Paulo Ricardo Lima

Avaliação morfofisiológica em mudas de Handroanthus impetiginosus (Mart. ex DC.) Mattos durante a rustificação

The present study aimed to quantify the effects of hydric management during the hardening process of Handroanthus impetiginosus seedlings by means of foliar thermography and morphometric parameters of quality. Irrigation treatments of 60 seedlings each were carried out at the following frequencies: daily (control), and every two, three, and four days for four weeks. Measures of leaf temperature (LT), height increment, collar diameter, and root dry mass were performed. Quantification of LT occurred at the end of each irrigation management cycle and analysis of the other variables studied was performed at the beginning and end of the hardening process. Seedlings of H. impetiginosus irrigated daily presented higher diameter increment in relation to those irrigated every three days, and the seedlings irrigated every four days showed higher root system growth and reduction of aerial part growth. The use of infrared thermometry allowed LT assessment in seedlings of H. impetiginosus during hardening. It was possible to verify that the longer the water stress period, the higher the leaf temperature, with the highest temperature observed in seedlings irrigated every four days.

Avaliação Morfofisiológica em Mudas de Handroanthus impetiginosus (Mart. ex DC.) Mattos Durante a Rustificação / Morphophysiological Evaluation in Seedlings of Handroanthus impetiginosus (Mart. ex DC.) Mattos During Hardening

The present study aimed to quantify the effects of hydric management during the hardening process of Handroanthus impetiginosus seedlings by means of foliar thermography and morphometric parameters of quality. Irrigation treatments of 60 seedlings each were carried out at the following frequencies: daily (control), and every two, three, and four days for four weeks. Measures of leaf temperature (LT), height increment, collar diameter, and root dry mass were performed. Quantification of LT occurred at the end of each irrigation management cycle and analysis of the other variables studied was performed at the beginning and end of the hardening process. Seedlings of H. impetiginosus irrigated daily presented higher diameter increment in relation to those irrigated every three days, and the seedlings irrigated every four days showed higher root system growth and reduction of aerial part growth. The use of infrared thermometry allowed LT assessment in seedlings of H. impetiginosus during hardening. It was possible to verify that the longer the water stress period, the higher the leaf temperature, with the highest temperature observed in seedlings irrigated every four days.

Agronomic characteristics and oil content of Brazilian sunflower hybrdids under different sowing densities

The sunflower (Helianthus annuus L.) has good productive capacity and the increase in production is possible by using hybrids adapted to the sowing region and an adequate arrangement of plants without losing quality and oil content. The objective of this work was to evaluate two sunflower hybrids cultivated in different sowing densities, observing the influence on the agronomic characteristics and oil content of the cultivation. The experiment was conducted at the experimental field of the Pontifical Catholic University of Paraná, Toledo. The experimental design was randomized blocks in 2 × 4 factorial scheme, with four repetitions consisted of two plant genotypes (BRS324 and M734) and four plant densities (30, 40, 50 and 60 thousand ha-1 plants). The variables analyzed in the field were: plant height, stem diameter, number of leaves, chapter thickness and chapter size. On the other hand, the variables: mass of one thousand sunflower achene, yield and oil content were analyzed at PUCPR laboratory. According to the results obtained, there was interaction between the density of the BRS324 genotype with plant height, stem diameter and mass of a thousand sunflower achene. For the other variables there was a significant difference as a function of the genotype. The cultivar BRS324 produced a better oil content. For plant height and stem diameter, the cultivar showed opposite behavior, possibly due to adaptation in the western region of Paraná. The variable mass of one thousand sunflower achene was decreased due to the increase of the population density for cultivar BRS324.

Maturidade fisiológica de sementes de tungue (Aleurites fordii Hemsl.)

The test aimed to determine the physiological maturity of the seeds from tung nut trees (Aleurites fordii Hemsl.). Ten four-year-old fruits trees were collected in Cascavel - PR. The experiment followed a completely randomized design, with four fruit maturation stages and five replicates with 25 seeds each. The fruits were classified into three classes using the color of the epicarp and collected directly from the ground. To characterize the physiological maturity, digital colorimetric and biometric parameters were utilized. In seeds, the mass of dry matter, moisture content, germination and emergence speed index were determined. The seeds extracted from fruits with light brown eye color had higher dry matter, lower water content and percentage of germination and emergence rate, indicating the physiological maturity of seeds. Fruits collected from the ground are not suitable for seed collection. The harvest of the fruits to obtain seeds with physiological maturity is recommended when the fruits show light brown visual staining reflectance values in the visible spectrum (RGB) of 96.1, 69.9 and 64.1, respectively.

Physiological maturity of seeds and colorimetry of yellow passion fruit (Passiflora edulis f. flavicarpa Degener)

The passion fruit is among the major fruit crops grown in Brazil, being propagated by seeds due to ease of implementation. However, obtaining seeds of quality is associated with the proper time of collection. Thus, the objective was to determinate the physiological maturity of seeds of passion fruit (

Chlorophyll a fluorescence in two varieties of sugar cane subjected to aluminum and water stress

Soils of open pasture in the Cerrado (brazilian savanna) have farming limitations related to the high content of aluminum and water restrictions in the superficial horizons, due to easy drainage and large exposure to high levels of irradiance. Aiming to assess chlorophyll a fluorescence’s responses in two varieties of sugar cane in the State of Mato Grosso do Sul subjected to water restriction and different aluminum contents, an experiment was conducted in a controlled environment. The experimental lineation consisted of random blocks in a factorial scheme (2 varieties x 2 levels of water available in the soil based on field capacity [cc] and 3 contents of Al +3 ), with 15 replications. Significant differences were observed throughout and at the end of the experiment between the averages of some parameters of chlorophyll a fluorescence for treatment EH1 and between varieties. Results obtained by means of the OJIP test were the most efficient for variety distinction. RB1 (RB 8555536) proved to be more responsive to treatments, variety RB2 (RB867515) did not present significant alterations between treatments; its suggests that most part of the radiation was efficiently used in the photochemical stage of photosynthesis, that makes it more tolerant to the subjected stresses.