scholarly journals Relationship of black layer and milk line development on maize seed maturity

1995 ◽  
Vol 52 (1) ◽  
pp. 142-147 ◽  
Author(s):  
R.D. Vieira ◽  
L. Minohara ◽  
N.M. de Carvalho ◽  
M.C.M. Bergamaschi

The relationship of black layer and milk line development on maize seed maturity was evaluated under tropical conditions. Seed moisture (g.kg-1), standard germination - SG (7 days, 25°C), and vigor, using accelerated aging-AA (96 hours, 42°C and 100% of RH), cold test-CT only in 1991/92 (7 days at 10°C and 7 days at 25°C) and electrical conductivity-EC (four 50-seed samples, 24 hours imbibition at 25°C) and milk line and black layer formation (using a five-stage rating system) were determined at 3 to 4 days intervals, using two genotypes (hybrid CX 133 and variety IAC 100) during the crop seasons of 1990/91 and 1991/92. The results showed that physiological maturity was reached before stage 4, based on seed germination and vigor (AA and CT) values, which occurred before that stage and presented the lowest values of EC. On the other hand, moisture content levels of 300 to 350 g.kg-1 were reached only at stage 4. The milk line ratings proved useful in predicting physiological maturity as well as the harvest maturity.

1995 ◽  
Vol 22 (1) ◽  
pp. 22-26 ◽  
Author(s):  
J. F. Spears ◽  
G. A. Sullivan

Abstract Classification of peanuts (Arachis hypogaea L.) based on pod mesocarp color has become a popular means of estimating maturity of runner peanuts. This study was initiated to determine if the hull mesocarp color is related to seed maturity of virginia-type peanuts and to evaluate changes in quality as seed mature. Cultivars NC 7 and NC 9 peanuts were harvested by hand in 1990, 1991, and 1992. Pods were separated according to mesocarp color. Seed moisture content and dry weight within a maturity class varied with cultivar and production year. Germination of NC 7 seed grown in 1990 and 1992 increased as seed approached maturity. Immature NC 9 seed grown in 1991 and 1992 had substantially lower germination than seed from mature pods. There was no increase in germination during maturation of NC 7 seed harvested in 1991 or NC 9 from 1990. Seed leakage during imbibition, measured by electrical conductivity, decreased as seed matured. The lowest leakage levels occurred when seed had reached physiological maturity. Germination following accelerated aging (AA) increased as seed matured. Maximum AA germination of NC 7 occurred when seed had reached 77, 84, and 100% of their final dry weight in 1990, 1991, and 1992, respectively. NC 9 seed achieved maximum germination following AA after the seed amassed at least 90% of their final dry weight.


2013 ◽  
Vol 35 (3) ◽  
pp. 276-283 ◽  
Author(s):  
Valquíria de Fátima Ferreira ◽  
João Almir Oliveira ◽  
Thaís Francielle Ferreira ◽  
Leandro Vilela Reis ◽  
Vanessa de Andrade ◽  
...  

Harvest of maize seeds with high moisture levels has been recommended; nevertheless, after harvest, the ears undergo the process of husking and there is a need to assess the compatibility of these processes. The purpose of this study was to assess the effects of mechanical husking on the quality of maize seeds collected at high moisture levels. Dent BM 3061 hybrid maize seeds, manually collected from the ear, with moisture contents of 45%, 40% and 35%, and a 20/64 round sieve were used. The ears were mechanically husked (CWA machine, 312 rpm), dried in a stationary drier at 35 ⁰C until reaching 22% moisture, followed by drying at 42 ºC until reaching 12%. Then, they underwent shelling, followed by a chemical treatment with Maxin® + K-obiol® + Actellic®. Seed quality was assessed according to the occurrence tests of mechanical damage, first count, germination, seedling emergence, emergence speed index, average emergence time, electrical conductivity, accelerated aging, cold test, and seed health test at every quarter for 9 months. The mechanical husking affects maize seed quality, depending on the degree of seed moisture at harvest and on the material studied. This hybrid's seeds can be collected with seed moisture levels at 40% with the use of mechanical husking.


2005 ◽  
Vol 30 (5) ◽  
pp. 470-474 ◽  
Author(s):  
Juliana A Galli ◽  
Simone A Fessel ◽  
Rita C Panizzi

Pathogens in maize (Zea mays) seeds cause serious problems, such as the loss of their capacity to germinative. The objectives of this study were to identify the optimal period for infection of maize seeds on agar colonized by Fusarium graminearum, when incubated for 4, 8, 16 and 32 h, and to evaluate the effect of the fungus on the germination and vigor of seeds with different infection levels. After the respective incubation periods, the seeds were removed from the culture medium and submitted to the blotter test for 3 min with and without superficial disinfection with 1% solution of sodium hypochlorite. Once the optimal period for seed incubation was identified, seeds from the same sample were again placed on the colonized agar for infection. Germination and vigor tests (accelerated aging and cold test) were performed with a mixture of healthy seeds (placed on PDA medium) and inoculated seeds, resulting in seeds with 0, 20, 40, 60, 80 and 100% rates of infection. The results showed that a period of 32 h was long enough to obtain seeds infected by the pathogen. There were no significant effects of fungal infection on seed germination at any of the infection levels, probably due to the high vigor of the maize seed lot tested. Regarding vigor tests, infection levels differed significantly from the control (0% infection), but there were no significant differences among the infection levels.


2020 ◽  
Vol 57 (3) ◽  
pp. 87-92
Author(s):  
Gordana Tamindžić ◽  
Maja Ignjatov ◽  
Dragana Milošević ◽  
Zorica Nikolić ◽  
Aleksandra Nastasić ◽  
...  

Good crop establishment is essential for achieving high yield and constraints to good establishment include untimely sowing and low seed quality combined with various adverse growing conditions after sowing. Seed priming is a pre-sowing technique used for the improvement of germination, reduction of the time from sowing to emergence and improvement of emergence uniformity. Various seed priming techniques, such as hydropriming and priming with zinc, are used nowadays to improve crop establishment. The importance of seed priming with zinc for better germination, improved stand establishment, and higher maize yield are well documented. However, there is still a lack of results on the effects of seed priming with water and zinc on seed quality and viability, given that maize seed can be kept in storage for many years without a significant reduction in germination. The study was aimed to evaluate the effects of seed priming with water and Zn on the quality and viability of the maize seed. In order to evaluate the response of four maize hybrids to priming with water (hydropriming) and 4 mM zinc sulphate, primed seeds were subjected to laboratory tests, namely to the germination test, the cold test, and the accelerated aging test. Both priming treatments increased the seed quality, but the beneficial effect of Zn-priming maintained to a larger extent than hydropriming in cold-treated and aged seeds. The negative effects of hydropriming on the viability o f the aged seed of hybrid NS 4023 imply a possible limitation to deferred sowing of primed maize seed.


2015 ◽  
Vol 39 (4) ◽  
pp. 339-347 ◽  
Author(s):  
Raquel Stefanello ◽  
Marlove Fátima Brião Muniz ◽  
Ubirajara Russi Nunes ◽  
Cláudia Braga Dutra ◽  
Iana Somavilla

The preservation of seed quality during the storage period depends not only on the conditions during production and harvesting but also on the storage and maintenance of appropriate storage product conditions. Thus, the aim of this study was to evaluate the physiological and sanitary qualities of maize landrace seeds stored under two conditions. The maize seed batch varieties Oito carreiras, Cabo roxo and Lombo baio were used. Tests included germination, first count, cold test, accelerated aging and sanity. Based on the results it was concluded that the physiological quality of these seed varieties decreased with the storage period. The major fungi identified in the maize seeds during storage were from the genera Aspergillus, Fusarium and Penicillium, which caused deterioration and reduction of the physiological quality. Storage using a paper bag at a temperature of 10 °C did not prevent the deterioration of maize seeds but was more effective at preserving the quality of the seed compared with a plastic bag at room temperature.


2007 ◽  
Vol 47 (6) ◽  
pp. 683 ◽  
Author(s):  
Pippa J. Michael ◽  
Kathryn J. Steadman ◽  
Julie A. Plummer

Seed development was examined in Malva parviflora. The first flower opened 51 days after germination; flowers were tagged on the day that they opened and monitored for 33 days. Seeds were collected at 12 stages during this period and used to determine moisture content, germination of fresh seeds and desiccation tolerance (seeds dried to 10% moisture content followed by germination testing). Seed moisture content decreased as seeds developed, whereas fresh (max. 296 mg) and dry weight (max. 212 mg) increased to peak at 12–15 and ~21 days after flowering (DAF), respectively. Therefore, physiological maturity occurred at 21 DAF, when seed moisture content was 16–21%. Seeds were capable of germinating early in development, reaching a maximum of 63% at 9 DAF, but germination declined as development continued, presumably due to the imposition of physiological dormancy. Physical dormancy developed at or after physiological maturity, once seed moisture content declined below 20%. Seeds were able to tolerate desiccation from 18 DAF; desiccation hastened development of physical dormancy and improved germination. These results provide important information regarding M. parviflora seed development, which will ultimately improve weed control techniques aimed at preventing seed set and further additions to the seed bank.


2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Jorgiani de Ávila ◽  
Fernanda Brito Cardoso ◽  
Sebastião Ferreira de Lima ◽  
Gustavo Ribeiro Barzotto ◽  
Mayara Santana Zanella

It is possible to cultivate common beans for a third harvest in one agricultural year due to varietal characteristics. For calendar adequacy, performing desiccation and planting often occur almost simultaneously. Germination performance of many plant species can improve with biostimulant use on seeds, however the interaction with herbicide residual molecules is unknown. The hypothesis is that seeds treated with a biostimulant in soil with glyphosate residues can eliminate the advantage of the biostimulant or increase the damage caused by the herbicide. The aim of this study was to evaluate the effect of different glyphosate reduce doses and the interaction with biostimulant on bean seed germination and vigor. The experiment was conducted using a completely randomized 2 x 5 factorial block designing factorial 2 x 5, corresponding to the presence and absence of biostimulant and five different doses of glyphosate reduce rates, with four repetitions. The conducted evaluations were first count germination, germination test, accelerated aging, cold test, root and shoot length, root and shoot dry matter and electrical conductivity. It can be concluded that the biostimulant treatment on bean seeds increased germination, seed vigor and early seedling growth, but glyphosate presence reduced those advantages, increasing electrical conductivity. However, the herbicide presence provided higher germination on the accelerated aging test.  


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.


2003 ◽  
Vol 60 (3) ◽  
pp. 465-469 ◽  
Author(s):  
Angelica Brod Rodo ◽  
Julio Marcos Filho

International research on vegetable seed vigor is not at the same level attained for grain crops species. This study was conducted to identify reliable procedures for the accelerated aging and controlled deterioration tests to rank onion (Allium cepa L.) seed lots according to their physiological potential. Six seed lots of the cultivars Aurora and Petroline were evaluated in the laboratory for germination, first count, seedling vigor classification, traditional and saturated salt accelerated aging (41ºC / 48 and 72 h), controlled deterioration (24% of water / 45ºC / 24 h) and seedling emergence tests. Seed moisture content after the saturated salt accelerated aging test was lower and uniform, which is considered an important advantage in comparison to the traditional procedure. The saturated salt accelerated aging (41ºC / 48 and 72 h) and controlled deterioration (moisture content adjusted to 24% / 45ºC / 24 h) tests were the best procedures to assess the physiological potential of onion seeds, and are indicated for use in quality control programs.


Sign in / Sign up

Export Citation Format

Share Document