Eight cultivation programs with several equipment combinations were co
mpared with each other and with an atrazine plus pendimethalin herbici
de program with and without supplemental cultivation from 1992 to 1994
. In two of the three years, cultivation with a rotary hoe or tine wee
der reduced weed seedling density by 39 to 74%. Tine weeding was more
effective than rotary hoeing in 1992. Rotary hoeing or tine weeding re
duced corn populations by an average of 6%. Weed control by different
types of inter-row cultivators varied little, except that an in-row cu
ltivator provided better control than a rolling cultivator in two-year
s and better control than a shovel cultivator in one year. Weeds estab
lishing from seeds were better controlled by herbicides in all three y
ears, but weeds establishing from roots, rhizomes, and tubers were con
trolled as well or better by cultivation. Weed control was sometimes b
etter using herbicides plus cultivation than with herbicides alone, bu
t the combination damaged the crop in two of the three years. Cost of
mechanical treatments which combined inter-row cultivation with rotary
hoeing or tine weeding differed from that for the herbicide treatment
by less than 2%. Yields of the best mechanical treatment and the herb
icide treatment were nearly equal in all years, but the best mechanica
l regime varied between years. Consequently, mean net return was moder
ately higher for the herbicide treatment.