It has been reported that foliar application of glycinebetaine reduces the effect of abiotic stresses on crops, including tobacco (Nicotiana tabacum L.), soybean [Glycine max (L.) Merr.], and maize (Zea mays L.), especially during the recovery period. The aims of this study were to determine the effect of foliar application of glycinebetaine on biomass accumulation and photosynthetic capacity of turnip rape (Brassica rapa L. ssp. oleifera) and pea (Pisum sativum L.). Experiments were carried out in a greenhouse and in the field, and records were taken on differentiation and emergence of floral organs. Biomass accumulation, relative growth rate (RGR), specific leaf area, leaf chlorophyll content, and nitrogen uptake were also measured for pea. In the experiment in the greenhouse, glycinebetaine application increased relative growth rate of both crops, especially when drought‐stressed and when recovering from drought. Application of 0.20 M glycinebetaine increased RGR of pea, recovering from drought, by 13% compared with untreated plants, while the RGR of the drought‐stressed pea increased by 45%, measured 14 days after glycinebetaine application. However, the difference in effect between treatments diminished one week later. The response of turnip rape was less marked than that of pea in the greenhouse experiment. The RGR of drought‐stressed turnip rape treated with 0.05 M glycinebetaine application was 10% higher than that of untreated drought‐stressed plants, being 6% in plants treated before recovery, and 17% under adequate watering. Glycinebetaine application also increased the RGR of both crops in field experiments. However, no clear effects of foliar application of glycinebetaine on duration of different development phases and emergence of floral organs were recorded in the field.