The growth and yield of late-season tomato was studied at Akure, Nigeria, from 1995 to 1998. In each year, treatments were 0 (bare ground) or 12 kg/ha grass mulch applied to tomatoes at densities of 1·9, 2·8, 3·7 and 5·6 plants/m2 in a factorial combination. Increase in plant density and mulching reduced soil temperature at 5 cm depth while only the latter enhanced soil moisture at 10 cm depth throughout tomato growth. The improved soil hydrothermal regime resulted in earlier onset of flowering, 50% flowering date and date of first harvest respectively and shorter fruit harvest duration in tomato grown on either bare ground or at increased plant density.

Although increased plant density reduced shoot dry weight per plant at final harvest, both root length per plant and root dry weight per plant were enhanced. Fruit yield/ha increased as plant density increased although yield of the individual plants and their components were significantly reduced. Because of compensation at higher plant population densities, it is economical to grow late-season tomato at 5·6 plants/m2. Mulching enhanced growth and yield of tomato compared to bare ground and the result emphasizes the need for early and rapid growth of late-season tomato before the onset of terminal drought.