Fm. Fishel et Ge. Coats, EFFECT OF COMMONLY USED TURFGRASS HERBICIDES ON BERMUDAGRASS (CYNODON-DACTYLON) ROOT-GROWTH, Weed science, 41(4), 1993, pp. 641-647
Experiments were conducted in 1990 and 1991 to determine bioavailabili
ty of PRE herbicides at three soil profile depths and two soil types i
n established common bermudagrass sods. Prodiamine and oryzalin reduce
d 'Tifgreen' bermudagrass root growth in the 5- to 7.5-cm layer of a B
osket very fine sandy loam soil at 2 and 4 wk after treatment in 1991.
These herbicides decreased bermudagrass root weight in both the Boske
t and Marietta sandy clay loam both years in samples taken from the 2.
5- to 5-cm depth layer. In the O- to 2.5-cm soil layer, all herbicides
reduced root weight in 1990. In a bioassay, prodiamine caused decreas
ed Tifgreen bermudagrass root growth at concentrations as low as 4 ppb
by wt in the very fine sandy loam soil, while 8 ppb was necessary in
the sandy clay loam soil. Prodiamine was detected in the very fine san
dy loam at 4 wk after treatment at all depths in 1991 (65, 45, and 39
ppb in the O- to 2.5-, 2.5- to 5-, and 5- to 7.5-cm soil layers, respe
ctively). Oryzalin was also detected at all depths in 1991 when sample
d at 2 and 4 wk after treatment in the very fine sandy loam. Pendimeth
alin was present in concentrations of 38, 39, and 37 ppb in the sandy
clay loam at 2 wk after treatment in the O- to 2.5-, 2.5- to 5-, and t
he 5- to 7.5-cm soil layers, respectively. Pendimethalin was also dete
cted in the very fine sandy loam at 2 wk after treatment at concentrat
ions of 55, 69, and 36 ppb in the O- to 2.5-, 2.5- to 5-, and 5- to 7.
5-cm soil layers, respectively.