scholarly journals Biological response of maize hybrids to simulated glyphosate drift

2020 ◽  
Vol 29 (2) ◽  
pp. 155-164
Author(s):  
Maja Meseldžija ◽  
Goran Jaćimović ◽  
Milica Dudić ◽  
Daniel Gaža
Keyword(s):  
Biological Response ◽  
Growth Stages ◽  
Herbicide Application ◽  
Lower Yield ◽  
Maize Hybrids ◽  
Application Analysis ◽  
Maize Leaves ◽  
Sublethal Doses ◽  
Maize Plants ◽  
Glyphosate Drift

The effect of simulated glyphosate drift on six maize hybrids (NS 6102, as 334, Lucius, Confites, DKC 5031 and P0216) was investigated in Kulpin during the vegetation season of 2018. Glyphosate was applied in two growth stages: in stages 3-4 and 6-7 of fully formed maize leaves, with five different sublethal doses of the herbicide: 10, 20, 40, 80, 160 g ha-1. Phytotoxicity assessments of glyphosate were performed 7, 14, and 21 days after herbicide application. Analysis of the results has shown that glyphosate in the dose of 160 g ha-1 in the phase of 3-4 maize leaves caused only slight damages, without affecting the height and grain yield, while phytotoxicity was not observed at lower applied doses. Significant phytotoxicity on maize plants in the form of chlorosis, leaf curling and notable necrotic area was found when applying glyphosate in the dose of 160 g ha-1 in the phase of 6-7 leaves. Maize hybrids tested in this treatment have achieved an 81% lower yield on average, when compared to the control. Hybrids treated with the dose of 80 g ha-1 of glyphosate had a reduced yield by 30%, while in other lower doses the reduction in yield ranged between 25 and 18%, compared to the control.

scholarly journals Impact of nicosulfuron on biochemical markers of oxidative stress in maize leaves and roots

Biljni lekar ◽  
2021 ◽  
Vol 49 (2) ◽  
pp. 201-217
Author(s):  
Anđela Kuvelja ◽  
Biljana Davidović-Plavšić ◽  
Danijela Lukić ◽  
Nemanja Gajić ◽  
Mirjana Žabić ◽  
...  
Keyword(s):  
Zea Mays L ◽  
Early Stage ◽  
Class Iii ◽  
Maize Hybrids ◽  
Genetic Potential ◽  
Maize Leaves ◽  
Markers Of Oxidative Stress ◽  
Activity Of Enzymes ◽  
Maize Plants ◽  
The Impact

Maize (Zea mays L.) is one of the most important crops. It is the object of many studies, aiming to utilize its full genetic potential and quality, while protecting it from the harmful external factors. Considering that weeds in the early stage of maize development can severely affect the yield, effective weed control is of great importance. As the most significant herbicides in fighting maize weeds, sulfonylurea herbicides are singled out. The aim of this research was to test the impact of different concentrations of nicosulfuron (150 and 250 mg/mL) on the biochemical (oxidative and anti-oxidative) parameters of two maize hybrids (ZP 555 and ZP 606). After treating maize plants with different concentrations of nicosulfuron for five days, concentrations of hydrogen peroxide (H2 O2 ), phenolic compounds and total chlorophyll were measured, as well as the activity of enzymes Peroxidase Class III (POD) and ascorbate peroxidase (APX). The results showed that nicosulfuron significantly impacted the biochemical parameters in the root and leaves of maize. Differences in impact of nicosulfuron at different concentrations and differences in the tolerance of two hybrids to treatment were also observed.

scholarly journals Assessment of physiological races of Exserohilum turcicum isolates from maize in Argentina and Brazil

2021 ◽  
Author(s):  
Barbara Ludwig Navarro ◽  
Lucia Ramos Romero ◽  
María Belén Kistner ◽  
Juliana Iglesias ◽  
Andreas von Tiedemann
Keyword(s):  
Exserohilum Turcicum ◽  
Breeding Programs ◽  
Physiological Races ◽  
Maize Leaves ◽  
Race 1 ◽  
Resistance Reaction ◽  
Qualitative Resistance ◽  
Maize Plants ◽  
Corn Leaf Blight ◽  
Resistant Genotypes

AbstractNorthern corn leaf blight (NCLB) is one of the most important diseases in maize worldwide. It is caused by the fungus Exserohilum turcicum, which exhibits a high genetic variability for virulence, and hence physiological races have been reported. Disease control is based mainly on fungicide application and host resistance. Qualitative resistance has been widely used to control NCLB through the deployment of Ht genes. Known pathogen races are designated according to their virulence to the corresponding Ht gene. Knowledge about of E. turcicum race distribution in maize-producing areas is essential to develop and exploit resistant genotypes. Maize leaves showing distinct elliptical grey-green lesions were collected from maize-producing areas of Argentina and Brazil, and 184 monosporic E. turcicum isolates were obtained. A total of 66 isolates were collected from Argentina during 2015, 2018 and 2019, while 118 isolates from Brazil were collected during 2017, 2018 and 2019. All isolates were screened on maize differential lines containing Ht1, Ht2, Ht3 and Htn1 resistance genes. In greenhouse experiments, inoculated maize plants were evaluated at 14 days after inoculation. Resistance reaction was characterized by chlorosis, and susceptibility was defined by necrosis in the absence of chlorosis. The most frequent race was 0 in both Argentina (83%) and Brazil (65%). Frequencies of race 1 (6% and 24%) and race 23N (5% and 10%) were very low in Argentina and Brazil, respectively. The high frequency of race 0 isolates provides evidence that qualitative resistance based on the tested Ht genes is not being used extensively in Argentina and Brazil to control NCLB. This information may be relevant for growers and breeding programs as the incidence of NCLB is increasing in both countries.

scholarly journals Development of a Protocol and a Diagrammatic Scale for Quantification of Bacterial Leaf Streak Disease on Young Plants of Maize

Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 2921-2927
Author(s):  
Renata Rodrigues Robaina ◽  
Talita Vigo Longhi ◽  
Douglas Mariani Zeffa ◽  
Leandro Simões Azeredo Gonçalves ◽  
Rui Pereira Leite
Keyword(s):  
Disease Incidence ◽  
The United States ◽  
Bacterial Suspension ◽  
Bacterial Leaf Streak ◽  
Experimental Conditions ◽  
Maize Production ◽  
Maize Hybrids ◽  
Controlled Conditions ◽  
Maize Plants ◽  
Diagrammatic Scale

Bacterial leaf streak (BLS), caused Xanthomonas vasicola pv. vasculorum (Xvv), has become a major concern for maize production, mainly in the United States and South America. Therefore, this study aimed to establish a protocol for Xvv inoculation in young maize plants under controlled conditions and to develop and validate a diagrammatic scale for evaluation of maize hybrids in regard to BLS resistance. The study was carried out in three steps: the establishment of a protocol for inoculation of Xvv in young maize plants under controlled conditions; the development and validation of a diagrammatic scale for BLS severity evaluation; and the screening for BLS resistance of 45 hybrids using the proposed protocol for bacterial inoculation and the diagrammatic scale developed in this study. Besides reproducing a more natural Xvv infection, the bacterial suspension spraying without injury inoculation method induced higher disease incidence and severity, as well as reproducibility of results under the experimental conditions established in this study. The proposed diagrammatic scale allowed evaluating BLS severity with up to 97.49% of the leaf area affected by the disease. Further, the use of the diagrammatic scale resulted in an increase of accuracy from 0.909 up to 0.992. The reaction of 45 maize hybrids to BLS allowed establishing six major groups of susceptibility to the disease. The most resistant maize hybrids to BLS formed a group of 13 hybrids, with disease severity below 5%.

scholarly journals Hormesis with glyphosate depends on coffee growth stage

2013 ◽  
Vol 85 (2) ◽  
pp. 813-822 ◽  
Author(s):  
LEONARDO B. DE CARVALHO ◽  
PEDRO L.C.A. ALVES ◽  
STEPHEN O. DUKE
Keyword(s):  
Plant Growth ◽  
Weed Management ◽  
Growth Stage ◽  
Growth Stages ◽  
Coffee Plant ◽  
Herbicide Application ◽  
Coffee Plantations ◽  
Plant Growth Stages ◽  
Coffee Plants ◽  
Almost All

Weed management systems in almost all Brazilian coffee plantations allow herbicide spray to drift on crop plants. In order to evaluate if there is any effect of the most commonly used herbicide in coffee production, glyphosate, on coffee plants, a range of glyphosate doses were applied directly on coffee plants at two distinct plant growth stages. Although growth of both young and old plants was reduced at higher glyphosate doses, low doses caused no effects on growth characteristics of young plants and stimulated growth of older plants. Therefore, hormesis with glyphosate is dependent on coffee plant growth stage at the time of herbicide application.

scholarly journals Interactions Between Herbicide Application and Timing of Nitrogen Fertilization in Maize Hybrids

2019 ◽  
Vol 11 (9) ◽  
pp. 21
Author(s):  
Guilherme V. Pimentel ◽  
Silvino G. Moreira ◽  
Mateus O. T. de Avila ◽  
Antonio Henrique F. de Carvalho ◽  
Alessandro A. P. da Silva ◽  
...  
Keyword(s):  
Nitrogen Fertilization ◽  
No Reduction ◽  
Block Design ◽  
Climatic Conditions ◽  
Limited Information ◽  
Herbicide Application ◽  
Maize Hybrids ◽  
Growing Seasons ◽  
Randomized Block Design ◽  
Different Levels

Maize hybrids have different levels of tolerance to the herbicide nicosulfuron, depending on the dose, the environment, the phenological stage of the plant and the timing of nitrogen fertilization, and phytotoxic effects can occur without proper management. There is also limited information on the selectivity of current genetically modified hybrids for other recommended herbicides, such as tembotrione. Thus, the objective of this study was to evaluate the effects of herbicides (tembotrione and nicosulfuron) and the timing of nitrogen fertilization on the yield of maize hybrids. The experimental design was a randomized block design, in a 4 × 2 factorial arrangement, with 4 replicates. The treatments consisted of four treatments [weeding; nicosulfuron + atrazine (20 and 32 + 1250 g ha-1 ai) and tembotrione + atrazine (75.6 + 1250 g ha-1 ai)] and two nitrogen fertilization times (0 and 7 days after application). Maize hybrids P30F53 Leptra, DKB 230PRO3 and KWS 9004PRO2 were assessed in two growing seasons (1st and 2nd harvest) during the 2016/2017 growing season. The percentages of weed control; phytotoxicity at 7, 14 and 21 days after application (DAA); plant height; number of rows per ear; and yield at harvest were evaluated. All herbicides were more effective in controlling weeds at the 1st harvest because of favourable climatic conditions. Nitrogen fertilization can be carried out on the same day as the application of the herbicides nicosulfuron and tembotrione with no reduction in yield for the hybrids P30F53 Leptra, DKB 230PRO3 and KWS 9004PRO2.

Effect of Three Desiccant Herbicides on Soybean (Glycine max) Seed Quality

Weed Science ◽  
1982 ◽  
Vol 30 (5) ◽  
pp. 484-490 ◽  
Author(s):  
Raymond F. Cerkauskas ◽  
Onkar D. Dhingra ◽  
James B. Sinclair ◽  
Stephen R. Foor
Keyword(s):  
Glycine Max ◽  
Seed Germination ◽  
Seed Weight ◽  
Seed Quality ◽  
Sodium Chlorate ◽  
Sodium Borate ◽  
Growth Stages ◽  
Seed Infection ◽  
Herbicide Application ◽  
Combined Data

Soybean [Glycine max(L.) Merr.] cultivars ‘UFV1’ and ‘UFV2’ grown at Viçosa and Florestal, Brazil, and ‘Bonus' and ‘Wells' at Urbana, Illinois, were sprayed at growth stages R5.5to R6(full-pod) or R7(50% defoliation) with the desiccant/herbicides glyphosate [N-(phosphonomethyl)glycine], paraquat (1,1′-dimethyl-4,4′-bipyridinium ion), or sodium chlorate:sodium borate (50:50, w/v). Desiccation of plants by paraquat significantly reduced seed weight and germination at all locations and increased the incidence ofAlternariaandPhomopsisspp. at Urbana. Analysis of the combined data from the Brazilian locations showed a significant decrease in seed germination for all treatments except paraquat sprayed on the UFV2at R7and sodium chlorate: sodium borate sprayed on UFV1at R7. Herbicide application at R7did not result in consistent increases in seedborneFusariumorPhomopsisspp. at any Brazilian location. Rainfall and temperature at seed maturation were more important variables in pod-to-seed infection by these fungi than increased rates of tissue senescence caused by the desiccants.

scholarly journals Effect of Maize Hybrid and Foliar Fungicides on Yield Under Low Foliar Disease Severity Conditions

2015 ◽  
Vol 105 (8) ◽  
pp. 1080-1089 ◽  
Author(s):  
Sally O. Mallowa ◽  
Paul D. Esker ◽  
Pierce A. Paul ◽  
Carl A. Bradley ◽  
Venkata R. Chapara ◽  
...  
Keyword(s):  
Disease Severity ◽  
Field Trials ◽  
Gray Leaf Spot ◽  
Growth Stages ◽  
Lower Yield ◽  
Fungicide Application ◽  
Cercospora Zeae Maydis ◽  
Physiological Benefits ◽  
Foliar Fungicide ◽  
Corn Leaf Blight

Foliar fungicide use in the U.S. Corn Belt increased in the last decade; however, questions persist pertaining to its value and sustainability. Multistate field trials were established from 2010 to 2012 in Illinois, Iowa, Ohio, and Wisconsin to examine how hybrid and foliar fungicide influenced disease intensity and yield. The experimental design was in a split-split plot with main plots consisting of hybrids varying in resistance to gray leaf spot (caused by Cercospora zeae-maydis) and northern corn leaf blight (caused by Setosphaera turcica), subplots corresponding to four application timings of the fungicide pyraclostrobin, and sub-subplots represented by inoculations with either C. zeae-maydis, S. turcica, or both at two vegetative growth stages. Fungicide application (VT/R1) significantly reduced total disease severity relative to the control in five of eight site-years (P < 0.05). Disease was reduced by approximately 30% at Wisconsin in 2011, 20% at Illinois in 2010, 29% at Iowa in 2010, and 32 and 30% at Ohio in 2010 and 2012, respectively. These disease severities ranged from 0.2 to 0.3% in Wisconsin in 2011 to 16.7 to 22.1% in Illinois in 2010. The untreated control had significantly lower yield (P < 0.05) than the fungicide-treated in three site-years. Fungicide application increased the yield by approximately 6% at Ohio in 2010, 5% at Wisconsin in 2010 and 6% in 2011. Yield differences ranged from 8,403 to 8,890 kg/ha in Wisconsin 2011 to 11,362 to 11,919 kg/ha in Wisconsin 2010. Results suggest susceptibility to disease and prevailing environment are important drivers of observed differences. Yield increases as a result of the physiological benefits of plant health benefits under low disease were not consistent.

Potassium application mitigates salt stress differentially at different growth stages in tolerant and sensitive maize hybrids

2015 ◽  
Vol 76 (1) ◽  
pp. 111-125 ◽  
Author(s):  
Ghulam Hasan Abbasi ◽  
Javaid Akhtar ◽  
Rafiq Ahmad ◽  
Moazzam Jamil ◽  
Muhammad Anwar-ul-Haq ◽  
...  
Keyword(s):  
Salt Stress ◽  
Growth Stages ◽  
Maize Hybrids ◽  
Potassium Application ◽  
Different Growth Stages

scholarly journals Effects of Gallery Applied at Different Growth Stages to Dwarf Burning Bush (Euonymus alatus ‘Compacts’)

1998 ◽  
Vol 16 (3) ◽  
pp. 155-158 ◽  
Author(s):  
Sydha Salihu ◽  
Jeffrey F. Derr ◽  
Kriton K. Hatzios
Keyword(s):  
Leaf Size ◽  
Field Trials ◽  
The Other ◽  
Growth Stages ◽  
Bud Break ◽  
Herbicide Application ◽  
Application Timing ◽  
Euonymus Alatus ◽  
Dormant Stage ◽  
Different Growth Stages

Abstract The effect of Gallery application timing on dwarf burning bush tolerance was determined in field trials. Gallery was applied foliarly at 0.84, 1.69 and 3.39 kg ai/ha (0.75, 1.5 and 3 lb ai/A) to dwarf burning bush at different growth stages. Gallery applied at the dormant stage and two months after bud-break did not injure dwarf burning bush. Plants treated one month after bud-break with all three rates were injured approximately 30 to 45% at one and three months after herbicide application. Injury symptoms were manifested as decreased leaf size and leaf distortions. Gallery applied at 0.84 and 1.69 kg/ha (0.75 and 1.5 lb/A) one month after bud-break decreased plant width. Shoot-dieback was also observed in plants treated with Gallery at all rates one month after bud-break. Gallery at all three rates applied one month after bud-break caused 60 to 75% of the leaves to defoliate six weeks earlier in the fall compared to the other application timings.

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