Flávio Gonçalves Oliveira

Produção e parâmetros fisiológicos do amendoim em função do estresse salino

EnglishThe present study aims to evaluate the effect of water salinity from irrigation on the electrical conductivity of the saturated extract of soil (CEes) and the alterations of the physiological parameters and productivity on peanut cultivation. The experiment was conducted in a randomized block design with six treatments and four replications. The treatments consisted of a control with low electrical conductivity water (0.1dS m-1) and five leaching fractions (0.4; 0.3; 0.2; 0.1; and 0.05) with water of 3 dS m-1. The results showed that the CEes decreased significantly with the increase of the leaching fractions; the decrease of the leaf osmotic potential in the peanut plant implied the reduction of productivity; the content chlorophyll and the total dry matter decreased significantly with the increase of the CEes portuguesO trabalho teve por objetivo avaliar os efeitos da salinidade da agua de irrigacao sobre o a condutividade eletrica do extrato da pasta saturada do solo (CEes) e as alteracoes dos parâmetros fisiologicos e de produtividade da cultura do amendoim. O experimento foi instalado no delineamento em blocos casualizados, com seis tratamentos e quatro repeticoes. Os tratamentos consistiram de seis fracoes de lixiviacao, equivalentes a 40, 30, 20, 10, 5 e 0% da lâmina de agua de irrigacao, sendo que para a fracao de lixiviacao de 0% usou-se agua doce (0,1 dS m-1) e para as demais agua salina (3 dS m-1). Os resultados mostraram que aCEes diminuiu significativamente com o aumento das fracoes de lixiviacao, o decrescimo do potencial osmotico foliar na planta de amendoim implicou na reducao da produtividade e o teor de clorofila e a massa de materia seca total reduziram significativamente com o aumento da CEes

Produtividade e qualidade da banana prata anã, influenciada por lâminas de água, cultivada no Norte de Minas Gerais

This study evaluated the effects of different irrigation water depths on the vegetative development, yield and quality of banana. The basic parameters of the irrigation management were determined fo a banana crop, for the first and second cycles in the Northern Minas Gerais, Brazil. The irrigation water depths applied to the treatments were 40, 60, 80, 100 and 120% of the reference evapotranspiration (ETo) estimated by Penman-Monteith equation. The leaf area index and the degrees-day accumulated for each phenological stage, as wellas the shade percentages, were determined. The results show that the treatment corresponding to 120% of the ETo provided higher productivities in comparison to other treatments. The irrigation water depths affected the fruit quality at the harvesting time, showing that the irrigation depth of 120% of the ETo was superior. The amount of water applied in treatments of 100 and 120% of the ETo in relation to the other treatments promoted earls flowering and, consequently, harvest. The crop coefficients (Kc) presented for the first cycle values of 0.71, 1.00 and 0.87 for the phenological stages corresponding to II, III and IV, respectively, and 0.97 for the only one stage for the second cycle.

Fator de resposta do alecrim-pimenta a diferentes lâminas de irrigação

Evaluating the response of medicinal plants to irrigation is not very common, especially when they are native species with economic potential , such as the Lippia sidoides . Thus, this study aimed at evaluating the Lippia sidoides response, by using the Ky coefficient, and growth, under different irrigation depths. The coefficients were determined from the dry matter and essential oil yields. The experiment used a randomized blocks design, with treatments consisting of seven irrigation depths (0.5, 0.75, 1.0, 1.2, 1.4, 1.65 and 1.9 of the Eto), with three replications. The ETo was evaluated by using the Penman-Monteith method and the ETr according to the soil water balance. Growth was determined by measuring the stem diameter and height, at 35, 56, 77, 98 and 119 days after transplanting. At 120 days of cultivation, samples were collected to determine the dry matter and essential oil yields. The plant responded to water deficit with coefficients above 1.0, for both dry matter and essential oil yields. Growth was positively affected by irrigation, reaching higher values for stem diameter and height when the highest irrigation depths were used.

Water stress before harvest of pepper-rosmarin

The objective of this work was to assess the effect of different periods of water stress before harvest of pepper-rosmarin (Lippia sidoides) on the contents of essential oil and flavonoids. The experiment was carried out during 270 days of cultivation, with drainage lysimeters, in a completely randomized block design with five treatments: 0, 2, 4, 6, and 8 days of water suppression before harvest, with four replicates. Fresh and dry matter yield, essential oil content, total flavonoids content, and water potential and temperature of leaves were determined. There was a decrease of approximately 50% in oil content and of 60% in total flavonoid content with the reduction of leaf water potential in 0.3 MPa. Essential oil is more sensitive to water stress than total flavonoids.

Efeito de diferentes lâminas de irrigação sobre a população de meloidogyne javanica e a produtividade de bananeira no norte de minas gerais

The present work aimed to assess in the field the effect of irrigation different levels (100%, 125%, 150% and 175%) determined by evapotranspiration from the tank class A (ETtca), on the population of Meloidogyne javanica in the soil, banana productivity and number of days needs for flowering and yield of Prata-Ana cultivar of banana on the North of Minas Gerais state, Brazil. The number of second stage juveniles of M. javanica increased reaching the maximum J2 level at 118% of ETtca. The irrigation levels, 125, 150 and 175% ETtca increased the banana productity in kg/ha-1 significantly as compared to 100% level. However, no effect was observed on the number of days for flowering and for harvesting of Prata-Ana banana.

Analysis of reference evapotranspiration of Janaúba, mg

espanolEl conocimiento acerca de la evapotranspiracion de referencia (ETo) es esencial para el manejo del riego en los cultivos agricolas en todo el mundo. El metodo de Penman Monteith utiliza diversas variables meteorologicas, dificultando su utilizacion en regiones con pocas estaciones meteorologicas, como es el caso del norte de Minas Gerais. El objetivo de este trabajo fue realizar una comparacion entre los metodos de Hargreaves Samani y Penman Monteith asi como determinar la frecuencia de ocurrencia de la evapotranspiracion de referencia en el municipio de Janauba. Para evaluar el ajuste de la ecuacion de Hargreaves Samani con el metodo de Penman Monteith se utilizo el coeficiente de determinacion (r²), desempeno (c), correlacion (r), error estandar de estimativa (EPE) y el indice de concordancia (d). Para determinar la frecuencia de ocurrencia se utilizo el metodo de Kimbal. Los resultados indicaron que el metodo de Hargreaves Samani sobreestima los valores de Penman Monteith en 8%, por lo que en el analisis mensual se observa que entre los meses de abril y agosto los valores de Penman fueron superiores a los de Hargreaves. En todos los criterios estadisticos utilizados la ecuacion ajustada de Hargreaves Samani presento mejor comportamiento al compararla con el metodo de Penman Monteith. La mayor frecuencia de ocurrencia estuvo entre 4,5 y 4,7 mm dia-1 con 6,62% y la ecuacion que indico la probabilidad de igualar o superar la evapotranspiracion presento un r² igual a 0,9676. EnglishKnowledge of the reference evapotranspiration (ETo) is essential for the irrigation management of agricultural crops worldwide. The Penman Monteith demand different weather variables, which hinders its application in areas with few weather stations such as the north of Minas Gerais. This work, compare the method of Hargreaves Samani with Penman Monteith and determine the frequency of occurrence of the reference evapotranspiration in the city of Janauba, MG. To assess the fit of Hargreaves Samani equation with Penman Monteith used the coefficient of determination (r²), the coefficient of correlation (r), the standard error of estimate (SEE), the index agreement (d) and the index performance (c). Kimballs method was used for determining the frequency of occurrence. The results indicate that the Hargreaves Samani method overestimates the values of Penman Monteith at 8%, but in the monthly analysis, it is observed that between the months April to August Penman values were superior to Hargreaves. All statistical criteria used showed Hargreaves Samani fitted equation with a better assessment when compared with the Penman Monteith. The higher frequency of occurrence was between 4.5 and 4.7 mm day-1 (6.62%) and the equation that indicates the probability of being equaled or exceeded evaporation showed an r² equal to 0.9676.