Inhibition Effects of Localized Growth Regulator Sprays on Mature Lemon Trees1

Abstract

Sprays of a plant growth regulator ammonium ethyl carbamoylphosphonoate (Krenite), applied to top regrowth of mature Lisbon lemon trees [Citrus limon (L.) Burmann] resulted in significant inhibition of growth for over 1 year. At concentrations above 0.2% there was excessive foliar and small branch damage.

Inhibition of Regrowth and Yield of Mature Lemon Trees with Ammonium Ethyl Carbamoylphosphonate1

“…A field trial to evaluate the effective ness of Krenite on production, leaf N concentration and retardation of lemon Fruit samples were picked at random from treated and untreated trees during the trial period. Observation of cut fruit showed no difference in rind thickness; this agrees with previous work (1).…”

“…Several methods have been tried to control top regrowth of mature lemon trees, including hand, mechanical, and chemical pruning. Hand pruning is ex pensive, and with both hand and mechan ical pruning there is the expense of brush shredding (1,9). Chemical pruning has many drawbacks such as undesirable rind thickness (6,7), chemicals not available 'R eceived for publication July 3, 1980.…”