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.

EFFECT OF TEMPERATURE DURING GRAIN FILLING ON WHOLE PLANT AND GRAIN YIELD IN MAIZE (Zea mays L.)

1983 ◽  
Vol 63 (2) ◽  
pp. 357-363 ◽  
Author(s):  
B. BADU-APRAKU ◽  
R. B. HUNTER ◽  
M. TOLLENAAR
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Leaf Senescence ◽  
Zea Mays L ◽  
Growth Yield ◽  
Grain Filling ◽  
Kernel Weight ◽  
Effect Of Temperature ◽  
Plant Parts ◽  
Whole Plant

In a 2-yr study, plants of an adapted, short-season single cross maize (Zea mays L.) hybrid were grown outdoors until 18 days post-silking. At that stage, the plants were transferred to controlled-environment growth cabinets where temperature effects on leaf senescence, grain and whole plant dry matter (DM) production and DM distribution were studied. The day/night temperature regimes were 25/15 °C, 25/25 °C, 35/15 °C and 35/25 °C. Higher temperatures reduced whole plant DM accumulation during grain filling. The reduction in DM accumulation was primarily related to a reduction in the period of time from 18 days post-silking until 100% leaf senescence and, to a limited extent, to a lower rate of whole plant DM production. Grain yield per plant was also lower under higher temperatures. The decreases in grain yield were almost entirely determined by a shorter duration of grain filling, while no temperature effect was observed on kernel growth rates or on kernel number per ear. During rapid grain filling, the increase in kernel DM results from utilization of a combination of assimilates temporarily stored in the vegetative plant parts and assimilates produced through current photosynthesis. Under the highest temperature regime, assimilates remobilized from other plant parts accounted for a greater proportion of kernel weight gain. In addition, there was an indication that higher night temperatures resulted in an increased proportion of gain in kernel weight resulting from remobilization of stored DM.Key words: Corn, temperature, grain-filling period, grain growth, yield components, leaf senescence

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.

PERFORMANCE UNDER STRESS OF ADVANCED CYCLES OF FOUR POPULATIONS OF CORN (Zea mays L.) IN AN S1 PER SE RECURRENT SELECTION PROGRAM

1981 ◽  
Vol 61 (1) ◽  
pp. 29-36
Author(s):  
O. A. ADARA ◽  
L. W. KANNENBERG
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Recurrent Selection ◽  
Zea Mays L ◽  
Selection Criterion ◽  
Grain Filling ◽  
Primary Selection ◽  
Per Se ◽  
Selection For ◽  
Advanced Cycles

Two cycles of S1 per se recurrent selection were conducted in four populations of corn (Zea mays L.). The primary selection criterion was a performance index: grain yield divided by percent moisture at harvest. The original (C0) source material and first cycle (C1) of selection for each population were evaluated in a favorable (1977) and an unfavorable (1978) growing season. Second cycle (C2) materials were also included in the 1978 comparisons. In 1977, C1 yielded significantly more grain than C0 in three of the four populations. In contrast, performance of C1 and C2 materials in 1978 was inferior to C0 in all populations but one. The advanced cycles of only one population showed improvement over C0 in both years. Comparisons of the 1977 data for days to silking, grain yield, and percent ear moisture at harvest suggest that rate of grain filling in C1 was higher than in C0 for all populations. The higher rates of grain filling in the advanced cycles may have caused a carbohydrate deficiency under stress (1978) so that the leaves no longer functioned normally and kernel filling was terminated prematurely. In general, the four populations showed inherent differences in their respective responses to selection, to environmental stress, and to inbreeding.

Studies of grain production in Sorghum bicolor (L. Moench). VII.* Contribution of plant parts to canopy photosynthesis and grain yield in field stations

1976 ◽  
Vol 27 (2) ◽  
pp. 235 ◽  
Author(s):  
KS Fischer ◽  
GL Wilson ◽  
I Duthie
Keyword(s):  
Grain Yield ◽  
Flag Leaf ◽  
Net Photosynthesis ◽  
Grain Filling ◽  
Carbon Dioxide Exchange ◽  
Relative Importance ◽  
Leaf Position ◽  
Canopy Photosynthesis ◽  
Photosynthetic Rates ◽  
Plant Parts

A method based on 14CO2 uptake and carbon dioxide exchange in sorghum canopies at medium and high density populations allowed the estimation of photosynthesis by plant parts (heads, and leaves at each level of insertion) after anthesis. The relative importance of corresponding parts did not differ between populations, nor did photosynthetic rates per unit leaf area. The latter did decline with successive leaf position down the canopy but were generally compensated by increasing area of these leaves. Averaged over the two populations, which differed little, the heads provided 14% of canopy photosynthesis, and the flag leaf and leaves 2, 3 and 4 were responsible for 21, 24, 21 and 13% respectively. Greater leaf areas per unit land area in the higher population, for each leaf position, resulted in higher total canopy photosynthesis. Previous studies having shown that net photosynthesis after heading corresponds closely to grain yield, the relative importance of plant parts to overall net photosynthesis may be regarded as their relative contribution to grain filling. A direct estimate of their importance in this regard, based on another method, showed the head to contribute 17%, and the next four leaves 17, 25, 20 and 17%. Factors controlling photosynthetic rates of parts are discussed, and the estimates of the importance of photosynthetic sites to grain filling are compared with those reported in previous work. _____________________ *Part VI, Aust. J. Agric. Res., 27: 35 (1976).

scholarly journals REAPLICAÇÃO DE NITROGÊNIO NA MITIGAÇÃO DO EFEITO DA DESFOLHA EM DIFERENTES FASES FENOLÓGICAS DO MILHO

2019 ◽  
Vol 18 (1) ◽  
pp. 30-46
Author(s):  
ANDRÉ PRECHLAK BARBOSA ◽  
CLAUDEMIR ZUCARELI ◽  
RODRIGO YOITI TSUKAHARA ◽  
EDSON GIOVANNI KOCHINSKI ◽  
JOSE HENRIQUE BIZZARRI BAZZO
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Leaf Area ◽  
Nitrogen Fertilization ◽  
Zea Mays L ◽  
Total Yield ◽  
Grain Filling ◽  
Production Performance ◽  
Phenological Stages ◽  
Corn Production

RESUMO - O manejo adequado da adubação nitrogenada para atenuar efeitos da perda de área foliar é uma soluçãopouco explorada. Portanto, objetivou-se avaliar, em campo, o efeito da reaplicação de nitrogênio e intensidade dedesfolha em diferentes fases fenológicas sobre a incidência de grãos ardidos e o desempenho produtivo do milho. Odelineamento experimental foi em blocos casualizados, com quatro repetições, em esquema fatorial 2x7x4+2, sendo,a reaplicação de N em cobertura (0 e 40 kg ha-1), os estádios fenológicos de desfolha (V2, V4, V6, V10, R1, R3 e R5),as intensidades de desfolha (25, 50, 75 e 100%) e dois controles adicionais (0% de desfolha com e sem a reaplicaçãode N). As avaliações realizadas foram percentagem de grãos ardidos, massa de 100 grãos e produtividade de grãos. Osdados foram submetidos à análise de variância, testes de Tukey, Dunnett e regressão até 2º grau (p0,05). A reaplicaçãode nitrogênio após a desfolha atenua os efeitos desse estresse na massa e no rendimento total de grãos, com maiorefetividade quando ocorre nos estádios vegetativos. O prejuízo ao desempenho produtivo em razão da desfolha éacentuado quando ocorre no florescimento e enchimento de grãos, pois desequilibra a relação fonte-dreno. A desfolhaem estádios iniciais proporciona maior intensidade de grãos ardidos nas plantas de milho.Palavras-chave: Adubação nitrogenada, Área foliar, Estádios fenológicos, Zea mays L.REAPPLICATION OF NITROGEN AS MITIGATIONTO THE DEFOLIATION EFFECT AT STAGES OF MAIZEABSTRACT - The proper management of nitrogen fertilization to mitigate the effects of the loss of leaf area ispoorly explored. Therefore, the present study evaluated the effect of nitrogen reapplication and defoliation intensity atdifferent phenological stages on the incidence of rot grains and corn production performance. The experimental designwas a randomized complete block with four replications, in a 2x7x4 + 2 factorial scheme, with the reapplication of Ntopdressed (0 and 40 kg ha-1), the defoliation stages (V2, V4, V6, V10, R1, R3 and R5), defoliation intensities (25, 50, 75and 100%) and two additional controls (0% defoliation with and without reapplication of N). Percentage of rot grains,mass of 100 grains and grain yield were evaluated. Data were subjected to analysis of variance, Tukey’s, Dunnett’s testsand regression up to grade 2 (p 0.05). Reapplication of nitrogen after defoliation attenuates the effects of this stress onthe mass and the total yield of grains, with greater effectiveness in the vegetative stages. The damage to the productiveperformance due to defoliation was accentuated when occurred at the flowering and grain filling as it unbalancesthe source-drain relation. Depletion in the early stages caused higher occurrence of grain burned in maize plants.Keywords: Nitrogen fertilization, Leaf area, Phenological stages, Zea mays L.

scholarly journals Effect of citric acid on the proteolytic activity of Zea mays L.

2011 ◽  
Vol 35 (5) ◽  
pp. 908-915 ◽  
Author(s):  
Mauro Manuel Martinez-Pacheco ◽  
Alberto Flores-Garcia ◽  
Eulalio Venegas-Gonzalez ◽  
Mario Alberto Cepeda-Villegas
Keyword(s):  
Zea Mays ◽  
Citric Acid ◽  
Grain Yield ◽  
Proteolytic Activity ◽  
Soluble Protein ◽  
Serine Proteases ◽  
Zea Mays L ◽  
Flag Leaf ◽  
Corn Hybrids ◽  
Physiological Maturity

Hybrids of Zea mays L. (Buffalo, Falcon, H360 y HV313) were treated with citric acid (2000 ppm). Grain yield, soluble protein and proteolytic activity were monitored when the crop reached physiological maturity. Citric acid was applied before the appearance of the flag leaf, and induced an increase in the grain yield from 4222 to 5780 kg/ha, in the soluble protein from 6.34 to 7.91 mg/mg and into the proteolytic activity from 14.3 to 65.7 µU mg prot-1. This is an increase of 2 to 12 times in the Falcon, H360 and HV313 hybrids, while the Buffalo hybrid responded with less intensity to the treatment with citric acid. In the H360 hybrid treated with citric acid, an increase in the proteolytic activity of aspartyl serine proteases was observed. The results indicate that citric acid differentially induces proteolytic activity and vigor in the corn hybrids analyzed.

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.

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