Published online by Cambridge University Press: 12 June 2017
The effects of repeated annual applications of nine herbicides on a planting of asparagus (Asparagus officinalis L. ‘Martha Washington’) were studied over a 7-year period. Weed competition during the cutting season seriously reduced yields. Large populations of common lambsquarters (Chenopodium album L.) developed where 3-amino-2,5-dichlorobenzoic acid (chloramben) and N,N-dimethyl-2,2-diphenylacetamide (diphenamid) were used. Large increases in redroot pigweed (Amaranthus retroflexus L.) occurred where dimethyl tetrachloroterephthalate (DCPA) was used. The fiber content of asparagus treated with 3-(p-chlorophenyl)-1,1-dimethylurea (monuron) and 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea (linuron) increased during slow growing conditions. Spear emergence in the spring was delayed when 2,6-dichlorobenzonitrile (dichlobenil) was applied near bud break. There was no indication that continuous use of any of the herbicides studied resulted in a buildup in the soil or plants causing a deleterious effect upon the yield of asparagus.