Source–sink relations and effects of post-anthesis canopy defoliation in wheat at low latitudes

1990 ◽  
Vol 114 (1) ◽  
pp. 93-99 ◽  
Author(s):  
P. K. Aggarwal ◽  
R. A. Fischer ◽  
S. P. Liboon
Keyword(s):  
Grain Yield ◽  
Flag Leaf ◽  
Dry Weight ◽  
Grain Filling ◽  
The Philippines ◽  
New Delhi ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Grain Nitrogen ◽  
Source Sink

SUMMARYSource–sink balance was studied by imposing different canopy defoliation treatments on wheat crops grown in Los Banos (Philippines) in 1985/86 and 1986/87, Sonora (Mexico) in 1972/73 and 1974/75 and New Delhi (India) in 1987/88. The crops were grown in replicated trials with optimum cultural management. Six defoliation treatments were imposed at anthesis on all shoots in the canopy in an area ranging between 1·65 and 3·0 m2. Defoliation reduced dry weight in proportion to the reduction in percentage light interception. The number of grains per unit land area was reduced slightly, and in most cases not significantly, except when all leaves were removed. Despite reduction of leaf lamina area index to as low as 0·5, the decrease in grain yield was small. In particular, flag leaf removal led to a remarkably small reduction in grain yield. Grain nitrogen content in defoliated crops decreased much less than expected from the amount of N removed by defoliation. The slope of the relation between reduction in grain yield with defoliation and reduction in post-anthesis dry matter accumulation was 0·56, indicating moderate source limitation for grain filling. The crops at the hottest site, in the Philippines, were less limited by source than the other crops. It is suggested that selection for smaller flag leaves may be worthwhile for high-input wheat crops.

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.

The effect of changes of assimilate supply around flowering on grain sink size and yield of maize (Zea mays L.) cultivars of tropical and temperate adaptation

1988 ◽  
Vol 39 (2) ◽  
pp. 153 ◽  
Author(s):  
GK Aluko ◽  
KS Fischer
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Zea Mays L ◽  
Flag Leaf ◽  
Dry Weight ◽  
Grain Filling ◽  
Plant Parts ◽  
Male Inflorescence ◽  
Female Inflorescence ◽  
Sink Size

Two maize (Zea mays L.) cultivars of temperate and one of tropical adaptation were grown in a subtropical (27�s.) environment under favourable conditions of plant population density, water and nutrient supply. The radiation incident to the plant during the period from flag leaf to 10 days after flowering was varied from the control by either shading or temporarily restraining leaves of neighbouring plants. The effects of these changes in assimilate supply, and of the presence of the male inflorescence, on the immediate dry weight of various plant parts and grain sink size, and consequential on dry matter production and grain yield was investigated. The radiation treatments effected small but significant changes in crop growth rate. Shading reduced the dry weight of the ear, and husk of the female inflorescence and male inflorescence (tassel). There were increases due to enhanced radiation. While removal of tassels also enhanced the dry weight of the female inflorescence, there was no evidence that the male inflorescence was a preferred sink for assimilates during this stage of growth.In the temperate cultivars, grain number m-2 was associated with ear dry weight at 10 days after anthesis (r = 0.95**). However, only in the tropical cultivar did the larger grain sink result in an increase in grain yield. Shading reduced grain yield in all cultivars probably because of a reduction in the supply of labile assimilates for grain filling.

Variation between and within species of rapeseed (Brassica campestris and B. napus) in response to drought stress. II.* Growth and development under natural drought stresses

1978 ◽  
Vol 29 (3) ◽  
pp. 479 ◽  
Author(s):  
RA Richards ◽  
N Thurling
Keyword(s):  
Soil Moisture ◽  
Grain Yield ◽  
Genotypic Variation ◽  
Dry Weight ◽  
Grain Filling ◽  
Moisture Stress ◽  
Sowing Date ◽  
Soil Types ◽  
Dry Matter Accumulation ◽  
Plant Weight

Two rapeseed species and cultivars within each of these species differed significantly with respect to the influence of variation in sowing date on growth, development and yield on two different soil types. Soil moisture stress, particularly after anthesis, was the major environmental factor affecting these processes. Grain yield declined markedly with later sowings in both species, and B. napus, despite its later maturity, was more tolerant of severe soil moisture deficits since its grain yield was consistently higher than B. campestris in the more stressed environments. The major distinguishing feature between species contributing most to this difference in yield was the pattern of dry matter accumulation. In B. campestris most of the dry weight of the plant was accumulated after anthesis when drought was most severe, whereas in B. napus dry weight accumulation occurred before anthesis. This resulted in a greater contribution of reserves accumulated by anthesis to grain-filling in B. napus. Most of the variation in seed yield resulted from differences in sowing dates and soil types. When these environmental effects were excluded, the main determinants of genotypic variation in yield were the numbers of pods and branches and harvest index in both species, growth rate in the post-anthesis phase in B. campestris, and plant weight and root/shoot ratio at anthesis in B. napus. Selection strategies for yield improvement in rapeseed growing in drought-stressed environments are discussed. _____________________ *Part I, Aust. J. Agric. Res., 29: 469 (1978).

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.

RELATIONSHIPS BETWEEN LENGTH OF THE ACTUAL AND EFFECTIVE GRAIN FILLING PERIODS AND THE GRAIN YIELD OF CORN

1976 ◽  
Vol 56 (2) ◽  
pp. 237-242 ◽  
Author(s):  
T. B. DAYNARD ◽  
L. W. KANNENBERG
Keyword(s):  
Grain Yield ◽  
Correlation Coefficients ◽  
Dry Weight ◽  
Grain Filling ◽  
High Rate ◽  
Dry Matter Accumulation ◽  
Black Layer ◽  
Grain Filling Period ◽  
Highly Correlated ◽  
Period Duration

Studies were conducted near Guelph, Ontario in 1970 and 1971 to examine the relationship between grain yield of corn and two measures of the length of the grain filling period, AFPD (actual filling period duration — days from mid-silking to black layer maturity) and EFPD (effective filling period duration — final kernel size divided by mean rate of kernel dry weight accumulation during the middle of the grain filling period). The studies involved 30 adapted commercial hybrids in 1970 and 35 in 1971, with 27 common to both years. Measures of AFPD and EFPD were highly correlated across years. Positive relationships were evident in each year, and over the averages of 2 yr, between AFPD and EFPD, and between both parameters and grain yield; averaged over 2 yr for 27 hybrids, the correlation coefficients between AFPD and yield, and EFPD and yield, were 0.56 and 0.53, respectively (both significant at [Formula: see text]). In general, results provided support for earlier suggestions that selection for an extended grain filling period could result in increased grain yield. However, notable exceptions existed among hybrids to the overall relationship between length of filling period and yield. The existence of these exceptions may indicate that the general relationships observed between length of filling period and yield were only indirect rather than direct, and that exceptional hybrids with high grain yield, high rate of grain dry matter accumulation, and short grain filling period may represent a better breeding objective in short-season corn-growing regions.

scholarly journals Nitrogen Supply Affects Grain Yield by Regulating Antioxidant Enzyme Activity and Photosynthetic Capacity of Maize Plant in the Loess Plateau

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1094
Author(s):  
Kai Yue ◽  
Lingling Li ◽  
Junhong Xie ◽  
Setor Kwami Fudjoe ◽  
Renzhi Zhang ◽  
...  
Keyword(s):  
Grain Yield ◽  
Antioxidant Enzyme ◽  
Loess Plateau ◽  
Photosynthetic Capacity ◽  
Growth And Yield ◽  
Dry Matter Accumulation ◽  
The Loess Plateau ◽  
Area Index ◽  
Leaf Stage ◽  
Significant Difference

Nitrogen (N) is the most limiting nutrient for maize, and appropriate N fertilization can promote maize growth and yield. The effect of N fertilizer rates and timings on morphology, antioxidant enzymes, and grain yield of maize (Zea mays L.) in the Loess Plateau of China was evaluated. The four N levels, i.e., 0 (N0), 100 (N1), 200 (N2), and 300 (N3) kg ha−1, were applied at two timings (T1, one-third N at sowing and two-thirds at the six-leaf stage of maize; T2, one-third applied at sowing, six-leaf stage, and eleven-leaf stage of maize). The results show that N2 and N3 significantly increased the plant height, stem and leaf dry weight, and leaf area index of maize compared with a non-N-fertilized control (N0). The net photosynthetic rate, transpiration rate, stomatal conductance, and leaf chlorophyll contents were lower, while the intercellular carbon dioxide concentration was higher for non-fertilized plants compared to fertilized plants. The activities of peroxidase (POD) and superoxide dismutase (SOD) increased with N rate, but the difference between 200 and 300 kg ha−1 was not significant; further, the isozyme bands of POD and SOD also changed with their activities. Compared with a non-N-fertilized control, N2 and N3 significantly increased grain yield by 2.76- and 3.11-fold in 2018, 2.74- and 2.80-fold in 2019, and 2.71- and 2.89-fold in 2020, and there was no significant difference between N2 and N3. N application timing only affected yield in 2018. In conclusion, 200 kg N ha−1 application increased yield through optimizing the antioxidant enzyme system, increasing photosynthetic capacity, and promoting dry matter accumulation. Further research is necessary to evaluate the response of more cultivars under more seasons to validate the results obtained.

scholarly journals Effect of Heat Stress on Inter-relationship of Physiological and Biochemical Traits with Grain Yield in Wheat (Triticum aestivum L.)

2020 ◽  
pp. 19-29
Author(s):  
Amrita Kumari ◽  
R. D. Ranjan ◽  
Chandan Roy ◽  
Awadesh Kumar Pal ◽  
S. Kumar
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Flag Leaf ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
Seedling Stage ◽  
Biochemical Traits ◽  
Highly Correlated ◽  
Complex Phenomena ◽  
Physiological And Biochemical

Heat stress, particularly the stress appears at the time of flowering to grain filling stages causing severe yield loss in wheat. Heat tolerance is complex phenomena that include adjustment in morphological, physiological and biochemical traits of the crop. Present investigation was carried out to understand the effect of terminal heat stress on different traits of wheat. The experiment was conducted in three dates of sowing as timely sown, late sown and very late sown to expose the crop to heat stress at later stages of the crop growth. Significant genetic variations for all the traits evaluated under three conditions indicated the presence of variability for the traits. Trait association analysis revealed that flag leaf chlorophyll content and MSI at seedling stage; MDA at reproductive stage had direct relationship with grain yield. While under very late sown condition MDA and RWC at seedling stages were found to be highly correlated with grain yield. It indicates that MDA, RWC at seedling stage and days to booting, days to milking plays important role in very late sown condition that can be used as selection criteria in breeding programme.

scholarly journals Studies on Potential of Different Dates of Sowing and Varieties on Productivity of Aerobic Rice in Assam

2020 ◽  
pp. 557-565
Author(s):  
Bidisha Borah ◽  
Kalyan Pathak
Keyword(s):  
Grain Yield ◽  
Rice Variety ◽  
Canopy Temperature ◽  
Index Number ◽  
Dry Matter Accumulation ◽  
Rice Varieties ◽  
Area Index ◽  
Main Plot ◽  
Positive Effect ◽  
Plot Design

An investigation was carried out to determine an optimum micro-climate regimes for different promising varieties of rice for realizing higher yields under aerobic conditions. A field experiment was conducted in the Instructional Cum Research (ICR) Farm of Assam Agricultural University, Jorhat, Assam during autumn season of 2017. The experiment was laid out in a split-plot design with three replications. The treatments consisted of four micro-climatic regimes (M) in main plot viz., sowing of seed on 15th February (M1), 1st March (M2), 16th March (M3) and 1st April (M4) along with four different rice varieties (V) viz., CR-Dhan 205 (V1), CR-Dhan 203 (V2), CR-Dhan 204 (V3) and Inglongkiri (V4) in sub plot. The results of the experiment revealed that among the different micro-climatic regimes, the micro-climate associated with 1st April recorded positive effect on micro-climate related and yield parameters in terms of canopy temperature, light intensity, soil moister content, soil temperature, dry matter accumulation, leaf area index, number of effective tillers and grain yield (3004 kg/ha), followed by the micro-climate associated with 16th March sown crop. Among the varieties evaluated, CR-Dhan 203 recorded the highest value in terms of number of effective tillers (187/m2) followed by Inglongkiri, CR-Dhan 204 and CR-Dhan 205. The highest grain yield of 2860 kg/ha recorded in rice variety CR-Dhan 203 was significantly superior to that of other varieties except Inglongkiri. In terms of economics, the crop sown on 1st April recorded the highest net return (INR 51755 /ha) and B:C ratio (2.30) which was found to be the greatest.

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.

Dry Matter, Nodulation and Nutrient Uptake in Chickpea (Cicer arietinum) as Influenced by Irrigation and Phosphorus

1989 ◽  
Vol 25 (3) ◽  
pp. 349-355 ◽  
Author(s):  
S. S. Parihar ◽  
R. S. Tripathi
Keyword(s):  
Grain Yield ◽  
Nutrient Uptake ◽  
Irrigation Water ◽  
Vegetative Growth ◽  
Dry Matter ◽  
Dry Weight ◽  
Irrigation Scheduling ◽  
Dry Matter Accumulation ◽  
Pan Evaporation ◽  
Eastern India

SUMMARYThe response of chickpea to irrigation and phosphorus was studied at Kharagpur in Eastern India. Irrigation scheduling was based on the ratio between irrigation water applied and cumulative pan evaporation (ID/CPE), and had little effect on dry matter accumulation. Increasing the frequency and amount of irrigation reduced the number and dry weight of nodules per plant, which increased to a maximum 70 days after sowing and then declined. Irrigation significantly reduced grain yield as a result of excessive vegetative growth at the expense of pod formation. Application of phosphorus promoted nodulation and increased both nodule dry weight and the concentration of N, P and K in grain and stover. Uptake of N, P and K by the crop was also increased.

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