Algodoeiro fertirrigado com nitrogênio via gotejamento

• Autor(a) principal: Silva, Paula Caroline Lima
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFMT
• Texto Completo: http://ri.ufmt.br/handle/1/3702
• topic: Gossypium hirsutum L.; Fertirrigação; Manejo do nitrogênio; CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA; Gossypium hirsutum L.; Fertigation; Nitrogen management

The production of cotton in Brazil has a great worldwide prominence with the predominance of dry crop, in few studies on the irrigated cotton. The objective of this study was to evaluate the performance of cotton fertigation with nitrogen via drip irrigation. The study was carried out in the experimental area of the Graduate Program in Agricultural Engineering of the Federal University of Mato Grosso, University Campus of Rondonópolis, from June to November 2017 and May to October 2018. The experimental design was in a randomized complete block design with four replications, in a 3 x 3 factorial scheme based on the central compound with 9 treatments, with three levels of irrigation (50, 100 and 150% ETc) via drip irrigation and three levels of nitrogen fertilization (20, 110 and 200% of 155 kg ha-1 ) via fertigation. The analyzed variables were phytometric, productive characteristics and quality of the cotton plume. The variables were submitted to statistical analysis on the response surface using software R, up to the 5% probability level. Not meeting the selection criteria of the response surface model, we studied the isolated effects and interaction of the factors through the polynomial regression analysis. In the year 2017, no significant difference was observed for the surface response model for plant height at 67.82 and 97 DAE, SPAD chlorophyll index at 67.82, 112, 127 and 142 DAE, cotton yield at cotton seed yield and fiber yield. Nitrogen fertilization of 200% N (310 kg ha-1 ) provided higher plant height (53.63 cm) at 67 DAE, SPAD chlorophyll index (54.06) at 97 DAE, cotton yield at (514.14 kg ha-1 ), cotton yield in feather (241.13 kg ha-1 ) and water use efficiency (2.30 kg ha-1 mm -1 ). The irrigation of 110% ETc provided higher cotton seed yield (469.34 kg ha-1 ) and feather (234.00 kg ha-1 ). In the year 2018, all variables were adjusted to the surface model of responses, except stem diameter at 55 DAE, SPAD chlorophyll index at 70 DAE and fiber yield in the two years of cultivation. Nitrogen fertilization and irrigation have a positive influence on herbaceous cotton production with significant gains in its production.