31 research outputs found
Carpochron: a concept for the time interval between the appearance of fruits in consecutive harvests
The aim of this research was to estimate the base temperature for the appearance of fruits at harvest point in the strawberry and to propose a concept to represent the time required for the appearance of fruits in consecutive harvests. The experiment was conducted in 2021 in four seedling transplanting seasons: May (season 1), June (season 2), July (season 3) and August (season 4) of two cultivars: Fronteras and Merced. Twenty-four consecutive fruit harvests were carried out from September 9, 2021, to December 1, 2021, when the number, length (cm), diameter (mm), and fresh weight of the fruits (g) were evaluated. The base temperature for the fruit emission of the strawberry was calculated using the method of the smallest mean square error. Carpochron was estimated at each season and for each cultivar, obtaining a simple linear regression between the number of fruits and the accumulated thermal sum (ºC day) and the number of days after transplanting (DAT), using as base temperature the one estimated in this work. The base temperature for the appearance of consecutive fruits at the harvest point in the strawberry is 11ºC. Carpochron increases with the delay of the transplanting season and the values ranged from 81.97ºC fruit day to 144.93ºC fruit day for cultivars Merced and Fronteras.The aim of this research was to estimate the base temperature for the appearance of fruits at harvest point in the strawberry and to propose a concept to represent the time required for the appearance of fruits in consecutive harvests. The experiment was conducted in 2021 in four seedling transplanting seasons: May (season 1), June (season 2), July (season 3) and August (season 4) of two cultivars: Fronteras and Merced. Twenty-four consecutive fruit harvests were carried out from September 9, 2021, to December 1, 2021, when the number, length (cm), diameter (mm), and fresh weight of the fruits (g) were evaluated. The base temperature for the fruit emission of the strawberry was calculated using the method of the smallest mean square error. Carpochron was estimated at each season and for each cultivar, obtaining a simple linear regression between the number of fruits and the accumulated thermal sum (ºC day) and the number of days after transplanting (DAT), using as base temperature the one estimated in this work. The base temperature for the appearance of consecutive fruits at the harvest point in the strawberry is 11ºC. Carpochron increases with the delay of the transplanting season and the values ranged from 81.97ºC fruit day to 144.93ºC fruit day for cultivars Merced and Fronteras
Fungicides application in corn disease control and mycotoxin accumulation in grain
In Brazil, corn planted area increased by 30%. Therefore, there was also an increase in the incidence of pathogens in the crop. The objective of this work was to evaluate the influence of fungicide applications on corn crops in the different growth stages for the control of the diseases and its effect on the occurrence of mycotoxins in the grain. The experiment was carried out in the 2017/2018 summer crop, in the municipality of Cruz Alta, state of Rio Grande do Sul/BR. This study used P 1630 hybrid, in a randomized block design with eight treatments (control, V8, PT, V4 + V8, V4 + V8 + PT, V8 + PT, V8 + PT + 15, PT + 15) and three replicates. The fungicide fluxapiroxade + pyraclostrobin + epoxiconazole at the dose of 1.0 L/ha-1 was used. The diseases that affected the crop were the white spot and helmintosporiosis, therefore, reducing the incidence of diseases. Also the highest yields were obtained where the applications started at the phenological stage V4 and V8. The levels of mycotoxins detected in this work remained within the limits of the legislation, with a significant reduction in the accumulation of fumonisin and aflatoxin with fungicide applications
Sample size for estimation of averages of agronomic traits in cassava seedlings
O método de multiplicação rápida melhora o uso de material de propagação. No entanto, melhorar o gerenciamento e as técnicas experimentais é crucial para avaliar a produção e a qualidade da planta. Este estudo calculou o tamanho da amostra para estimar médias de caracteres agronômicos em mudas de mandioca originárias de estacas de caule com um número diferente de folhas e diâmetros diferentes. Um total de 600 mudas (cada uma com duas gemas) com um diâmetro de 15,00 a 19,99 mm (N = 300) ou 20,00 a 25,00 mm (N = 300) da cultivar Apronta Mesa foram plantadas em diferentes épocas de cultivo (julho, agosto, Setembro e outubro). Em cada estação de plantio (22 de setembro, 7 de outubro, 19 de outubro e 25 de novembro), 300 estacas, com três a cinco ou até mais de cinco folhas visÃveis, foram coletadas. As seguintes estatÃsticas foram analisadas: mÃnimo, máximo, intervalo, média, mediana, variação, desvio padrão e coeficiente de variação. O tamanho da amostra foi determinado por reamostragem usando 2.000 reamostragens, com substituição, e foi definido pelo número de plantas a partir das quais o intervalo de confiança de 95% foi de 10%, 15% e 20% da estimativa média. O uso de estacas de caule com diâmetro superior a 20 mm e com mais de cinco folhas foi adequado para a produção de mudas de mandioca. Independentemente da faixa no diâmetro de corte e número de folhas, 87 plantas foram suficientes para estimar as médias das caracterÃsticas quando a faixa do intervalo de confiança foi de 20% da estimativa média. e 20% da estimativa média. O uso de estacas de caule com diâmetro superior a 20 mm e com mais de cinco folhas foi adequado para a produção de mudas de mandioca. Independentemente da faixa no diâmetro de corte e número de folhas, 87 plantas foram suficientes para estimar as médias das caracterÃsticas quando a faixa do intervalo de confiança foi de 20% da estimativa média. e 20% da estimativa média. O uso de estacas de caule com diâmetro superior a 20 mm e com mais de cinco folhas foi adequado para a produção de mudas de mandioca. Independentemente da faixa no diâmetro de corte e número de folhas, 87 plantas foram suficientes para estimar as médias das caracterÃsticas quando a faixa do intervalo de confiança foi de 20% da estimativa média
Efficiency of fungicide chemical group in the preventive and curative control of Puccinia sorghi in corn and Cercospora zeae-maydis sporulation in different culture media
The chemical control of diseases is one of the most used measures, especially for a rapid and precise control. The objectives of this work were to verify the behavior of three chemical groups of fungicides applied in a preventive and curative way aiming the control of common corn rust and the sporulation of Cercospora zeae-maydis in different culture media. Two experiments were installed, one for chemical control and the other for sporulation. For the chemical control experiment, propiconazole, azoxystrobin, ciproconazole + azoxystrobin and benzovindiflupir + azoxystrobin were the fungicides preventively and curatively applied for the control of common corn rust in a random block experimental design with three replicates. In relation to cercosporiosis sporulation experiment, five culture media were used: potato sucrose agar (PSA), V8 agar juice (V8), (LCHA), corn leaf extract (CL) and seasoned tomato extract (STE) were used. Discs with Mycelial of the fungus were placed on the media and submitted to the 12-hour light/12-hour dark continuous dark in a double factorial (culture media and light treatments) experimental design with four replicates. The fungicides azoxystrobin and ciproconazole + azoxystrobin were efficient for up to 21 days after inoculation of P. sorghi, the fungicide azoxystrobin was efficient for the curative control of P. sorghi. The greatest sporulation of the fungus was verified in the medium with seasoned tomato extract submitted to the photoperiod
Use of isolated fungicides for the control of Phakopsora pachyrhizi in soybean
The occurrence of diseases in soybean crop has negatively affected its development and caused significant losses in productivity. Among the diseases, Asian rust caused by the fungus Phakopsora pachyrhizi Sydow stands out because of its high severity. As a way of controlling, chemical fungicides is a tool used to mitigate the damage. The objective of this work was to evaluate the efficiency of different isolated fungicides in the control of Asian rust. The experiment was carried out in the experimental area of ​​the University of Cruz Alta in the state of Rio Grande do Sul with a randomized block design and four replications. The cultivar used was BMX Ativa, and the fungicide applications occurred before the interline closure and later with 15 days of interval between applications. The fungicides tested in the experiment were: metominostrobin + tebuconazole, piraclostrobin + fluxpyroxade, picoxystrobin + cyproconazole, Azoxystrobin + benzovindiflupir, picoxystrobin + benzovindiflupir, Trifloxystrobin + protioconazole, Pyraclostrobin + epoxiconazole + fluxpyroxade, Bixafen + protioconazole + Trifloxystrobin, Mancozebe + picoxystrobin + tebuconazole and control. The variables analyzed were yield kg ha-1, weight of one thousand seeds and disease severity. The fungicides Mancozebe + picoxystrobin + tebuconazole and bixafen + protioconazole + trifloxystrobin showed the highest yield, one thousand grain weight and lower severity of Asian soybean rust
BIOESTIMULANTE APLICADO NA SEMENTE E VIA FOLIAR NA PRODUÇÃO DE REPOLHO
O objetivo foi avaliar o efeito de doses do bioestimulante ácido 4-indol-3-ilbutÃrico + ácido giberélico + cinetina no crescimento, desenvolvimento e produtividade do repolho hibrido cultivar Musashi. Conduziu-se dois experimentos com doses de bioestimulante (0, 3, 5, 7 e 9 ml) no delineamento inteiramente casualizado com 5 repetições. O bioestimulante ácido 4-indol-3-ilbutÃrico + ácido giberélico + cinetina não influencia o crescimento, o desenvolvimento, e a produtividade de repolho
In Vitro Antioxidant Potential of Baccharis trimera and Baccharis articulata Infusions in Postmenopausal Women
Considering that postmenopausal women generally have high levels of oxidative markers and low levels of antioxidant defense markers due to the reduction of estrogen levels, and because of the vast popular use of several species of carja in the form of infusion, this study aimed to evaluate in vitro if infusions of B. trimera and B. articulata have antioxidant potential in erythrocytes of postmenopausal women and which are the most effective. The erythrocytes from 40 postmenopausal women were treated in vitro for 1 hour with infusions of B. trimera and B. articulata at the following concentrations: 4, 8, 16, 33, 66 g/L. The negative control consisted of erythrocytes from postmenopausal women without treatment with the plants. After treatment, the levels of thiobarbituric acid reactive substances (TBARS), carbonylated proteins (CP), and reduced glutathione (GSH) were measured. The infusions of B. trimera and B. articulata at concentrations of 33 (p<0.001) and 66 g/L (p<0.001) reduced the level of TBARS in comparison to the negative control, and the effect size (ES) for this reduction was small. The levels of GSH increased after treating with B. trimera infusion at a concentration of 66 (p<0.001) and with B. articulata at concentrations of 33 (p<0.001) and 66 g/L (p<0.001), when compared with the negative control, and the ES for this increase was average. The infusions of B. trimera and B. articulata show antioxidant potential in vitro, thus showing a similar effect with regards to the reduction of oxidative damage to lipids and increased endogenous antioxidant protection