tailieunhanh - Handbook of Plant Nutrition - chapter 15

15 Zinc Discovery of zinc as an essential element for higher plants was made by Sommer and Lipman (1) while working with barley (Hordeum vulgare L.) and sunflower (Helianthus annuus L.). However, Chandler et al. (2) stated that Raulin, as early as 1869. | 7 1 2006 7 36 AM Page 411 15 Zinc J. Benton Storey Texas A M University College Station Texas CONTENTS Introduction .411 Early Research on Zinc Nutrition of Absorption and Function of Zinc in Zinc Deficiency .412 Zinc Trunk Zinc in Phosphorus-Zinc Tryptophan and Indole Acetic and Root Foliar Influence of Humidity on Foliar Role of Zinc in DNA and RNA Metabolism and Protein Zinc Transporters and Zinc Summary .429 INTRODUCTION Early Research on Zinc Nutrition of Crops Discovery of zinc as an essential element for higher plants was made by Sommer and Lipman 1 while working with barley Hordeum vulgare L. and sunflower Helianthus annuus L. . However Chandler et al. 2 stated that Raulin as early as 1869 reported zinc to be essential in the culture media for some fungi and speculated that zinc was probably essential in higher plants. Skinner and Demaree 3 reported on a typical Dougherty county pecan Carya illinoinensis K. Koch orchard in Georgia. Pecan trees that were placed in a study that started in 1918 increased in trunk diameter but their tops had dieback each year and their condition appeared hopeless in 1922. Fertilizers N P K cover crops and all known means were of no avail. Rosette or related dieback had been recognized since around 1900 but it was in 1932 before zinc was found to be the corrective element 4 5 . The common assumption among pecan growers was that a deficiency of iron was responsible for rosette as pecans were brought into cultivation in the early 1900s. Alben used to solutions of FeCl2 and FeSO4 in his rosette treatments in 1931 and obtained conflicting results. The 1932 treatments included injections into dormant trees soil applications while the trees