Enhancement of ammonium and potassium root influxes by the application of marine bioactive substances positively affects Vitis vinifera plant growth

The enhancing effect of three marine bioactive substances (MBS) - EXT1116, NA9158 and 251104 - on the absorption of ammonium and potassium by the root system and the growth of potted grapevine (Vitis vinifera L.) plants is reported. Root ion influxes were determined in vivo by the non-invasive vibrating probe technique. Treatment with MBS generally enhanced nutrient absorption only in the root region between 0.8 and 1.7 mm from the root apex. Among the three substances tested, EXT1116 was the most effective in terms of enhancing the absorption of both ions, with significantly higher values than those of the other two substances and the control. NA9158 and 251104 were more effective in improving ammonium absorption than potassium absorption, while NA9158 was the most effective MBS in enhancing both biomorphometric parameters (shoot length, number of leaves, visual assessment of root system) and dry weight. Based on these results, we suggest that a combination of NA9158 and EXT1116 may be useful in enhancing plant growth by combining the capacity of NA9158 to increase root biomass and that of EXT1116 to enhance mineral absorption.