ABSTRACT
Potassium (K) directly influences the productivity of coconut dwarf to be activator of enzymes involved in respiration and photosynthesis, among other functions. However in many cases their implementation on the ground has not provided adequate leaf levels. It was evaluated the influence of doses of KCl applied via soil and via leaf axil on the leaf nutrient concentration in green dwarf coconut tree (Cocos nucifera L.). The experiment was driven at a commercial orchard in Campos dos Goytacazes, Brazil, in a Typic Quartzipsamments, in the period from May 31, 2007 to May 31, 2008, using a randomized complete block design with five treatments and sixteen replicates. Treatments consisted of two application ways (on soil and on the axil of the leaf number nine) and two levels of KCl (1666 and 3333 g of KCl per plant, per year) level 1 and 2 for soil and (833 and 1666 g per plant, per year) level 1 and 2 in for plant axil, with three month interval applications), besides a control, without KCl. Leaf samples were collected before the first fertilization and three months after each fertilization. Application of KCl increased leaf concentrations of K and Cl and it reduced Mg concentration in plant tissue. Leaf concentrations of N; P; Ca; S; B; Cu; Fe; Mn and Zn were not influenced by treatments. Potassium application in the frond axils is an alternative due to better absorption of nutrients compared to conventional fertilization. In addition, frond axils fertilization minimizes loss of nutrients and it is possible to reduce the amounts of potassium applied.
Key words:
Cocos nucifera L; potassium chloride; leaf axil
