Vegetational Responses Following Control of Sand Shinnery Oak with Tebuthiuron

Abstract

Tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thia-diazol-2-yl]-N,N′-dimethylurea} pellets were applied aerially in April 1979 at rates of 0.5 and 1.0 kg ai./ha to rangelands supporting a uniform stand of sand shinnery oak (Quercus havardii Rydb.) near Andrews, Texas. Tebuthiuron pellets were applied at 1.1 kg ai/ha to a second location near Jayton, Texas, in March 1980. Sand shinnery oak was significantly reduced (P is lesser than or equal to 0.05) in treated plots at both locations. Yields of annual and perennial grasses were significantly greater (P is lesser than or equal to 0.05) and those of forbs significantly less (P is less than or equal to 0.05) on tebuthiuron-treated plots at Andrews. Untreated plots at Andrews had more bare soil than those treated with tebuthiuron after 18 and 30 months. Grass yields at the Jayton site were greater, although no significant (P is less than or equal to 0.05) differences occurred with forb yields.