Antitranspirant Effects on Leaf Water Potential and Winter Injury of Holly1,23

Abstract

Abstract Three of 6 antitranspirants significantly reduced winter injury 1 of 5 years when applied 1 and 2 times to Ilex × attenuata Ashe ‘Foster's No. 2’. No reduction of winter injury was observed during 1979 and 1980 even though leaf water potentials recorded during winter stress periods indicated that Exhalt 4-10, Vapor Gard, Wilt Pruf, Folicote, and Foligard significantly reduced transpirational loss of water in midwinter. Two applications of Folicote and Exhalt 4-10 increased water potential more than the single fall application, but did not reduce winter injury significantly. Clear Spray did not increase leaf water potential and appeared to crack and peel within 3 weeks aftef application. Scanning electron micrographs indicated better coverage of leaf surfaces by dipping them by spraying and verified the rapid cracking of Clear Spray.