Studies of grain production in Sorghum bicolor (L. Moench). III.* The relative importance of assimilate supply, grain growth capacity and transport system

1975 ◽  
Vol 26 (1) ◽  
pp. 11 ◽  
Author(s):  
KS Fischer ◽  
GL Wilson
Keyword(s):  
Grain Size ◽  
Grain Yield ◽  
Transport System ◽  
Dry Matter ◽  
Storage Capacity ◽  
Net Photosynthesis ◽  
Grain Filling ◽  
Plant Parts ◽  
Root Potential ◽  
Sorghum Bicolor L

In field and glasshouse experiments with grain sorghum (cv. RS610), the assimilate supply was varied by increasing or decreasing radiation and carbon dioxide supply; the potential grain storage capacity was altered by spikelet removal; and the transport system was reduced by incision of the culm. Plants grown at four population densities in the field were manipulated to increase (by removing neighbouring plants) or decrease (by shading) the supply of photosynthates during grain filling. These treatments affected grain size and thus yield. Removal of some of the spikelets at three-quarter anthesis resulted in a significant increase in the size of those grains remaining at maturity. From anthesis onward, a reduction in the capacity of the transport system in the culm had no significant effect on grain yield. These results are interpreted as evidence that grain yield is not limited by the storage capacity of the grain, or by the transport system involved in moving material from the stem to the grain. Treatments which altered the demand for assimilates by the grain, relative to the supply, did not affect net photosynthesis. Dry matter produced in excess of grain requirements accumulated in other plant parts, including the root. Potential grain size was influenced by interspikelet competition operating within 1 week after three-quarter anthesis. *Part II, Aust. J. Agric. Res., 22: 39-47 (1971).

Studies of grain production in Sorghum bicolor (L. Moench). IV.* Some effects of increasing and decreasing photosynthesis at different stages of the plant's development on the storage capacity of the inflorescence

1975 ◽  
Vol 26 (1) ◽  
pp. 25 ◽  
Author(s):  
KS Fischer ◽  
GL Wilson
Keyword(s):  
Storage Capacity ◽  
Developmental Stages ◽  
Light Transmission ◽  
Plant Competition ◽  
Grain Filling ◽  
Floral Initiation ◽  
Grain Production ◽  
Grain Number ◽  
Plant Parts ◽  
Sorghum Bicolor L

Sorghum plants (cv. RS610) grown in field stands at two population densities were manipulated to increase the supply of assimilates (by removing neighbouring plants) at one of three developmental stages—10-15 days after floral initiation, 1 week prior to three-quarters anthesis, and 1 week after three-quarters anthesis. Post-initiation exposure increased the number of grains per inflorescence 1.8-fold and 3.5-fold in medium and high density populations respectively, but had relatively less effect on grain size. Higher grain number resulted largely from more grains per secondary branch in the lower part of the inflorescence. Neither of the post-heading exposure treatments influenced grain number, but the higher supply of assimilates resulted in larger grains at both densities. Differences at one density only between yield characteristics of plants exposed at the two times provide evidence of inter-plant competition for assimilates to the extent that the potential size of the grain may be affected. Shading (10% light transmission) of plants grown in a glasshouse, whether for 1 week at anthesis or during grain filling, reduced grain yield at maturity by the same amount as the immediate reduction at the end of the shading period. The experiment was unable to demonstrate changes in the potential size of grains resulting from the loss of assimilates at anthesis. There was substantial compensation for the loss by translocation from other plant parts. *Part III, Aust. J. Agric. Res., 26: 11 (1975).

Photosynthetic and storage limitations to yield in Sorghum bicolor (L. Moench)

1976 ◽  
Vol 27 (4) ◽  
pp. 489 ◽  
Author(s):  
RC Muchow ◽  
GL Wilson
Keyword(s):  
Grain Size ◽  
Transport System ◽  
Storage Capacity ◽  
Population Densities ◽  
Net Assimilation ◽  
Growing Conditions ◽  
Source Sink ◽  
And Storage ◽  
Sorghum Bicolor L ◽  
Source And Sink

Under favourable growing conditions, the source-sink relationships in grain yield of sorghum were analysed in terms of capacities for net assimilation, of head storage, and of the transport system to move assimilates between source and sink. In four commercial hybrids (Dekalb E57, Pacific Goldfinger, Texas 610SR, and Texas 626) grown at three population densities (20.2, 40.4 and 80.8 plants m-1), the assimilates supply was varied by increasing or decreasing the radiation available per plant (by thinning or shading), the potential gram storage capacity was decreased by spikelet removal, and the transport system was reduced by incision of the culm, all manipulations being performed at anthesis. Decreasing the number of grains increased the size of those remaining in all cultivars at all population densities The degree of Increase was greatest for T626 and T610 and least for E57 Thinning increased the grain size In all cultivars, but only sufficiently to cause a significant increase In gram yield In T610 and T626 Reduction in the assimilate supply by shading decreased the gram size and yield in all cultivars. Reduction In the transport system had no significant effect on gram yield. These results showed that there was surplus capacity for storage and transport In all cultivars In T626, T6L0, and Goldfinger, all post-anthesis assimilate was stored as gram and grams could grow larger The yield was therefore completely source-limited In E57, however, not all port-anthesis assimilate was stored as gram, and these grams showed little capacity to grow larger, which suggests that the yield was partially limited by both source and sink.

Growth and productivity of irrigated Sorghum bicolor (L. Moench) in northern Australia. I. Plant density and arrangement effects on light interception and distribution, and grain yield, in the hybrid Texas 610SR in low and medium latitudes

1982 ◽  
Vol 33 (5) ◽  
pp. 773 ◽  
Author(s):  
RC Muchow ◽  
DB Coates ◽  
GL Wilson ◽  
MA Foale
Keyword(s):  
Grain Yield ◽  
Structural Adjustment ◽  
Dry Matter ◽  
Plant Density ◽  
Grain Filling ◽  
Dry Matter Production ◽  
Northern Australia ◽  
Low Latitude ◽  
Matter Production ◽  
Sorghum Bicolor L

The influence of plant arrangement and density on yield of the grain sorghum hybrid Texas 610SR grown as an irrigated dry season crop in the Ord Irrigation Area (lat. 16�S) was determined. Neither the rate of dry matter production nor the pattern of partitioning of dry matter during grain-filling varied between treatments, and grain yield was unresponsive to row spacings below 75 cm and densities above 267000 plants ha-1. The results were analysed by considering the effect of radiation interception and distribution in the canopy on dry matter production. The opportunity was then taken to compare this trial, and two others conducted at the same low latitude where grain yield was unresponsive to density, with four trials conducted at higher latitudes (27�S.) where Texas 610SR was very responsive to density. The effect is shown to be associated with radiation penetration into canopies. In the low latitude trials the poorer penetration of photosynthetically active radiation (PAR) into high density stands could have resulted from lack of structural adjustment of the canopy, in contrast to the experience at medium latitude. Equally, there may have been an effect of lower solar angles at low latitude, resulting in the poorer PAR distribution. The consequence was a failure of response of dry matter production to increasing density, reflected in grain yield.

Studies of grain production in Sorghum bicolor (L. Moench). VII.* Contribution of plant parts to canopy photosynthesis and grain yield in field stations

1976 ◽  
Vol 27 (2) ◽  
pp. 235 ◽  
Author(s):  
KS Fischer ◽  
GL Wilson ◽  
I Duthie
Keyword(s):  
Grain Yield ◽  
Flag Leaf ◽  
Net Photosynthesis ◽  
Grain Filling ◽  
Carbon Dioxide Exchange ◽  
Relative Importance ◽  
Leaf Position ◽  
Canopy Photosynthesis ◽  
Photosynthetic Rates ◽  
Plant Parts

A method based on 14CO2 uptake and carbon dioxide exchange in sorghum canopies at medium and high density populations allowed the estimation of photosynthesis by plant parts (heads, and leaves at each level of insertion) after anthesis. The relative importance of corresponding parts did not differ between populations, nor did photosynthetic rates per unit leaf area. The latter did decline with successive leaf position down the canopy but were generally compensated by increasing area of these leaves. Averaged over the two populations, which differed little, the heads provided 14% of canopy photosynthesis, and the flag leaf and leaves 2, 3 and 4 were responsible for 21, 24, 21 and 13% respectively. Greater leaf areas per unit land area in the higher population, for each leaf position, resulted in higher total canopy photosynthesis. Previous studies having shown that net photosynthesis after heading corresponds closely to grain yield, the relative importance of plant parts to overall net photosynthesis may be regarded as their relative contribution to grain filling. A direct estimate of their importance in this regard, based on another method, showed the head to contribute 17%, and the next four leaves 17, 25, 20 and 17%. Factors controlling photosynthetic rates of parts are discussed, and the estimates of the importance of photosynthetic sites to grain filling are compared with those reported in previous work. _____________________ *Part VI, Aust. J. Agric. Res., 27: 35 (1976).

scholarly journals Influence of High Temperature Stress on Net Photosynthesis, Dry Matter Partitioning and Rice Grain Yield at Flowering and Grain Filling Stages

2013 ◽  
Vol 12 (4) ◽  
pp. 603-609 ◽  
Author(s):  
Guo-hua LÜ ◽  
Yong-feng WU ◽  
Wen-bo BAI ◽  
Bao MA ◽  
Chun-yan WANG ◽  
...  
Keyword(s):  
High Temperature ◽  
Grain Yield ◽  
Temperature Stress ◽  
Dry Matter ◽  
Net Photosynthesis ◽  
Grain Filling ◽  
High Temperature Stress ◽  
Rice Grain ◽  
Dry Matter Partitioning

Studies on the physiological determinants of grain yield in five varieties of sorghum

1973 ◽  
Vol 81 (3) ◽  
pp. 537-548 ◽  
Author(s):  
R. W. Willey ◽  
D. R. Basiime
Keyword(s):  
Grain Yield ◽  
Storage Capacity ◽  
Leaf Growth ◽  
Grain Filling ◽  
Maximum Efficiency ◽  
Relative Importance ◽  
Varietal Differences ◽  
Plant Parts ◽  
Yield Production

SUMMARYExperiments are described in which the relative importance of head storage capacity and carbohydrate supply was examined in five sorghum varieties of different heights. The varieties were: Namatera (270 cm), Dobbs (180 cm), MUS 78 (100 cm), MUS 23 (85 cm) and MUS 70 (85 cm). Techniques used were (i) cutting off part of the head or part of the leaf at anthesis, (ii) shading during different periods of development, and (iii) thinning the plants at different physiological stages. Varietal differences ranged from a situation where the head was little more than half-filled by the available carbohydrate (MUS 78), through intermediate stages (Dobbs and Namatera), to a situation where the head capacity limited the amount of carbohydrate which could be stored (MUS 23 and MUS 70). Some differences could be attributed to pre-anthesis competition between head and stem, but in the dwarfs a more important factor appeared to be pre-anthesis competition between head and leaf. It is suggested that for maximum efficiency of grain-yield production, maximum carbohydrate should be utilized for pre-anthesis head and leaf growth and that partitioning between these plant parts should be such that the supply of carbohydrate for grain filling is in balance with head storage capacity.

scholarly journals Diethyl Aminoethyl Hexanoate Increase Relay Strip Intercropping Soybean Grain by Optimizing Photosynthesis Aera and Delaying Leaf Senescence

2022 ◽  
Vol 12 ◽  
Author(s):  
Kai Luo ◽  
Xiaoting Yuan ◽  
Chen Xie ◽  
Shanshan Liu ◽  
Ping Chen ◽  
...  
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Net Photosynthesis ◽  
Grain Filling ◽  
Grain Weight ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Yield Increase ◽  
Strip Intercropping ◽  
Pod Number

Insufficient and unbalanced biomass supply inhibited soybean [Glycine max (L.) Merr.] yield formation in the maize-soybean relay strip intercropping (IS) and monoculture soybean (SS). A field experiment was conducted to explore the soybean yield increase mechanism of DA-6 in IS and SS treatments. In this 2-year experiment, compact maize “Denghai 605” and shade-tolerant soybean “Nandou 25” were selected as cultivated materials. DA-6 with four concentrations, i.e., 0 mg/L (CK), 40 mg/L (D40), 60 mg/L (D60), and 80 mg/L (D80), were sprayed on soybean leaves at the beginning of flowering stage of soybean. Results showed that DA-6 treatments significantly (p < 0.05) increased soybean grain yield, and the yield increase ratio was higher in IS than SS. The leaf area index values and net photosynthesis rate of IS peaked at D60 and were increased by 32.2–49.3% and 24.1–27.2% compared with the corresponding CK. Similarly, DA-6 treatments increased the aboveground dry matter and the amount of soybean dry matter accumulation from the R1 stage to the R8 stage (VDMT) and highest at D60 both in IS and SS. D60 increased the VDMT by 29.0–47.1% in IS and 20.7–29.2% in SS. The TRG at D60 ranged 72.4–77.6% in IS and 61.4–62.5% in SS. The MDA content at D60 treatment was decreased by 38.3% in IS and 25.8% in SS. The active grain-filling day in IS was about 7 days longer than in SS. In D60 treatment, the Vmean and Vmax increased by 6.5% and 6.5% in IS and 5.7% and 4.3% in SS compared with the corresponding CK. Although the pod number and hundred-grain weight were significantly (p < 0.05) increased by DA-6 treatments, the grains per pod were maintained stable. The pod number and hundred-grain weight were increased by 30.1–36.8% and 4.5–6.7% in IS and 6.3–13% and 3.6–5.6% in SS. Thus, the grain yield at D60 was increased by 36.7–38.4% in IS and 21.7–26.6% in SS. DA-6 treatments significantly (p < 0.05) increased soybean grain yield and peaked D60 treatments both in IS and SS.

Characteristics of the canopy, root system and grain yield of a crop of Lupinus angustifolius cv. Unicrop

1975 ◽  
Vol 26 (3) ◽  
pp. 497 ◽  
Author(s):  
EAN Greenwood ◽  
P Farrington ◽  
JD Beresford
Keyword(s):  
Carbon Dioxide ◽  
Grain Yield ◽  
Leaf Area ◽  
Time Course ◽  
Dry Weight ◽  
Grain Filling ◽  
Main Axis ◽  
Carbon Dioxide Exchange ◽  
Area Index ◽  
Plant Parts

The time course of development of a lupin crop was studied at Bakers Hill, Western Australia. The aim was to gain insight into the crop factors influencing yield. Weekly measurements were made of numbers and weights of plant parts, and profiles of roots, leaf area and light interception. A profile of carbon dioxide in the crop atmosphere was taken at the time of maximum leaf area, and the net carbon dioxide exchange (NCE) of pods was estimated for three successive weeks. The crop took 10 weeks to attain a leaf area index (LAI) of 1 and a further 9 weeks to reach a maximum LAI of 3.75, at which time only 33% of daylight reached the pods on the main axis. Once the maximum LAI was attained at week 19, leaf fall accelerated and rapid grain filling commenced almost simultaneously on all of the three orders of axes which had formed pods. Measurements of NCE between pods on the main axis and the air suggest that the assimilation of external carbon dioxide by the pods contributed little to grain filling. Grain dry weight was 2100 kg ha-1 of which 30%, 60% and 10% came from the main axis, first and second order apical axes respectively. Only 23% of the flowers set pods and this constitutes an important physiological limitation to grain yield.

scholarly journals The Rho-family GTPase OsRac1 controls rice grain size and yield by regulating cell division

2019 ◽  
Vol 116 (32) ◽  
pp. 16121-16126 ◽  
Author(s):  
Ying Zhang ◽  
Yan Xiong ◽  
Renyi Liu ◽  
Hong-Wei Xue ◽  
Zhenbiao Yang
Keyword(s):  
Grain Size ◽  
Cell Division ◽  
Grain Yield ◽  
Molecular Mechanisms ◽  
Grain Filling ◽  
High Yield ◽  
Rice Grain ◽  
Rop Gtpase ◽  
Key Factor ◽  
Grain Width

Grain size is a key factor for determining grain yield in crops and is a target trait for both domestication and breeding, yet the mechanisms underlying the regulation of grain size are largely unclear. Here we show that the grain size and yield of rice (Oryza sativa) is positively regulated by ROP GTPase (Rho-like GTPase from plants), a versatile molecular switch modulating plant growth, development, and responses to the environment. Overexpression of rice OsRac1ROP not only increases cell numbers, resulting in a larger spikelet hull, but also accelerates grain filling rate, causing greater grain width and weight. As a result, OsRac1 overexpression improves grain yield in O. sativa by nearly 16%. In contrast, down-regulation or deletion of OsRac1 causes the opposite effects. RNA-seq and cell cycle analyses suggest that OsRac1 promotes cell division. Interestingly, OsRac1 interacts with and regulates the phosphorylation level of OsMAPK6, which is known to regulate cell division and grain size in rice. Thus, our findings suggest OsRac1 modulates rice grain size and yield by influencing cell division. This study provides insights into the molecular mechanisms underlying the control of rice grain size and suggests that OsRac1 could serve as a potential target gene for breeding high-yield crops.

Effects of plant density and tillage on growth and grain yield of sorghum (Sorghum bicolor (L.) Moench) under dryland conditions in a semi-arid area in Ethiopia

1987 ◽  
Vol 108 (2) ◽  
pp. 395-401 ◽  
Author(s):  
D. C. Adjei-Twum
Keyword(s):  
Soil Moisture ◽  
Grain Yield ◽  
Plant Density ◽  
Grain Filling ◽  
Arid Area ◽  
Tillage Practices ◽  
Available Soil Moisture ◽  
Cropping Seasons ◽  
Sorghum Bicolor L ◽  
Semi Arid

SummaryEffects of plant density ranging from 44444 to 133333 plants/ha and tillage practices (planting in flat beds (control), in the furrows of open ridges, on the top of open ridges, in the furrows of tie-ridges and on the top of tie-ridges) on growth and grain yield of sorghum were investigated at Kobo, a typical semi-arid area in Ethiopia, during 1980, 1981 and 1982 cropping seasons. Plant growth was limited in the flat beds because they were likely to be deficient in soil moisture and sometimes in the tie-ridging treatments, due to waterlogging. However, planting on the top of tie-ridges produced 1·6, 0·4 and 1·8 t/ha more yield than in the flat beds, the method commonly practised by the Kobo farmers, during 1980, 1981 and 1982 respectively. In all seasons, the effect of plant density did not show marked differences. The plants rather adjusted their reproductive growth and development to the seasonal rainfall and presumably to the available soil moisture at the grain-filling periods. It was concluded that the highest plant density did not reach the optimum for the area. Planting sorghum on the top of tie-ridges is recommended.

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