Nitrite Concentration Effects on NO3-N Uptake and Reduction, Growth, and Fruit Yield in Strawberry

Summary

Strawberries (Fragaria xananassa Duch. .Osogrande.) were grown hydroponically with three NO 3 -N concentrations (3.75, 7.5, or 15.0 mM) to determine effects of varying concentration on NO 3 -N uptake and reduction rates, and to relate these processes to growth and fruit yield. Plants were grown for 32 weeks, and NO 3 -N uptake and nitrate reductase (NR) activities in roots and shoots were measured during vegetative and reproductive growth. In general, NO3-N uptake rates increased as NO 3 -N concentration in the hydroponics system increased. Tissue NO 3 -. concentration also increased as external NO 3 -N concentration increased, reflecting the differences in uptake rates. There was no effect of external NO 3 -N concentration on NR activities in leaves or roots during either stage of develop