scholarly journals Milk line as an indicator of the harvesting time of three hybrid seeds of corn (Zea mays L.)

2005 ◽  
Vol 48 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Célio Trzeciak dos Santos ◽  
Valdecir Antoninho Dalpasquale ◽  
Carlos Alberto Scapim ◽  
Alessandro de Lucca e Braccini ◽  
Francisco Carlos Krzyzanowski

The experiment was carried out to evaluate the time for harvesting seeds of three hybrids of corn (Zea mays L.) at their best physiological quality and the use of the milk line as an indicator of the physiological seed maturity. Single hybrids CD 1723 and CD 5501 and double hybrid OC 705 seeds were collected for 59 days, every four days, starting 23 days after female flowering. Seed dry weight, moisture content, germination, vigour (cold and accelerated aging tests), black layer formation and seed milk line development were analysed. The harvesting time started 47 days after female flowering with high physiological quality of the seeds identified by a joint analysis of those seven characteristics of them. The milk line at stage 4 proved to be the best indicator of the time to harvest corn seeds for maximum physiological quality, because different stages of milk line development in corn seeds could be easily identified in the filed without any special equipment.

1988 ◽  
Vol 68 (4) ◽  
pp. 935-940 ◽  
Author(s):  
M. TOLLENAAR ◽  
T. W. BRUULSEMA

The response of rate and duration of kernel dry matter accumulation to temperatures in the range 10–25 °C was studied for two maize (Zea mays L.) hybrids grown under controlled-environment conditions. Kernel growth rates during the period of linear kernel growth increased linearly with temperature (b = 0.3 mg kernel−1 d−1 °C−1). Kernel dry weight at physiological maturity varied little among temperature treatments because the increase in kernel growth rate with increase in temperature was associated with a decline in the duration of kernel growth proportional to the increase in kernel growth rate.Key words: Zea mays L, period of linear kernel dry matter accumulation, controlled-environment conditions, kernel growth rate


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.


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 67 (3) ◽  
pp. 993-1000 ◽  
Author(s):  
Lydia Shtereva ◽  
Roumiana Vassilevska-Ivanova ◽  
Tanya Karceva

An experiment was carried out hydroponically under laboratory conditions to investigate the effect of salt stress on several physiological and biochemical parameters of three sweet corn (Zea mays L. var. saccharata) genotypes: lines 6-13, C-6 (pollen source) and their heterotic F1 hybrid ?Zaharina?. The degree of salinity tolerance among these genotypes was evaluated at three different sodium chloride (NaCl) concentrations: 0 mM, 100 mM, 125 mM and 150 mM. Seed germination, plant growth and biochemical stress determining parameters such as malondialdehyde (MDA), proline content and hydrogen peroxide (H2O2) levels were compared between seedlings of lines and hybrid. The obtained results indicated that both lines and hybrid have similar responses at different salinity levels for all examined traits. All the seedlings? growth parameters, such as germination percentage, root length, shoot length, root and shoot fresh and dry weight, decreased with increasing salinity level. MDA, proline and H2O2 increased at different saline conditions in comparison to the control. Based on the results, of the three genotypes examined, the hybrid Zaharina, followed by line C-6, was more salt-sensitive than line 6-13 in salt stress condition.


2019 ◽  
Vol 50 (7) ◽  
pp. 811-826 ◽  
Author(s):  
Hakan Çelik ◽  
Murat Ali Turan ◽  
Barış Bülent Aşık ◽  
Sencer Öztüfekçi ◽  
Ali Vahap Katkat

1977 ◽  
Vol 4 (6) ◽  
pp. 857 ◽  
Author(s):  
MF Beardsell

Maize (Zea mays L. cv. XL45) plants were grown from seed in controlled-environment rooms. Twice-daily weighings of the plants and containers for 7 days reduced height, and removing plants from the rooms for two 20-min periods daily for 7 days gave significant reductions in stem and leaf dry weights and total leaf area. Transpiration rates were not affected by either of these treatments. Short-term removal from the rooms (up to 10 min daily) produced no significant reductions in plant characteristics. Measuring leaf lengths daily for 10 days resulted in significant reductions in stem dry weight and plant height. It is suggested that control plants should always be subjected to the same degree of handling as treated plants.


2014 ◽  
Vol 36 (4) ◽  
pp. 392-398 ◽  
Author(s):  
Julia Abati ◽  
Claudemir Zucareli ◽  
José Salvador Simoneti Foloni ◽  
Fernando Augusto Henning ◽  
Cristian Rafael Brzezinski ◽  
...  

Seed treatment with insecticides and fungicides has become an important practice for ensuring initial plant stand in establishing crops. In this context, the aim of this study was to evaluate the influence of chemical seed treatment with insecticides and fungicides on the physiological quality and health of the seeds of wheat cultivars. Seeds of the wheat cultivars BRS Pardela and BRS Gaivota were used, subjected to the following chemical treatments: 1- control, 2- carboxin + thiram + imidacloprid + thiodicarb, 3- carbendazim + thiram + imidacloprid + thiodicarb, 4- fipronil + thiophanate-methyl + pyraclostrobin, 5- triadimenol + imidacloprid + thiodicarb, 6- fipronil, and 7- imidacloprid + thiodicarb. Physiological quality was evaluated by tests of germination, accelerated aging, the length and dry weight of shoots and roots, and seedling emergence in the field. Seed health quality was evaluated by the blotter test method. The seeds of the wheat cultivars tested respond differently to the chemical treatments in regard to effects on germination and vigor. The treatment with triadimenol + imidacloprid + thiodicarb is harmful to seedling development. For the BRS Gaivota cultivar, the seed treatment with carboxin + thiram + imidacloprid + thiodicarb; and carbendazim + thiram + imidacloprid + thiodicarb improved seedling establishment in the field compared to the control.


1999 ◽  
Vol 62 (10) ◽  
pp. 1218-1222 ◽  
Author(s):  
FILMORE I. MEREDITH ◽  
OLGA R. TORRES ◽  
SANDRA SAENZ de TEJADA ◽  
RONALD T. RILEY ◽  
ALFRED H. MERRILL

Fumonisin B1 (FB1) is a common contaminant of corn worldwide and is responsible for several diseases of animals. In the preparation of tortillas, corn is treated with lime (producing nixtamal) that when heated hydrolyzes at least a portion of the FB1 to the aminopentol backbone (AP1), another known toxin. This study analyzed the amounts of FB1 and AP1 in tortillas and nixtamal from two communities in the central highlands of Guatemala where corn is a major dietary staple (Santa Maria de Jesus, Sacatepequez, and Patzicia, Chimaltenango). The amounts of FB1 and AP1 in tortillas from Santa Maria de Jesus were, respectively, 0.85 ± 2.0 and 26.1 ± 38.5 μg/g dry weight (mean ± SD), and from Patzicia were 2.2 ± 3.6 and 5.7 ± 9.4 μg/g dry weight. Less than 6% of the tortillas from both locations contained ≥10 μg FB1/g dry weight; whereas, 66% of the samples from Santa Maria de Jesus and 29% from Patzicia contained ≥10 μg AP1/g dry weight. The highest amount of AP1 (185 μg/g dry weight) was found in tortillas from Santa Maria de Jesus. The highest amounts of FB1 were 6.5 and 11.6 μg/g dry weight in tortillas from Santa Maria de Jesus and Patzicia, respectively. The mean concentration of FB1 in nixtamal was significantly higher in Santa Maria de Jesus compared to Patzicia. Surprisingly, AP1 was not detected in any of the nixtamal samples. The human impact of exposure to these amounts of fumonisins is not known. However, based on findings with other animals, where corn is a dietary staple, long-term consumption of FB1 and AP1 (especially at ≥10 μg/g of the diet) may pose a risk to human health.


1984 ◽  
Vol 64 (3) ◽  
pp. 487-496 ◽  
Author(s):  
ROBERT J. NAVRATIL ◽  
JOSEPH S. BURRIS

Seed produced on three widely grown public corn (Zea mays L.) inbreds were tested for tolerance to drying injury. Inbred parents A632, B73, and Mo17 were grown in 1979 and 1980. The single cross H99 × H95 was used as a pollinator both years. Random ear samples were collected, to obtain ears with moisture percentages ranging from approximately 50 to 20%, and dried to 12% moisture at 35 °C, 40 °C, 45 °C, and 50 °C. Inbred parents were found to differ in tolerance to high drying temperatures. A632 was the most tolerant to high drying temperatures whereas B73 and Mo17 were relatively intolerant. Field performance of dried seed was similar to that observed in laboratory tests. Combined analyses yielded significant inbred-parent by harvest-moisture by drying-temperature interactions for germination and cold-test emergence percentages. These interactions do not allow for simple recommendations of safe harvest moistures and drying temperatures. Components from the combined analysis that had a P > F of 0.30 or less were then used to predict mean values for A632, B73, and Mo17 germination, cold-test emergence, seedling dry weight and the ratio of shoot to root dry weight. Values for the ratio variable indicated that root development is more susceptible to injury than is shoot development. These predicted values provide seed producers with information on the quality responses that they could expect when seed of A632, B73, or Mo17 is harvested at different moisture contents and dried at different drying temperatures.Key words: Drying, seed quality, Zea mays L.


1974 ◽  
Vol 54 (1) ◽  
pp. 71-78 ◽  
Author(s):  
R. B. HUNTER ◽  
L. A. HUNT ◽  
L. W. KANNENBERG

The open-pollinated corn (Zea mays L.) cult Gaspé Flint and three hybrids, Guelph GX122, Harrow 691, and Pioneer X306, were selected to examine the effects of photoperiod and temperature on the number of days to tassel initiation. The range of maturity of this material varied from extremely early to subtropical. The experiments, conducted in growth cabinets, examined photoperiods of from 10 to 20 h in 21/2-h increments. Constant day–night temperatures examined were 20, 25, and 30 C. Photoperiod and temperature affected number of days to tassel initiation. The response was not consistent for each genotype. As daylength increased from 10 to 20 h all but the earliest genotype, Gaspé Flint, took longer to reach tassel initiation. The latest hybrid, Pioneer X306, was affected relatively more by photoperiod. The delay in tassel initiation with longer photoperiods was apparent at all temperatures; however, the magnitude of the response was less at the high temperature. With longer photoperiods, there was an increase in the amount of vegetative growth and development prior to tassel initiation. This was apparent from the greater number of emerged leaves, the longer stem length, and the greater plant dry weight at tassel initiation.


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