NPK fertilization in production of eucalypt minicuttings in nutrient solution.

O sucesso da propaga??o vegetativa depende do estado nutricional da planta-matriz. Entretanto, padr?es ideais das concentra??es dos nutrientes n?o est?o ainda bem estabelecidos para a miniestaquia. Assim, o objetivo deste trabalho foi avaliar a influ?ncia da aduba??o NPK na produ??o de miniestacas de eucalipto em solu??o nutritiva. O trabalho foi realizado de novembro de 2008 a janeiro de 2009, em casa de vegeta??o. Foi utilizado delineamento inteiramente casualizado em esquema fatorial fracionado (4x4x4)?, perfazendo 32 tratamentos com tr?s repeti??es. Os tratamentos se constitu?ram de quatro doses dos nutrientes de N (50; 100; 200 e 400 mg L-1) na forma de ur?ia, P (7,5; 15; 30 e 60 mg L-1) na forma de ?cido fosf?rico e K (50; 100; 200 e 400 mg L-1) na forma de cloreto de pot?ssio em solu??o nutritiva. Houve apenas efeito significativo para as doses de N isoladamente. Observou-se efeito linear decrescente com o aumento das doses de N para as vari?veis como n?mero de miniestacas, massa seca das miniestacas, massa seca da raiz e parte a?rea da minicepa de eucalipto. O n?mero de miniestacas e os teores de nutrientes foliares das miniestacas se apresentaram adequados ? literatura existente. A distribui??o percentual da massa seca e dos nutrientes variou em fun??o do aumento das doses de N. O maior ac?mulo percentual de nutrientes e de massa seca ocorreu na parte a?rea das minicepas e nas miniestacas. A dose recomendada para o material gen?tico em estudo foi de 50, 7,5 e 50 mg L-1 para NPK, com produtividade de 12 miniestacas por minicepas num per?odo de 30 dias de coleta, com ac?mulo de nutrientes na miniestaca de 6,0 cm de eucalipto de: 86% do N, 56% do P, 42% do K, 42% do Ca, 36% do Mg, 84% do S, 26% do B, 04% do Cu, 15% do Fe, 23% do Mn e 12% do Zn.Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes)Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2010.ABSTRACT The success of vegetative spread depends on the nutritional state of the matrix plant. However, ideal standards of nutrients concentration are not well established for the minicutting yet. So, the objective of this work was to evaluate the influence of NPK fertilizer in the production of minicuttings in a simple hybrid of Eucalyptus urophylla in?nutrient solution. The experiment was realized from November, 2008 to January, 2009 in vegetation ambient. The experimental design was a completely randomized in fractional factorial scheme (4x4x4)1/2 totaling 32 treatments with three replicates. The treatments consisted by four nutrient doses of N (50, 100, 200 and 400 mg L-1) in the urea form, P (7.5, 15, 30 and 60 mg L-1) in the phosphoric acid form and K (50, 100, 200 and 400 mg L-1) in the potassium chloride form, in the nutrient solution. There was a significant effect only for the isolated N doses for the minicuttings. It was observed that the effect with the number and dry mass of minicuttings and dry mass of root and shoots of ministumps of eucalypt decreased linearly with increasing doses of N. The number of minicuttings and the content of the leaf nutrients in minicuttings were appropriate according to the literature. The percentage distribution of dry mass and nutrients varied in function of the N doses increase. The highest percentage accumulation of nutrients and of dry mass occurred in ministumps and miniccutings shoots, except for Cu and Fe. The recommended dose to the genetic material was respectively about 50, 7,5 e 50 mg L-1 for NPK, with productivity of 12 miniccutings per ministumps in a period of 30 days of collecting and with nutrient accumulation in the ministumps about 6,0cm of eucalypt in the following values: 86% of N, 56% of P, 42% of K, 42 of Ca, 36% of Mg, 84% of S, 26% of B, 04% of Cu, 15% of Fe, 23% of Mn, and 12% of Zn