Yield components and water use efficiency in coriander under irrigation and nitrogen fertilization

ABSTRACT Among the determining factors of yield, nitrogen (N) fertilization and the correct supply of water play an important role in the quality and yield aspects of coriander. Therefore, the aim of this study was to evaluate the yield components and the water use efficiency (WUE) in coriander subjected to different depths and N doses. A completely randomized design in split plot was used. Water depths were applied in the plots at the rates of 25, 50, 75, 100 and 125% of the Required Real Irrigation (RRI). N doses were distributed within the subplots at the following proportions: 50, 100 and 150% of the recommendation for the crop (70 kg ha-1). The N dose of 94 kg ha-1 and irrigation depth of 115% of RRI promoted the greatest yield (29.0 t ha-1) and number of bunches (29 bunches m-2). The highest number of leaves per plant was obtained with the N dose of 103.2 kg ha-1 and irrigation depth of 68% of the RRI. The maximum plant height (43 cm) was obtained with N dose of 105 kg ha-1 and irrigation depth of 121% of RRI. The highest WUE in coriander (71 kg m-3) occurred at the irrigation depth of 26% of RRI and N dose of 105 kg ha-1

Response of bell pepper crop subjected to irrigation depths calculated by different methodologies

ABSTRACT Water must be supplied to a crop in the proper amount and in a timely manner. Vegetables require a good water availability in soil during their entire cycle. Thus, it is very important the implementation of an irrigation management and accurate estimation of water requirement. The objective of this work was to evaluate the effect of five irrigation depths estimated by the dual-Kc and single-Kc methodologies on the characteristics of growth, production and water use efficiency in the pepper crop. A randomized block design was adopted in a split plot arrangement. The effect of five irrigation depths (50, 75, 100, 125 and 150% of crop evapotranspiration - ETc) was evaluated in the plots, and the methodologies were evaluated in the subplots. It was evaluated the root dry matter, total fruit production, leaf temperature, number of aborted flowers and water use efficiency. The interaction between both effects was not significant for any of the variables. The effect of methodology was observed only on the number of aborted flowers. The effect of the irrigation depths was significant on all variables. The irrigation depths that lead to the best agronomic characteristics were superior to 100% of ETc. The ratio between the irrigation depths estimated by single-Kc and dual-Kc methodologies was 1.14. Single-Kc methodology and irrigation depth of 143% ETc were more suitable for the horticulturist. The most efficient irrigation depth in the use of water was 105% ETc

Reference evapotranspiration estimation by the Irrigameter in Southern Tocantins State, Brazil

The choice for the most appropriate method to estimate evapotranspiration depends on the availability of meteorological data, required level of precision and cost of equipment acquisition. For this estimate, the Irrigameter is simple to operate, precise and economically viable to farmers. In addition, it collaborates in the application of the necessary water depth to crops, thus avoiding unnecessary energy consumption, environmental degradation, and increasing crop yield and improving crop quality. In this context, the objective of this research was to estimate the reference evapotranspiration using the Irrigameter, for the climatic conditions of the Southern Tocantins state, Brazil. The experimental design was completely randomized with Irrigameters operating with seven water heights in the evaporator, as treatments, with three replicates. The reference evapotranspiration was obtained by FAO-56 Penman-Monteith method. For the analyzed climatic conditions, the water height in the evaporator recommended to estimate the reference evaporation in the spring is 3.4 cm; summer, 4.0 cm; fall, 3.8 cm; and winter, 2.3 cm.A escolha do método mais apropriado para estimar a evapotranspiração depende da disponibilidade de dados meteorológicos, do nível de precisão exigido e do custo de aquisição dos equipamentos. Para tal estimativa, o Irrigâmetro é de simples operação, preciso e economicamente viável aos produtores rurais, haja vista que colabora para a aplicação da lâmina de água necessária às culturas, evitando o consumo desnecessário de energia e a degradação do meio ambiente, além de aumentar a produtividade e melhorar a qualidade das culturas. Neste contexto, objetivou-se, por esta pesquisa, estimar a evapotranspiração de referência utilizando o Irrigâmetro, para as condições climáticas do Sul do Estado do Tocantins. O delineamento experimental foi inteiramente casualizado com Irrigâmetros operando com sete alturas da água no evaporatório do aparelho, representando os tratamentos, e três repetições. A evapotranspiração de referência foi obtida pelo método de Penman-Monteith – FAO 56. Para as condições climáticas analisadas, a altura da água recomendada no evaporatório do aparelho para estimar a evapotranspiração de referência na primavera é 3,4 cm; no verão, 4,0 cm; no outono, 3,8 cm e no inverno, 2,3 cm

Reference evapotranspiration estimation by the Irrigameter in Southern Tocantins State, Brazil

ABSTRACT The choice for the most appropriate method to estimate evapotranspiration depends on the availability of meteorological data, required level of precision and cost of equipment acquisition. For this estimate, the Irrigameter is simple to operate, precise and economically viable to farmers. In addition, it collaborates in the application of the necessary water depth to crops, thus avoiding unnecessary energy consumption, environmental degradation, and increasing crop yield and improving crop quality. In this context, the objective of this research was to estimate the reference evapotranspiration using the Irrigameter, for the climatic conditions of the Southern Tocantins state, Brazil. The experimental design was completely randomized with Irrigameters operating with seven water heights in the evaporator, as treatments, with three replicates. The reference evapotranspiration was obtained by FAO-56 Penman-Monteith method. For the analyzed climatic conditions, the water height in the evaporator recommended to estimate the reference evaporation in the spring is 3.4 cm; summer, 4.0 cm; fall, 3.8 cm; and winter, 2.3 cm

Arugula production as a function of irrigation depths and potassium fertilization

ABSTRACT Arugula is a vegetable that has gained more highlight in the consumption, being rich in potassium, sulfur, iron, omega-3 and vitamins A and C. Availability of water and nutrients are limiting factors for production of this crop. In this context, the objective of this study was to evaluate the production of arugula subjected to different irrigation depths and potassium fertilization. The experiment was conduct between August and September 2015. The experimental design was completely randomized in split-plot scheme. Irrigation depths L1, L2, L3 and L4 (25, 50, 75 and 100% of crop evapotranspiration, respectively) represented the plots and potassium doses K1 and K2 (200 and 400 kg ha-1, respectively) represented the subplots. Although the highest yield was obtained with highest irrigation depth and highest potassium dose, it is recommended the cultivation of arugula with the lowest irrigation depth and the lowest potassium dose, considering the higher value of water use efficiency for this treatment

Morpho-physiological characteristics by sweet potato cultivars as function of irrigation depth

Abstract The sweet potato is an alternative energy source, but its sustainability depends on efficient water use. The objective of this study was to evaluate sweet potato morpho-physiological characteristics, and water use efficiency (WUE). Irrigation depths of 50, 75, 100, and 125% of crop evapotranspiration (ETc) were applied. The morpho-physiological indicators, WUE, leaf area index (LAI), leaf water potential, leaf temperature, and leaf chlorophyll index (ICF), were evaluated. The WUE of the sweet potato cultivars increased until the 75% water depth of the ETc. The LAI of these cultivars increased with irrigation depth, with higher values at 100% of the ETc. The leaf water potential of the two sweet potato cultivars was lowest with the lower irrigation depth. Leaf temperature was closer to that of ambient temperatures in treatments with greater irrigation depth. The increase of the WUE with the greater accumulation of dry biomass is due to greater CO2 diffusion by stomata. The reduction in the growth of these plants is due to water stress limiting stomatal conductance, transpiration, leaf growth (LAI) and chlorophyll concentration, proportional to soil moisture conditions. The functional relationship between soil moisture and growth is essential to optimize irrigation management at different growth stages