Do Wetting Agents Applied Via Irrigation Have Potential for Maintaining Turf Quality Under Reduced Irrigation?.

Wetting agents are commonly used for the remediation of localized dry spot.  In addition to broadcast applications, wetting agent compounds may also be applied through overhead irrigation.  A greenhouse study was conducted in order to investigate if wetting agents applied by overhead irrigation have potential to maintain turf quality at reduced level of irrigation.   This study was arranged as a factorial combination of three irrigation schedules and three wetting agent compounds in addition to an untreated control, with three replications.  The three irrigation schedules tested included fertigation every two weeks with no supplemental irrigation (FNFN), fertigation every two weeks with supplemental irrigation at 2.54 cm each week (FIFI), and fertigation once per month with supplemental irrigation at the same amount described above (FIII).  Irrigation or wetting agent treatments were applied at a rate of 0.6 cm h^-1 to ‘Rembrandt’ tall fescue (Festuca arundinacea Screb.) established in a Mexico silt-loam soil under greenhouse conditions. Wetting agents tested included three compounds hereafter refer to Compound A, B, and C, respectively.  Preliminary results suggest that the irrigation schedule of FNFN did not provide adequate water to sustain tall fescue growth, regardless of wetting agent treatment.  The other irrigation schedules, FIFI and FIII, both resulted in significantly higher turf quality over an 8-week period, compared with FNFN treatment.  Compared with FIII, fertigation twice per month (FIFI) appeared to improve weekly clipping water content by 10%, but did not affect dry clipping biomass.  Compared to the untreated control, two out of three wetting agent compounds showed improved turf quality following FIFI treatment by 15, 8, and 12%, respectively, at 2, 3, or 4 weeks after initial application (WAIA). A similar trend was also found following the FIII irrigation schedule.  This study is ongoing; more details will be discussed.