Efect of great brome (Bromus diandrus Roth.) on the growth of wheat and great brome and their uptake of nitrogen and phosphorus

1984 ◽  
Vol 35 (1) ◽  
pp. 1 ◽  
Author(s):  
GS Gill ◽  
WM Blacklow
Keyword(s):  
Field Experiment ◽  
Grain Yield ◽  
Dry Matter ◽  
Grain Filling ◽  
Nitrogen And Phosphorus ◽  
Bromus Diandrus ◽  
Yield Determinants

A field experiment was conducted at Badgingarra, W.A., during 1981 to study competition between wheat (cv. Gamenya) and great brome (Bromus diandrus Roth.). Shoot dry matter per plant of wheat was reduced from 1.41 g per plant in wheat monoculture to 0.50 g per plant after competing for 71 days with great brome at density of 400 plants m-2. Tiller production was reduced from 605 tillers m-2 in monocultures of wheat to 336 tillers m-2 when growing in association with 400 plants m-2 of great brome. Competition with great brome reduced the concentration of nitrogen and phosphorus in wheat shoots; at Feeke's scale 3 (tillers formed) wheat plants competing with 400 plants m-2 of great brome had 3.15 � 0.09% (mean � s.e., w/w) nitrogen and 0.58% phosphorus against a concentration of 4.05 � 0.1% nitrogen and 0.77% phosphorus in the monoculture of wheat. The reduction in the nitrogen - and phosphorus concentrations in wheat shoots earlier than any significant reductions in their dry matter suggested that great brome competed with wheat for absorption of nitrogen and phosphorus. Competition with great brome also resulted in significant reduction in the grain yield (r = - 0.77) and yield determinants of wheat. Reduction in mass per grain (r = - 0.77) was probably due to competition with great brome for water during grain-filling.

Plant population and shading studies in barley

1971 ◽  
Vol 77 (3) ◽  
pp. 445-452 ◽  
Author(s):  
R. W. Willey ◽  
R. Holliday
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Unit Area ◽  
Grain Filling ◽  
Crop Growth ◽  
Plant Population ◽  
Grain Number ◽  
Ear Development ◽  
Development Period ◽  
Lower Production

SUMMARYTwo barley experiments are described in which a range of plant populations were shaded during different periods of development. Shading during the ear development period caused considerable reductions in grain yield, largely by reducing the number of grains per ear. Shading during the grain-filling period caused no reduction in grain yield. It is suggested that under conditions of these experiments there was probably a potential surplus of carbohydrate available for grain filling and that grain yield was largely determined by the storage capacity of the ears. The importance of the number of grains per ear as an indicator of individual ear capacity is emphasized.The effects of plant population on grain yield and its components are also examined. It is concluded that the number of grains per ear is the component having greatest influence on the decrease in grain yield at above-optimum populations and attention is again drawn to the possible importance of ear capacity. It is argued that on an area basis the number of grains per unit area may give a good indication of ear capacity. Examination of this parameter shows a close relationship with grain yield per unit area for both the shading and population treatments. It is particularly evident that a decrease in grain yield at high populations was associated with a comparable decrease in the number of grains per unit area. It is suggested that this decrease in grain number may be due to a lower production of total dry matter during ear development rather than an unfavourable partitioning of this dry matter between the ear and the rest of the plant. This lower production of total dry matter is attributed to the crop growth rates of the higher populations having reached their peak and then having declined before the end of the ear development period. This crop growth rate pattern, through its effect on grain number per unit area, is put forward as the basic reason why, in the final crop, grain yield per unit area decreases at above-optimum populations.

Dry matter accumulation and partitioning and its relationship to grain yield in wheat

1995 ◽  
Vol 35 (4) ◽  
pp. 495 ◽  
Author(s):  
RG Flood ◽  
PJ Martin ◽  
WK Gardner
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Grain Filling ◽  
Dry Matter Accumulation ◽  
The North ◽  
Similar Range ◽  
Total Crop ◽  
Grain Filling Period ◽  
Stem Reserves ◽  
North Western

Total crop dry matter (DM) production and its components, remobilisation of stem reserves, and the relation of these to grain yield were studied in 10 wheat cultivars sown at Walpeup, Boort, and Horsham in the north-western Victorian wheatbelt. Between sites, all DM components decreased in the order Horsham > Boort > Walpeup. Differences between Boort and Walpeup were not always significant. Total DM at anthesis for Walpeu,p and Boort was in a similar range, and less than that for Horsham. Yields increased in the order Walpeup < Boort < Horsham. When data from the 3 sites were combined, leaf, stem (excluding cv. Argentine IX), and total DM were related to grain yield. Within sites, ear DM at anthesis was related to grain yield. Grain yield for all cultivars at Horsham and Walpeup and 5 cultivars at Boort was greater than the increases in crop DM from anthesis to maturity, indicating that pre-anthesis stored assimilates (stem reserves) were used for grain filling. Post-anthesis decrease in stem weight was inversely related to grain yield only at Horsham, which supports the view of utilisation of stem reserves for grain filling at this site. At Boort and Walpeup there was a similar negative trend, but values for 2 cultivars at each site were outliers, which weakened the trend. The wide adaptability of the Australian cultivars used in this study may be related to the differential remobilisation of stem reserves at each site. A measure of yield stability, however, was not related to stem weight loss during the grain-filling period.

The ability of wheat cultivars to withstand drought in UK conditions: formation of grain yield

2002 ◽  
Vol 138 (2) ◽  
pp. 153-169 ◽  
Author(s):  
M. J. FOULKES ◽  
R. K. SCOTT ◽  
R. SYLVESTER-BRADLEY
Keyword(s):  
Grain Yield ◽  
Drought Resistance ◽  
Water Availability ◽  
Dry Matter ◽  
Grain Filling ◽  
Temperate Climate ◽  
Soluble Carbohydrate ◽  
Wheat Cultivars ◽  
Effects Of Drought ◽  
Yield Responses

Experiments in three dry years, 1993/94, 1994/95 and 1995/96, on a medium sand at ADAS Gleadthorpe, England, tested responses of six winter wheat cultivars to irrigation of dry-matter growth, partitioning of dry matter to leaf, stem and ear throughout the season, and to grain at final harvest. Cultivars (Haven, Maris Huntsman, Mercia, Rialto, Riband and Soissons) were selected for contrasts in flowering date and stem soluble carbohydrate. Maximum soil moisture deficit (SMD) exceeded 140 mm in all years, with large deficits (>75 mm) from early June in 1994 and from May in 1995 and 1996. The main effects of drought on partitioning of biomass were for a decrease in the proportion of the crop as lamina in the pre-flowering period, and then earlier retranslocation of stem reserves to grains during the first half of grain filling. Restricted water availability decreased grain yield by 1·83 t/ha in 1994 (P<0·05), and with more prolonged droughts, by 3·06 t/ha in 1995 (P<0·001) and by 4·55 t/ha in 1996 (P<0·001). Averaged over the three years, grain yield responses of the six cultivars differed significantly (P<0·05). Rialto and Mercia lost only 2·8 t/ha compared with Riband and Haven which lost 3·5 t/ha. Losses for Soissons and Maris Huntsman were intermediate. In the two years with prolonged drought, the biomass depression was on average greater for Haven (6·0 t/ha) than for Maris Huntsman (4·2 t/ha) (P<0·05). Thus, the grain yield sensitivity of Haven to drought derived, in part, from a sensitivity of biomass growth to drought. Harvest index (HI; ratio of grain to above-ground dry matter at harvest) responses of the six cultivars to irrigation also differed (P<0·05) and contributed to the yield responses. The smallest decrease in HI of the six cultivars with restricted water availability was shown by Rialto (−0·033); this partially explained the drought resistance for this cultivar. The largest decrease was for Maris Huntsman (−0·072). The cultivars differed in flowering dates by up to 9 days but these were poorly correlated with grain yield responses to irrigation. Stem soluble carbohydrate at flowering varied amongst cultivars from 220 to 300 g/m2 in the unirrigated crop; greater accumulation appeared to be associated with better maintenance of HI under drought. It is concluded that high stem-soluble carbohydrate reserves could be used to improve drought resistance in the UK's temperate climate, but that early flowering seems less likely to be useful.

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).

Growth and yield of sorghum lines extracted from a population for differences in osmotic adjustment

1995 ◽  
Vol 46 (1) ◽  
pp. 61 ◽  
Author(s):  
T Tangpremsri ◽  
S Fukai ◽  
KS Fischer
Keyword(s):  
Water Stress ◽  
Grain Yield ◽  
Leaf Area ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
Dry Matter ◽  
Grain Filling ◽  
Grain Number ◽  
Glasshouse Experiment ◽  
The Difference

From 47 S2 lines which had been extracted from a random mated population of sorghum, eight lines for a glasshouse experiment and four lines for a field experiment were divergently selected for variation in osmotic adjustment, and were grouped into two, High and Low osmotic adjustment (OA). Both the glasshouse and field experiments examined whether osmotic adjustment modified the plants' response to soil water deficit and also whether grain sink demand for assimilates, varied by removal of 50% spikelets, affected osmotic adjustment. In each experiment, there were well-watered control and water stress treatments. In both experiments, the dawn osmotic potential in the High OA group was always lower than in the Low OA group under water limiting conditions, and the difference was significant after anthesis. The difference in osmotic potential was about 0.1 MPa in the field and up to 0.25 MPa in the glasshouse. In the glasshouse experiment, removal of 50% spikelets at anthesis significantly decreased osmotic potential during grain filling, suggesting that osmotic adjustment is influenced by the availability of assimilates in the leaves. Under well-watered conditions, the two groups behaved very similarly in terms of maximum leaf area, green leaf area retention during grain filling, total dry matter production, grain yield and grain number in both experiments. Under water-limiting conditions, the High OA group produced larger maximum leaf area and had better leaf retention during grain filling. Despite similar water use, total dry matter was also significantly higher in the High OA group though the difference was small. Grain number was also greater in this group in both experiments, whereas grain yield was significantly higher in the High OA group in the field, but not in the glasshouse where severe water stress developed more rapidly. It is concluded that the adverse effect of water stress can be reduced by adopting sorghum genotypes with high osmotic adjustment. However, selection for high osmotic adjustment needs to ensure that osmotic adjustment is not solely due to small head size.

SOURCE-SINK LIMITATIONS OF MAIZE GROWING IN AN OUTDOOR HYDROPONIC SYSTEM

1988 ◽  
Vol 68 (4) ◽  
pp. 947-955 ◽  
Author(s):  
G. K. WALKER ◽  
M. H. MILLER ◽  
M. TOLLENAAR
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Yield Components ◽  
Dry Matter ◽  
Grain Filling ◽  
Sink Strength ◽  
Plant Spacing ◽  
Kernel Number ◽  
Hydroponic System ◽  
Crop Growth Rate

Experiments were conducted from 1983 to 1985 to test the hypothesis that rate of dry matter accumulation by maize (Zea mays L.) during grain filling can be enhanced by an increase in assimilate demand for grain filling (i.e., sink strength).The sink strength of maize plants grown in an outdoor hydroponic system was varied independently of the source strength by manipulating the plant spacing during the period in which final kernel number is established. The crop growth rate during grain filling, the dry matter of leaves, stems, ears and roots, and grain yield components were determined. In all 3 yr the crop growth rate during grain filling of plants that had been growing at a 20 000 plants ha−1 spacing for variable periods and were returned to the control density of 80 000 plants ha−1 at the start of the grain-filling period was lower than that of plants grown continuously at a spacing of 80 000 plants ha−1. In 1985, plants grown at 20 000 plants ha−1 from 3 wk preanthesis until 2 wk postanthesis and at 80 000 plants ha−1 thereafter had 50% more kernels per plant than the control plants. However, the net photosynthesis during grain filling was not increased; in fact it was somewhat lower. Final grain yield was not significantly different, mainly due to greater translocation from the stems to the grain in the spaced plants than in the controls. These studies indicate that maize growing in a nonlimiting below-ground environment is not sink limited. Hence adding sink capacity by maintaining kernel number while increasing plant density or by adding more kernels per plant would not appear to be a promising route for raising the yield potential.Key words: Sink strength, hydroponics, plant spacing, kernel number, yield components

scholarly journals Evaluating Dry Matter Production and Grain Yield of Dual-Purpose Winter Wheat Using Field Experiment and Modelling

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 338
Author(s):  
Ketema Tilahun Zeleke
Keyword(s):  
Winter Wheat ◽  
Field Experiment ◽  
Grain Yield ◽  
Dry Matter ◽  
Growth Stage ◽  
Production Systems ◽  
Triticum Aestivum L ◽  
Simulation Modelling ◽  
Sowing Time ◽  
Simulated Grazing

The potential of a winter wheat (Triticum aestivum L.) cultivar Wedgetail to provide grazing and grain yield under different sowing times, grazing times, and watering regimes, under current and future climate, was investigated using field experiment and simulation modelling. For the field experiment, there were two watering treatments (unirrigated (D) and irrigated (I)) and four simulated grazing treatments (ungrazed, simulated grazed at growth stage (GS) 25, simulated grazed at growth stage (GS) 32, and grazed at both GS 25 and GS 32). These were designated as D0, D1, D2, and D3, respectively, for the unirrigated treatment and I0, I1, I2, and I3, respectively, for the irrigated treatment. It was found that the soil water depletion was significantly higher (p < 0.05) for the irrigated/ungrazed treatment than that for the simulated grazed treatment. The crop simulated grazed at GS 25 recovered quicker than the crop grazed at GS 32, especially for the unirrigated treatment. As the sowing time is delayed, above-ground dry matter (AGDM) production decreases. For D2 and D3, the amount of simulated grazed AGDM was 3.46 t ha−1 and 3.55 t ha−1, respectively. For I2 and I3, the amount of simulated grazed AGDM was 4.73 t ha−1 and 4.34 t ha−1, respectively. For D1, simulated grazing increased grain yield by 7%, while for D2 and D3, it increased by 18% and 24%, respectively. For I1, simulated grazing reduced grain yield by 16%, while for I2 and I3, it decreased by 42% and 42%, respectively. Simulation using the Agricultural Production Systems sIMulator (APSIM) showed that, for winter wheat sown in the second week of March, the maximum AGDM expected one in two years at the ends of May, June, and July is 4.5 t ha−1, 5.8 t ha−1, and 6.8 t ha−1, respectively. If the crop is sown mid-April, these values are 0.8 t ha−1, 2.2 t ha−1, and 4.3 t ha−1, respectively. Yield did not show response to times of sowing from March to early April. The maximum value reached was about 4.5 t ha−1 when sown in the fourth week of March, after which it started decreasing and reached the lowest value of about 4.1 t ha−1 when sown by the end of May. The total above-ground dry matter (AGDM) obtained by grazing earlier during the feasible grazing period and again towards the end of this period was not significantly different from grazing only once towards the end of this period. The simulation results showed that winter wheat Wedgetail flowering date was less sensitive to sowing time and that yield did not show a significant response to times of sowing, with the maximum occurring for the fourth week of March sowing and the lowest for the fourth week of May sowing.

scholarly journals Effect of the duration of the vegetative phase on crop growth, development and yield in two contrasting pearl millet hybrids

1988 ◽  
Vol 110 (1) ◽  
pp. 71-79 ◽  
Author(s):  
P. Q. Craufurd ◽  
F. R. Bidinger
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Pearl Millet ◽  
Harvest Index ◽  
Dry Matter ◽  
Grain Filling ◽  
Stem Growth ◽  
Dry Matter Accumulation ◽  
Dry Matter Partitioning ◽  
Vegetative Phase

SummaryThe phenotype of medium duration pearl millet varieties grown in West Africa differs from that of the shorter duration millets grown in India. African varieties are usually much taller, have longer panicles, fewer productive tillers, and a lower ratio of grain to above-ground dry-matter (harvest index). The effect of crop duration on plant phenotype was investigated in two hybrids using extended daylengths to increase the duration of the vegetative phase (GSl: sowing to panicle initiation). The two hybrids, 841A × J104 and 81A × Souna B, were considered to represent the Indian and African phenotype, respectively. Tiller production and survival, leaf area, and dry-matter accumulation and partition, were monitored over the season. Grain yield and its components were determined at maturity.The two hybrids responded similarly to the short and long daylength treatments. The duration of GSl was increased from 20 to 30 days, resulting in increased number of leaves, leaf area, and stem and total dry-matter accumulation; there was no effect on tiller production and survival, or on panicle growth rate. Grain yield was, therefore, the same in both GSl treatments, and harvest index (HI) was much reduced in the long GSl treatment owing to the increased stem growth. One evident effect of a longer GSl was on dry-matter partitioning between shoots; partitioning to the main stem (MS) was increased, whereas partitioning to the tillers was reduced.There was no difference in crop development, growth or yield between the two hybrids in either GSl treatment. The only significant differences were in the efficiency with which intercepted radiation was converted to dry matter, which was greater in 841A × J104 than in 81A × Souna B, and in the balance between MS and tillers; the grain yield of the MS was significantly greater in 81A x Souna B than in 841A × J104, but at the expense of number of productive tillers.The results demonstrate that both African and Indian phenotypes are equally productive under good agronomic conditions. The lower HI in longer duration African millets is a consequence of a much extended stem growth phase and therefore increased competition between stem and panicle during grain filling. Possible ways to increase grain yield in the medium duration African millets are considered.

Genotypic variation in osmotic adjustment in grain sorghum. II. Relation with some growth attributes

1991 ◽  
Vol 42 (5) ◽  
pp. 759 ◽  
Author(s):  
T Tangpremsri ◽  
S Fukai ◽  
KS Fischer ◽  
RG Henzell
Keyword(s):  
Water Stress ◽  
Grain Yield ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
Dry Matter ◽  
Genotypic Variation ◽  
Grain Filling ◽  
Stages Of Growth ◽  
Early Stages ◽  
Positive Effect

Two sets containing large numbers (23 and 47 entries) of sorghum genotypes were grown in the glasshouse to examine the effect of osmotic adjustment on water extraction, dry matter growth and grain yield. Water stress was developed in two periods, one before and one after anthesis. The results were similar in the two experiments despite a large difference in the genetic background of the plant material. Since osmotic potential did not differ significantly among genotypes before water stress was induced, osmotic potential obtained under stress was used directly to indicate the genotype's ability to adjust osmotically. Osmotic adjustment was positively associated with green leaf area retention during grain filling and to root length density at 70 cm depth. Genotypes with high osmotic adjustment used more water during the second drying period. As a result, total dry matter was well related to osmotic adjustment during grain filling, but grain yield was negatively associated with osmotic adjustment in one experiment and not significantly related in the other. When comparison was made for lines which had similar leaf water potential during early stages of growth but which differed in osmotic adjustment during grain filling, there was still a positive effect of osmotic adjustment on total dry matter. This suggests that the positive effect was not caused by large plants extracting more water during early stages of growth, but was due to the difference in line's ability to extract water during grain filling.

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