A key for stages of development of the pea (Pisum sativum)

SUMMARY A key is presented to described stages of development of the pea ( Pisum sativum ). The aim was to produce a simple system to aid accuracy in communicating instructions for timing of field operations. The coded description is divided into four principal stages: germination and emergence, vegetative, reproductive and senescence. These are sub‐divided into secondary stages. The practical use of the key is discussed with particular reference to the timing of application of agrochemicals.