Tech Notes Issue 14

Need aSpring Lift?

Although this issue would bemore timely in early summer,the information is new and mightbe considered in this year’s managementprogram especially for sportsfields. The study reported here wasdone by Pam Sherratt, at The Ohio StateUniversity over the last few years…Note:keep in mind the dates reported reflectseasons in the northern Hemisphere.

Turf managers looking for earlyspring green-up in 2010 might considerapplications of trinexapac-ethyl (PRIMO MAXX).

Trinexapac-ethyl (TE) is a growthregulator that can be applied eitheras a liquid or dispersable granule.TE regulates top growth by ~50%, somowings can be reduced duringspring and fall when the grass isgrowing quickly. Considerable researchwith TE (particularly with golfcourse turf) has shown that besidesgrowth suppression TE provides: (1)wear and stress tolerance, (2) bettercolor and density, (3)extending thelife of painted lines and logos, (4)improved turf peformance in shade,and (5) quicker spring green-up.

Our research at The Ohio State Universityover the last five years suggeststhat TE does not adversely affectwear tolerance, recuperative potentialor over-seeding and soddingpractices with regard to sportsfieldmanagement.

More and more sports turf managersare using TE as a standard part oftheir turf management program.Rates are typically lower than labelrate, applied more frequently. In arecent survey of sports turf managersin the United States, typical rateswere anything from 0.03 to 0.16 mlm-2 every two weeks, depending ongrass species.

One of the main advantages to usingTE is the spring green-up, which isespecially important for early springgames like baseball, soccer and lacrosse.In our studies, applications ofTE on Kentucky bluegrass turf attwo rates - 0.08 and 0.16 ml m-2were madeevery two weeksbetween mid-Mayand mid-September. The last applicationin each year was made onSeptember 19, 2007 and September26, 2008 in Columbus Ohio.

In both 2008 and 2009, spring greenupwas significantly quicker and theturf density and color were significantlyimproved (see pictures takenin April & May 2009).

Sports turf managers that would liketo enhance much quicker springgreen-up should be making applicationsevery two weeks, until mid tothe end September. If fields are notbeing used this fall, the higher ratemight be suggested. If fields are beingused, lower rate would be recommended.There may be a small flushof growth mid-October as the grassgrows out of TE suppression.

As always, read the label carefullybefore application as there are somestipulations. For example, TE shouldnot be applied to drought or stressed  turf.