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

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

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.


1992 ◽  
Vol 72 (1) ◽  
pp. 27-33 ◽  
Author(s):  
R. T. Weiland

Recent studies have shown that pollen from a long-season maize (Zea mays L.) hybrid increased yield of a short-season hybrid by lengthening the effective grain-filling period, while the reciprocal cross did not alter this period or yield. This effect (metaxenia) was evaluated further in the studies reported here with hybrids of more diverse maturity and under both high and low N fertility. In the first year of this study (1989), sib- and cross-pollinations were made among B73Ht × Mo17 (B × 7) and two early-silking hybrids, LH59 × LH146 (L × 6) and Pioneer 3732 (3732) under N-sufficient (275 kg ha−1) and two lower N regimes (17 and 67 kg ha−1). Only a few significant effects were observed and these were noted at high N with one exception. With 3732 pollen, grain yield of B × 7 was decreased at 275 kg N ha−1, and physiological maturity occurred 3 d earlier. Yield of 3732 was increased by L × 6 pollen in comparison with B × 7 pollen. Kernel number and average kernel weight were not altered by pollen source. Pollen type did not affect yields under low N fertility, except for a reduction when B × 7 was pollinated by L × 6 at the 67-kg N ha−1 rate. In 1990, under N-sufficient fertility, B73Ht × LH156 (B × 6), a late-silking hybrid, and LH146 × LH82 (L × 2), an earlier hybrid, were sib- and cross-pollinated with B × 7 and 3732. The only significant effect observed was that L × 2 pollen increased B × 6 yield. Thus with the hybrids used, yields of early-season types were not altered by cross-pollination with long-season types. Previous results showing increased yields when 3732 was pollinated by B × 7 were not duplicated in either year, suggesting metaxenia effects are highly dependent upon environment.Key words: Metaxenia, xenia, cross-pollination, maize, yield, N levels


2010 ◽  
Vol 61 (9) ◽  
pp. 700 ◽  
Author(s):  
Saeed Safari Dolatabad ◽  
Rajab Choukan ◽  
Eslam Majidi Hervan ◽  
Hamid Dehghani

Adapted maize (Zea mays L.) hybrids should be identified and chosen based on multi-environment trials analysing several traits. The objectives of this study were to identify mega-environments and suitable adapted maize hybrids based on both mean grain yield and grain yield stability and were to evaluate the 14 maize hybrids based on several desirable traits. Biplot analysis determined one mega-environment and two sectors that consist of one location in each sector for maize in Iran. The mega-environment included Kerman (KRM), Kermanshah (KSH), Moghan (MGN), Dezfol A (DZF A), Karaj (KRJ), Darab (DRB), Dezfol B (DZF B), Shiraz B (SHZ B), and Esfahan (ESF), where hybrid OSSK 602 was the best performing hybrid. The first sector included Khoramabad (KHM) where BC 678 was the best hybrid, and the second sector included Shiraz A (SHZ A) where ZP 599 was the hybrid with the highest performance. OSSK 602 was the best hybrid among all of the studied hybrids followed by ZP 677 and ZP 684. The genotype × trait biplot indicated that ZP 677 and OSSK 602 had greater thousand-kernel weight and grain number, whereas ZP 684 had longer day to maturity and larger cob diameter. KSC 700, KSC 704, and BC 678 had higher ear height and more days to tasseling than other hybrids. The genotype × trait biplot graphically displayed the interrelationships among traits and it was used in identifying hybrids that are good for some particular traits.


1981 ◽  
Vol 61 (1) ◽  
pp. 29-36
Author(s):  
O. A. ADARA ◽  
L. W. KANNENBERG

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.


Author(s):  
Ayse Gulgun Oktem ◽  
Abdullah Oktem

Aims: It was aimed to determine the effect of different levels of farmyard manure on yield and quality attributes of the popcorn (Zea mays L. everta Sturt) grown under second crop conditions. Study Design: The experiment was set up according to randomized complete blocks experimental design with 3 replicates. Place and Duration of Study: Research was conducted in 2018 under Harran Plain conditions as second crop, Sanliurfa, Turkey. Methodology: Antcin hybrid popcorn variety was used as a plant material. Farmyard manure (FYM) applications were 0 (control), 1 tone da-1 FYM, 2 tone da-1 FYM, 3 tone da-1 FYM, 4 tone da-1 FYM, 5 tone da-1 FYM and 6 tone da-1 FYM. In study, plant height, stem diameter, grain yield, 1000 kernel weight, popping volume and protein ratio values were researched. Results: Farmyard manure levels were significant in all tested characteristics. Farmyard manure levels effected positively on plant height (P≤0.05), stem diameter, grain yield, 1000 kernel weight, popping volume and protein ratio (P≤0.01). The highest plant height value was seen 6 tone da-1 application of FYM application whereas the lowest plant height value was found at control parcel. Stem diameter value ranged from 19.33 mm (control) to 23.87 mm (5 tone da-1 FYM). The highest grain yield value obtained from 6 tone da-1 FYM (489.71 kg da-1) while the lowest value was seen at control parcel (219.95 kg da-1). But 4, 5 and 6 tone da-1 FYM applications were found in same statistical groups. 1000 kernel weight values ranged from 159.60 g to 204.67 g. The highest popping volume value was seen 6 tone da-1 FYM treatment. Protein ratio (%) values ranged from % 9.27 to %14.01. The highest protein ratio was obtained from 6 tone da-1 FYM while the lowest protein ratio value was found at control parcel. Conclusion: All farmyard manure levels effected positively on plant height, stem diameter, grain yield, popping volume and protein ratio. The highest grain yield value was seen at 6 tone da-1 FYM. But, 4, 5 and 6 tone da-1 FYM treatments were in the same statistical groups. There was no statistically significant increase in grain yield after 4 tone da-1 farmyard application (478.57 kg da-1). According to research results, considering grain yield, popping volume and protein ratio values, 4 tone da-1 farmyard manure was seen sufficient in organic popcorn cultivation.


2019 ◽  
Vol 18 (1) ◽  
pp. 30-46
Author(s):  
ANDRÉ PRECHLAK BARBOSA ◽  
CLAUDEMIR ZUCARELI ◽  
RODRIGO YOITI TSUKAHARA ◽  
EDSON GIOVANNI KOCHINSKI ◽  
JOSE HENRIQUE BIZZARRI BAZZO

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.


1992 ◽  
Vol 72 (3) ◽  
pp. 689-698 ◽  
Author(s):  
D. J. Major ◽  
H. H. Janzen ◽  
R. S. Sadasivaiah ◽  
J. M. Carefoot

Eight wheat (Triticum aestivum L.) cultivars including soft white spring, hard red spring, Canada Prairie Spring (CPS) and durum types were grown on rain-fed and irrigated land from 1987 to 1990 at Lethbridge, AB, to assess the relationship between yield components and radiation-use efficiency. Canopy reflectance measurements were used to estimate seasonal absorption of photosynthetically active radiation (APAR). At maturity, yield components including tillers per plant, heads per plant, kernels per head and kernel weight were determined. Whole-plant phytomass and grain yield were also determined. Harvest index was determined from the ratio of grain yield to whole-plant (excluding roots) phytomass and radiation-use efficiency (RUE) was calculated from the ratio of whole-plant phytomass to APAR. Significant grain yield differences confirmed that soft white and CPS wheats yielded more and responded more to irrigation than hard red or durum wheats. The yield components that were consistently different among cultivars were kernels per head and kernel weight which would be expected to increase if a consistent supply of assimilate was available during grain filling. Soft white and CPS wheats had higher harvest indices than the hard red or durum wheats, particularly under irrigation. Whole-plant phytomass was closely related to APAR and there were few differences among cultivars for RUE. There was no difference in RUE between rain-fed and irrigated treatments, indicating that there was probably no crop water stress on the rain-fed plots. RUE estimates for 1988 were lower than for the succeeding years, indicating an environmental or edaphic stress in that year.Key words: Remote sensing, radiation-use efficiency, yield components


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