Comportamento da tiririca (Cyperus rotundus) sob diferentes níveis de adubação fosfatada e de sombreamento
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Data
1995-01-01
Autores
Nemoto, Marta C.M. [UNESP]
Alves, Pedro L.C.A. [UNESP]
Pitelli, Robinson A. [UNESP]
Nemoto, Luiz R.P. [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira da Ciência das Plantas Daninhas
Resumo
O trabalho, instalado e conduzido em casa de vegetação da FCAV, campus de Jaboticabal, UNESP, teve por objetivos estudar os efeitos de diferentes doses de adubação fosfatada (0, 33,5, 67,0 e 100,5 ppm de P2O5) e níveis de sombreamento (0, 30, 50 e 70%) sobre parâmetros de crescimento de tiririca (Cyperrus rotundus). Quatro tubérculos previamente brotados foram colocados em cada vaso com capacidade para três litros de solo. Utilizou-se Latossolo Vermelho-Escuro textura média, moderado, distrófico, peneirado. Para efeito de análise estatística, os vasos (parcelas) foram dispostos num esquema inteiramente casualisado, com quatro repetições. Os resultados obtidos mostraram o efeito prejudicial do sombreamento sobre o desenvolvimento da tiririca. Já ao nível de 30%, o sombreamento causou redução na densidade das plantas , principalmente por reduzir o número de bulbos + tubérculos. em conseqüência, houve redução no acúmulo de matéria seca nas diferentes partes da planta, redução esta mais acentuada no sistema subterrâneo (bulbos + tubérculos + raízes), causando incremento nas relações PA/B+T+R e B+T/R. A adubação fosfatada, no entanto, incrementou os parâmetros de crescimento da espécie, principalmente no desenvolvimento das manifestações epígeas, refletido tanto pelo aumento em número quanto em acúmulo de matéria seca.
This research was carried out under greenhouse conditions at the College of Agriculture, campus of Jaboticabal, UNESP, with the objective of studying the effects of different levels of phosphoric fertilization (0, 33.5, 67.0 and 100.5 ppm P2O5) and shading levels (0, 30, 50 and 70% of light interception) on some growth parameters of purple nutsedge (Cyperus rotundus). The tubers emerged were placed (in numbers of 4) in plastic pots containing three liters of dark Red Latossoil (soil), medium texture, being previously screened. The experiment was land out in a completely randomized design with four replications. The results showed the detrimental effect of shading on purple nutsedge development; at a level of 30% shading there was a reduction in plant density, mainly due to a reduction in the number of bulds and tubers. As a consequence there was a reduction in the dry matter accumulation in the subterranean parts (bulbs, tubers and roots), causing na increase in the ratios PA/B+T+R and B+T/R. Phosphoric fertilization, however, increased the growth parameters of the species, mainly in the development of the PA by na increase in the number and dry matter accumulation.
This research was carried out under greenhouse conditions at the College of Agriculture, campus of Jaboticabal, UNESP, with the objective of studying the effects of different levels of phosphoric fertilization (0, 33.5, 67.0 and 100.5 ppm P2O5) and shading levels (0, 30, 50 and 70% of light interception) on some growth parameters of purple nutsedge (Cyperus rotundus). The tubers emerged were placed (in numbers of 4) in plastic pots containing three liters of dark Red Latossoil (soil), medium texture, being previously screened. The experiment was land out in a completely randomized design with four replications. The results showed the detrimental effect of shading on purple nutsedge development; at a level of 30% shading there was a reduction in plant density, mainly due to a reduction in the number of bulds and tubers. As a consequence there was a reduction in the dry matter accumulation in the subterranean parts (bulbs, tubers and roots), causing na increase in the ratios PA/B+T+R and B+T/R. Phosphoric fertilization, however, increased the growth parameters of the species, mainly in the development of the PA by na increase in the number and dry matter accumulation.
Descrição
Palavras-chave
Biologia, alocação de recursos, Biology
Como citar
Planta Daninha. Sociedade Brasileira da Ciência das Plantas Daninhas , v. 13, n. 1, p. 50-55, 1995.