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 Dry matter accumulation and remobilization in winter barley as affected by genotype and sowing date

Genetika ◽  
2015 ◽  
Vol 47 (2) ◽  
pp. 751-763 ◽  
Author(s):  
Milan Mirosavljevic ◽  
Novo Przulj ◽  
Vojislava Momcilovic ◽  
Nikola Hristov ◽  
Ivana Maksimovic
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Genotypic Variation ◽  
Sowing Date ◽  
Matter Content ◽  
Winter Barley ◽  
Dry Matter Content ◽  
Dry Matter Accumulation ◽  
Sowing Dates ◽  
Barley Genotypes

Knowledge about the effect of genotypic variation and sowing date on dry matter accumulation, remobilization and partitioning in winter barley is important for crop management. Therefore, in field studies, six winter barley genotypes of various origin and maturity groups were studied across four sowing dates. In general, grain yield and dry matter content decreased with delayed sowing, after mid-October, and average grain yield in late October and November sowing was lower 14.2% and 16.9%, respectively, compared to the yield in the optimal sowing date. Among the tested genotypes, high grain yield and dry matter content was obtained from late and medium early barley genotypes. Delayed sowing dates, on average, reduced dry matter remobilization and contribution of vegetative dry matter to grain yield. In years characterized by high spring precipitation, late September and early October sowing of medium early and late barley genotypes enable increased accumulation and remobilization of dry matter and obtainment of high grain yield.

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.

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.

Assessing photosynthetic limitation to grain yield in a field crop

1973 ◽  
Vol 24 (3) ◽  
pp. 297 ◽  
Author(s):  
RM Gifford ◽  
PM Bremner ◽  
DB Jones
Keyword(s):  
Carbon Dioxide ◽  
Grain Yield ◽  
Dry Weight ◽  
Grain Filling ◽  
Kernel Weight ◽  
Yield Component ◽  
Carbon Dioxide Enrichment ◽  
Plant Weight ◽  
Source Limitation ◽  
Different Levels

A method is proposed for assessing the degree to which the availability of photosynthate during grain filling limits the yield of a cereal ('source limitation'). The technique uses shading and carbon dioxide enrichment to alter photosynthesis after anthesis, and may be applied in the field. From only final dry weight determinations, the degree of source limitation of grain yield is quantified on a 0 to 1 scale by relating differences in grain weight to differences in plant weight. For a crop of barley (cv. Resibee) on which the method was tried, the degree of source limitation was about one-half, which suggested that for this particular crop neither the source nor the sink presented an overriding limitation to grain yield. This was so for four stands of the cultivar produced by different levels of shading and carbon dioxide enrichment before anthesis. A yield component analysis indicated that kernel weight was the major component changed by post-anthesis treatments. Pre-anthesis treatments, which also affected grain yield, mainly influenced the numbers of ears produced.

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.

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.

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.

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.

The effects of soil moisture stress on the growth of barley. I. Vegetative development and grain yield

1964 ◽  
Vol 15 (5) ◽  
pp. 729 ◽  
Author(s):  
D Aspinall ◽  
PB Nicholls ◽  
LH May
Keyword(s):  
Grain Size ◽  
Soil Moisture ◽  
Grain Yield ◽  
Stem Elongation ◽  
Moisture Stress ◽  
The Other ◽  
Vegetative Development ◽  
Soil Moisture Stress ◽  
The One ◽  
Periods Of Stress

The effects of soil moisture stress on tillering, stem elongation, and grain yield of barley (cv. Prior) have been studied by subjecting the plants to periods of stress at different stages of development. Soil moisture stress treatments consisted of repeated short cycles of stress, single short cycles (both in large pots), or single long cycles (in large lysimeters). The data collected support the contention that the organ which is growing most rapidly at the time of a stress is the one most affected. Grain numbers per ear were seriously affected by stress occurring prior to anthesis, an effect probably associated with the process of spikelet initiation and, later, with the formation of the gametes. Grain size, on the other hand, was reduced more by stress at anthesis and shortly after. Elongation of the internodes was reduced mostly by stress at or just before earing, and was less seriously affected by earlier or later stress. Tillering, although being suppressed during a drought cycle, was actually stimulated upon rewatering. The effect was greater the earlier the period of stress, and was probably related to nutrient uptake and distribution within the plant.

Sign in / Sign up

Export Citation Format

Share Document