Impatiens wallerana `Accent Red' were grown in a peat : perlite : vermiculite (PPV) or bark : peat : perlite (BPP) medium amended with SuperSorb-C (SS) or Soil Moist (SM) hydrophilic polymer and/or AquaGro-G (AG) wetting agent. In PPV or BPP, neither SS nor SM significantly increased shoot dry weight. In PPV, quality ratings were higher for plants grown in nonamended or SS- or SM- amended medium than for plants in AG-amended medium. In BPP, quality ratings were highest for plants grown in nonamended, AG-, or SM + AG-treated medium. Number of days from final irrigation to permanent wilting point (PWP) was greater in AG, SS + AG, or SM + AG treatments in PPV than in control, SS, or SM treatments, due to smaller plants in AG-amended media. In both media, root dry weight was not significantly greater with the use of either hydrophilic polymer or wetting agent. However, in PPV, AG suppressed root growth compared to the control.
Allyson M. Blodgett, David J. Beattie and John W. White
Allyson M. Blodgett, David J. Beattie, John W. White and George C. Elliott
A plantless system using subirrigation was developed to measure water absorption and loss in soilless media amended with hydrophilic polymers, a wetting agent, or combinations of these amendments. Peat-perlite-vermiculite and bark-peat-perlite controls achieved 67% and 52% of container capacity, respectively, after 20 daily irrigation cycles. Maximum water content of amended media was 78% of container capacity. Adding only a hydrophilic polymer did not increase total water content significantly. Adding a wetting agent increased water absorption in both media. However, when hydrophilic polymer and wetting agent were present, the medium absorbed more water than with wetting agent alone. More extractable water was removed from media containing wetting agent. Water loss rate by evaporation was not affected significantly by medium, hydrophilic polymer, wetting agent, or any combination of these variables.