SISTEMA LASER SCANNER AEROTRANSPORTADO APLICADO NA DETERMINAÇÃO DE VOLUMES DE PILHAS DE MINÉRIO: ESTUDO COMPARATIVO

A tecnologia Laser Scanner revolucionou a forma de coletar e registrar informações topográficas bem como de detalhes construtivos. Sua aplicação, em função de suas características, tem se expandido às mais diversificadas áreas. Este artigo apresenta uma aplicação do sistema Laser Scanner Aerotransportado (LSA) na coleta de dados para a geração de Modelos Digitais de Terrenos (MDT), destinados à determinação de volumes de pilhas de minério estocado. A maioria das pilhas apresenta conformações físicas bastante irregulares, com pontos de difícil acesso, comprometendo assim, a segurança dos operadores responsáveis pela coleta de dados em campo, quando se utiliza técnicas diretas de levantamentos como, por exemplo, a tecnologia GPS (Global Positioning System). Foram realizadas coletas de dados em campo, utilizando as tecnologias GPS e LSA, e observados alguns parâmetros variáveis que podem influenciar nos resultados e/ou nos processos operacionais. Os resultados obtidos pelo emprego das duas tecnologias são analisados e comparados, e também relacionados aos valores advindos do processo produtivo da mina, mostrando que os levantamentos pelo LSA apresentam algumas vantagens, como um alto rendimento, um maior detalhamento nos MDT e uma maior segurança ocupacional

Parâmetros fisiológicos em plantas de tomate submetidas à salinidade e tratadas com brassinosteroide

The objective of this work was to evaluate the effects of brassinosteroid on chlorophyll a fluorescence parameters, the SPAD index, and leaf succulence in young tomato (Lycopersicon esculentum) plants under salt stress. The experimental design was a randomized complete block, in a 5×2 factorial arrangement – five levels of water salinity (0.5, 1.5, 3.0, 4.5, and 6.0 dS m-1) × two rates of 24-epibrassinolide (0 and 10-6 mol L-1 EBL). At 23 days, the treatment without EBL showed that the increase of water salinity reduced the maximum, primary, and effective photochemical efficiency of PSII, as well as the electron transport rate, the SPAD index, leaf succulence, total dry mass, and the stress tolerance index, but increased initial fluorescence and relative excess energy in PSII. With the increase of water salinity, in the EBL treatments, there was an increase in the effective photochemical efficiency of PSII, the electron transport rate, the SPAD index, leaf succulence, total dry mass, and the stress tolerance index. EBL promotes beneficial effects on PSII integrity, the chlorophyll index, and leaf succulence in young tomato plants subjected to salinity levels of up to 6.0 dS m-1.O objetivo deste trabalho foi avaliar os efeitos de brassinosteroide sobre os parâmetros de fluorescência da clorofila a, o índice SPAD e a suculência foliar em plantas jovens de tomate (Lycopersicon esculentum) sob estresse salino. O delineamento experimental utilizado foi o em blocos ao acaso, em arranjo fatorial 5×2 – cinco níveis de salinidade da água (0,5, 1,5, 3,0, 4,5 e 6,0 dS m-1) × duas doses de 24-epibrassinolídeo (0 e 10-6  mol L-1 de EBL). Aos 23 dias, o tratamento sem EBL mostrou que o aumento da salinidade da água reduziu a eficiência fotoquímica máxima, primária e efetiva do PSII, assim como a taxa de transporte de elétrons, o índice SPAD, a suculência foliar, a massa de matéria seca total e o índice de tolerância ao estresse, mas aumentou a fluorescência inicial e o excesso relativo de energia no PSII. Com o aumento da salinidade, nos tratamentos com EBL, houve aumento da eficiência efetiva do PSII, da taxa de transporte de elétrons, do índice SPAD, da suculência foliar, da matéria seca total e do índice de tolerância ao estresse. O epibrassinolídeo promove efeitos benéficos sobre a integridade do PSII, o índice de clorofila e a suculência foliar em plantas jovens de tomate submetidas a níveis de até salinidade 6,0 dS m-1

EFFECTS OF 24-EPIBRASSINOLIDE ON GERMINATION AND GROWTH OF TOMATO SEEDLINGS UNDER SALT STRESS

Salinity is one of the environmental stresses that most affects plants' vital processes, especially germination. Brassinosteroids, including 24-epibrassinolide (EBL), have multiple actions in essential processes in plants. Thus, this research's objective was to evaluate the effects of EBL on tomato seeds' physiological conditioning on germination, growth, and production of dry seedling mass under salinity conditions. The experiment was carried out in a 2x5 factorial scheme, as follows: two concentrations of EBL (0 and 10-6 M) and five levels of salinity (0.5 control; 1.5; 3.0; 4.5 and 6.0 dS m-1), consisting of ten treatments, with four replications of 50 seeds. In isolation, the salt stress reduced the percentage of germination and germination speed index from four to 14 days, besides all the plants' growth traits. In turn, the EBL increased the percentage of germination, germination speed index, seedling length, and radicle dry matter. The application of 10-6 M of EBL in seed immersion no effect on the seed germination of IPA 6 tomato cultivar under salt stress but increases the root length and the dry matter of the seedlings.Salinity is one of the environmental stresses that most affects plants' vital processes, especially germination. Brassinosteroids, including 24-epibrassinolide (EBL), have multiple actions in essential processes in plants. Thus, this research's objective was to evaluate the effects of EBL on tomato seeds' physiological conditioning on germination, growth, and production of dry seedling mass under salinity conditions. The experiment was carried out in a 2x5 factorial scheme, as follows: two concentrations of EBL (0 and 10-6 M) and five levels of salinity (0.5 control; 1.5; 3.0; 4.5 and 6.0 dS m-1), consisting of ten treatments, with four replications of 50 seeds. In isolation, the salt stress reduced the percentage of germination and germination speed index from four to 14 days, besides all the plants' growth traits. In turn, the EBL increased the percentage of germination, germination speed index, seedling length, and radicle dry matter. The application of 10-6 M of EBL in seed immersion no effect on the seed germination of IPA 6 tomato cultivar under salt stress but increases the root length and the dry matter of the seedlings

Chlorophyll fluorescence as a tool to select salinity-tolerant cowpea genotypes

The use of saline water reduces the growth and productivity of crops, so the need for techniques that make possible the use of this resource such as the use of salinity tolerant genotypes and efficient selection methods are of great importance. Thus, this study aimed to evaluate the tolerance of cowpea (Vigna unguiculata L. Walp.) genotypes to salt stress, through the chlorophyll fluorescence analysis. The experiment was conducted in a protected environment at the Federal University of Campina Grande, Paraíba, Brazil, using a completely randomized design in a 2 x 10 factorial arrangement, with three replications, consisting of two levels of irrigation water salinity (0.6 and 5.1 dS m-1) and ten cowpea genotypes: (G1: MNCO1-649F-2-1, G2: MNCO3-736F-2, G3: PINGO DE OURO-1-2, G4: BRS GURGUÉIA, G5: BRS MARATAOÃ, G6: MNCO2-676F-3, G7: MNCO2-683F-1, G8: MNCO3-737F-5-4, G9: MNCO3-737F-5-9, and G10: BRS TUMUCUMAQUE). The stem length, stem diameter, SPAD index, and chlorophyll fluorescence transients were evaluated. The G2 and G4 genotypes had the lowest reductions in the growth, stem diameter, initial fluorescence, and primary and maximum photochemical efficiency of PSII, proving to be tolerant to salinity. Chlorophyll fluorescence is a tool that can be used in the selection of salinity-tolerant cowpea genotypes.The use of saline water reduces the growth and productivity of crops, so the need for techniques that make possible the use of this resource such as the use of salinity tolerant genotypes and efficient selection methods are of great importance. Thus, this study aimed to evaluate the tolerance of cowpea (Vigna unguiculata L. Walp.) genotypes to salt stress, through the chlorophyll fluorescence analysis. The experiment was conducted in a protected environment at the Federal University of Campina Grande, Paraíba, Brazil, using a completely randomized design in a 2 x 10 factorial arrangement, with three replications, consisting of two levels of irrigation water salinity (0.6 and 5.1 dS m-1) and ten cowpea genotypes: (G1: MNCO1-649F-2-1, G2: MNCO3-736F-2, G3: PINGO DE OURO-1-2, G4: BRS GURGUÉIA, G5: BRS MARATAOÃ, G6: MNCO2-676F-3, G7: MNCO2-683F-1, G8: MNCO3-737F-5-4, G9: MNCO3-737F-5-9, and G10: BRS TUMUCUMAQUE). The stem length, stem diameter, SPAD index, and chlorophyll fluorescence transients were evaluated. The G2 and G4 genotypes had the lowest reductions in the growth, stem diameter, initial fluorescence, and primary and maximum photochemical efficiency of PSII, proving to be tolerant to salinity. Chlorophyll fluorescence is a tool that can be used in the selection of salinity-tolerant cowpea genotypes

WEED CONTROL BY SOLARIZATION AND MULCHING IN COWPEA DEVELOPMENT

Weeds are a serious threat to agriculture because they compete with crops, thereby interfering in production. As such, this study aimed to assess weed control using soil solarization and mulching on the growth and yield of cowpea. A completely randomized design was used, with eight treatments and four repetitions. The treatments consisted of a combination of two management practices, namely soil solarization (with and without) and three mulches (castor bean, rattlepod and spontaneous vegetation), as well as no mulching. Non-solarized soil and without mulch increased the number and dry weight of weeds, while the main stem length of the cowpea plants decreased. Mulching increased the pod length and number of seeds per pod regardless of solarization, as well as shoot dry weight and moisture content. By contrast, root dry weight increased in the absence of mulching, particularly in non-solarized soil. Soil solarization reduces weed infestation in cowpea crops, especially when associated with mulching

Soil management and mulching for weed control in cowpea

More efficient weed control managements can be achieved through different strategies, given that the population of these plants changes according to the system used. This study aimed at assessing solarization methods associated with different mulches for weed control in the cowpea crop. The methods used were soil solarization, with plastic sheeting and with solar collector, associated with the following mulches: castor bean, rattlepod and spontaneous vegetation. Weed phytosociology was calculated by frequency, density and abundance. The most infesting families were Asteraceae, Poaceae and Amaranthaceae. The species with the highest frequency, density and abundance in the treatments without mulching was Cyperus rotundus, while Bidens spp. occurred only in non-solarized soil and without mulching. The largest number of weeds was found in the treatments without mulching in non-solarized soil or soil solarized with plastic sheeting, the latter being less efficient than the solar collector. Mulching inhibits the weed infestation in cowpea crops, irrespective of soil solarization. However, rattlepod as mulch is more efficient in the solarization with plastic sheeting than with a solar collector

Effects of different resistance training frequencies on flexibility in older women

Objective The main purpose of the investigation reported here was to analyze the effect of resistance training (RT) performed at different weekly frequencies on flexibility in older women. Participants and methods Fifty-three older women (≥60 years old) were randomly assigned to perform RT either two (n=28; group “G2x”), or three (n=25; group “G3x”) times per week. The RT program comprised eight exercises in which the participants performed one set of 10–15 repetitions maximum for a period of 12 weeks. Anthropometric, body-composition, and flexibility measurements were made at baseline and post-study. The flexibility measurements were obtained by a fleximeter. Results A significant group-by-time interaction (P\u3c0.01) was observed for frontal hip flexion, in which G3x showed a higher increase than G2x (+12.8% and +3.0%, respectively). Both groups increased flexibility in cervical extension (G2x=+19.1%, G3x=+20.0%), right hip flexion (G2x=+14.6%, G3x=+15.9%), and left hip flexion (G2x=+25.7%, G3x=+19.2%), with no statistical difference between groups. No statistically significant differences were noted for the increase in skeletal muscle mass between training three versus two times a week (+7.4% vs +4.4%, respectively). Conclusion Twelve weeks of RT improves the flexibility of different joint movements in older women, and the higher frequency induces greater increases for frontal hip flexion

Indução de tolerância ao estresse salino em sementes de tomateiro condicionadas com ácido salicílico

Salinity affects millions of acres of farmland worldwide, and is increasing every day. Therefore, tolerance inducers in plants have been widely used, among them salicylic acid. Thus, it was aimed to investigate the effects of different concentrations of salicylic acid on germination and growth of tomato seedlings in saline conditions. The treatments were arranged in a completely randomized design, in a 4 × 2 factorial (four concentrations of salicylic acid: 0, 0.25, 0.5 and 1.0 mM; and two stress treatments: control and saline stress), with four replicates. The salicylic acid, when at the concentration of 1.0 mM and in saline condition, inhibits the percentage and rate of germination speed in tomato seeds in the initial phase. The salinity reduces the percentage and rate of germination speed of tomato seeds, besides the growth and water content in the seedlings, but increases the dry mass of the aerial part. The increase in salicylic acid concentrations, in salinity condition, increases seedling growth and relative water content, and decreases the extravasation of electrolytes, improving growth vigor index.La salinidad afecta a millones de hectáreas de tierra cultivable en todo el mundo y aumenta cada día. Por lo tanto, los inductores de tolerancia en plantas se han usado ampliamente, incluido el ácido salicílico. Por lo tanto, el objetivo fue investigar los efectos de diferentes concentraciones de ácido salicílico en la germinación y el crecimiento de las plántulas de tomate, en condiciones de salinidad. Los tratamientos se organizaron en un diseño completamente al azar, en un factorial 4 × 2 (cuatro concentraciones de ácido salicílico: 0; 0.25; 0.5 y 1.0 mM; y dos tratamientos de estrés: control y estrés salino), con cuatro repeticiones El ácido salicílico, cuando está a una concentración de 1.0 mM y en condiciones salinas, inhibe el porcentaje y la velocidad de germinación en las semillas de tomate en la fase inicial. La salinidad reduce el porcentaje y la velocidad de germinación de las semillas de tomate, además del crecimiento y el contenido de agua en las plántulas, pero aumenta la masa seca de la parte aérea. El aumento en las concentraciones de ácido salicílico, en condiciones de salinidad, aumenta el crecimiento de las plántulas y el contenido relativo de agua, y disminuye la fuga de electrolitos, mejorando el índice de vigor del crecimiento.A salinidade afeta milhões de hectares de terras agricultáveis em todo o mundo, e vem aumentando a cada dia. Portanto, indutores de tolerância em plantas têm sido largamente utilizados, entre eles o ácido salicílico. Assim, objetivou-se investigar os efeitos de diferentes concentrações de ácido salicílico na germinação e no crescimento de plântulas de tomate, em condições de salinidade. Os tratamentos foram arranjados em delineamento inteiramente casualizado, em fatorial 4 × 2 (quatro concentrações de ácido salicílico: 0; 0,25; 0,5 e 1,0 mM; e dois tratamentos de estresse: controle e estresse salino), com quatro repetições. O ácido salicílico, quando na concentração de 1,0 mM e em condição salina, inibe a porcentagem e o índice de velocidade de germinação em sementes de tomate na fase inicial. A salinidade reduz a porcentagem e o índice de velocidade de germinação das sementes de tomate, além do crescimento e teor de água nas plântulas, mas aumenta a massa seca da parte aérea. O acréscimo nas concentrações de ácido salicílico, em condição de salinidade, aumenta o crescimento das plântulas e o teor relativo de água, e diminui o extravasamento de eletrólitos, melhorando o índice de vigor do crescimento