USE OF PLANT AND MINERAL POWDERS AS AN ALTERNATIVE FOR THE CONTROL OF FUNGI IN STORED MAIZE GRAIN

Abstract

The efficiency of powders (at 1 %) of vegetal and mineral origin for the control of fungi associated with stored maize (Zea mays L.) grain, was evaluated. Plants were: Gliricidia sepium, Guazuma tomentosa, Gnaphalium inortatum, Melia azedarach, Neurolaena lobata, Pyracantha koidzumii, and Ricinus communis; minerals were: adsorcite, lime, marble, rob, and light teckies, in five tropical locations in México. The control treatments were Malathion 4 % D (in 1 % doses), and absolute control. The samples were processed in the laboratory to prepare disinfected grains (D) and grains without disinfection (ND). Thirty-two species of fungi were identified; the most common were Rhizopus sp., Penicillium sp., Aspergillus spp., and Fusarium spp. There were inconsistencies in the results obtained among locations. The treatments of G. sepium marble, N. lobata, G. tomentosa and R. communis inhibited the development of all colonies of fungi in D and ND grain in relation to all parallel control treatments. G. sepium showed the most fungi inhibition; G. inortatum and P. koidzumii were less effective. The vegetal powders inhibited the development of Aspergillus spp. Besides, Rhizopus sp., Penicillium sp., Aspergillus sp., and Fusarium spp., required different enviromental conditions for their development and showed interspecific antagonism.