R wrote:
: I have seen advice here and there about 'pinching out' the growing tip
: of some plants (e.g. tomatoes and peppers) to encourage lots of fruit.

: I assume that 'pinching' out means 'cutting off' and if so,

No it means pinching

: a) how should it be done (e.g. would a pair of scissors do? should it
: be straight or at an angle? does the end have to be treated to prevent
: infection?

using the finger and thumb and the nails. Good question as to why.
not usual treated.

: b) when should it be done? Is it when the first fruit appears?

for tomatos it is usually advised for removing side shoots, and "stopping"
the plant when it gets to 3 or 4 trusses of fruit setting. I think in this
case it discourages new sprouting of side shoots. A clean cut often seems
to encourage new shoots to sprout. In fruit trees you often are advised to
tear out suckers etc, in an effort to take young buds with them no doubt?

: c) what plants other than peppers and tomatoes does this apply to?

Another reason to pinch out the grow point, is to form a more bushy plant.
The main growing point of a plant sends hormones down the stem that
prevents side shoots forming. Take the gorwing point off, and the side
shoots sprout and form a bushy plant, which may give more blooms or fruit,
depending on the plant.