SUMMARYThe effects of waterlogging the soil for up to 5 days on the growth of peas at different stages of development were investigated in glasshouse and outdoor experiments. During waterlogging the oxygen content of the soil declined to less than 2% within 2–3 days. Subsequently, leaf senescence was hastened, stem growth rate was slowed and yield was decreased. The effects on yield were mainly attributable to the development of fewer nodes and fewer pods. Waterlogging for 24 h or more just before flowering restricted growth and yield. The effects of waterlogging at earlier and later stages were less marked. Waterlogging at any period after flower buds were visible prevented further increase in root dry weight.