Tolerance of Tomato (Lycopersicon esculentum) Cultivars to Metribuzin

Abstract

Twenty-six cultivars of tomatoes from several countries were divided into four metribuzin [4-amino-6-tert-butyl-3-(methylthio)-1,2,4-triazin-5(4H)-one] tolerance groups: tolerant, semi-tolerant, semi-susceptible, and susceptible. Early maturity and tolerance to metribuzin were correlated (r = −0.78) in the field experiment and (r = −0.72) in a sinking leaf-disc bioassay. New super early cultivars were especially sensitive to metribuzin. Chlorophyll a and b content were not highly correlated with tolerance to metribuzin. Metribuzin rates used for weed control are close to toxic concentrations for very early cultivars of tomatoes. Plants in the 9-leaf stage were less sensitive than plants in the 5- or 7-leaf stage. Metribuzin tolerance came at later stages in early maturing cultivars than in later maturing cultivars.

Differential Tolerance of Sweet Potato (Ipomoea batatas) Clones to Metribuzin

“…Differential genotypic tolerance to metribuzin has been reported for soybean (11,20), tomato (5,21,22), Irish potato (4,6,9), barley (Hordeum vulgare L.) (8), and, winter wheat (Triticum aestivum L.) (10,18). The basis of differential cultivar tolerance was reportedly due to differential rates of metribuzin metabolism in soybean (2,20), tomato (19), barley (8), and potato (7).…”

Genetic Improvement of Tomato

“…Field experiments have been conducted to screen the cultivars and breeding material. Fireball and Vision (Machado et al1976); C28 (Aclan 1977), UGA 1113 MT and UGA 1160 MT (Gawronski 1983), UGA 1113 MT and UGA 1160 MT were tolerant to metribuzin (Phatak and Jaworski 1985). In this case, germinating seedlings are assessed after 15 days of floating in half-strength Hoaglands solution plus 0.25 ppm metribuzine maintained at 25°C and 24.2 Klux for 14 h/day and 80% RH (Machado et al 1978).…”

Development of High Levels of Metribuzin Tolerance in Lentil

“…These include soybean [ Glycine max (L.) Merr.] (Hardcastle 1974; Mangeot et al 1979; Barrentine et al 1982), tomato ( Solanum lycopersicum L.) (Souza Machado et al 1978; Gawronski 1983), potato ( Solanum tuberosum L.) (Ivany 1979; Gawronski et al 1985), sweetpotato [ Ipomoea batatas (L.) Lam.] (Harrison et al 1985; Motsenbocker and Monaco 1993), cowpea [ Vigna unguiculata (L.) Walp.]…”