Effects of Prodiamine on Tall Fescue (Festuca arundinacea) Rooting

Abstract

With the increased development of new tall fescue cultivars used in turf, it is important to understand their individual response to herbicide treatment. The effect of prodiamine on tall fescue root dry weight and root length of selected tall fescue cultivars was studied in the greenhouse in 1.3-m-deep pots of calcined clay. Prodiamine at 0.8 kg ai/ha did not significantly affect either root dry weight or root length. However, the mean root dry weight and maximum root length averaged over all cultivars were significantly reduced at 4 wk after treatment with 1.7 kg/ha. When the prodiamine treatments were repeated in a second experiment, both rates caused a significant reduction in the mean root dry weight and maximum root length but there was no significant difference between prodiamine rates. Single degree of freedom contrasts between the untreated and treated turfs for each cultivar had some differential response in root dry weight. The reduction in root dry weight in the prodiamine treatments was more pronounced in the second study because the turf was less mature. ‘Olympic’ and ‘Rebel’ tall fescue had significantly reduced root dry weight at the 1.7 kg/ha rate in first study; whereas, ‘Amigo,’ Olympic, ‘Sundance,’ and ‘Taurus' tall fescue had significant reduction in root dry weight at both 0.8 and 1.7 kg/ha prodiamine rates. ‘Midnight’ Kentucky bluegrass had significantly reduced root length at both prodiamine rates in the second experiment but in general there was little difference among tall fescue cultivars treated with prodiamine.