scholarly journals Yield, Insect-Derived Ear Injury, and Aflatoxin Among Developmental and Commercial Maize Hybrids Adapted to the North American Subtropics

2020 ◽  
Vol 113 (6) ◽  
pp. 2950-2958
Author(s):  
Luke S Pruter ◽  
Michael J Brewer ◽  
Seth C Murray ◽  
Thomas Isakeit ◽  
Jacob J Pekar ◽  
...  
Keyword(s):  
Field Experiments ◽  
Insect Herbivory ◽  
Moisture Stress ◽  
Yield Potential ◽  
Maize Hybrid ◽  
Maize Hybrids ◽  
Corpus Christi ◽  
Aflatoxin Accumulation ◽  
Ear Injury ◽  
Heat And Moisture

Abstract The development of maize (Zea mays L.) hybrids that are adapted to subtropical areas of North America should consider yield potential under heat and moisture stress, and reduced susceptibility to insect herbivory and disease. To aid in this process, maize hybrids (43 developmental and seven non-Bt commercial hybrids) were evaluated for severity of ear injury to Helicoverpa zea (Boddie) and Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), susceptibility to Aspergillus flavus (Link) (Deuteromycetes: Moniliales), and yield. In subtropical Corpus Christi and College Station, TX, field experiments conducted over three years revealed significant differences among maize hybrids with the rank of the selected measurements differing across the two locations. When the location by maize hybrid interaction was not significant, variation across the main factors of maize hybrid genetics (in all cases) and location (in some cases) was detected. In 2014, a significant location by maize hybrid interaction in yield but not aflatoxin and ear injury were likely associated with differences in weather between locations. In Corpus Christi in 2015, a location by maize hybrid interaction was detected for ear injury only. Overall, experimental maize hybrids, containing the inbred line Tx777, displayed partial resistance to insect derived ear injury in both locations, and some hybrid testcrosses exhibited low rates of aflatoxin accumulation while maintaining relatively high yields. Tx777 was selected from populations originating in Bolivia and adapted to subtropical climates. The most promising hybrid testcrosses had lower ear injury and aflatoxin accumulation, and good yield under varying heat and moisture stress at the two subtropical maize growing areas in this study.

New maize hybrids from Szeged and their specific production technology

2005 ◽  
Vol 53 (2) ◽  
pp. 143-151 ◽  
Author(s):  
E. Széll ◽  
S. Szél ◽  
L. Kálmán
Keyword(s):  
Quality Control ◽  
Agronomic Traits ◽  
Commercial Production ◽  
Yield Potential ◽  
Specific Production ◽  
The European Union ◽  
Maize Hybrid ◽  
Non Profit ◽  
Maize Hybrids ◽  
Genetic Potential

Four maize hybrids bred at the Cereal Research Non-Profit Company in Szeged were registered at the National Institute for Agricultural Quality Control (OMMI) during the period 2001-2004. The registration of five Szeged hybrids is expected on the territory of the European Union in 2005-2006. The hybrids are accompanied by specific production technological guides for commercial production based on the results of agronomy trials, so that the genetic potential of the hybrids can be utilised in practical farming to the highest possible extent. The specific agronomic traits of hybrids with different vegetation periods and genotypes are investigated. If a maize hybrid is to be recommended to farmers, it is necessary to know not only its yield potential, but also its yield stability. For this reason, investigations are also made on the effect of soil and climate on the grain yield potential of each hybrid individually.

Ear secondary traits related to aflatoxin accumulation in commercial maize hybrids under artificial field inoculation

2010 ◽  
Vol 3 (3) ◽  
pp. 239-250 ◽  
Author(s):  
C. Balconi ◽  
M. Motto ◽  
G. Mazzinelli ◽  
N. Berardo
Keyword(s):  
Rating Scales ◽  
Field Experiments ◽  
Channel Length ◽  
Artificial Inoculation ◽  
Field Inoculation ◽  
Maize Hybrids ◽  
Aflatoxin Concentration ◽  
Aflatoxin Accumulation ◽  
Secondary Traits ◽  
Relationship Of

Aims of the research were: (1) to evaluate and compare 24 maize hybrids for Aspergillus flavus resistance and for aflatoxin accumulation under artificial inoculation in field experiments grown during 2005 and 2006; (2) to estimate the relationship of aflatoxin concentration with ear secondary traits. Primary ears were inoculated with a fresh spore suspension (mixture of five A. flavus isolates from Northern Italy), by spraying silks, as a modification of the non-wounding silk channel inoculation technique (SCIA); controls were both non-inoculated and sterile water-inoculated ears. Ear secondary traits, such as silk channel length measured at pollination and husk coverage at maturity, were recorded for each hybrid. The severity of ear A. flavus attack was estimated using rating scales based on the percentage of kernels with visible symptoms of infection. The aflatoxin concentration in the inoculated ears resulted, during both years, higher than in the controls; this indication confirmed that the A. flavus isolates used for the inoculum procedure were successful in accumulating mycotoxin in grains. Variability was found among the hybrids under study: aflatoxin accumulation, after artificial inoculation, ranged from 0.13 to 705.25 ng/g. The data herein presented supported the implication of two ear secondary traits in determining aflatoxin accumulation. Silk channel length recorded at pollination was negatively correlated (r = -0.54; P<0.05) with aflatoxin accumulation; on the contrary, a positive correlation (r = 0.48; P<0.05) between husk coverage rating at maturity and aflatoxin concentration suggested that a looser husk coverage is associated with higher aflatoxin accumulation. The correlation between the two mentioned ear-related traits was negative (r = -0.73; P<0.05); this indicated that hybrids showing a good coverage at pollination stage, are favoured in keeping the ear tip covered until maturity, reducing the risk of aflatoxin accumulation.

Association of Insect-Derived Ear Injury With Yield and Aflatoxin of Maize Hybrids Varying in Bt Transgenes

2019 ◽  
Vol 48 (6) ◽  
pp. 1401-1411 ◽  
Author(s):  
Luke S Pruter ◽  
Michael J Brewer ◽  
Mark A Weaver ◽  
Seth C Murray ◽  
Thomas S Isakeit ◽  
...  
Keyword(s):  
Helicoverpa Zea ◽  
Fall Armyworm ◽  
Integrated Approach ◽  
Corn Earworm ◽  
Data Sets ◽  
Maize Production ◽  
Maize Hybrids ◽  
Corpus Christi ◽  
Bt Protein ◽  
Ear Injury

Abstract Environmental factors have been associated with the production of aflatoxin in maize, Zea mays L., and it is inconclusive whether transgenic, Bacillus thuringiensis (Bt), maize has an impact on aflatoxin accumulation. Maize hybrids differing in transgenes were planted in two locations from 2014 to 2017. Yield, aflatoxin, and ear injury caused by corn earworm, Helicoverpa zea (Boddie), and fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), were measured across three groups of hybrids differing in transgenes including near-isogenic hybrids, and water-stressed conditions. The hybrid groups consisted of non-Bt hybrids with no Bt transgenes, a second group with one or more Cry-Bt transgenes, and the third group with vegetative insecticidal Bt protein and Cry-Bt transgenes (Cry/Vip-Bt). Across the six data sets derived from 11 experiments, the Cry-Bt and Cry/Vip-Bt hybrids had less ear injury and aflatoxin on average than non-Bt hybrids. The effects of ear injury on yield and aflatoxin were more prominent and consistent in Corpus Christi, TX, where hybrids experienced more water-limited conditions than in College Station, TX. The trend of increased aflatoxin among hybrids with increased ear injury was further resolved when looking at Cry-Bt and Cry/Vip-Bt isogenic hybrids in Corpus Christi. The results supported that the maize hybrids with the inclusion of Cry-Bt and Cry/Vip-Bt transgenes warrant further investigation in an integrated approach to insect and aflatoxin management in sub-tropical rain-fed maize production regions. Research outcomes may be improved by focusing on areas prone to water-stress and by using hybrids with similar genetic backgrounds.

scholarly journals Identification of Resistance to Aflatoxin Accumulation and Yield Potential in Maize Hybrids in the Southeast Regional Aflatoxin Trials (SERAT)

Crop Science ◽  
2016 ◽  
Vol 57 (1) ◽  
pp. 202-215 ◽  
Author(s):  
Nancy Wahl ◽  
Seth C. Murray ◽  
Thomas Isakeit ◽  
Matthew Krakowsky ◽  
Gary L. Windham ◽  
...  
Keyword(s):  
Yield Potential ◽  
Maize Hybrids ◽  
Aflatoxin Accumulation

scholarly journals Assessing the Potential of Extra-Early Maturing Landraces for Improving Tolerance to Drought, Heat, and Both Combined Stresses in Maize

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 318 ◽  
Author(s):  
Charles Nelimor ◽  
Baffour Badu-Apraku ◽  
Antonia Yarney Tetteh ◽  
Ana Luísa Garcia-Oliveira ◽  
Assanvo Simon-Pierre N’guetta
Keyword(s):  
Heat Stress ◽  
Abiotic Stress ◽  
Field Experiments ◽  
Yield Loss ◽  
Yield Potential ◽  
Genetic Base ◽  
Maize Varieties ◽  
Early Maturing ◽  
Maize Landraces ◽  
Landrace Accessions

Maize landrace accessions constitute an invaluable gene pool of unexplored alleles that can be harnessed to mitigate the challenges of the narrowing genetic base, declined genetic gains, and reduced resilience to abiotic stress in modern varieties developed from repeated recycling of few superior breeding lines. The objective of this study was to identify extra-early maize landraces that express tolerance to drought and/or heat stress and maintain high grain yield (GY) with other desirable agronomic/morpho-physiological traits. Field experiments were carried out over two years on 66 extra-early maturing maize landraces and six drought and/or heat-tolerant populations under drought stress (DS), heat stress (HS), combined both stresses (DSHS), and non-stress (NS) conditions as a control. Wide variations were observed across the accessions for measured traits under each stress, demonstrating the existence of substantial natural variation for tolerance to the abiotic stresses in the maize accessions. Performance under DS was predictive of yield potential under DSHS, but tolerance to HS was independent of tolerance to DS and DSHS. The accessions displayed greater tolerance to HS (23% yield loss) relative to DS (49% yield loss) and DSHS (yield loss = 58%). Accessions TZm-1162, TZm-1167, TZm-1472, and TZm-1508 showed particularly good adaptation to the three stresses. These landrace accessions should be further explored to identify the genes underlying their high tolerance and they could be exploited in maize breeding as a resource for broadening the genetic base and increasing the abiotic stress resilience of elite maize varieties.

Contribution of Stem Dry Matter to Grain Yield in Wheat Cultivars

1991 ◽  
Vol 18 (1) ◽  
pp. 53 ◽  
Author(s):  
PC Pheloung ◽  
KHM Siddique
Keyword(s):  
Water Stress ◽  
Grain Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Yield Potential ◽  
Percentage Reduction ◽  
Wheat Cultivars ◽  
Activity Increase ◽  
Structural Carbohydrate ◽  
Days After Anthesis

Field experiments were conducted in the eastern wheat belt of Western Australia in a dry year with and without irrigation (1987) and in a wet year (1988), comparing three cultivars of wheat differing in height and yield potential. The aim of the study was to determine the contribution of remobilisable stem dry matter to grain dry matter under different water regimes in old and modern wheats. Stem non-structural carbohydrate was labelled with 14C 1 day after anthesis and the activity and weight of this pool and the grain was measured at 2, 18 and 58 days after anthesis. Gutha and Kulin, modern tall and semi-dwarf cultivars respectively, yielded higher than Gamenya, a tall older cultivar in all conditions, but the percentage reduction in yield under water stress was greater for the modern cultivars (41, 34 and 23%). In the grain of Gamenya, the increase in 14C activity after the initial labelling was highest under water stress. Generally, loss of 14C activity from the non-structural stem dry matter was less than the increase in grain activity under water stress but similar to or greater than grain activity increase under well watered conditions. Averaged over environments and cultivars, non-structural dry matter stored in the stem contributed at least 20% of the grain dry matter.

scholarly journals Field Evaluations of Leaf Spot Resistance and Yield in Peanut Genotypes in the United States and Bolivia

Plant Disease ◽  
2011 ◽  
Vol 95 (3) ◽  
pp. 263-268 ◽  
Author(s):  
S. K. Gremillion ◽  
A. K. Culbreath ◽  
D. W. Gorbet ◽  
B. G. Mullinix ◽  
R. N. Pittman ◽  
...  
Keyword(s):  
United States ◽  
Disease Resistance ◽  
Leaf Spot ◽  
Field Experiments ◽  
Disease Incidence ◽  
The United States ◽  
Yield Potential ◽  
Cercospora Arachidicola ◽  
Breeding Lines ◽  
Progress Curve

Field experiments were conducted in 2002 to 2006 to characterize yield potential and disease resistance in the Bolivian landrace peanut (Arachis hypogaea) cv. Bayo Grande, and breeding lines developed from crosses of Bayo Grande and U.S. cv. Florida MDR-98. Diseases of interest included early leaf spot, caused by the fungus Cercospora arachidicola, and late leaf spot, caused by the fungus Cercosporidium personatum. Bayo Grande, MDR-98, and three breeding lines, along with U.S. cvs. C-99R and Georgia Green, were included in split-plot field experiments in six locations across the United States and Bolivia. Whole-plot treatments consisted of two tebuconazole applications and a nontreated control. Genotypes were the subplot treatments. Area under the disease progress curve (AUDPC) for percent defoliation due to leaf spot was lower for Bayo Grande and all breeding lines than for Georgia Green at all U.S. locations across years. AUDPC for disease incidence from one U.S. location indicated similar results. Severity of leaf spot epidemics and relative effects of the genotypes were less consistent in the Bolivian experiments. In Bolivia, there were no indications of greater levels of disease resistance in any of the breeding lines than in Bayo Grande. In the United States, yields of Bayo Grande and the breeding lines were greater than those of the other genotypes in 1 of 2 years. In Bolivia, low disease intensity resulted in the highest yields in Georgia Green, while high disease intensity resulted in comparable yields among the breeding lines, MDR-98, and C-99R. Leaf spot suppression by tebuconazole was greater in Bolivia than in the United States. This result indicates a possible higher level of fungicide resistance in the U.S. population of leaf spot pathogens. Overall, data from this study suggest that Bayo Grande and the breeding lines may be desirable germplasm for U.S. and Bolivian breeding programs or production.

Agronomic studies on irrigated soybean in southern New South Wales. II. Broadening options for sowing date

2011 ◽  
Vol 62 (12) ◽  
pp. 1067 ◽  
Author(s):  
L. G. Gaynor ◽  
R. J. Lawn ◽  
A. T. James
Keyword(s):  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Sowing Date ◽  
Plant Population ◽  
Yield Potential ◽  
Higher Plant ◽  
Winter Cereal ◽  
Double Cropping ◽  
South Wales

The response of irrigated soybean to sowing date and to plant population was evaluated in field experiments over three years at Leeton, in the Murrumbidgee Irrigation Area (MIA) in southern New South Wales. The aim was to explore the options for later sowings to improve the flexibility for growing soybean in double-cropping rotations with a winter cereal. The experiments were grown on 1.83-m-wide raised soil beds, with 2, 4, or 6 rows per bed (years 1 and 2) or 2 rows per bed only (year 3). Plant population, which was manipulated by changing either the number of rows per bed (years 1 and 2) or the within-row plant spacing (year 3), ranged from 15 to 60 plants/m2 depending on the experiment. Two sowings dates, late November and late December, were compared in years 1 and 3, while in year 2, sowings in early and late January were also included. Three genotypes (early, medium, and late maturity) were grown in years 1 and 2, and four medium-maturing genotypes were grown in year 3. In general, machine-harvested seed yields were highest in the November sowings, and declined as sowing was delayed. Physiological analyses suggested two underlying causes for the yield decline as sowing date was delayed. First and most importantly, the later sown crops flowered sooner after sowing, shortening crop duration and reducing total dry matter (TDM) production. Second, in the late January sowings of the medium- and late-maturing genotypes, harvest index (HI) declined as maturity was pushed later into autumn, exposing the crops to cooler temperatures during pod filling. Attempts to offset the decline in TDM production as sowing was delayed by using higher plant populations were unsuccessful, in part because HI decreased, apparently due to greater severity of lodging. The studies indicated that, in the near term, the yield potential of current indeterminate cultivars at the late December sowing date is adequate, given appropriate management, for commercially viable double-cropping of soybean in the MIA. In the longer term, it is suggested that development of earlier maturing, lodging-resistant genotypes that retain high HI at high sowing density may allow sowing to be delayed to early January.

scholarly journals Importance of Different Pathways for Maize Kernel Infection by Fusarium moniliforme

1997 ◽  
Vol 87 (2) ◽  
pp. 209-217 ◽  
Author(s):  
G. P. Munkvold ◽  
D. C. McGee ◽  
W. M. Carlton
Keyword(s):  
Fusarium Moniliforme ◽  
Field Experiments ◽  
Systemic Infection ◽  
Seed Transmission ◽  
Maize Hybrids ◽  
Systemic Movement ◽  
Kernel Infection ◽  
Important Pathway ◽  
Infection Pathways ◽  
Systemic Development

The relative importance of several infection pathways (silks, stalks, and seed) leading to kernel infection of maize hybrids by Fusarium moniliforme was investigated in field experiments in 1993 and 1994. Systemic movement of specific fungal strains within plants was detected by using vegetative compatibility as a marker. Transmission of F. moniliforme from inoculated seed to stalks and developing kernels was detected in two of three field experiments; the seed-inoculated strain was detected in kernels on approximately 10% of ears. The percentage of kernels infected with the seed-inoculated strain ranged from 0 to 70%, with a mean of 0 to 2.5% (0 to 8.3% of F. moniliforme-infected kernels). Other pathways to kernel infection were more effective than seed transmission and systemic infection. F. moniliforme strains inoculated into the crowns and stalks of plants were found throughout the stalks and in up to 95% of the kernels in individual plants. Infection through the silks was clearly the most effective pathway to kernel infection. This was the only inoculation method that significantly increased overall incidence of F. moniliforme infection in kernels; the silk-inoculated strain infected up to 100% of the kernels in individual ears, with a treatment mean as high as 83.7% of kernels. When plants were silk-inoculated, the percentage of kernels infected by other F. moniliforme strains from the seed or stalk was reduced, apparently due to competition among strains. This study provides evidence that systemic development of F. moniliforme from maize seed and stalk infections can contribute to kernel infection, but silk infection is a more important pathway for this fungus to reach the kernels.

scholarly journals Nickel Toxicity Induced Changes in Nutrient Dynamics and Antioxidant Profiling in Two Maize (Zea mays L.) Hybrids

Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 5 ◽  
Author(s):  
Muhammad Amjad ◽  
Hasan Raza ◽  
Behzad Murtaza ◽  
Ghulam Abbas ◽  
Muhammad Imran ◽  
...  
Keyword(s):  
Nutrient Solution ◽  
Elevated Level ◽  
Nutrient Dynamics ◽  
Zea Mays L ◽  
Nutrient Concentrations ◽  
Nickel Toxicity ◽  
Maize Hybrid ◽  
Maize Hybrids ◽  
Growth Physiology ◽  
Induced Changes

Nickel (Ni) is among the essential micronutrient heavy metals utilized by plants. However, an elevated level of Ni causes serious concerns for plants’ physiology and their survival. This study evaluated the mechanisms influencing the growth, physiology, and nutrient dynamics in two commercial maize hybrids (Syngenta and Pioneer) exposed to Ni treatments in hydroponics nutrient solution (NS). Seedlings were raised in plastic trays with quartz sand, and subsequently transferred to Hoagland’s NS at the two leaves stage. After three days of transplantation, Ni levels of 0, 20, and 40 mg L−1 were maintained in the nutrient solution. After 30 days of Ni treatments, seedlings were harvested and different growth, physiological, and nutrient concentrations were determined. The results showed that with increasing Ni concentration, the growth of maize hybrids was significantly reduced, and the maize hybrid, Pioneer, showed significantly higher growth than that of Syngenta at all levels of Ni. Higher growth in Pioneer is ascribed to elevated levels of antioxidant enzymes (SOD, CAT, GR, APX, and POX), lower damage to cellular membranes (i.e., higher MSI and lower MDA), and higher tissue nutrient concentrations (N, P, K, Ca, Mg, Fe, Mn, Zn, and Cu). Furthermore, the maize hybrids showed a difference in nutrient translocation from root to shoot which could be one of the factors responsible for differential response of these hybrids against Ni treatments.

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