Prospection de Materiaux Organiques Utilisables en Amendement du Sol pour Controler le Sclerotium Rolfsii Sacc

Organic materials of different types and origins were mixed with soil to a 1 % (W/W) concentration in two artificially contaminated soils (a ferrallitic soil and a vertisol) and incubated in pots in a greenhouse during 15 days in order to control Sclerotium rolfsii on "Contender" Bean (Phaseolus vulgaris L.) seedlings. Those which, compared to the control soils (non amended), decrease significantly the seedling death are except chitine (in the vertisol), plant residues. Some of these residues are effective in the two soils: seeds of Adonidia merrillii, senescent leaves of Artocarpus altilis, Coccolaba uvifera and Tabebuia pallida, dry Delonix regia pods, rachis of Banana inflorescence and dried green leaves of sugarcane. Others are interesting only for one or another soil: senescent leaves of Banana and dried green leaves of Penisetum purpureum for the ferrallytic soil; dry pods and seeds of Albizia lebbeck, skin and pulp of ripe Coffea arabica berries, senescent leaves of Bambusa sp. and Terminalia catappa, and compost made with different grasses for the vertisol. Among other phytopathogenic fungi affecting Bean, Macrophomina phaseolina may be important in the vertisol amended with senescent leaves of A. altilis, T. pallida and T. catappa, or the compost of grasses.