Staking and trellising are farming practices are carried out to offer mechanical support to crop plants with either twining stems, or crops possessing tropism-growth towards stimuli-characteristics. Where the support is not provided, the stem will creep on the ground. Since the ground is moist most of the time, any pods or fruits formed will rot, while, also predisposing them to pests like cutworms or rodents.
The support given to peas or passion fruits is known as a trellis and the operation,trellising of which for peas according to my own finding at my kitchen garden does not need training. For it specialized leaves known as tendril automatically attach themselves to immediate cylindrical hard surfaces. But the twining stem had to be trained by twisting the tender part of the stem upwards the stack the operation, referred as stacking.