Effect of goat grazing on the growth, propagation and survival of a do
ck, Rumex obtusifolius L. was investigated during a period of 3 years
in a permanent pasture divided into 2 parts. Three cows were grazed on
one part (namely, cow-grazing plot) and 3 cows plus 4 goats were graz
ed on the other part (mixed-grazing plot). In both plots, 3 belt trans
ects were set up to determine the degree of defoliation, plant height,
maximum leaf length and the number of bolting stalks of adult docks.
Apart from the transects, typical adults were collected to determine t
he dry weight of seeds in both plots in late July. Five permanent quad
rats were set up to take a census of the seedlings of the dock. The ad
ult docks were defoliated more severely up to August in the mixed-graz
ing plot than in the cow-grazing plot. In the former plot, the leaf le
ngth was shortened to 67%, the plant height was lowered to 26% and the
number of bolting stalks was reduced to 41% of the respective ones in
the latter plot in July. Moreover, the adults formed shorter bolting
stalks in the mixed-grazing plot. This suppression of reproduction of
the dock led to a decrease in the number of seedlings. In the mixed-gr
azing plot, the seedlings emerged at a rate of 18% of that in the cow-
grazing plot in the autumn of the first grazing year and 30% in the sp
ring of the second year. There were few differences between the surviv
orship curves of the dock in the two plots. A low percentage of seedli
ngs survived during one year, although with a slightly higher rate in
the mixed-grazing plot than in the cow-grazing plot. The established i
ndividuals could set numerous seeds in the latter plots. It was conclu
ded that goats controlled Rumex obtusifolius effectively through a pro
cess of defoliation, suppression of the propagation and decline of the
population of the dock. Mixed-grazing could afford both weed control
and improvement of pasture production.