ABSORPTION AND TRANSLOCATION OF FOLIAR APPLIED TRIAZONE-N AS COMPARED TO OTHER NITROGEN-SOURCES IN TOMATO

Absorption and translocation of foliar applied N-15 labeled S-tetrahydrotriazone (triazone), as compared to other N forms, was evaluated in tomato plants. Triazone-N was taken up into leaf tissue in quantities similar to urea, ammonium, and nitrate-N when applied at a N concentration of 0.35% w/v. Although > 40% of the N-15 label was exported from the treated leaf after 7 days, nearly 50% of the translocated triazone N-15 label accumulated in non-treated leaf tissue as compared to only 10% or less for the other N sources. The largest percentage of the translocated urea-, ammonium-, and nitrate-N-15 label accumulated within developing fruit tissue. Multiple (3) foliar applications of triazone and urea at concentrations of 0.94% or higher and 1.0% N (w/v), respectively, enhanced both leaf and fruit tissue N concentrations. No growth responses to foliar applied N were observed.