Juliana Sawada Buratto

Trinexapac-ethyl (TE) is used on oat to reduce plant lodging, but little is known about its influence on seed quality. The aim of this study was to evaluate the effects of different application rates of the plant growth regulator TE on the physiological quality and yield of seeds from oat cultivars. The experiment was conducted in the 2019 and 2020 crop seasons in a randomized block design, with four replications, consisting of four rates of TE (0, 50, 100, and 150 g a.i. ha-1) applied when the primary stalk had the first visible node and the second node perceptible node on the oat cultivars URS Altiva and URS Corona. The following variables were evaluated: germination rate, accelerated aging, electrical conductivity, seedling length, seedling dry matter, seedling emergence, and seed yield. Yield response varied, as the URS Altiva cultivar showed no response, while URS Corona showed a positive response only in the 2019 crop season. Both seed germination and seed vigor, evaluated by different tests, were negatively affected as the TE application rates increased. Oat seeds remained within the minimum standards for the seed trade up to the application rate of 100 g a.i. ha-1. The application of TE reduces the germination and vigor of oat seeds.

Early maturing common-bean cultivars lack information referring to Euschistus heros (Fabricius, 1798) (Hemiptera: Pentatomidae) feeding damage assessment. This information is pertinent towards establishing economic threshold for an integrated pest management program. The aim of this study was to analyze the relationship, between the density of stink bugs and the degree of injuries towards the pod and grain production, quantity and quality, of the IPR Curió cultivar. The experiments were conducted during two seasons at the IDR-Paraná in Londrina, Paraná, in field conditions. The experimental design was randomized blocks with five repetitions. The treatments were: 0 (control); 1; 2; 3; 4; 5 E. heros m-1. The evaluated variables were number of grained and flat pods; healthy, damaged and aborted grain mass; grain yield. The economic injury level (EIL), economic threshold (ET) and spraying efficiency influence on the ET were calculated. The total number of grained pods was not affected. More than three brown stink bugs, during the summer season, significantly increases flat pod output. The rainy season resulted in greater aborted grains. Increasing E. heros densities, during the summer season, significantly reduces the healthy grain output. The damaged grain mass doubles at higher than one E. heros population densities. The total grain mass produced was not affected. During the summer season, each E. heros reduces 11% of healthy grain output, and during the rainy season 6%. During the summer season was 1.50 of E. heros m-1 and for the rainy season 1.00 E. heros m-1. The spraying efficiency should directly affect the EIL, modifying the value, thus better resembling the field conditions.

Growth regulators can mitigate lodging damage. However, their effects on the physiological quality of seeds are not widely known. This study aimed to assess the effects of trinexapac-ethyl application rate and timing on the yield and physiological quality of white oat seeds. The experiment was conducted in Londrina, Paraná, Brazil, in the 2019 and 2020 cropping seasons using a randomized block design with a 4 × 3 factorial arrangement and four replications. Treatments consisted of four trinexapac-ethyl rates (0, 50, 100, and 150 g ha−1) and three application timings (E1, first node detectable; E2, stem elongation phase from first node visible to second node detectable; and E3, second node visible to third node detectable). Seed yield, thousand seed weight, germination rate, seedling length, seedling dry weight, accelerated aging, electrical conductivity, and seedling emergence in sand were evaluated. The results showed that trinexapac-ethyl at 100 and 150 g ha−1 at E2 and E3 increased seed yield in white oat IPR Artemis. However, all rates negatively affected thousand seed weight, germination rate, and seed vigor, reducing the establishment capacity and initial development of white oat plants. Uso de reguladores de crescimento podem mitigar danos provocados pelo acamamento. No entanto, seus efeitos na qualidade fisiológica de sementes não são amplamente conhecidos. O objetivo deste trabalho foi avaliar o efeito de diferentes doses e épocas de aplicação do trinexapac-etil na produtividade e na qualidade fisiológica de sementes de aveia branca. O experimento foi conduzido no município de Londrina-PR, nas safras 2019 e 2020, sob o delineamento experimental de blocos ao acaso com quatro repetições, em esquema fatorial 4 x 3, sendo quatro doses de trinexapac-etil (0, 50, 100 e 150 g ha-1) e três épocas de aplicação (E1: plantas com o 1º nó perceptível; E2: plantas na fase de elongação do colmo, entre o 1° nó visível e o 2° nó perceptível e E3: plantas com o 2º nó visível e 3º nó perceptível). Foram avaliados: produtividade de sementes, massa de mil sementes, germinação, comprimento e massa seca de plântulas, envelhecimento acelerado, condutividade elétrica e emergência de plântulas em areia. Ao término do estudo verificou-se que a aplicação do trinexapac-etil nas doses de 100 e 150 g ha-1 nas épocas de aplicação E2 e E3 aumentou a produtividade de sementes da cultivar IPR Artemis, porém todas as doses de trinexapac-etil afetou a massa de mil sementes, a porcentagem de germinação e o vigor destas, reduzindo a capacidade de estabelecimento e desenvolvimento inicial das plantas.

Quantitative colorimetry can be used to characterize the color of triticale seeds submitted to the phenol test. This study aimed to characterize the color of triticale seeds after the phenol test by visual color evaluation and quantitative colorimetry using the CIELAB color space. The evaluated seeds came from 88 triticale genotypes from the IDR-Paraná Germplasm Bank. The colorimetric data for L (lightness) and chromaticity coordinates a* and b* of the seeds before and after phenol reaction were obtained using a Minolta CR-400 colorimeter. The score scale ranged from 1 (very weak or absent color) to 9 (very dark color) and evaluated visually the seed color after phenol reaction. Seeds classified as score 1 showed mean values of 46.3, 6.6, and 16.4 for L, a*, and b*, respectively. On the other hand, seeds classified as dark or very dark showed values equal to or lower than 28.4 for L, 5.6 for chromaticity a*, and 6.0 for chromaticity b*. The use of colorimetric parameters showed a practical application and low subjectivity in the classification of the color of triticale seeds after phenol reaction.

The loss caused by the shoot-fly (Neosilba perezi) was simulated through the elimination of the cassava`s terminal buds, with the objective to quantify this effect towards the roots productivity, flour production and propagative material production (stem cuts). The experimental design was random blocks, with three repetitions, in a factorial scheme with an additional treatment (10 × 4 + 1). Ten damage levels (10, 20, 30, 40, 50, 60, 70, 80, 90 and 100%) were studied, including a witness treatment (0%). The cassavas were treated during each of the four seasons of the year. The studied variables were: root productivity (t ha-1), flour production (t ha-1) and number of stem cuttings with a diameter greater than 20 and 25 mm. The induced damage in the cassava`s meristem did not significantly affect the root, nor the flour production. However, the stem cuttings production demonstrated a linear decrease in relation to the apical meristem damage level.

O presente estudo teve como objetivo avaliar o desempenho agronômico e estimar a dissimilaridade genética entre acessos de amendoim do banco de germoplasma do Instituto Agronômico do Paraná (IAPAR), visando à identificação de acessos potencialmente úteis para o programa de melhoramento genético. O ensaio foi conduzido em Londrina, no ano agrícola 2011/2012 em delineamento experimental de blocos ao acaso, com quatro repetições. A severidade da mancha castanha (Cercospora arachidicola), mancha preta (Cercosporidium personatum), mancha barrenta (Phoma arachidicola), ferrugem (Puccinia arachidis) e verrugose (Sphaceloma arachidis) foram mensuradas com o auxílio da escala diagramática proposta pela Biodiversity International. O rendimento de grãos foi transformado para kg ha-1 e corrigido para 10% de umidade.

RESUMO O déficit hídrico durante o desenvolvimento do amendoinzeiro prejudica vários processos fisiológicos da planta e reduz sua produtividade. Este estudo objetivou avaliar o rendimento de grãos, componentes de produção e crescimento de cultivares e linhagens de amendoim submetidas a déficit hídrico, em condições de campo. O delineamento experimental foi o de blocos ao acaso, com parcelas subdivididas e três repetições. Os tratamentos de déficit hídrico (com e sem) constituíram as parcelas e os genótipos avaliados (IAC Tatu ST, BR1, BRS Havana, Col 72 e Col 82) as subparcelas. A irrigação foi suspensa nas parcelas submetidas à deficiência hídrica entre 35 e 75 dias após a emergência. O crescimento das plantas, massa seca da parte aérea e área foliar foram afetados negativamente pelo déficit hídrico. Verificou-se incremento da diferença entre as parcelas com e sem deficiência hídrica, conforme o aumento do período de supressão de água. A cultivar BRS Havana e a linhagem Col 82 apresentaram tolerância moderada à seca, com os maiores rendimentos de grãos em condição de déficit hídrico. O déficit hídrico foi responsável por redução de 68 % no rendimento de grãos na cultivar IAC Tatu ST, 44 % no número de vagens por planta na linhagem Col 82, 11 % no número de sementes por vagem na linhagem Col 72 e 11 % na massa de 100 sementes na cultivar BRS1.