São José dos Campos, Brazil
São José dos Campos, Brazil

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The indirect methods for the determination of leaf area index (LAI), which are characterized in total that measures radiation penetrate inside the cover, are currently the most used, because they are more practical. The study was to measure and estimate the leaf area index, adjust an equation through product (length x width x leaf area) and determine the light extinction coefficient in pumpkin Cucurbita moschata var. japanese. To develop a model, twenty sheets were measured by calculating the length and width and to the estimation of leaf area index were used five repetitions of 1 m2, being made three measures inside the leaves and a measure at the top of the plants. Later, its leaves were collected for leaf are a measurements in the laboratory. For obtaining the light extinction coefficient (k) were measured fifteen points of culture, in conditions of sun and shade. The LAI was measured and estimated 2.624 and 1.145, showing a mathematical model with linear growth and yields a straight and the extinction coefficient was 0.59. This work was important to determine the values of LAI measured, estimated and the extinction coefficient for the cultivation of pumpkin.


Silva G.M.C.,UENF CCTA | Biazatti M.A.,UENF CCTA | Da Silva M.P.S.,UENF CCTA | Cordeiro M.H.M.,UNIMONTES CCTA | Mizobutsi G.P.,UNIMONTES CCTA
Revista Brasileira de Fruticultura | Year: 2014

The commercial interest by atemoya is increasing more and more in Brazil. The increased respiratory activity accompanied by rapid changes in the physical composition of the fruits may prevent their distribution to distant markets. In this context, the aim of this study was to evaluate the physical attributes in atemoya fruits treated with 1-methylcyclopropene (1-MCP) and modified atmosphere associated with refrigeration. The experiment was carried out in a randomized design, in a factorial 4x5, four concentrations of 1-MCP (0, 200, 400 and 600 nL L-¹1), and five evaluation periods after harvest, in the range of five days, with four replications and four fruits per experimental unit. The atemoya were harvested, from a commercial orchard in the municipality of Matias Cardoso, North of Minas Gerais, at the physiological maturity, rinsed, sanitized and air dried, then treated with concentrations of 1-MCP for eight hours at room temperature. Soon after, four fruits were placed in polystyrene trays. Some remained without membrane, while others were packed with plastic film of LDPE 16 μm. The variables evaluated in the fruits were: fresh biomass loss, firmness, concentration of CO2, ethylene and peel color. The use of modified atmosphere and 1-MCP alone or combined, were effective in delaying fruits ripening allowing the preservation of its physical quality. Fruits treated with 1-MCP were firmer, as well as preservation of staining, verified by luminosity, chroma and Hue ° angle, which proved to be superior when compared to untreated fruits. © 2014, Sociedade Brasileira de Fruticultura. All rights reserved.


Ramos M.J.M.,EMPAER MT | Monnerat P.H.,UENF CCTA | Pinho L.G.R.,IFES
Revista Brasileira de Fruticultura | Year: 2013

The equipment Minolta SPAD-502 measures the intensity of green color of leaves and has been used in the quantification of chlorophyll, characterized by speed, simplicity, and especially by allowing a non-destructive evaluation of the leaf tissue. The objective of this study was to calibrate the SPAD reading and its correlation with the diagnosis of induced deficiencies of macronutrients and boron deficiencies involving the vegetative growth of the pineapple. The experiment consisted of eight treatments: complete, -N,-P, -K, -Ca, -Mg, -S and -B in randomized complete block with six replicates. It was evaluated the length and the width of the sheet "D" (marked) and readings taken with the SPAD 502 chlorophyll meter. The use of the method of indirect measurement of chlorophyll is suitable for assessing the nutritional status of N and vegetative growth of 'Imperial' pineapple. The value Spad and concentration of leaf N in the complete treatment are respectively: 75.7 and 14.8 g kg-1 and deficient in N: 36.6 and 9,7 g kg-1. With the exception of the deficiencies of N and P, the other treatments did not affect SPAD readings.

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