Congo-Kinshasa (1) Instruction and study (1) Testing (1) Adaptation (1) Adventive plants (1) Water (1) Production (Economic theory) (1) Pipe (1) Necessity (Philosophy) (1) Intertropical convergence zone (1) Foreign exchange (1) Food relief (1) Food--Composition (1) Farmers (1) Crop zones (1) Corn (1) Use studies (1) Use studies (1) Management (1) Technique (1) Yields (1) Use (1) Usage (1) Last years (1) Soils (1) Practice (1) Effectiveness (1) Alimentos--Composición (1) Ensayos (Tecnología) (1) Tuberías (1)