Kernel weight dependence upon plant growth at different grain-filling stages in maize and sorghum

2008 ◽  
Vol 59 (3) ◽  
pp. 280 ◽  
Author(s):  
Brenda L. Gambín ◽  
Lucas Borrás ◽  
María E. Otegui
Keyword(s):  
Plant Growth ◽  
Developmental Stages ◽  
Environmental Variability ◽  
Grain Filling ◽  
Kernel Weight ◽  
Kernel Number ◽  
Kernel Size ◽  
Simple Estimate ◽  
Kernel Set ◽  
Grain Filling Period

In the present study we tested how assimilate availability per kernel at different grain-filling stages may affect maize (Zea mays L.) and sorghum (Sorghum bicolor L. Moench) individual kernel weight (KW). These two species have shown a contrasting KW response to increased assimilate availability at similar seed developmental stages. Plant growth rate (PGR) per kernel was used to estimate the assimilate availability per kernel at two stages: around the early grain-filling period when kernel number per plant is also being established, and around the effective grain-filling period. We tested 3 commercial genotypes from each species, and modified the PGR by thinning or shading the stand at different developmental stages. In both species, each genotype showed a particular relationship between PGR around flowering and kernel number, which gave a range of responses in the PGR per kernel set around flowering. Final KW always increased whenever PGR per kernel around flowering was enhanced. Only sorghum showed a consistent KW increase when PGR per kernel during the effective grain-filling period was enhanced. Results confirmed that increasing assimilate availability per kernel will affect maize kernel size only if the potential set early in development is altered. Most important, we showed that linking specific KW sensibility across species at different seed developmental stages using a simple estimate of assimilate availability per seed (i.e. PGR per kernel) at each grain-filling stage helped explain most of the explored genotypic and environmental variability in final kernel size.

Cross-pollination effects on maize (Zea mays L.) hybrid yields

1992 ◽  
Vol 72 (1) ◽  
pp. 27-33 ◽  
Author(s):  
R. T. Weiland
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Grain Filling ◽  
Maize Yield ◽  
Kernel Weight ◽  
First Year ◽  
Kernel Number ◽  
Cross Pollination ◽  
Grain Filling Period ◽  
N Fertility

Recent studies have shown that pollen from a long-season maize (Zea mays L.) hybrid increased yield of a short-season hybrid by lengthening the effective grain-filling period, while the reciprocal cross did not alter this period or yield. This effect (metaxenia) was evaluated further in the studies reported here with hybrids of more diverse maturity and under both high and low N fertility. In the first year of this study (1989), sib- and cross-pollinations were made among B73Ht × Mo17 (B × 7) and two early-silking hybrids, LH59 × LH146 (L × 6) and Pioneer 3732 (3732) under N-sufficient (275 kg ha−1) and two lower N regimes (17 and 67 kg ha−1). Only a few significant effects were observed and these were noted at high N with one exception. With 3732 pollen, grain yield of B × 7 was decreased at 275 kg N ha−1, and physiological maturity occurred 3 d earlier. Yield of 3732 was increased by L × 6 pollen in comparison with B × 7 pollen. Kernel number and average kernel weight were not altered by pollen source. Pollen type did not affect yields under low N fertility, except for a reduction when B × 7 was pollinated by L × 6 at the 67-kg N ha−1 rate. In 1990, under N-sufficient fertility, B73Ht × LH156 (B × 6), a late-silking hybrid, and LH146 × LH82 (L × 2), an earlier hybrid, were sib- and cross-pollinated with B × 7 and 3732. The only significant effect observed was that L × 2 pollen increased B × 6 yield. Thus with the hybrids used, yields of early-season types were not altered by cross-pollination with long-season types. Previous results showing increased yields when 3732 was pollinated by B × 7 were not duplicated in either year, suggesting metaxenia effects are highly dependent upon environment.Key words: Metaxenia, xenia, cross-pollination, maize, yield, N levels

scholarly journals Soil drying and rewatering applied at three grain developmental stages affect differentially growth and grain protein deposition in wheat (Triticum aestivum L.)

2006 ◽  
Vol 18 (2) ◽  
pp. 341-350 ◽  
Author(s):  
José Beltrano ◽  
Marta Guillermina Ronco ◽  
María Cecilia Arango
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Developmental Stages ◽  
Flag Leaf ◽  
Grain Filling ◽  
Kernel Weight ◽  
Yield Losses ◽  
Protein Patterns ◽  
Grain Number Per Spike ◽  
Ripe Stage

Water deficits cause large yield losses in wheat. Although anthesis is generally considered the most vulnerable period, water deficit during grain filling can also cause yield losses. The objective of this study was to investigate the effect of water stress and rewatering, at three different grain developmental stages, on physiological and grain filling parameters and on yield components. Wheat plants were subjected to water deficit and rewatering at the watery ripe, milk and soft dough stages. In the flag leaf, water stress decreased the relative water content, the chlorophyll and protein content and increased the leakage of solutes, at all three studied grain filling stages. Water stress at the watery ripe and milk stages reduced the final grain dry mass by 47 % and 20 %, respectively. This reduction was due to a decrease in the grain filling period and to a significant reduction in the maximum rate of grain-fill. Water stress imposed at the watery ripe stage reduced not only the linear growth phase but also its slope; grain number per spike and the 1000-kernel weight were also significantly reduced. SDS-PAGE patterns of grain proteins at the watery ripe stage did not differ between the controls, stressed or rewatered treatments. Protein patterns at the milk stage changed substantially with water stress, mainly for the high molecular weight glutenin subunits and gliadins. Three new bands were observed with apparent molecular weights of 108.5 kDa, 84.8 kDa and 63 kDa. Rewatering reverted water stress effects when it was imposed at the milk stage. Water deficit at the soft dough stage did not have any effect on protein grain patterns.

scholarly journals Barley response to seeding date in central Alberta

2003 ◽  
Vol 83 (2) ◽  
pp. 275-281 ◽  
Author(s):  
P. E. Juskiw ◽  
J. H. Helm
Keyword(s):  
Hordeum Vulgare ◽  
Grain Yield ◽  
Grain Filling ◽  
Kernel Weight ◽  
Seeding Rate ◽  
Hordeum Vulgare L ◽  
Vegetative Period ◽  
Seeding Date ◽  
The Mean ◽  
Grain Filling Period

Seeding date is an important factor influencing productivity of barley (Hordeum vulgare L.). When conditions are conducive to early seeding or result in delayed seeding, producers need to know how cultivars will respond to these seeding situations. In this study, five cultivars (Abee, Harrington, Jackson, Noble and Virden) registered for western Canada were studied for 4 yr (1990 to 1993) when seeded early (late April or early May), in mid-May, in late-May, or late (mid-June) at Lacombe, AB. For all cultivars, early seeding resulted in grain yield advantages of 113 to 134% of the mean site yield, while with late seeding, grain yields were reduced to 54 to 76% of the mean site yield. The reduction in yield was least for Jackson, the earliest maturing cultivar tested. Late seeding reduced the period from sowing to emergence, vegetative period, grain-filling period, time from emergence to physiological maturity, test weight, grain yield, kernel weight, and tillers per plant; and increased plant height and percent thins. Late seeding had no significant effect on phyllochron, stand establishment, scald, lodging, protein content of the grain, kernel number per spike, and spikelet number per spike. Barley responded positively to early seeding in central Alberta, but when seeding was delayed (in this study to mid-June) the early and mid-maturing six-rowed cultivars with short phyllochrons performed better than the two-rowed and late six-rowed cultivars. Key words: Hordeum vulgare L., seeding rate, phenological development, grain quality, grain yield, components

Enhanced kernel set promoted by synchronous pollination determines a tradeoff between kernel number and kernel weight in temperate maize hybrids

2008 ◽  
Vol 105 (3) ◽  
pp. 172-181 ◽  
Author(s):  
Martín Uribelarrea ◽  
Jorgelina Cárcova ◽  
Lucas Borrás ◽  
María E. Otegui
Keyword(s):  
Kernel Weight ◽  
Kernel Number ◽  
Maize Hybrids ◽  
Kernel Set

scholarly journals Grain filling and fatty acid composition of safflower fertilized with integrated nitrogen fertilizer and biofertilizers

2017 ◽  
Vol 52 (4) ◽  
pp. 236-243 ◽  
Author(s):  
Raouf Seyed Sharifi ◽  
Ali Namvar ◽  
Reza Seyed Sharifi
Keyword(s):  
Fatty Acids ◽  
Plant Growth ◽  
Nitrogen Fertilizer ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Plant Growth Promoting Rhizobacteria ◽  
Grain Filling ◽  
N Fertilizer ◽  
Seed Inoculation ◽  
Grain Filling Period

Abstract: The objective of this work was to evaluate the effects of the integrated application of nitrogen fertilizer and biofertilizers on the yield, grain filling period, and composition of fatty acids of safflower (Carthamus tinctorius). Split-plot experiments were carried out during the 2011 and 2012 crop seasons. The treatments consisted of seed inoculation with plant growth-promoting rhizobacteria (Azotobacter chroococcum strain 5, Azospirillum lipoferum strain F, and Pseudomonas putida strain 186) in the subplots, including a control without seed inoculation; and of the application of N fertilizer at different rates (60, 120, and 180 kg ha-1 urea) in the main plots, including a control without N. The highest grain yield, grain filling period, and effective grain filling period were obtained by the application of 180 kg ha-1 urea and by seed inoculation with P. putida. The application of high N rates and P. putida inoculation resulted in 25.66% increase of the potential rate of grain filling. Biofertilizer inoculation in seed reduced the contents of saturated fatty acids (palmetic and stearic acids) and increased the contents of unsaturated fatty acids (linoleic, linolenic, and oleic acids). The suitable amount of N fertilizer (between 120 and 180 kg ha-1 urea) can improve plant growth, and the quantity and quality of oil in seeds treated with P. putida in safflower plants.

scholarly journals Yield Loss Potential of Phaeosphaeria Leaf Spot of Maize Caused by Phaeosphaeria maydis in the United States

Plant Disease ◽  
2005 ◽  
Vol 89 (9) ◽  
pp. 986-988 ◽  
Author(s):  
M. L. Carson
Keyword(s):  
United States ◽  
Leaf Spot ◽  
Grain Filling ◽  
The United States ◽  
Kernel Weight ◽  
Maize Hybrids ◽  
Growing Seasons ◽  
Kernel Weights ◽  
Grain Filling Period ◽  
Southern Florida

The ability of Phaeosphaeria leaf spot (PLS) to reduce yields of maize was evaluated over two winter growing seasons in southern Florida. Nine commercial maize hybrids, varying in reaction to PLS, were planted in a split-plot design with hybrids as whole plots and inoculated versus uninoculated treatments as subplots. The most susceptible hybrid, Pioneer brand 3489, sustained a significant reduction in grain yield (11 to 13%) and 400-kernel weight (5 to 10%) in the trials. Regression analyses indicated that grain yields and 400-kernel weights were reduced 0.23 and 0.16%, respectively, for each percent increase in PLS severity at the mid-dent stage. Because most U.S. maize hybrids are resistant, and PLS develops late in the grain-filling period, its potential to cause substantial losses in the United States appears limited at this time.

scholarly journals Türkiye Kökenli Yulaf Genotiplerinin Bazı Tarımsal Özellikler Bakımından Değerlendirilmesi

2017 ◽  
Vol 5 (7) ◽  
pp. 763 ◽  
Author(s):  
Ziya Dumlupınar ◽  
Ali Tekin ◽  
Sevgi Herek ◽  
Abdulkadir Tanrıkulu ◽  
Tevrican Dokuyucu ◽  
...  
Keyword(s):  
Barley Yellow Dwarf Virus ◽  
Grain Filling ◽  
Kernel Weight ◽  
Vegetative Period ◽  
Barley Yellow Dwarf ◽  
Yellow Dwarf Virus ◽  
Grain Filling Period ◽  
Agronomical Traits ◽  
Better Than ◽  
Grain Number Per Panicle

In this study 384 Turkish originated oat genotypes obtained from different gene banks, were characterized and evaluated for agronomical traits with four commercial cultivars (Checota, Sebat, Faikbey and Seydişehir) under augmented experiment design for 2012-2013 and 2013-2014 cropping years. Oat landraces were evaluated for stem diameter (SD), plant height (PH), panicle length (PL), vegetative period (VP), grain filling period (GFP), days to maturity (DM), grain number per panicle (GNP), grain weight per panicle (GWP), thousand kernel weight (TKW), lodging (LOD), barley yellow dwarf virus (BYDV) and single row yield (SRY) under Kahramanmaraş conditions. According to the results of field trail for two years, differences of genotypes were significant for SD, PH, PL, VP, DM, TKW and SRY. However, the components such as SD, PL, VP, GFP, DM, GNP, GWP, TKW and SRY were significantly changed for the years and year x genotype interactions were also significant for PL, VP, DM, TKW and SRY. The landraces performed better than the commercial ones for the most of the evaluated traits. The SRW ranged between 4.65 g (TL444) to 202.1 g (TL614). Moreover, the other genotypes with the higher SRY were TL708, TL714, TL734 and TL703 genotypes with 167.85, 160.25, 153.90 and 149.7 g SRY, respectively.

Yield components of maize as affected by short shading periods and thinning

2013 ◽  
Vol 64 (6) ◽  
pp. 580 ◽  
Author(s):  
A. Cerrudo ◽  
J. Di Matteo ◽  
E. Fernandez ◽  
M. Robles ◽  
L. Olmedo Pico ◽  
...  
Keyword(s):  
Grain Yield ◽  
Resource Availability ◽  
Yield Components ◽  
Extended Period ◽  
Grain Filling ◽  
Base Temperature ◽  
Kernel Number ◽  
Subsequent Increase ◽  
Grain Filling Period ◽  
Source Limitation

Maize (Zea mays) grain yield has been described to be particularly susceptible to environmental conditions around silking; however, a better temporal description of the effect of resource deprivation during this period is needed. Additionally, yield progress and the subsequent increase in the demand of assimilates may result in source limitation during the grain-filling period in current hybrids. This work assessed the effect of (i) short (~5 days) and intense shading stresses imposed at different times, and (ii) thinning during the effective grain-filling period, on yield components of an Argentinean, widespread hybrid. Grain yield was affected by resource availability during an extended period from ~300 growing degree-days (GDD) before silking to ~780 GDD after silking (base temperature = 8°C). Kernel number (KN) was reduced by shading treatments imposed within a relatively extended period of ~700 GDD centred on silking. Within this period, we establish a critical period of ~30 days around silking (i.e. –200 to 250 GDD after silking), in which KN susceptibility was maximal. The variation in KN during this period of 450 GDD was mainly accounted for by resource availability and not by timing of treatment imposition within this window. A direct relationship between KN and weight per kernel (KW) for shading treatments imposed from 0 to 200 GDD after silking indicated that compensation of KN reduction by KW increase might not be expected when stress occurred immediately after silking. Kernel number and KW presented an inverse relationship when shading took place after 200 GDD after silking. In addition, thinning after the onset of the effective grain-filling period increased KW. The results indicate that, even in the undisturbed crop, KW was limited by source capacity during grain filling. It is suggested that there is a need to reconsider current agronomic practices and breeding strategies, focusing on the source capacity during the grain-filling period.

Yield potential in a dwarf spring wheat and response to crop thinning

1976 ◽  
Vol 87 (1) ◽  
pp. 113-122 ◽  
Author(s):  
R. A. Fischer ◽  
D. R. Laing
Keyword(s):  
Grain Yield ◽  
Spring Wheat ◽  
Wheat Variety ◽  
Grain Filling ◽  
Kernel Weight ◽  
Yield Potential ◽  
High Fertility ◽  
Northwest Mexico ◽  
Grain Filling Period ◽  
Spring Wheat Variety

SummaryExperiments with wheat describing the effects of crop thinning on grain yield and its components are presented. These were carried out over 5 years in northwest Mexico, using a high-yielding dwarf spring-wheat variety (Triticum aestivum cv. ‘Yecora 70’) grown under irrigation and high fertility. It was shown that thinning largely relieved competition for light, thus increasing photosynthate levels in the plants remaining after thinning. The objective was to evaluate this simple technique as a guide to understanding when grain yield and its components were determined and, in particular, the extent to which post-anthesis photosynthate supply limited yield.There were major responses in grain yield with thinning between about 50 and 100 days after seeding, and in number of spikes and of grains with thinning between 50 and 90 days (50% anthesis was reached at 87 days). Number of spikelets per spike showed small responses to early thinning (before 50 days). Number of grains/spikelet and kernel weight snowed positive responses to thinning between 65 and 90 days, and 90 and 115 days, respectively. These results agreed with adjacent shading and CO2 fertilization studies but, because of certain difficulties in interpretation of responses, pre-anthesis thinning was not considered a very useful technique.Anthesis thinning was carried out on 21 separate crops: the kernel weight increase relative to the unthinned control ranged from 6 to 41%, averaging 20%. Anthesis thinning led to increases in stem weight during the first half of the grain filling period, followed by increases in grain growth rate in the latter half. The increase in final kernel weight was greater with higher temperature and lower radiation during grain filling; these variables explained 64% of the variation in kernel weight response. It is suggested that the kernel weight response does indicate the degree of photosynthate limitation during grain filling, showing reasonable agreement with adjacent shading and CO2 fertilization studies. It was concluded that anthesis thinning, because of its relative simplicity, is a useful technique. Implications for yield improvement in Yecora of the results provided by this technique are discussed.

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