Factors Affecting Murdannia Nudiflora Seed Germination.

Doveweed (Murdannia nudiflora (L.) Brenan) is a problematic weed of golf course roughs, fairways, and tees that germinates much later in the growing season than traditional summer annual grassy weeds such as crabgrass (Digitaria spp.) and goosegrass (Eleusine indica (L.) Gaertn.). 

            Previous research demonstrated the optimum temperature for doveweed germination to be 27.8 C with a rapid decline in germination above and below this temperature.  In addition, light was not shown to be necessary for doveweed germination and increasing burial depth of doveweed seeds decreased seedling emergence.

Further understanding of environmental parameters which effect doveweed seed germination and emergence would help to predict potential spread of doveweed into new areas and would be useful in developing effective control measures.  The objectives of this study were to determine the effect of pH, osmotic stress, salt stress, and nitrate concentration on doveweed seed germination and emergence.

            Greenhouse experiments were conducted at Clemson University in Clemson, SC between 2011 and 2013 to evaluate numerous environmental factors for their effect on doveweed germination and emergence.  Experiments were conducted by placing 5 mL of each treatment solution into a 9 cm diameter petri dish containing two sheets of Whatman No. 2 filter paper and 50 evenly spaced doveweed seeds.  Germinated seeds were counted every 2 d for 14 d after experiment initiation.  For each experiment, statistical design was a randomized complete block replicated three times.

More than 47% of doveweed seeds germinated at pH 4 to 8 while germination fell below 40% at pH 9 and 10.  Germination was > 42% between concentrations of 10-40 mM NaCl with germination dropping to < 25% at 160 mM NaCl.  Osmotic stress higher than -0.4 MPa reduced germination to < 35% from ~75% in other treatments.  Nitrate concentration did not effect doveweed germination.