SOIL PREPARATION

Steel frame

1.5 m

Trapdoor

1.0 m

Galvanised window frame

Wooden side panel

Glass panel

2.5 m

FIGURE 4.2: Root observation chamber with glass panels for studying grapevine root growth in situ (Van Zyl, 1984).

FIGURE 4.3: The quantitative excavation of roots to determine their lateral as well as vertical distribution is time-consuming and labour-intensive (Photo: ARC Infruitec- Nietvoorbij).

50 | ROOT RESPONSE TO SOIL CONDITIONS