Comparison of the elemental composition of sweetpotato grown in a bioreactor effluent and modified half Hoagland solution

Controlled environment chamber experiments were conducted with 'TU-82-155' and 'Georgia Jet' sweetpotato [Ipomoea batatas (L,)], grown in either modif ied half Hoagland (MHH) nutrient solution (control treatment) or in a nutri ent medium composed of 20% effluent from an aerobic bioreactor (Filtrate Tr eatment). Plants were grown for 120 days with a day/night cycle of 14 h at 28 degrees C and 10 h at 22 degrees C. The filtrate used in this study was filtered (0.2 mu m) effluent from the bacterial degradation of residual bio mass from hydroponic culture of sweetpotato. Plant tissue analysis showed d ifferences in elemental composition between plants grown in control and fil trate-amended crop nutrient media. Control plants for both 'Georgia Jet' an d 'TU-82-155' were high in K (4736 +/- 167 and 3693 +/- 202 mg 100 g(-1) pl ant dry weight, respectively), The filtrate-treated plants were higher in F e (3.9 +/- 0.8 mg 100 g(-1) dry weight), and lower in most macronutrients, for 'TU-82-155', Generally, filtrate incorporation in the crop nutrient med ium resulted in reduced levels of the selected elements (Ca, Mg, K, Zn, Fe, and total Kjeldahl N) in 'TU-82-155'. For 'Georgia Jet', although nutrient s levels were also reduced, when filtrate was added to the nutrient solutio n, the difference was, generally, not significant.