Comportamento agronômico do lúpulo (Humulus lupulus L.) em cultivo protegido submetido a irrigações com diferentes faixas de pH da água na região de Botucatu-SP
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Data
2020-02-20
Autores
Guimarães, João de Jesus
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Universidade Estadual Paulista (Unesp)
Resumo
O cultivo de lúpulo (Humulus Lupulus L) exige um adequado fornecimento de água, principalmente na fase de desenvolvimento, o qual envolve a formação e crescimento dos ramos laterais, florescimento, formação das inflorescências e maturação dos cones. Sabendo da importância do fornecimento de água na fase de desenvolvimento, a irrigação passou a ser utilizada nas áreas de cultivo desde o século XIX. No contexto da irrigação, a qualidade da água é um fator importante e que, quando não se dá a devida atenção, pode causar efeitos deletérios no sistema de irrigação, solo e na planta. O potencial hidrogeniônico (pH) é um dos parâmetros que caracteriza a qualidade de água para irrigação podendo influenciar na microbiologia do solo e no processo de intercâmbio de cátions (solo para a solução e vice-versa). Em virtude da importância da irrigação e dos poucos estudos relacionados ao pH da água da irrigação da cultura do lúpulo, este trabalho teve como objetivo avaliar o efeito da irrigação com diferentes faixas de pH da água sob o desenvolvimento agronômico do lúpulo, variedade Cascade, cultivado em ambiente protegido. A pesquisa foi conduzida em casa de vegetação no Departamento de Bioprocessos e Biotecnologia – DBB da Faculdade de Ciências Agronômicas – FCA/UNESP, Campus de Botucatu. O delineamento estatístico utilizado foi o inteiramente casualizados (DIC) com três tratamentos e dez repetições. Os tratamentos foram constituídos por três faixas de pH da água, sendo: T1 – pH 6 a 6,5, T2 – pH 6,5 a 7 e T3 – 7 a 7,5. Para a obtenção dos tratamentos, soluções de 0,1 mol L-1 de hidróxido de sódio (NaOH) e ácido fosfórico (H3PO4) foram utilizadas para elevar e baixar, respectivamente, o pH da água. As características avaliadas foram: altura de planta (AP), diâmetro do caule (DC), área foliar (AF), biomassa da planta (massa fresca e seca da folha e do caule), índices de crescimento, trocas gasosas, teor nutricional no tecido foliar vegetal, perda de eletrólitos, teor de pigmentos foliares, produtividade e teor de alfa e beta-ácidos. As irrigações com as diferentes faixas de pH promoveram a elevação do pH da solução do solo, influenciaram na disponibilidade, absorção e acúmulo de nutrientes no tecido vegetal foliar e na taxa fotossintética. Consequentemente, afetaram a AP e a produção de matéria seca do caule. Não houve efeito das faixas de pH da água sob o DC, AF, massa fresca e seca da folha, índices de crescimento, perda de eletrólitos e teor de pigmentos foliares. Contudo, houve diferença significativa entre as épocas de avaliação para a perda de eletrólitos, clorofila b e carotenoides totais. A produtividade de cones por planta foi significativamente afetada pelas faixas de pH. Os teores de alfa e beta-ácidos reduziram com o aumento das faixas de pH da água. A faixa de pH da água 6,5 a 7 promoveu a maior disponibilidade de potássio, melhor taxa fotossintética, maiores AP, produção de massa fresca e seca do caule e maior produtividade de cones por planta. Os teores de alfa e beta-ácidos apresentaram maiores valores nas plantas do tratamento 1.
Hop cultivation (Humulus Lupulus L) requires a adequate supply of water, especially at the developmental stage, or as involved in lateral branch formation and growth, flowering, inflorescence formation and cone maturation. Knowing the importance of water supply in the development phase, irrigation has been used in cultivated areas since the 19th century. In the context of irrigation, water quality for irrigation is an important factor which, when not given due attention, can have deleterious effects on the irrigation system, soil and the plant. The hydrogen potential (pH) of water is one of the parameters that characterizes the quality of water for irrigation and can influence soil microbiology and the cation exchange process (soil for solution and vice versa). Due to the importance of irrigation and the few studies related to the water pH of the irrigation of the hop culture, this work had as objective evaluate the effect of irrigation with different water pH ranges on the agronomic development of hops, Cascade variety cultivated in protected environment. The research was conducted in a greenhouse at the Department of Bioprocesses and Biotechnology – DBB of the Faculty of Agronomic Sciences - FCA/UNESP, Botucatu Campus. The statistical design used was the completely randomized design (CRD) with three treatments and ten replications. The treatments consisted of three water pH ranges: T1 - pH 6 to 6.5, T2 - pH 6.5 to 7 and T3 - 7 to 7.5. To obtain the treatments, 0,1 mol L-1 solutions of sodium hydroxide (NaOH) and phosphoric acid (H3PO4) were used to increase and decrease the water pH, respectively. The characteristics evaluated were: plant height (AP), stem diameter (DC), leaf area (AF), plant biomass (fresh and leaf and stem mass), growth indices, gas exchange, nutritional content in plant leaf tissue, electrolyte loss, leaf pigment content, productivity and alpha and beta acid content. Irrigations with different pH ranges promote elevation of soil solution pH, influenced the availability, absorption and accumulation of nutrients in leaf tissue and in photosynthetic rates. Consequently, affected the AP and the stem dry matter production. There was no effect of water pH under DC, FA, fresh and dry leaf mass, growth rates, electrolyte loss and leaf pigment content. However, there was a significant difference between the evaluation times for electrolyte loss, chlorophyll b and total carotenoids. Cone productivity per plant was significantly affected by water pH. Alpha and beta-acid levels decreased with increasing water pH. The pH water range of 6.5 to 7 promoted higher potassium availability, better photosynthetic rate, higher AP, fresh and dry stem production and higher yield per plant. Alpha and beta-acid contents were higher in treatment plants 1.
Hop cultivation (Humulus Lupulus L) requires a adequate supply of water, especially at the developmental stage, or as involved in lateral branch formation and growth, flowering, inflorescence formation and cone maturation. Knowing the importance of water supply in the development phase, irrigation has been used in cultivated areas since the 19th century. In the context of irrigation, water quality for irrigation is an important factor which, when not given due attention, can have deleterious effects on the irrigation system, soil and the plant. The hydrogen potential (pH) of water is one of the parameters that characterizes the quality of water for irrigation and can influence soil microbiology and the cation exchange process (soil for solution and vice versa). Due to the importance of irrigation and the few studies related to the water pH of the irrigation of the hop culture, this work had as objective evaluate the effect of irrigation with different water pH ranges on the agronomic development of hops, Cascade variety cultivated in protected environment. The research was conducted in a greenhouse at the Department of Bioprocesses and Biotechnology – DBB of the Faculty of Agronomic Sciences - FCA/UNESP, Botucatu Campus. The statistical design used was the completely randomized design (CRD) with three treatments and ten replications. The treatments consisted of three water pH ranges: T1 - pH 6 to 6.5, T2 - pH 6.5 to 7 and T3 - 7 to 7.5. To obtain the treatments, 0,1 mol L-1 solutions of sodium hydroxide (NaOH) and phosphoric acid (H3PO4) were used to increase and decrease the water pH, respectively. The characteristics evaluated were: plant height (AP), stem diameter (DC), leaf area (AF), plant biomass (fresh and leaf and stem mass), growth indices, gas exchange, nutritional content in plant leaf tissue, electrolyte loss, leaf pigment content, productivity and alpha and beta acid content. Irrigations with different pH ranges promote elevation of soil solution pH, influenced the availability, absorption and accumulation of nutrients in leaf tissue and in photosynthetic rates. Consequently, affected the AP and the stem dry matter production. There was no effect of water pH under DC, FA, fresh and dry leaf mass, growth rates, electrolyte loss and leaf pigment content. However, there was a significant difference between the evaluation times for electrolyte loss, chlorophyll b and total carotenoids. Cone productivity per plant was significantly affected by water pH. Alpha and beta-acid levels decreased with increasing water pH. The pH water range of 6.5 to 7 promoted higher potassium availability, better photosynthetic rate, higher AP, fresh and dry stem production and higher yield per plant. Alpha and beta-acid contents were higher in treatment plants 1.
Descrição
Palavras-chave
Lúpulo (Humulus lupulus L.), Cascade, Irrigação, Qualidade da água, Potencial hidrogeniônico, Ambiente protegido, Water quality, Hydrogen potential, Protected environment