EFFECTS OF PHOTOPERIOD AND TEMPERATURE ON VEGETATIVE AND REPRODUCTIVE GROWTH OF A MAIZE (ZEA MAYS) HYBRID

1977 ◽  
Vol 57 (4) ◽  
pp. 1127-1133 ◽  
Author(s):  
R. B. HUNTER ◽  
M. TOLLENAAR ◽  
C. M. BREUER

A single-cross maize (Zea mays L.) hybrid was grown to maturity in the four combinations of two temperatures, 20 and 30 C, and two photoperiods, 10 and 20 h, in controlled-environment growth cabinets. Measurements of dry weights of plant components were made at tassel initiation, mid-anthesis, mid-anthesis plus 16 days, and maturity. The longer photoperiod and cooler temperature treatment produced the highest final plant dry weight. Average daily dry matter (DM) production was greater for plants grown at the longer photoperiod. This could largely be attributed to a higher leaf area per plant. The duration of DM production was longer at the cooler temperature. Grain yields were higher under the lower temperature because of an increase in the length of the grain-filling period and because a greater proportion of the post-anthesis DM was allocated to the grain. The results of this study showed a significant photoperiod × temperature interaction for length of the grain-filling period, kernel number and grain yield. Post-anthesis DM accumulation did not appear to be a limiting factor for grain yield. The effects of temperature and photoperiod on length of the grain-filling period and grain yield may have been partly mediated through the size of the grain sink.

1976 ◽  
Vol 56 (4) ◽  
pp. 795-798 ◽  
Author(s):  
C. M. BREUER ◽  
R. B. HUNTER ◽  
L. W. KANNENBERG

A single-cross maize (Zea mays L.) hybrid was grown under two photoperiods (10 and 20 h) at two constant temperatures (20 and 30 C). Rate of development was characterized by the number of days from planting to tassel initiation, tassel initiation to silking, and silking to maturity. Long photoperiod and low temperature independently increased the number of days between planting and tassel initiation. The interval between tassel initiation and silking was not affected by photoperiod, but was increased significantly by the low temperature treatment. During the grain filling period (silking to maturity), temperature had the principal effect, but a photoperiod by temperature interaction did occur. Although plants grown at 20 C required more days to reach maturity than those grown at 30 C, the filling period at 20 C was shorter under the 10-h photoperiod than under the 20-h photoperiod, but at 30 C, the 10-h photoperiod treatment had the longer filling period. The delay in development at the low temperature, although apparent at all three stages of development, was not of the same magnitude. When the delay in development at 20 C is expressed as a percent of time required at 30 C, the 20 C treatment took 28% longer between planting and tassel initiation than the 30 C treatment. The corresponding figures for days between tassel initiation and silking and between silking and maturity were 58 and 46%, respectively.


1988 ◽  
Vol 39 (2) ◽  
pp. 153 ◽  
Author(s):  
GK Aluko ◽  
KS Fischer

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.


1976 ◽  
Vol 56 (2) ◽  
pp. 237-242 ◽  
Author(s):  
T. B. DAYNARD ◽  
L. W. KANNENBERG

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.


1987 ◽  
Vol 65 (3) ◽  
pp. 607-611 ◽  
Author(s):  
Herminia Loza-Tavera ◽  
Bernardo Serrano ◽  
José D. Molina ◽  
Ma. Luisa Ortega-Delgado ◽  
Estela Sanchez-de-Jiménez

Maize variety Zacatecas 58 (Z0), was used to select, after 12 cycles of mass selection for grain yield, an improved population (Z12). Some agronomical traits were characterized at the end of the selected period in both populations. Ribulose-1,5-bisphosphate carboxylase–oxygenase (RuBPcase) activity, phosphoenolpyruvate carboxylase (PEPcase) activity, protein content, and chlorophyll content were measured in the leaves above the ear, throughout the grain filling period (from anthesis to 40 days afterwards). Various agronomical traits associated with increase in yield, such as length and diameter of ear, rows per ear, and kernels per row, were greater in the Z12 than in the Z0 population. Likewise, the Z12 population showed 50% more yield than Z0, although days to anthesis did not increase significantly. During the grain filling period the leaves of the Z12 population had more activity of RuBPcase but not PEPcase compared with the Z0 population. It is suggested that the higher level of RuBPcase activity observed in the Z12 population might be related to its improved grain yield.


1975 ◽  
Vol 26 (3) ◽  
pp. 497 ◽  
Author(s):  
EAN Greenwood ◽  
P Farrington ◽  
JD Beresford

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.


2008 ◽  
Vol 59 (4) ◽  
pp. 354 ◽  
Author(s):  
J. T. Christopher ◽  
A. M. Manschadi ◽  
G. L. Hammer ◽  
A. K. Borrell

Water availability is a key limiting factor in wheat production in the northern grain belt of Australia. Varieties with improved adaptation to such conditions are actively sought. The CIMMYT wheat line SeriM82 has shown a significant yield advantage in multi-environment screening trials in this region. The objective of this study was to identify the physiological basis of the adaptive traits underpinning this advantage. Six detailed experiments were conducted to compare the growth, development, and yield of SeriM82 with that of the adapted cultivar, Hartog. The experiments were undertaken in field environments that represented the range of moisture availability conditions commonly encountered by winter crops grown on the deep Vertosol soils of this region. The yield of SeriM82 was 6–28% greater than that of Hartog, and SeriM82 exhibited a stay-green phenotype by maintaining green leaf area longer during the grain-filling period in all environments where yield was significantly greater than Hartog. However, where the availability of deep soil moisture was limited, SeriM82 failed to exhibit significantly greater yield or to express the stay-green phenotype. Thus, the stay-green phenotype was closely associated with the yield advantage of SeriM82. SeriM82 also exhibited higher mean grain mass than Hartog in all environments. It is suggested that small differences in water use before anthesis, or greater water extraction from depth after anthesis, could underlie the stay-green phenotype. The inability of SeriM82 to exhibit stay-green and higher yield where deep soil moisture was depleted indicates that extraction of deep soil moisture is important.


1977 ◽  
Vol 4 (5) ◽  
pp. 785 ◽  
Author(s):  
I Sofield ◽  
LT Evans ◽  
MG Cook ◽  
IF Wardlaw

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.


2020 ◽  
Vol 12 (14) ◽  
pp. 5610
Author(s):  
Alireza Pour-Aboughadareh ◽  
Reza Mohammadi ◽  
Alireza Etminan ◽  
Lia Shooshtari ◽  
Neda Maleki-Tabrizi ◽  
...  

Durum wheat performance in the Mediterranean climate is limited when water scarcity occurs before and during anthesis. The present research was performed to determine the effect of drought stress on several physiological and agro-morphological traits in 17 durum wheat genotypes under two conditions (control and drought) over two years. The results of analysis of variance indicated that the various durum wheat genotypes responded differently to drought stress. Drought stress significantly reduced the grain filling period, plant height, peduncle length, number of spikes per plot, number of grains per spike, thousand grains weight, grain yield, biomass, and harvest index in all genotypes compared to the control condition. The heatmap-based correlation analysis indicated that grain yield was positively and significantly associated with phenological characters (days to heading, days to physiological maturity, and grain filling period), as well as number of spikes per plant, biomass, and harvest index under drought conditions. The yield-based drought and susceptible indices revealed that stress tolerance index (STI), geometric mean productivity (GMP), mean productivity (MP), and harmonic mean (HM) were positively and significantly correlated with grain yields in both conditions. Based on the average of the sum of ranks across all indices and a three-dimensional plot, two genotypes (G9 and G12) along with the control variety (G1) were identified as the most tolerant genotypes. Among the investigated genotypes, the new breeding genotype G12 showed a high drought tolerance and yield performance under both conditions. Hence, this genotype can be a candidate for further multi-years and locations test as recommended for cultivation under rainfed conditions in arid and semi-arid regions.


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.


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