) farmer practice, mandarin orchard with herbicide (Glyphosate) every 2 months, and (ii) mandarin orchard in association with Neonotonia wightii. Despite some difficulties in setting up the system, N. wightii efficiently suppressed weeds after 6 months. No more herbicide was sprayed on the associated plot while the bare ground plot received 5 herbicides a year. Meanwhile, no significant difference in the predawn water potential of the soil has been revealed between N. wightii and bare ground conditions. This indicates that N. wightii use growth does not entail additional water supply. After 3 years of experimentation, no impact on the orchard performance of the field has been observed. Experimentation is still on-going to estimate the transfer of this new technique to the farmer.
Le Bellec, F., Damas, O., Boullenger, G., Vannière , H., Lesueur Jannoyer, M., Tournebize , R. and Ozier Lafontaine, H. (2012). WEED CONTROL WITH A COVER CROP (NEONOTONIA WIGHTII) IN MANDARIN ORCHARDS IN GUADELOUPE (FWI). Acta Hortic. 928, 359-366
weed management, tangerine, herbicides, glyphosate