Parâmetros fisiológicos de genótipos de algodoeiro herbáceo (Gossypium hirsutum L. var. latifolium Hutch) em função da aplicação de regulador de crescimento e estresse hídrico

• Autor(a) principal: Machado, Luis Henrique Marani Daruichi [UNESP]
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/149287; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2016-12-05/000875099.pdf
• topic: Algodão - Cultivo; Reguladores de crescimento; Giberelina; Cotton growing

The herbaceous cotton (Gossypium hirsutum L. var. Latifolium Hutch), belonging to the Malvaceae family, is an indeterminate plant growth, that is, growth continues sending successive terminal buds, unless it is stopped by external or internal factors. Among the cultural techniques used in modern cotton production, there is the use of growth regulators, which are natural or synthetic substances which involve interactions with plant hormones, and the use of mepiquat chloride (MC) inhibits the natural production of gibberellin reducing the vegetative growth in excess without decreasing the productivity of the plant. The use of growth regulators in increasing doses and the occurrence of extreme water can initiate different physiological responses in plants, since it may change the cell metabolism regulation. The cotton genotype FMT 701 features high size and Fibermax 966 features low size, genetically distinct. The objective of this study was to evaluate two cotton genotypes with different genetic characteristics, depending on the application of increasing doses of MC and water stress, the physiological aspects of growth. The experiment was conducted in the UNESP greenhouse, Ilha Solteira-SP, in November 2014, whose experimental design was randomized blocks, with four repetitions, in a factorial 2X4X2, being the factors: 2 cotton genotypes (FMT 701 and Fibermax 966), three growth regulator doses (1, 2, 4 L ha-1) and the witness equivalent to study in pots, and 2 water levels in the soil (field capacity, FC and 1/3 field capacity, 1/3FC), for a total of 64 vessels. 30 days after plant emergence (DAE) was begun to differentiate the water regimes, and the MC was sprayed directly on the plants, parceled in three applications performed at 50, 60 and 70 DAE. With the results, it was found that the implementation of the MC in genotypes was efficient in terms of growth limitation in time, highlighting the idea that the growth regulator interfere in the...