Danatonium is a highly bitter compound, with bitterness thresholds of 0.05 ppm for the benzoate and 0.01 ppm for the saccharinate, and is used to deter ingestion.
Kennedy and Connery (2008) evaluated 2 l/tonne of Bitrex (Denatonium benzoate 25) at concentrations ranging between 0.02 g/l to 80 g/l to reduce the impact of rooks (Corvus frugilegus L) on wheat plant density in an Irish study. The study concluded that the product was ineffective in preventing damage, and difference in plant density between treatment and control plots varied inconclusively between – 21 % to + 35 % for different dosage. In an Israeli study, Moran (1996) evaluated Ro-pel® (Denatonium Saccharide) for its potential to reduce rock hyrax (Procavia capensis) damage to fruit trees. No reduced risk of leaf damage were observed for neither mango (RR = 1.0) nor avocado (RR = 1.0) seedlings over 13 days. Rock hyrax damage to mature red pomelo leaves was 43 – 52 % lower in treatment seedlings between day 2 – 8 of the study. Finally, Swihart and Conover (1990) tested Ro-pel ® for its effectiveness in reducing white-tailed deer (Odocoileus virginianus) damage on twigs of Japanese yews trees in Connecticut, USA and found no reduced risk of damage in the treatment nurseries (RR = 1.1).
