Nutrição mineral de plantas ornamentais: VII. estudos de adubação NPK na cultura de gladíolo (Gladiolus grandiflorus, cv. 'Perusi')

Abstract

RESUMOTrês doses de Ν, Ρ e Κ foram testadas em culturas de gladíolos (Gladiolus grandiílorus cv. 'Perusi') provenientes de três tamanhos diferentes de bulbos (Nº 3, Nº 1 e Jumbo). Todos os tratos culturais necessários foram dispensados aos experimentos cuja instalação se deu em um solo podzolizado da Cooperativa Agrícola de Ho¬ lambra, em Jaguariúna -SP. Estudaram-se os efeitos de adubação sobre produção de flores, produção de bulbos e de bulbilhos.A resposta do gladíolo aos níveis de fertilização variou bastante com o tamanho de bulbo plantado. São discutidos os efeitos de cada nutriente sobre as características estudadas. INTRODUÇÃO Em nossas condições são escassos os trabalhos de nutrição mineral do gladíolo. Em vários países vem sendo conduzidos ensaios

Effects of Nitrogen Fertilization and Water Replacement Level on the Production of Gladiolus Corms in a Protected Environment

“…Inadequate plant nutrition causes serious disorders and may eventually lead to a decline in plant vigor and production (Hossian et al, 2011). Despite positive responses to nitrogen fertilization, Fernandes et al (1974) observed that nitrogen top dressing had no effect on the mean weight of gladiolus corms.…”

“…Moreover, the production of flowers from medium-sized corms is not influenced by fertilizer applications (Tamura & Mega, 1959). Fernandes et al (1974) evaluated the N dose effects on gladioli grown from three different corm sizes. They observed that, in general, the greatest nitrogen fertilization effects on the production of flowers, corms and cormels were observed in plants grown from the smallest corms (3 cm in diameter) because they had a higher nutrient requirement, given their lower nutritional reserve.The same trend was also found in plants grown from jumbo corms (6 cm in diameter) because they have less vitality and are in the final stage of life.…”

“…They observed that, in general, the greatest nitrogen fertilization effects on the production of flowers, corms and cormels were observed in plants grown from the smallest corms (3 cm in diameter) because they had a higher nutrient requirement, given their lower nutritional reserve.The same trend was also found in plants grown from jumbo corms (6 cm in diameter) because they have less vitality and are in the final stage of life. Fernandes et al (1974) also reports that for plants grown from medium-sized corms (4 cm in diameter), there was no response to nitrogen fertilization due to the corm's nutrient reserve combined with the capacity of the more extensive root system, and even though the 4 cm corms did not respond to fertilization, the corm weight, number of corms, stem length and number of floral buds per stem were higher than those of the other corm sizes, indicating that the medium-sized corms had greater vigor. Pant (2005) also states that the initial growth and vigor are determined by the amount of food provided by corms for plant growth.…”