The plant needs air and light
If a plant is not in the light, it does not grow well.
Light
does not come through the leaves of a dense mango tree, and almost nothing grows
under it.
Grass needs light to grow.
Plants get most good from air and light:
· if you pull out weeds;
· if you prune trees such as
coffee, cocoa.
· if you grow crops on fairly
high ridges, as with groundnuts, cotton, salad plants.
· if you make stems climb on
sticks or branches, for instance, cowpeas, tomatoes, yams.

Weeds and cotton
With good air circulation, there is less disease.
Well
ventilated plants resist disease better.

Figure