Toxicity, Absorption, Translocation and Metabolism of 2, 4-D in Physalis Minima L. and Lycopersicon Esculentum Mill¹

Green house and field studies were made on the tolerancejand susceptibility of Physalis minima L. and Lycopersicon esculentum Mill to 2,4-D. The tolerance of minima to 2,4-D increased with the advancement of growth from the 4-leaf to the 10-leaf stage. Absorption was studied with 2,4-D — ¹⁴C and found to continue in treated leaves for 48 h in P. minima and 120 h in L. esculentum under green house conditions. The total amount of radioactivity recovered from the entire plant of P. minima decreased with time after application. The opposite was observed in L. esculentum. Absorption of 2,4-D by both species decreased as growth advanced from the 4-leaf to the 10-leaf stage. At 168 h after treatment, 38.6% of the absorbed radioactivity was identified as 2,4-D — ¹⁴C in. P. minima and 97.2% in L. esculentum. The rite of metabolism of 2,4-D in P. minima increased with the advancement of growth- The resumption of growth of P. minima plants after initial symptoms of 2,4-D injury demonstrated the ability of P minima to reduce a phjrtotoxic concentration of 2,4-D to a harmless level before the injury was sufficient to cause death of the plant.