Water relations of spruce seedlings sprayed with a surfactant.

This work assesses whether the water relations of Norway spruce (Picea abies Karst) seedlings are affected by repeated treatments with ABS (sodium dodecylbenzensulphonate). Beginning in August 1987 4-yr-old spruce seedlings were sprayed weekly with a 50 g - m3 ABS solution. Two experiments were performed in 1988 and 1989, during which water potential, transpiration rates and stomatal conductance were measured on treated and control plants, which were either wellwatered or exposed to periods of drought of different duration. Net photosynthesis and specific leaf area of needles were also measured. ABS did not alter transpiration or stomatal conductance associated with xylem water potential and had no effect on net photosynthesis and specific leaf area.