Friable callus of Solanum ptycanthum and L. peruvianum PI199380 clone 149 were subcultured on liquid Murashige and Skoog salts and Gamborg Vitamin medium with 2,4-D (1mg/l) until a fine suspension of cells was obtained. The suspension cultured cells were then plated on selection medium. Twenty-five acifluorfen-tolerant cell lines of Solanum ptycanthum and fourteen tolerant Lycopersicon peruvianum cell lines were obtained by a stepwise increase in concentration of acifluorfen. Acifluorfen-tolerant cell lines were transferred on to regeneration media with the herbicide. Shoot regeneration differed depending on the cell line and acifluorfen concentration, ranging from 0 to 37 plants per calli. As acifluorfen concentration increased in the regeneration media, the number of shoots and shoot height decreased. There was a wide range of variation in shoot morphology, which depended on the cell line.
Chang-Yeon Yu and John Masiunas
A.W. Caylor, W.A. Dozier Jr., G. Wehtje, D.G. Himelrick, J.A. McGuire, and J.A. Pitts
The postemergence-active herbicides lactofen, fomesafen, and acifluorfen were applied to established matted-row strawberry plants (Fragaria × ananassa) and evaluated for broadleaf weed control and foliar phytotoxicity. Strawberries were evaluated for yield and fruit quality. Treatments were applied following June renovation. All herbicide treatments resulted in acceptable control of broadleaf weeds present at the time of application; however, sicklepod (Cassia obtusifolia) germinated after herbicide application. All treatments caused foliar injury within 3 days after application. No injury symptoms were evident 21 days after treatment due to new foliage development. Fomesafen and acifluorfen were the only herbicides to suppress runner count. Yields the following year were not reduced by herbicide treatments. Chemical names used: (±)-2-ethoxy-l-methy1-2-oxoethyl 5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-nitrobenzate (lactofen); 5-[2-chloro-4-(trifluoromethyl)phenoxy] -N -(methylsu1fonyl)-2-nitrobenzamide (fomesafen); 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid (acifluorfen).
Vamsgita Kolasani and John Masiunas
Eastern black nightshade is one of the problematic weeds in vegetables and soybeans in the Midwest. It is representative of a rapidly growing complex of broadleaf weeds where herbicide resistance would be expected to occur. Eastern black nightshade calli lines that are resistant and susceptible to acifluorfen were maintained on the medium without the herbicide. After two years, these lines were tested for tolerance to acifluorfen and paraquat. Tolerance to acifluorfen was maintained in the previously selected lines. The lines were also cross tolerant to paraquat. Plants were regenerated from these calli lines and grown in the greenhouse. 14C-acifluorfen and 14C-paraquat uptake, translocation, and metabolism were studied.
Bielinski M. Santos and Jose P. Morales-Payan
Trials were conducted under controlled conditions to determine the tolerance of young papaya plants (15 cm tall) to postemergence herbicides. Herbicides used were paraquat (1.68 Kg ai/Ha), MSMA (2.24 Kg ai/Ha), 2,4-D (4.26 Kg ai/Ha), bromoxynil (0.28 Kg ai/Ha), cyanazine (1.12 Kg ai/Ha), dimethenamid (1.12 Kg ai/Ha), endothal (0.56 Kg ai/Ha), imazameth (0.067 Kg ai/Ha), imazethapyr (0.028 Kg ai/Ha) lactofen (0.12 Kg ai/Ha), oxyfluorfen (0.03 Kg ai/Ha), acifluorfen (0.28 Kg ai/Ha), atrazine (2.24 Kg ai/Ha), and bentazon (1.12 Kg ai/Ha) as well as the untreated control. Atrazine, bentazon, cyanazine, imazemeth, imazethapyr, and dimethenamid did not cause phytotoxicity at the rates used and were equal to the untreated control. Other herbicides caused severe injuries followed by total death at 10 days after treatment.
Chae Shin Lim, Seong Mo Kang, Jeoung Lai Cho, and Kenneth C. Gross
-radical scavenging activity in chilled and heat-shocked rice ( Oryza sativa L.) seedlings radicles J. Agr. Food Chem. 50 513 518 Kenyon, J.H. Duke, S.O. 1985 Effect of acifluorfen on endogenous antioxidants and protective