scholarly journals Physiological and sanitary quality of ryegrass seeds submitted to different defoliation frequencies

2022 ◽  
Vol 52 (6) ◽  
Author(s):  
Ricardo Pereira da Cunha ◽  
Joice Fernanda Lübke Bonow ◽  
Andréa Mittelmann ◽  
Manoel de Souza Maia ◽  
Alberto Bohn ◽  
...  

ABSTRACT: This study determined the effect of different defoliation frequencies in a long-cycle ryegrass cultivar on yield components and the physiological and sanitary quality of seeds. Four defoliation frequencies were applied (without, one, two, and three defoliations). The time between defoliations was 350 degree-days. At the first, second, and third defoliation time, the plants were 15 cm, 20 cm, and 35 cm, respectively, and were lowered to half their height. The yield components and plant structure were evaluated through the tillers, along with the physiological quality of the seeds, which was verified by germination tests, first germination count, accelerated aging, tetrazolium test, field emergence, and weight of a thousand seeds. For the sanitary quality analysis, the percentage (%) of fungi incidence in the seeds was verified. The second defoliation determined the seeds’ high physiological and sanitary quality due to the higher amount of primary and secondary tillers produced concerning the other treatments. However, there was no significant difference for the third defoliation since the aerial tillers issued the same quality of seeds originated from primary and secondary tillers. The average incidence of fungi such as Colletotrichum sp., Fusarium sp., Phoma sp., and Dreshslera spp. was lower in ryegrass plants subjected to three defoliations.

2013 ◽  
Vol 35 (4) ◽  
pp. 449-456 ◽  
Author(s):  
Daniele Nerling ◽  
Cileide Maria Medeiros Coelho ◽  
Rubens Onofre Nodari

The physiological quality is based on the genotype and may be accompanied since the first stages of selection through the study of genetic diversity. The purpose of this study was to evaluate the parental genetic contribution in the seed physiological quality in corn intervarietal crossbreeds. The intervarietal crossbreeds were performed using landraces genotypes, open pollinated varieties and commercial hybrids. The seeds obtained from the crossbreed, their equivalents and parentals were evaluated regarding their water percentage, germination, germination speed rate, accelerated aging, field emergence and electrical conductivity. The seeds obtained in the crossbreed are viable and vivid with heterosis when compared with the parentals. The accelerated aging test was more effective for selecting the strongest genotypes. The canonical variables were useful to group the genotypes that presented similar physiological characteristics. The genotypes MPA 01 x Pixurum 05, MPA 01 x AS1565, MPA 01 x SJC5886, SJC5886 x Pixurum 05 and Fundacep 35 x SCS 154 Fortuna were the best crossbreeds regarding the production of better physiological quality seeds.


2018 ◽  
Vol 39 (2) ◽  
pp. 855 ◽  
Author(s):  
Janete Denardi Munareto ◽  
Thomas Newton Martin ◽  
Tania Maria Müller ◽  
Ubirajara Russi Nunes ◽  
Guilherme Bergeijer da Rosa ◽  
...  

Seed treatment is a practice that helps the initial establishment of the crop without the effects caused by pests and diseases. The association of diazotrophic bacteria with grasses has been used in the supply of nitrogen to plants; however, these microorganisms produce growth-promoting substances, which promote benefits in the growth and development of the crops. Thus, the objective of this study was to evaluate the compatibility of Azospirillum brasilense associated with the fungicide difenoconazole and the insecticide thiamethoxam by observing the effects on the quality of seed emergence of three wheat cultivars (Triticum aestivum L.). Three wheat cultivars, arranged in a 4 x 2 factorial system with four replicates, were tested. The treatments were the control; difenoconazole (Spectro® at a dose of 150 mL per 100 kg of seed); thiamethoxam (Cruiser® FS 350 at a dose of 200 mL per 100 kg seed) and difenoconazole + thiamethoxam, applied on wheat cultivars TBIO Mestre, TBIO Itaipu and TBIO Sinuelo. Bacteria from the Azospirillum genus were used in the inoculation. The wheat seed retains its quality when it checks the germination, vigor and independent accelerated aging, whether or not fungicide, insecticide and A. brasilense were used. The insecticide thiamethoxam increased the length of shoots and roots and provided compatibility with A. brasilense, and fungicide inhibited the length of shoots and roots and was antagonistic to the bacterium A. brasilense.


Revista CERES ◽  
2013 ◽  
Vol 60 (2) ◽  
pp. 286-292
Author(s):  
Cristiane Fortes Gris ◽  
Edila Vilela de Resende Von Pinho ◽  
Maria Laene de Moreira Carvalho ◽  
Rafael Parreira Diniz ◽  
Thaís de Andrade

Differences in levels of lignin in the plant between conventional and transgenic cultivars RR has been reported by several authors, however, there are few studies evaluating the influence of spraying of glyphosate on the lignin in the plant and RR soybean seeds. The aim of this study was to evaluate the physiological quality of RR transgenic soybean seeds and the lignin contents of plants sprayed with the herbicide glyphosate. The assays were conducted both in greenhouse and field in the municipality of Lavras, MG, in the agricultural year 2007/08. The experiment was arranged in a splitplot design with four replicates, considering the treatments hand weeding and herbicide glyphosate as plots, and five RR soybean cultivars (BRS 245 RR, BRS 247 RR, Valiosa RR, Silvânia RR and Baliza RR) as splitplots. In the greenhouse, the cultivars tested were BRS 245 RR and Valiosa RR in a randomized block design with four replicates. The sprayings were carried out at stages V3, V7 and early R5 (3L/ha). The 1000 seed weight, mechanical injury, germination and germination velocity index, emergence velocity index, accelerated aging, electrical conductivity and water soaking seed test, lignin content in the seed coat, in the stem and legumes were determined. The spraying of glyphosate herbicide, in greenhouse and field, did not alter the physiological quality of seeds and the lignin contents in the plant.


2013 ◽  
Vol 35 (1) ◽  
pp. 86-91 ◽  
Author(s):  
Samantha Rigo Segalin ◽  
Caroline Huth ◽  
Thais D'Avila Rosa ◽  
Diógenes Barella Pahins ◽  
Liliane Marcia Mertz ◽  
...  

Adequate nutrients for plants are important for increasing the yield and quality of the seeds produced. The objective of this study was to evaluate foliar fertilization with silicon in wheat and its effect on seed yield and physiological quality. Treatments consisted of two silicon dosages (three and six liters silicon per hectare) and the control (no silicon) and five wheat cultivars: OR "Quartzo", OR "Ônix", Fundacep "Linhagem", Fundacep "Campo Real" and Fundacep "Horizonte". The experimental design was randomized blocks with four replications. After physiological maturity, harvesting and threshing of the seeds were done manually. Seed samples were evaluated for yield and physiological quality from the germination test, first germination count, seedling dry weight, accelerated aging, electrical conductivity, 1000 seeds and hectoliter weights. The results showed that the foliar application of silicon at the dosages tested did not affect the yield and physiological quality of the seeds produced by the wheat cultivars.


2015 ◽  
Vol 28 (4) ◽  
pp. 127-134
Author(s):  
CHARLINE ZARATIN ALVES ◽  
GUSTAVO MARTINS ZAQUEU ◽  
ERIC FABIANO SERAGUZI ◽  
AGUINALDO JOSÉ FREITAS LEAL ◽  
JOSUÉ BISPO DA SILVA

ABSTRACT: The aim of this study was to evaluate the effect of the sowing periods in production, productivity component and physiological quality of seeds of three soybean cultivars (TMG133RR, P98Y70RR and NS7670RR) in Orthic Quartzarenic Neosoil in the cerrado region. The design used was a randomized block a factorial scheme design with four repetitions, and each plot with useful space consisted of three rows of four meters length, spaced at 0.45 meters. Field evaluations were the final stand, the height of the plants, height of the first pod insertion, the mass of 100 seeds and productivity. Already in the lab seeds were evaluated for germination and vigor (first germination count, emergency, emergence speed index, length and dry mass of the aerial part of the plant and roots, electrical conductivity, accelerated aging and tetrazolium test). It concludes that it is possible to use Orthic Quartzarenic Neosoils, located in the Cerrado region at altitudes higher than 600 m, in years and places with good water distribution in the spring-summer seasons, for grain and soybeans production, but as a first goal, the crop should be sown in the first 20 days of November otherwise it should take place in early December.


2021 ◽  
Vol 43 ◽  
Author(s):  
Carolina Pereira Cardoso ◽  
José Henrique Bizzarri Bazzo ◽  
Jéssica de Lucena Marinho ◽  
Claudemir Zucareli

Abstract: Initial seed vigor and sowing density interact in establishment of plants in the field, and can thus affect expression of the plasticity of the wheat crop and the yield and physiological quality of the seeds produced. The aim of this study was to evaluate the effect of seed vigor levels in combination with sowing densities on the yield and physiological potential of wheat seeds. The cultivars BRS Gralha-Azul and BRS Sabiá were used in a randomized block experimental design in a 2 × 4 factorial arrangement, with four replications. The treatments consisted of seeds of high and low vigor and four sowing densities (150, 250, 350, and 450 seeds.m-2). The following evaluations were made: seed yield, germination, first germination count, seedling length, seedling dry matter, accelerated aging, emergence speed index, and seedling emergence in sand. An increase in sowing density favors the seed yield of both cultivars; however, it reduces the vigor of the seeds produced by the cultivar BRS Gralha-Azul, especially of the seeds produced by plants originating from high vigor seeds. For the cultivar BRS Sabiá, an increase in sowing density decreases the germination performance of seeds produced by plants originating from low vigor seeds.


2013 ◽  
Vol 35 (3) ◽  
pp. 353-360 ◽  
Author(s):  
Jacson Zuchi ◽  
José de Barros França-Neto ◽  
Carlos Sigueyuki Sediyama ◽  
Adílio Flauzino de Lacerda Filho ◽  
Múcio Silva Reis

Storage is an important step in the production of soybean seeds, mainly in tropical regions, where high temperatures can drastically reduce seed quality. The storage at cooler temperatures may be a feasible alternative to preserve seed quality during storage. The objective of this study was to evaluate the physiological quality of soybean seeds artificially cooled by a dynamic process and stored in an environment, with non controlled temperature and relativity humidity. Two seed lots of cultivars Monsoy 8757, TMG 115 RR and BRS Valiosa RR were used. After processing and during packaging the seeds were cooled to 18 ºC by a dynamic process. Seed samples were collected after 0, 60 and 120 days of storage, using the following parameters germination, accelerated aging, seedling emergence in sand, speed of emergence index, electrical conductivity, tetrazolium and seed health. Although soybean seeds artificially cooled by the dynamic method may have slightly superior performance in maintaining physiological quality during storage in non-refrigerated warehouse, for lots of high physiological quality, these advantages are not observed.


2019 ◽  
Vol 49 ◽  
Author(s):  
Cleisson Dener da Silva ◽  
Andréia Márcia Santos de Souza David ◽  
Josiane Cantuária Figueiredo ◽  
Jorge Luiz Rodrigues Barbosa ◽  
Rayane Aguiar Alves

ABSTRACT To obtain seeds of high physiological quality, it is of paramount importance to define the ideal harvest moment, which oftentimes corresponds to the period when the physiological maturity is reached. This experiment aimed to study the maturation process and determine the best harvest season of maroon cucumber fruits (Liso Gibão cultivar), in order to reach the maximum physiological seed quality. The flowers were labeled during the anthesis and the fruits harvested at 14, 21, 28, 35, 42, 49 and 56 days after the anthesis (DAA). The fruits had their visual aspects registered by photography analysis and, later, the seeds were extracted for physical (water and dry matter contents) and physiological (germination, seedling emergence, emergence speed index, accelerated aging and electrical conductivity) analyses. It was observed that the seeds reach the maximum dry mass (8.08 mg seed-1) between 47 and 49 DAA. However, the seed physiological maturity, characterized by a maximum germination (70 %) and vigor, occurs at 56 DDA. The best season to harvest seeds with a higher physiological quality takes place from 49 to 56 DDA, when the fruits present a yellowish color.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Zhonghao Ren ◽  
Liyan Xu ◽  
Qi Fan ◽  
Kaili Yang ◽  
Shengwei Ren ◽  
...  

Purpose. The study aimed to evaluate the visual quality of forme fruste keratoconus (FFK) and mild and moderate keratoconus by using an optical quality analysis system II (OQAS-II) and to explore the correlation between optical quality parameters and the disease progression. Methods. Twenty-one normal eyes, twenty-one FFK eyes, twenty-one mild keratoconus eyes, and twenty-one moderate keratoconus eyes were included in this prospective study. The optical quality parameters, such as object scatter index (OSI), modulation transfer function cutoff (MTF cutoff), strehl ratio (SR), and OQAS-II values at contrasts of 100% (OV-100), 20% (OV-20), and 9% (OV-9), were measured by OQAS-II. The repeatability of these parameters was analyzed by intraclass correlation coefficient (ICC), repeatability coefficient (RC), and coefficient of variation (CVw). Correlations between optical quality parameters and mean central keratometry readings (Kmean) were evaluated. The sensitivity and specificity of the parameters were analyzed using the receiver operating characteristic (ROC). Results. All the optical quality parameters among four groups showed good repeatability (all ICC≥0.75). The MTF cutoff, SR, OV-100, OV-20, OV-9 in FFK, mild and moderate keratoconus eyes were significantly lower than those in the normal group (all P<0.05). The ROC analyses of the MTF cutoff, SR, OV-100, OV-20, and OV-9 showed significant area under the curve (AUC) in discriminating FFK form normal, mild keratoconus from FFK, and moderate keratoconus from mild keratoconus (all P<0.05). The OSI in mild and moderate keratoconus eyes were significantly higher than that in FFK and normal group (all P<0.05), while the OSI showed no significant difference between the FFK group and normal group (P>0.05). The ROC analyses of the OSI showed significant AUC in discriminating mild keratoconus from FFK and moderate keratoconus from mild keratoconus (all P<0.05). In addition, the MTF cutoff was closely correlated to Kmean in keratoconus eyes (r = −0.710, P<0.001). Conclusion. The repeatability of OQAS-II is good in measuring visual quality of normal as well as FFK, mild, and moderate keratoconus. The visual quality of the FFK, mild, and moderate keratoconus is worse than that in normal eyes. The OQAS-II has the potential value in screening FFK from normal eyes and might be a useful tool for evaluating the progression of keratoconus.


2019 ◽  
Vol 41 (2) ◽  
pp. 196-204
Author(s):  
Roberto Caetano de Oliveira ◽  
Carlos Eduardo da Silva Pedroso ◽  
Vanessa Nogueira Soares ◽  
Lílian Madruga de Tunes ◽  
Géri Eduardo Meneghello ◽  
...  

Abstract: Annual ryegrass seeds having low physiological quality can lead to the formation of pastures with undesirable plant stands for soil cover and forage utilization pastures. Thus, the objective of this study was proposing a vigor test to classify annual ryegrass seeds. For that, different sowing depths (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 cm) over three substrates (sand, coconut fiber, and carbonized rice husk) were tested to differentiate the physiological quality of four seed lots of annual ryegrass cv. BRS Ponteio having similarities in germination and moisture. The seed lots were classified according to vigor through the field seedling emergence (FSE), 1,000-seeds weight, saturated salt accelerated aging, and germination first count. The 2.5 cm of sand sowing depth and 3.0 cm of coconut fiber sowing depth provided separation of seed lots in similar groups of those reported to FSE test through the seedling emergence and speed of seedling emergence tests.


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