The work of certain soils, carried out in bad conditions, leads to the constitution of a plow base. This, located at the bottom of the plow, constitutes an area that is difficult to cross for water and roots. Placed in such a context, the root system of tomato plants can present a particular very superficial configuration (figure 1). In addition, this waterproof sole, during excess irrigation or rainfall, can induce root asphyxia at the origin of the browning of a more or less important proportion of roots and a more limited growth of the plants accompanied by yellowing, and sometimes dryness. Similar symptoms can be observed on young plants that have been left in pots for too long and whose root system has a particular configuration that growers call a “bun”.