<Li> Striking or cuttings </Li> <Li> Twin - scaling </Li> <P> A heated propagator is a horticultural device to maintain a warm and damp environment for seeds and cuttings to grow in . </P> <P> This can be in the form of a clear enclosed bin sitting over a hotpad, or even a portable heater pointed at the bin . The key is to keep the moisture in the clear bin, while keeping lighting over the top of it, usually . </P>

Which of the following is not a human method of plant propagation