Indução de deficiências nutricionais em mudas de mogno africano (Khaya ivorensis A. Chev.)

• Autor(a) principal: Corcioli, Graciella
• Data de Publicação: 2013
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/001300000dfx1
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/3236
• topic: Macronutrientes; Micronutrientes; Solução nutritiva; Essências florestais; Macronutrients; Micronutrients; Nutrient solution; Forest species; CIENCIAS AGRARIAS::AGRONOMIA

The african mahogany (Khaya ivorensis) is a high value forest essence in the international trade and of great potential to replace the Brazilian mahogany (Swietenia macrophylla), which is one of the most valuable commercial species in the world, but presents serious difficulties in its cultivation. Currently, little is known about the nutritional requirements of the african mahogany. In this sense, this study aimed to characterize and induce the symptoms of the deficiencies of macro nutriens (nitrogen, phosphorus, potassium, calcium, magnesium, sulfur) and micro nutrients (iron, boron, copper, manganese, molybdenum and zinc) based on the diagnosis by the visual method and by means of chemical analysis on seedlings of african mahogany. In order to do that, two experiments were conducted with a nutritive solution with the following treatments: T1-Complete Solution; T2-Complete solution, with the omission of nitrogen; T3-complete solution, with the omission of phosphorus; T4-complete solution, with the omission of potassium, T5-complete solution, with the omission of calcium; T6-complete solution, with the omission of magnesium-T7 complete solution, with the omission of sulfur; T8-complete solution, with the omission of iron; T9-complete solution, with the omission of boron, T10-complete solution, with the omission of copper; T11-complete solution, with the omission of manganese; T12-complete solution, with the omission of zinc; T13-complete solution, with the omission of molybdenum and T14-Witness (deionized water). In Experiment 1 the evaluations were carried from the emergence of seedlings obtained by seed that were put to germinate in coarse washed sand and irrigated with deionized water until sixty days after sowing, starting then to receive daily 200 ml of nutrient solution. The experimental design used was completely randomized with fourteen treatments and ten replications. The dendrological data and the visual symptoms were described and photographed every fifteen days from the initial stage until they became well defined at 210 days. In Experiment 2 the evaluations were carried from commercial seedlings ready for the field planting, which were removed from the 180 cm3 tubes and transferred to the plastic tubes with capacity for 4.8 L, containing coarse washed sand as substrate. These seedlings remained in the greenhouse for fifteen days, just being irrigated with deionized water. After this period the process of rustification of the seedlings was begun to subsequently start up the daily irrigation with 200 ml of nutrient solution, described in the Experiment 1. The experimental design used was completely randomized with fourteen treatments and ten replications. The dendrological data and the visual symptoms were described and photographed every fifteen days from the initial stage until they became well defined, at 220 days. At forty days after the start of the irrigation with nutrient solutions,the first visual symptoms begin to revel, with easy visualization and characterization. In Experiment 1 isolated omissions of macronutrients and micronutrients respective induces deficiency symptoms associated with smaller contents (except Cu and Mg), but only the absence of N, P, Fe, Cu and B significantly affect plant development. In Experiment 2 the plants from seedlings ready for planting the development is affected only by the omission of N in the nutrient solution, showing deficiency symptoms and smaller contents of the element. The omissions of the other nutrients reaches their induce mild symptoms of nutritional deficiency typical and lower foliar Ca and Fe only.