Water utilization by S-ethyl dipropylthiocarbamate treated wheat

Wheat (Triticum aesticum L. var. Holley) was grown in 0.5 Hoaglands complete mineral nutrient solution containing sub-toxic concentrations of S-ethyl dipropyl-thiocarbamate (EPTC) (0, 0.0625, 0.125, 0.25, or 0.5mg/1). Total fresh and dry plant weights per pot decreasedas EPTC concentration increased. Leaf fresh and dry weight per pot decreased as EPTC concentration increased. Root fresh weight per pot was not greatly influenced by EPTC and dry weight per pot was statistically significantly decreased at the 0.5 mg/l EPTC concentration. Total plant water utilization and leaf water contents (mg/g DW) decreased as EPTC concentration increased, but evapotranspiration (ml/g FW or DW) per unit leaf tissue was increased to ca 145% of the untreated wheat. This increased evapotranspiration explains an EPTC induced accumulation of 14C-atrazine in leaves beyond the detoxification level which ultimately resulted in atrazine injury in EPTC pretreated plants.