Ear branching as a means of increasing grain uniformity in wheat

1972 ◽  
Vol 23 (4) ◽  
pp. 551 ◽  
Author(s):  
HM Rawson ◽  
KN Ruwali
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Grain Growth ◽  
Growth Rates ◽  
Grain Filling ◽  
Size At Maturity ◽  
Grain Number ◽  
Photosynthetic System ◽  
Temperature Changes ◽  
The Relationship

Grain growth was compared in two field-grown wheats, Kalyan Sona, a high-yielding, seinidwarf line with few spikelets per ear and many grains per spikelet, and a branched-eared cultivar with many spikelets, each with few grains. The basis of comparison was the spikelet in Kalyan Sona and the branch in the branched material. Within the central spikelets of the main ear in Kalyan Sona, grain growth rates for the greater part of filling were b > a = c > d > e; final weights per grain for these florets were 42, 40, 37,26, and 12 mg respectively. The gradation in growth rate for the eight grains along the branch in the branched-eared cultivar was relatively small with the consequence that all grains were similar in size at maturity (range 39–43 mg); peak growth rates for all positions were at least as high as for grains a, b, and c in Kalyan Sona. In another cultivar, Triple Dirk, increasing competition for assimilates by reducing the light intensity during grain filling had a differential effect on grains within the spikelet but scarcely on the pattern between spikelets. The relationship between all grains was unaffected by temperature changes. The results are discussed in relation to competition for assimilates between grains, and the suggestion made that a high number of grains per spikelet may not use the available assimilates most efficiently. Ear branching is proposed as a preferable alternative, as this also provides abundant grain sites to utilize assimilates to the potential of the photosynthetic system, yet ensures grain uniformity per ear, regardless of grain number, by having few grains in each spikelet.

Factors Influencing the Rate and Duration of Grain Filling in Wheat

1977 ◽  
Vol 4 (5) ◽  
pp. 785 ◽  
Author(s):  
I Sofield ◽  
LT Evans ◽  
MG Cook ◽  
IF Wardlaw
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Grain Growth ◽  
Dry Weight ◽  
Grain Filling ◽  
Close Relation ◽  
Grain Number ◽  
Lag Period ◽  
The Difference ◽  
Leaf Photosynthetic Rate

Controlled-environment conditions were used to examine the effects of cultivar and of temperature and illuminance after anthesis on grain setting and on the duration and rate of grain growth. After an initial lag period, which did not differ greatly between cultivars, grain dry weight increased linearly under most conditions until final grain weight was approached. Growth rate per grain depended on floret position within the ear, varied between cultivars (those with larger grains at maturity having a faster rate), and increased with rise in temperature. With cultivars in which grain number per ear was markedly affected by illuminance, light had relatively little effect on growth rate per grain. With those in which grain number was less affected by illuminance, growth rate per grain was highly responsive to it, especially in the more distal florets. In both cases there was a close relation between leaf photosynthetic rate as influenced by illuminance, the rate of grain growth per ear, and final grain yield per ear. The duration of linear grain growth, on the other hand, was scarcely influenced by illuminance, but was greatly reduced as temperature rose, with pronounced effects on grain yield per ear. Cultivars differed to some extent in their duration of linear growth, but these differences accounted for less of the difference in final weight per grain than did those in rate of grain growth. Under most conditions the cessation of grain growth did not appear to be due to lack of assimilates.

Growth and yield of highland maize in Mexico

1974 ◽  
Vol 83 (2) ◽  
pp. 213-221 ◽  
Author(s):  
P. R. Goldsworthy ◽  
M. Colegrove
Keyword(s):  
Growth Rate ◽  
Grain Growth ◽  
Growth Rates ◽  
Dry Weight ◽  
Grain Filling ◽  
Growth And Yield ◽  
Weight Changes ◽  
Highland Maize ◽  
Grain Filling Period ◽  
Tropical Varieties

SUMMARYThe growth and yield of five highland varieties of tropical maize were studied. Grain yields were between 4·7 and 8·8 t/ha. Crop growth rates (C) increased to a maximum of between 25 and 35 g/m2/day at silking and then declined. Grain growth rates (maximum 21 g/m2/day) exceeded current C during most of the grain-filling period.After silking, when C exceeded grain growth rate, dry matter accumulated in the stem and husk, resulting in an increase of from 200 to 600 g/m2. Later, as grain growth rate increased and exceeded current C, some of this accumulated material was incorporated into the grain, and stem weight decreased. A comparison of the dry weight changes after flowering in these varieties with those reported for a hybrid that yielded 12 t grain/ha indicates that the smaller yield of the Mexican varieties was associated with smaller grain growth rates and the incorporation into the grain of a smaller fraction of the dry weight produced after flowering. These results suggest that the capacity of the grain ‘sink’ to utilize assimilates limited yields in the tropical varieties.

Genotypic diversity in sorghum inbred lines for grain-filling patterns and other related agronomic traits

2011 ◽  
Vol 62 (12) ◽  
pp. 1026 ◽  
Author(s):  
Brenda L. Gambín ◽  
Lucas Borrás
Keyword(s):  
Growth Rate ◽  
Grain Growth ◽  
Agronomic Traits ◽  
Grain Filling ◽  
Inbred Lines ◽  
Degree Days ◽  
Grain Number ◽  
Trade Off ◽  
Maximum Water ◽  
Maximum Water Content

Opportunities for genetic improvement on specific traits require information on available diversity, together with knowledge on heritability estimates and possible trade-off relations among traits. Sixty-five sorghum inbred lines were evaluated for grain filling and other agronomic traits during 2008 and 29 re-evaluated in 2009. Time to anthesis, final grain weight (GW), grain growth rate, duration of grain filling, maximum water content, grain desiccation rate, moisture concentration at physiological maturity, plant height, panicle length, grain number per plant and final yield per plant were measured both years. Results highlighted the available variability for grain-filling patterns in sorghum, and genotypic differences (P < 0.05) for all traits were evident. Final GW variation (16–44 mg grain–1 in 2008, and 20–40 mg grain–1 in 2009) was achieved through different combinations of rate (3.27–9.78 mg degree-days grain–1 10−2) and duration of grain filling (413–853 degree-days). Calculated heritability for grain-filling traits ranged from 0.43 to 0.95, showing GW and maximum water content had the highest values. Grain number showed consistent negative associations with grain growth rate but not with GW due to grain-filling duration variability. This suggests selecting longer grain filling can increase GW (and yield) without negative trade-off relations with grain number.

scholarly journals Effect of Light Intensity and Quality on Growth Rate and Composition of Chlorella vulgaris

Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 31 ◽  
Author(s):  
Maria N. Metsoviti ◽  
George Papapolymerou ◽  
Ioannis T. Karapanagiotidis ◽  
Nikolaos Katsoulas
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Chlorella Vulgaris ◽  
Lipid Content ◽  
Growth Rates ◽  
Solar Irradiance ◽  
White Led ◽  
Microalgal Biomass ◽  
Nm Range ◽  
Effect Of Light

In this research, the effect of solar irradiance on Chlorella vulgaris cultivated in open bioreactors under greenhouse conditions was investigated, as well as of ratio of light intensity in the 420–520 nm range to light in the 580–680 nm range (I420–520/I580–680) and of artificial irradiation provided by red and white LED lamps in a closed flat plate laboratory bioreactor on the growth rate and composition. The increase in solar irradiance led to faster growth rates (μexp) of C. vulgaris under both environmental conditions studied in the greenhouse (in June up to 0.33 d−1 and in September up to 0.29 d−1) and higher lipid content in microalgal biomass (in June up to 25.6% and in September up to 24.7%). In the experiments conducted in the closed bioreactor, as the ratio I420–520/I580–680 increased, the specific growth rate and the biomass, protein and lipid productivities increased as well. Additionally, the increase in light intensity with red and white LED lamps resulted in faster growth rates (the μexp increased up to 0.36 d−1) and higher lipid content (up to 22.2%), while the protein, fiber, ash and moisture content remained relatively constant. Overall, the trend in biomass, lipid, and protein productivities as a function of light intensity was similar in the two systems (greenhouse and bioreactor).

scholarly journals Relationship between habitat distribution, growth rate, and plasticity in congeneric larval dragonflies

2005 ◽  
Vol 83 (8) ◽  
pp. 1128-1133 ◽  
Author(s):  
S J McCauley
Keyword(s):  
Growth Rate ◽  
Predation Risk ◽  
Growth Rates ◽  
Lepomis Macrochirus ◽  
Negative Relationship ◽  
Activity Level ◽  
Activity Levels ◽  
Habitat Distribution ◽  
Invertebrate Predators ◽  
The Relationship

The relationship between habitat distribution, growth rate, and plasticity was examined in the larvae of three species of dragonfly in the genus Libellula L., 1758. Growth rates were compared under three conditions: in the absence of predation risk, in the presence of sunfish (Lepomis macrochirus Rafinesque, 1819; Pisciformes: Centrachidae), and in the presence of invertebrate predators. I assessed how the habitat distributions of the three species of dragonfly, specifically how commonly they occur with fish, were related to growth rates and to the level of growth plasticity under different levels of perceived predation risk. There was a negative relationship between growth rate and the frequency with which species coexist with sunfish. Growth-rate plasticity was limited and does not appear to be important in determining the ability of species to coexist with alternative top predator types. Only one species exhibited growth-rate plasticity, decreasing growth in response to the predator with which it most commonly coexists but not to the species which poses the greatest predation risk. A comparison of growth rates and activity levels in the presence and absence of these predators suggests that growth and activity level parallel each other in these species.

scholarly journals Impurity influence on normal grain growth in the GISP2 ice core, Greenland

1996 ◽  
Vol 42 (141) ◽  
pp. 255-260 ◽  
Author(s):  
R. B Alley ◽  
G. A. Woods
Keyword(s):  
Growth Rate ◽  
Grain Size ◽  
Isotopic Composition ◽  
Grain Growth ◽  
Forest Fire ◽  
Growth Rates ◽  
Slow Growth ◽  
Ice Core ◽  
Isotopic Data ◽  
Thin Sections

AbstractIntercept analysis of approximately bi-yearly vertical thin sections from the upper part of the GISP2 ice Core, central Greenland, shows that grain-size ranges increase with increasing age. This demonstrates that something in the ice affects grain-growth rates, and that grain-size cannot be used directly in paleothermometry as has been proposed. Correlation of grain-growth rates to chemical and isotopic data indicates slower growth in ice with higher impurity concentrations, and especially slow growth in “forest-fire” layers containing abundant ammonium; however, the impurity/grain-growth relations are quite noisy. Little correlation is found between growth rate and isotopic composition of ice.

Growth Rate Responses of Lotic Periphytic Diatoms to Experimental Phosphorus Enrichment: The Influence of Temperature and Light

1988 ◽  
Vol 45 (2) ◽  
pp. 261-270 ◽  
Author(s):  
Max L. Bothwell
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Phosphorus Enrichment ◽  
Enrichment Experiments ◽  
Community Growth ◽  
Specific Growth Rates ◽  
The Relationship ◽  
River Water Temperature

Phosphate enrichment experiments were conducted year-round at the experimental troughs research apparatus (EXTRA) on the South Thompson River in British Columbia to determine the relationship between external concentration of orthophosphate and the growth rates of lotic periphytic diatom communities. Growth rate saturation always occurred at a phosphate concentration of approximately 0.3–0.6 μg P∙L−1. The maximum growth rate (μmax-P) with phosphorus enrichment varied seasonally with temperature. The relative specific growth rates (μ:μmax-P) as a function of external phosphate were constant. Seasonal changes in solar insolation (PAR) had no effect on the autotrophic community growth rates in unamended river water. Temperature exerted the most dominant influence on phosphorus-replete growth rates.

Growth responses of six bryophyte species to different light intensities

1993 ◽  
Vol 71 (5) ◽  
pp. 661-665 ◽  
Author(s):  
Emmanuel Rincón
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Growth Rates ◽  
Growth Analysis ◽  
Total Chlorophyll ◽  
Light Conditions ◽  
Growth Responses ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Plastic Responses

The growth responses of Brachythecium rutabulum, Eurhynchium praelongum, Lophocolea bidentata, Plagiomnium undulatum, Pseudoscleropodium purum, and Thuidiurn tamariscinum, growing under seven different light conditions, were determined in a 36-day laboratory experiment. Biomass production, relative growth rate, chlorophyll content, and morphological plastic responses (bending of the shoots) were determined following initial and final harvests. All species achieved greater biomass as irradiance increased. This trend was also observed in the relative growth rates, which were higher as irradiance increased, for all the bryophytes investigated. All species except L. bidentata showed an increased elevation of the shoot as irradiance decreased. Total chlorophyll was higher in all species at the lowest irradiance level, but no clear differences were observed in the ratios of chlorophyll a to b for all the species. Key words: grassland bryophytes, light intensity, growth analysis, plasticity.

The development of barley grain: comparisons between cultivars for growth rate and α-amylase activity

1976 ◽  
Vol 86 (3) ◽  
pp. 603-608 ◽  
Author(s):  
T. J. Riggs ◽  
P. G. Gothard
Keyword(s):  
Growth Rate ◽  
Grain Growth ◽  
Growth Rates ◽  
Amylase Activity ◽  
Spring Barley ◽  
Dry Weight ◽  
Barley Grain ◽  
Absolute Level ◽  
Barley Cultivars ◽  
Days After Anthesis

SummaryGrains from ears of known anthesis time in seven spring barley cultivars were measured for dry weight and α-amylase activity at regular intervals during grain maturation. During the period 10–31 days after anthesis, dry weight increase of the grain was found to be substantially linear in all the cultivars. Comparisons between linear slopes fitted for this phase of growth were found to provide an objective means of comparing grain growth rates in different cultivars.α-Amylase activity per grain reached a peak in all except one cultivar at between 10 and 16 days after anthesis but declined rapidly during the linear phase of grain growth. α-Amylase activity per gram grain dry weight decreased exponentially during this period and transformation of the data to logarithms allowed a substantially linear fit to be made. Slopes for each of the cultivars were compared.Differences were found between cultivars in grain growth rates, total α-amylase activity and rates of fall of α-amylase activity per gram for the period 10–31 days after anthesis. No relationship could be found between grain growth rate and either the absolute level of α-amylase activity achieved in the grain or the rate of fall in activity during development.

scholarly journals Effects of Soil Moisture, NPK Fertilizers and Varieties on Grain Growth of Barley (Hordeum vulgare L.)

2013 ◽  
Vol 19 (1) ◽  
pp. 13-21
Author(s):  
MSI Mollah ◽  
MH Rashid ◽  
MS Hossain ◽  
M Khalekuzzaman
Keyword(s):  
Growth Rate ◽  
Soil Moisture ◽  
Hordeum Vulgare ◽  
Relative Growth Rate ◽  
Grain Growth ◽  
Dry Weight ◽  
Spikelet Number ◽  
Grain Number ◽  
Npk Fertilizers ◽  
Relative Growth

The experiments are conducted in the experimental field of the Department of Botany, Rajshahi University during the winter season of 2005-2006 to study the effects of soil moisture and NPK fertilizers on grain growth of four barley varieties (Hordeum vulgare L.) following split-split plot design. The highest grain growth parameters like, spikelet number, spike dry weight, grain number and grain dry weight, spike relative growth rate and grain relative growth rate were observed in the I2 treatment at different days after anthesis. F3 treatment produced the highest spikelet number, spike dry weight, grain number, grain dry weight, spike relative growth rate and grain relative growth rate but the control produced the lowest values. BHL-3 produced higher spikelet number and grain relative growth rate. BL-1 produced higher spike dry weight, grain number, grain dry weight and spike relative growth rate.DOI: http://dx.doi.org/10.3329/pa.v19i1.16985 Progress. Agric. 19(1): 13 - 21, 2008 

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