Viruses pose a great threat to agriculture. An effective method for controlling the menace is raising plantlets by in vitro propagation in expensive greenhouses which require artificial lighting.

Now, scientists at the Institute of Plant Research and Biotechnology (IPRB) in Cuba, have invent- ed a method that does away with all this (Ceres 156, Vo127, No 61). By applying solar energy to all theIstages of propagation in 'biofacto- ries', the plants are nurtured under natural sunlight. This also shortens the process as the 'lab phase' and the 'nursery phase' are combined.