Manejo da irrigação na cultura Piper aduncum L
Arquivos
Data
2016-09-08
Autores
Souza, Leonardo Paula de [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A espécie Piper aduncum L ocorre espontaneamente em áreas destinadas à agropecuária na região amazônica, pouco estudada e em fase de domesticação apresenta em seu óleo essencial com alto teor de dilapiol comprovada atividade inseticida e fungicida, além de potencial sinérgico quando combinado com inseticidas convencionais. Nessa fase de domesticação, avaliações agronômicas em escala comercial são necessárias, entre elas se destaca a irrigação. Objetivou-se, com esta pesquisa, avaliar o efeito das tensões da água no solo sobre o desenvolvimento vegetativo e produtivo da Piper aduncum L irrigada por gotejamento, bem como determinar o momento de iniciar a irrigação na cultura. O experimento foi desenvolvido na unidade experimental da Embrapa Acre, na região de Rio Branco, Acre. Adotou-se o delineamento experimental em blocos ao acaso, com cinco tratamentos e quatro repetições. Os tratamentos corresponderam às tensões da água no solo de 20; 40; 60 e 100 kPa e sem irrigação. Foram realizados dois cortes da parte aérea da cultura para quantificação da biomassa e extração do óleo essencial. O primeiro corte foi realizado quando a cultura atingiu dez meses de cultivo e irrigada nos últimos quatro meses (junho a setembro do ano de 2015), conforme os tratamentos estabelecidos; o segundo corte foi realizado seis meses após, correspondente a rebrota da cultura, no período chuvoso. Em ambos os cortes se avaliou a altura da planta, diâmetro da copa, produtividade de massa fresca total, massa fresca de folhas e ramos finos, massa fresca de caule, massa seca de folhas e ramos finos, rendimento, produtividade e o teor de dilapiol no óleo essencial. No primeiro corte e em condições irrigadas, apenas a variável diâmetro da copa não apresentou diferença significativa entre os tratamentos avaliados, as demais variáveis apresentaram diferenças significativas entre as médias dos tratamentos pelo teste de Tukey a 5% de probabilidade. Após a comparação entre os tratamentos irrigados versus os não irrigados, avaliou-se, na sequência, apenas o efeito das tensões da água no solo sobre as variáveis. A análise de regressão permitiu verificar diferenças significativas das tensões da água no solo (kPa) somente em relação às variáveis massa fresca total e massa seca de folhas e ramos finos, reduzindo linearmente em função do aumento da tensão da água no solo. A redução média da massa fresca total e massa seca de folhas e ramos finos correspondeu a 61,84 kg ha-1 e 15,40 kg ha-1, respectivamente, para cada acréscimo unitário da tensão da água no solo. A faixa de tensão da água no solo para definir o momento de iniciar a irrigação na cultura é de 20 a 60 kPa. A Piper aduncum apresenta tolerância moderada ao déficit hídrico. No segundo corte, constatou-se que o efeito das tensões da água no solo no período seco do ano influenciou significativamente a produtividade de massa fresca de folhas e ramos finos, massa fresca do caule, massa seca de folhas e ramos finos e a produtividade do óleo essencial da rebrota da cultura, no período chuvoso.
The specie Piper aduncum L. occurs spontaneously in areas intended for farming in the Amazon region, poorly studied and domestication stage shows in its essential oil with high content dillapiole proven insecticidal and fungicidal activity, and potential synergistic when combined with conventional insecticides. In this round of domestication, agronomic evaluations on a commercial scale are needed, among them stands out irrigation. The objective of this research was to evaluate the effect of soil water tensions on vegetative and productive development for Piper aduncum L irrigated by drip system, and to determine the time to start watering the crop. Tests were taken at an experimental unit of Embrapa Acre, in the region of Rio Branco, Acre. The experimental design of randomized blocks, with five treatments and four repetitions, was adopted. Treatments corresponded to the soil water tension 20; 40; 60 and 100 kPa and also with no irrigation. Two harvest were made to quantify the biomass and, consequently, essential extraction. The first harvest was performed when the culture reached ten months of cultivation and was irrigated in the last four months (June to September 2015) accordingly to previously defined treatments and the second harvest after six months, corresponding to the natural regeneration during the rainy season. In both harvests, the plant height, crown diameter, total fresh mass yield, fresh weight of leaves and thin branches, fresh weight of stem, dry weight of leaves and thin branches, yield, productivity and dillapiole content in essential extraction were evaluated. The evaluation of the first harvest, under irrigated conditions, showed that the plant only the variable crown diameter showed no significant difference among the treatments, the other variables showed significant differences between the treatment means by Tukey test at 5% probability. After comparing the treatments irrigated versus non-irrigated, it was evaluated as a result, only the effect of soil water tension on the variables. The regression analysis has shown significant differences in soil water tensions (kPa) only in relation to the total fresh weight and dry weight variables leaves and thin branches, reducing linearly with increasing soil water tensions. The mean reduction of total fresh and dry weight of leaves and thin branches amounted to 61.84 kg ha-1 and 15.40 kg ha-1 , respectively, for each unit increase in soil water tensions. The soil water tension recommends to initiate irrigation from 20 to 60 kPa. Piper aduncum has moderate tolerance to water deficit. In the second harvest, it was found that the effect of soil water tensions during dry season significantly influences the fresh mass productivity leaves and thin branches, fresh stem weight, dry weight of leaves and thin branches and essential extraction productivity of the regeneration crop during rainy season.
The specie Piper aduncum L. occurs spontaneously in areas intended for farming in the Amazon region, poorly studied and domestication stage shows in its essential oil with high content dillapiole proven insecticidal and fungicidal activity, and potential synergistic when combined with conventional insecticides. In this round of domestication, agronomic evaluations on a commercial scale are needed, among them stands out irrigation. The objective of this research was to evaluate the effect of soil water tensions on vegetative and productive development for Piper aduncum L irrigated by drip system, and to determine the time to start watering the crop. Tests were taken at an experimental unit of Embrapa Acre, in the region of Rio Branco, Acre. The experimental design of randomized blocks, with five treatments and four repetitions, was adopted. Treatments corresponded to the soil water tension 20; 40; 60 and 100 kPa and also with no irrigation. Two harvest were made to quantify the biomass and, consequently, essential extraction. The first harvest was performed when the culture reached ten months of cultivation and was irrigated in the last four months (June to September 2015) accordingly to previously defined treatments and the second harvest after six months, corresponding to the natural regeneration during the rainy season. In both harvests, the plant height, crown diameter, total fresh mass yield, fresh weight of leaves and thin branches, fresh weight of stem, dry weight of leaves and thin branches, yield, productivity and dillapiole content in essential extraction were evaluated. The evaluation of the first harvest, under irrigated conditions, showed that the plant only the variable crown diameter showed no significant difference among the treatments, the other variables showed significant differences between the treatment means by Tukey test at 5% probability. After comparing the treatments irrigated versus non-irrigated, it was evaluated as a result, only the effect of soil water tension on the variables. The regression analysis has shown significant differences in soil water tensions (kPa) only in relation to the total fresh weight and dry weight variables leaves and thin branches, reducing linearly with increasing soil water tensions. The mean reduction of total fresh and dry weight of leaves and thin branches amounted to 61.84 kg ha-1 and 15.40 kg ha-1 , respectively, for each unit increase in soil water tensions. The soil water tension recommends to initiate irrigation from 20 to 60 kPa. Piper aduncum has moderate tolerance to water deficit. In the second harvest, it was found that the effect of soil water tensions during dry season significantly influences the fresh mass productivity leaves and thin branches, fresh stem weight, dry weight of leaves and thin branches and essential extraction productivity of the regeneration crop during rainy season.
Descrição
Palavras-chave
Óleo essencial, Dilapiol, Piperaceae, Irrigação por gotejamento, Essential oil, Dillapiole, Drip irrigation