scholarly journals Fungicide baseline for mycelial sensitivity of Exserohilum turcicum, causal agent of northern corn leaf blight

2015 ◽  
Vol 41 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Roberto Luis De Rossi ◽  
Erlei Melo Reis ◽  
Ricardo Brustolin

Northern corn leaf blight, caused by Exserohilum turcicum(Et), is one of the major corn diseases which can reduce grain yield and quality. The aim of this study was to determine the mycelial sensitivity of ten Etisolates, five from Argentina and five from Brazil, to six fungicides (carbendazim, captan, fludioxinil, metalaxyl, iprodione and thiram) used in seed treatment. The inhibitory concentration (IC50) was determined by using seven concentrations of the fungicides supplemented to the agar medium. The mycelial colony diameter was measured with a digital caliper. Experimental design was completely randomized with four replicates. Data on the percent mycelial growth inhibition were analyzed by logarithmic regression and the IC50 was calculated. The fungicide iprodione was the most potent, with IC50 < 0.01 mg/L, followed by fludioxonil, IC50 0.31 mg/L, and thiram, 1.37 mg/L. Carbendazim, metalaxyl and captan were classified as non-fungitoxic, showing IC50 > 50 mg/L for all isolates. Although iprodione is the most potent fungicide, it is not used for corn seed treatment. The IC50s obtained in this study can be used as baseline for future monitoring studies of Etsensitivity to fungicides.

2021 ◽  
Author(s):  
D.C. Balasundara ◽  
H. C. Lohithaswa ◽  
M. Rahul ◽  
R. L. Ravikumar ◽  
Anand Pandravada ◽  
...  

Abstract Background: Northern corn leaf blight (NCLB) of maize caused by Exserohilum turcicum is a serious foliar disease. Resistance to NCLB is complexly inherited and the highly significant genotype x environment interaction effect makes selection of resistant genotypes difficult through conventional breeding methods. Hence an attempt was made to identify the genomic regions associated with NCLB resistance and perform genomic selection (GS) in two F2:3 populations derived from the crosses CM212 × MAI172 (Population-1) and CM202 × SKV50 (Population-2). Results: Two populations, each comprising of 366 progenies, were phenotyped at three different locations in the disease screening nurseries. Linkage analysis using 297 polymorphic SNPs in Population-1 and 290 polymorphic SNPs in Population-2 revealed 10 linkage groups spanning 3623.88cM and 4261.92cM with an average distance of 12.40 cM and 14.9 cM, respectively. Location-wise and pooled data across locations indicated that QTL expression was population and environment specific. The genomic prediction accuracies of 0.83 and 0.79 were achieved for NCLB Population 1 and Population 2, respectively. The resistant progenies from both populations were advanced to derive inbred lines and crossed with four different testers in line x tester mating design to test for their combining ability. High overall general combining ability was exhibited by 21 inbred lines. Among crosses 48 % were assigned high overall specific combining ability status. Out of 136 single crosses, seven recorded significant positive standard heterosis over the best check for grain yield. The clustering pattern of inbred lines developed from the two populations revealed high molecular diversity. Conclusions: In this study, comparatively better genomic prediction accuracies were achieved for NCLB and the worth of F3 progenies with high genomic predictions was proved by advancing them to derive inbred lines and establishing their higher combining ability for yield and yield related traits.


2019 ◽  
Vol 86 ◽  
Author(s):  
Juliane Nicolodi Camera ◽  
Carlos Alberto Forcelini ◽  
Jana Koefender ◽  
Diego Pascoal Golle ◽  
André Schoffel ◽  
...  

ABSTRACT: Northern corn leaf blight (NCLB) and common rust are among the primary fungal diseases affecting maize production. This study aimed to evaluate the susceptibility of ten maize hybrids to NCLB and to common rust and to verify the efficiency of fungicides in the chemical control of Exserohilum turcicum. In the first experiment, hybrids Pioneer (30F53, P1630H, P2530), Monsanto (AG 8045, AG 9045), Dow AgroSciences (2A550, 2A106 and 2B587) and Syngenta (SYN7205 VIPTERA, SW 3949 TL) were used and in the experiment for effectiveness of fungicides in the control of NCLB. The efficiency of fungicides propiconazole, azoxystrobin, cyproconazole + azoxystrobin, prothioconazole + trifloxystrobin, benzovindiflupir + azoxystrobin, cyproconazole + azoxystrobin + mancozeb were tested in the Pioneer P1630H hybrid. In both experiments, the leaf disease severity (%), yield and the weight of one thousand seeds were evaluated. The experimental design was carried out in randomized blocks with four replicates. The hybrids SYN7205, P2530, SW 3949 TL, 2B587, AG 9045, 2A550, P1630H, 2A106 and AG 8025 showed the smallest areas under the common rust severity progress curve. Hybrids AG9045, 30F53, and 2A550 presented the smallest areas under the NCLB progress curve. Hybrids AG8025, 2B587, P1630H, AG9045, 2A106, 2A550, present the highest yields. The fungicides prothioconazole + trifloxystrobin present the highest chemical control efficiency for NCLB and the lowest area under the disease progress curve (AUDPC).


2019 ◽  
Vol 99 (6) ◽  
pp. 972-984
Author(s):  
L.M. Reid ◽  
X. Zhu ◽  
K.K. Jindal ◽  
T. Woldemariam ◽  
J. Wu ◽  
...  

CO468, CO469, CO470, CO471, CO472 and CO473 are the first corn (Zea mays L.) inbred lines released from the northern corn leaf blight [Exserohilum turcicum (Pass.) K.J. Leonard & E.G. Suggs; syn. = Helminthosporium turcicum Pass.] resistance breeding program of Agriculture and Agri-Food Canada. All six inbreds possess intermediate to very high levels of resistance, which is expressed in hybrids when these inbreds are combined with susceptible test lines. Expression is even higher when some of these lines are combined with each other. Acceptable grain yields and moistures are also achieved in several hybrid testcrosses. All six inbreds also possess intermediate to high levels of resistance to eyespot, common rust, Goss’s bacterial wilt, and grey leaf spot.


2020 ◽  
Vol 53 (1) ◽  
Author(s):  
Sadaf Naeem ◽  
Muhammad Tahir ◽  
Kiramat Khan ◽  
Amjad Hasan ◽  
Rafiq Ahmad

2021 ◽  
Vol 156 ◽  
pp. 104554
Author(s):  
Meng Zhang ◽  
Cheng Zhang ◽  
Sisheng Zhang ◽  
Huilin Yu ◽  
Hongyu Pan ◽  
...  

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