Description: Wild mustard is an annual
or winter annual, reproducing by seeds. The roots are shallow,
fibrous, and white in color. The stem is erect, branching,
covered with hairs, and grows to about two feet tall. The
leaves vary considerably in shape from the base to the top.
The lower leaves are lobed, slightly toothed, petioled, hairy
and rounded on the tips. The upper leaves are not lobed or
petioled, smaller, alternate, and broadly lanceolate, coming
to a blunt point. The yellow flowers are 4 petaled, conspicuous,
and in clusters. Flowers appear in May to July and seeds mature
in June to September.
Distribution: Wild mustard is found in Johnson County
in cultivated fields, waste places, hayland, and in roadsides.
What’s The Problem?: Although generally not
a serious weed pest in most of Johnson County, wild mustard
can become problematic in agricultural fields. Wild mustard
can reduce yields of crops such as alfalfa or hay crops, by
competing for light, sunshine, and nutrients.
Management Methods: Tillage and cultivation, along
with mowing, crop rotations, and careful use of herbicides
can provide acceptable levels of wild mustard control. Be
sure to read and fully understand chemical labels before usage.
Hand pulling and cutting or grazing can help with small infestations.
Above photos couresy of Weeds of Nebraska and the Great Plains published by Nebraska Department of Agriculture