Phytotoxic Interaction of Tridiphane and Metribuzin in Metribuzin Sensitive and Tolerant Soybean (Glycine max) and Tomato (Lycopersicon esculentum)

摘要

The joint action of metribuzin and tridiphane was investigated in metribuzin-tolerant (T) and metribuzin-sus-ceptible (S) soybean and tomato cultivars within species, respectively, under growth room studies. Maple Arrow (T) and Maple Amber (S) exhibited similar tolerance to tridiphane applied at soybean emergence. Vision (T) tomato was more sensitive to tridiphane than was Springset (S) tomato, the reverse of the relative tolerance to metribuzin. A phytotoxic interaction was demonstrated following application of tridiphane and metribuzin at the respective rates (kg ai ha~(-1)) of 0.1 and 1.1 in Maple Arrow (T) soybeans, 0.05 and 0.25 in Maple Amber (S) soybeans, and 0.25 and 0.2 in Springset (S) tomato. Tridiphane applied 1 or 4 h before metribuzin caused the greatest phytotoxicity in Maple Amber (S) soybeans. Soybean field results generally supported those of growth-room studies. Foliar spray pretreatment with tridiphane increased total radioactivity in Springset (S), decreased the total root radioactivity and increased total shoot radioactivity in both Vision (T) and Springset (S) and decreased metabolism of metribuzin to water soluble conjugates in Springset (S) roots over 24 h following ~(14)C-metribuzin application to roots of intact tomato seedlings. The increased uptake, translocation to the shoots, and decreased root metabolism of metribuzin in Springset when pretreated with tridiphane could explain the phytotoxic interaction (which was unexpected, based only on the glucose detoxification pathway of metribuzin in tomato). Nomenclature: Metribuzin, 4-amino-6-(1,1-dimethylethyl)-3-(methyl-thio-1,2,4-triazin-5(4H)-one), tridiphane, 2-(3,5-dichloro-phenyl)-2-(2,2,2-trichloroethyl)oxirane; soybean, [Glycine max (L.) Merr.] 'Maple Arrow' and 'Maple Amber'; tomato [Lycopersicon esculentum (L.)] 'Vision' and 'Springset.' Additional index words. Synergism, dose response, joint action, ED_(50), uptake, translocation, metabolism.