GROWTH-RESPONSE OF PEA AND SUMMER TURNIP RAPE TO FOLIAR APPLICATION OF GLYCINEBETAINE

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 (Zen mays L. ), especially during the recovery period. The aims of this study were to determine the effect of foliar application of glycinebetaine on bio mass accumulation and photosynthetic capacity of turnip rape (Brassica rapa L. ssp. oleifera) and pea (Pisum sativum L.). Experiments were c arried 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 cont ent, and nitrogen uptake were also measured for pea. In the experiment in the greenhouse, glycinebetaine application increased relative grow th rate of both crops, especially when drought-stressed and when recov ering from drought. Application of 0.20 M glycinebetaine increased RGR of pea, recovering from drought, by 13% compared with untreated plant s, while the RGR of the drought-stressed pea increased by 45%, measure d 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 experim ent. The RGR of drought-stressed turnip rape treated with 0.05 M glyci nebetaine application was 10% higher than that of untreated drought-st ressed plants, being 6% in plants treated before recovery, and 17% und er adequate watering. Glycinebetaine application also increased the RG R of both crops in held experiments. However, no clear effects of foli ar application of glycinebetaine on duration of different development phases and emergence of floral organs were recorded in the held.