Dry matter accumulation and distribution in winter wheat grown in a humid continental climate

1981 ◽  
Vol 59 (3) ◽  
pp. 415-420 ◽  
Author(s):  
L. A. Hunt ◽  
L. V. Edgington

The growth of a crop of 'Arrow' winter wheat (Triticum aestivum L. em Thell.) was studied in detail from 2 weeks before ear emergence to maturity. Aboveground dry weight increased up to 4 weeks after ear emergence, when it reached a maximum value of 1.4 kg∙m−2, and then decreased marginally. The rate of aboveground dry matter accumulation over a 6-week period beginning 2 weeks before ear emergence averaged 24.4 g∙m−2∙day−1.Rapid ear growth commenced some 2 weeks after ear emergence and continued until after the crop had lost all green coloration. Dry matter accumulation in the ears in the period beginning 3 weeks past ear emergence was greater than accumulation in the aboveground parts of the crop as a whole. This indicated that much of the ear dry matter increase in the latter part of the grain filling period occurred as a result of translocation of previously accumulated assimilates. The stem fraction (including leaf sheaths), the major aboveground reservoir of material that is translocated to the ear, decreased from 800 g∙m−2 at 3 weeks after ear emergence to 493 g∙m−2 at maturity.

1981 ◽  
Vol 96 (1) ◽  
pp. 167-186 ◽  
Author(s):  
D. W. Lawlor ◽  
W. Day ◽  
A. E. Johnston ◽  
B. J. Legg ◽  
K. J. Parkinson

SUMMARYThe effects of water deficit on growth of spring barley were analysed under five irrigation treatments. One crop was irrigated at weekly intervals from emergence throughout the growing season, and one was not irrigated at all after emergence. Soil water deficits in the other treatments were allowed to develop early, intermediate or late in the crop's development.Weekly irrigation produced a crop with a large leaf area index (maximum value 4) and maintained green leaf and awns throughout the grain-filling period. Early drought decreased leaf area index (maximum value 2) by slowing expansion of main-stem leaves and decreasing the number and growth of tiller leaves. Leaf senescence was also increased with drought. Drought late in the development of ears and leaves and during the grain-filling period caused leaves and awns to senesce so that the total photosynthetic areas decreased faster than with irrigation. Photosynthetic rate per unit leaf area was little affected by drought so total dry-matter production was most affected by differences in leaf area.Early drought gave fewer tillers (550/m2) and fewer grains per ear (18) than did irrigation (760 tillers/m2 and 21 grains per ear). Late irrigation after drought increased the number of grains per ear slightly but not the number of ears/m2. Thus at the start of the grain-filling period crops which had suffered drought early had fewer grains than irrigated (9·5 and 18·8 × 103/m2 respectively) or crops which suffered drought later in development (14 × 103/m2).During the first 2 weeks of filling, grains grew at almost the same rate in all treatments. Current assimilate supply was probably insufficient to provide this growth in crops which had suffered drought, and stem reserves were mobilized, as shown by the decrease in stem mass during the period. Grains filled for 8 days longer with irrigation and were heavier (36–38 mg) than without irrigation (29–30 mg). Drought throughout the grainfilling period after irrigation earlier in the season resulted in the smallest grains (29 mg).Grain yield depended on the number of ears, the number of grains per ear and mass per grain. Early drought decreased tillering and tiller ear production and the number of grains that filled in each ear. Late drought affected grain size via the effects on photosynthetic surface area.Drought decreased the concentrations of phosphorus, potassium and magnesium in the dry matter of crops, and irrigation after drought increased them. Concentration of nitrogen was little affected by treatment. Possible mechanisms by which water deficits and nutrient supply affect crop growth and yield are discussed.


Genetika ◽  
2011 ◽  
Vol 43 (3) ◽  
pp. 549-558 ◽  
Author(s):  
Novo Przulj ◽  
Vojislava Momcilovic

In wheat, rate and duration of dry matter accumulation and remobilization depend on genotype and growing conditions. The objective of this study was to determine the most appropriate polynomial regression of stepwise regression procedure for describing grain filling period in three winter wheat cultivars. The stepwise regression procedure showed that grain filling is a complex biological process and that it is difficult to offer a simple and appropriate polynomial equation that fits the pattern of changes in dry matter accumulation during the grain filling period, i.e., from anthesis to maximum grain weight, in winter wheat. If grain filling is to be represented with a high power polynomial, quartic and quintic equations showed to be most appropriate. In spite of certain disadvantages, a cubic equation of stepwise regression could be used for describing the pattern of winter wheat grain filling.


1995 ◽  
Vol 35 (4) ◽  
pp. 495 ◽  
Author(s):  
RG Flood ◽  
PJ Martin ◽  
WK Gardner

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.


1982 ◽  
Vol 62 (4) ◽  
pp. 855-860 ◽  
Author(s):  
M. TOLLENAAR ◽  
T. B. DAYNARD

The effect of source-sink ratio (i.e., the ability of the leaves to produce photosynthate versus the capacity of the grain to accommodate the assimilates) on dry matter accumulation and leaf senescence during the grain filling period of two short-season maize (Zea mays L.) hybrids was investigated in 1979 and 1980. Source-sink ratio of the maize hybrids was altered by ear removal at midsilking and at 3 wk after midsilking; by partial fertilization of the topmost ear so that treatment ears contained approximately 50% of kernel number of the control; and by removal of all leaf blades but that of the ear leaf at 2 wk after midsilking. Crop growth rate during the period from 3–5 wk after midsilking was reduced by 30% for the partly fertilized treatment and by 60% for both ear removal treatments. During the period from 5 to 7 wk after midsilking, the treatment-by-hybrid interaction for crop growth rate reflected different patterns of leaf senescence. In one hybrid, treatments which caused reductions in sink size delayed leaf senescence and increased the crop growth during the 5 to 7-wk postsilking interval, relative to the control. The reverse was evident for the other hybrid. Partial defoliation tended to cause the remaining ear leaf to senescence slightly earlier than in the control. Apparently two types of leaf senescence occurred: senescence due to assimilate starvation, and senescence due to excessive assimilate accumulation. The former caused by excessively low source-sink ratio and the latter caused by excessively high source-sink ratio. These results indicate that a delicate balance exists between sink and source during the grain-filling period of maize, and that disturbance of this balance can cause substantial yield reductions, plus an acceleration of leaf senescence and maturation processes.


1994 ◽  
Vol 21 (6) ◽  
pp. 771 ◽  
Author(s):  
A Blum ◽  
B Sinmena ◽  
J Mayer ◽  
G Golan ◽  
L Shpiler

The grain filling of wheat (Triticum aestivum L.) is seriously impaired by heat stress due to reductions in current leaf and ear photosynthesis at high temperatures. An alternative source of carbon for grain filling is stored stem reserves. Two spring wheat cultivars (V5 and V2183) of very similar phenology and plant stature, which had previously been found to differ in grain shrivelling under drought and heat stress conditions in the field, were used to evaluate the hypothesis that the mobilisation of stored stem reserves into the growing grain is an important source of carbon for supporting grain filling under heat stress. In two experiments in Israel (1990 and 1991), the rates of stem dry matter (DM) and stem total non-structural carbohydrates (TNC) loss, grain growth and leaf senescence were monitored under optimal (control) and high (stressed) temperatures in the glasshouse (1990) and the growth chamber (1991). Cultivar V5 always sustained a smaller reduction in grain dry weight under heat stress, than V2183. Irrespective of temperature, V5 had a higher stem DM and TNC content at the onset of grain filling, greater depletion of stem dry matter (or TNC) during grain filling, and longer duration of grain filling, than V2183. During grain filling V5 generally exported about two to three times more DM from the stems than V2183, under both non-stressed and stressed conditions. On the other hand, V5 was more heat-susceptible than V2183 in terms of leaf longevity, in vivo chlorophyll stability and grain abortion under heat stress. In a third experiment (1992) five cultivars (including V5 and V2183) were subjected to chemical desiccation (0.3% potassium iodide) of the canopy in the field in order to destroy the photosynthetic source ofthe plant after anthesis. The same cultivars were subjected to heat stress (35/25�C) or non-stressed (25/15�C) conditions after anthesis in the growth chamber. It was found that grain dry weight reduction by chemical desiccation was highly correlated with grain dry weight reduction by heat stress (r2 = 0.89). Therefore, the superior capacity of V5 for grain filling from mobilised stem reserves is a consti- tutive trait which supports grain filling under heat stress which can be tested for by chemical desiccation of plants under non-stressed conditions.


Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 12
Author(s):  
Witold Grzebisz ◽  
Jarosław Potarzycki

The application of magnesium significantly affects the components of the wheat yield and the dry matter partitioning in the grain-filling period (GFP). This hypothesis was tested in 2013, 2014, and 2015. A two-factorial experiment with three rates of magnesium (0, 25, 50 kg ha−1) and four stages of Mg foliar fertilization (without, BBCH 30, 49/50, two-stage) was carried out. Plant material collected at BBCH: 58, 79, 89 was divided into leaves, stems, ears, chaff, and grain. The wheat yield increased by 0.5 and 0.7 t ha−1 in response to the soil and foliar Mg application. The interaction of both systems gave + 0.9 t ha−1. The Mg application affected the grain yield by increasing grain density (GD), wheat biomass at the onset of wheat flowering, durability of leaves in GFP, and share of remobilized dry matter (REQ) in the grain yield. The current photosynthesis accounted for 66% and the REQ for 34%. The soil-applied Mg increased the REQ share in the grain yield to over 50% in 2014 and 2015. The highest yield is possible, but provided a sufficiently high GD, and a balanced share of both assimilate sources in the grain yield during the maturation phase of wheat growth.


Genetika ◽  
2011 ◽  
Vol 43 (2) ◽  
pp. 349-359 ◽  
Author(s):  
Novo Przulj ◽  
Vojislava Momcilovic

Modeling plant growth by mathematical functions is important for understanding plant development and growth. Most of the models of dry matter accumulation in small cereals simulated the period of grain filling while small attention has been devoted to mathematical simulation of vegetative period till anthesis. The aim of this research was to determine the most appropriate polynomial non-linear regression for dry matter accumulation till anthesis in winter wheat. Pobeda, a medium early variety, was used as model genotype for this research. A 5-year field data were analyzed by the forward procedure of stepwise regression. Although the procedure requires the maximum power of the polynomial regression to be used, we suggest using a lower power since it is easier for understanding and explanation and it is taking into account literature sources and biological laws. It can be accepted that quadratic regression model appropriately fits the process of dry matter accumulation till anthesis in winter wheat.


1994 ◽  
Vol 3 (2) ◽  
pp. 195-198 ◽  
Author(s):  
Pirjo Peltonen-Sainio

Duration of vegetative, generative, and grain-filling phases contribute to dry-matter accumulation and partitioning. Fourteen oat (Avena saliva L.) cultivars and six breeding lines were evaluated at the Viikki Experimental Farm, University of Helsinki, in 1988-1990. The following observations were made: (1) a short vegetative period accumulated less dry-matter into vegetative plant organs and resulted in higher grain yield and harvest index (HI), (2) a long period for maximum floret initiation yielded more grains per panicle and high panicle weight and (3) a short grain-filling period yielded high rates of panicle and grain filling associated with high HI. Hence, oat breeding and crop management should aim at improving the synchronization of the growth phases as shown in this study.


1995 ◽  
Vol 22 (3) ◽  
pp. 391 ◽  
Author(s):  
IF Wardlaw ◽  
L Moncur

Wheat (Triticum aestivum L.) plants were grown to anthesis at 18/13�C day/night and either retained at 18/13�C or transferred to a higher temperature (24/19 or 30/25�C) for the grain-filling period. It was confirmed that high temperature resulted in a considerable drop in kernel dry weight at maturity and there was significant cultivar variation in the degree of the response. ranging from a 30 to 60% decrease in kernel dry weight at maturity for a rise in temperature from 18/13 to 30/25�C. An analysis of the rate and duration of kernel filling of seven cultivars showed that those cultivars most tolerant of high temperature during kernel filling (least reduction of kernel dry weight at maturity) were those where the rate of kernel filling was most enhanced by high temperature, i.e. the increased rate compensated for the reduced duration of kernel filling. The importance of the rate of kernel filling in determining varietal responses to high temperature illustrates the need to isolate the effect of temperature on processes in the kernel during the linear phase of growth.


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