Published online by Cambridge University Press: 12 June 2017
Height, true-leaf area, shoot dry weight, and survival of the seedlings of four varieties of cucumber (Cucumis sativus L.) were measured for differences occurring when treated preemergence with naptalam (N-1-naphthylphthalamic acid) alone, chloramben (3-amino-2,5-dichlorobenzoic acid) methyl ester alone, or with combinations of these two herbicides. These factors were reduced, depending upon the variety of cucumber, with each of the herbicide treatments. The only reduction associated with naptalam alone was the true-leaf area of ‘Model’ and ‘Wisconsin SMR 58.’ ‘Ohio MR 17,’ ‘Model,’ and ‘Wisconsin SMR 58’ had less reduction of all measured responses than ‘Pixie’ when treated with chloramben methyl ester alone or with combinations of naptalam and chloramben methyl ester. The herbicide variety interactions present in seedling injury under greenhouse conditions were not reflected in the yields of these varieties when grown in the field. The only significant yield reduction occurring under field conditions was with the 4.48 kg/ha rate of chloramben methyl ester in the first harvest.