scholarly journals Combining Ability of Husk Extension, Maysin Content, and Corn Earworm Resistance

2021 ◽  
Vol 146 (1) ◽  
pp. 14-23
Author(s):  
Virginia M. Moore ◽  
William F. Tracy
Keyword(s):  
Zea Mays ◽  
Combining Ability ◽  
Helicoverpa Zea ◽  
Sweet Corn ◽  
Corn Earworm ◽  
Management Options ◽  
Mating Design ◽  
Cultivar Development ◽  
Factorial Mating ◽  
Factorial Mating Design

Corn earworm (Helicoverpa zea) is a destructive pest with limited management options in sweet corn (Zea mays) production. Increased husk extension and the presence of the C-glycosyl flavone maysin are two proposed mechanisms for improving corn earworm resistance in corn cultivars. A factorial mating design was conducted to test hybrid combinations of sweet corn inbreds with long husks and/or maysin to identify candidates for future cultivar development. The mating design had seven male parents, including three commercial sweet corn inbreds (Wh9261, We11401, and Wt1001) and four inbreds selected for maysin content (Maysin1, 2, 3, and 4), and five female parents, including two commercial sweet corn inbreds (Ia453su and Ia5125su) and three inbreds with long, thick, tight husks (A684su, A685su, and A686su). Hybrids were evaluated for ear length, husk length, maysin content, and corn earworm resistance at six environments in 2016 and 2017. Relationships between husk extension, maysin, and corn earworm resistance were inconsistent, but five inbreds produced hybrids with significantly lower corn earworm infestation and/or damage, demonstrating potential to confer resistance to the corn earworm.

Survey of organic sweet corn growers identifies corn earworm prevalence, management and opportunities for plant breeding

2020 ◽  
pp. 1-4
Author(s):  
Virginia M. Moore ◽  
William F. Tracy
Keyword(s):  
Plant Breeding ◽  
Helicoverpa Zea ◽  
Sweet Corn ◽  
Insect Pest ◽  
Corn Earworm ◽  
Management Options ◽  
Current Management ◽  
Corn Production ◽  
Resistant Varieties ◽  
The U.S

Abstract Corn earworm (Helicoverpa zea) is one of the most important pests in organic sweet corn (Zea mays) production. Breeding of corn earworm-resistant varieties has been identified as a potential approach to deal with this pest, but it is critical that plant breeding efforts reflect the contexts and needs of organic producers who might eventually adopt earworm-resistant varieties. In November–December 2017, we surveyed organic sweet corn producers in the U.S. to learn about impacts of corn earworm on organic sweet corn production, how producers are currently managing the pest and opportunities for plant breeding to reduce its overall impact. The survey confirmed that corn earworm is the most challenging insect pest for organic sweet corn producers, that current management options remain limited and that earworm-resistant varieties could improve the ability of growers to consistently produce damage-free sweet corn and to improve the value of sweet corn within organic operations.

Ear Pests and Damage to Organic, Conventional and Bt-Protected Sweet Corn Grown in Central Kentucky

2009 ◽  
Vol 44 (4) ◽  
pp. 383-390
Author(s):  
John D. Sedlacek ◽  
Karen L. Friley ◽  
Steve L. Hillman
Keyword(s):  
Helicoverpa Zea ◽  
European Corn Borer ◽  
Sweet Corn ◽  
Crop Protection ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Genetically Engineered ◽  
Corn Borer ◽  
Sap Beetles ◽  
Southwestern Corn Borer

Sweet corn (Zea mays L. var. rugosa) was grown in replicated plots in 2004 and 2006 using organic, conventional, and genetically-engineered (Bt) production practices. Organic plots were treated with Entrust® (Dow AgroSciences LLC, Indianapolis, IN) whereas conventional and Bt sweet corn plots were treated with Warrior® (Syngenta Crop Protection, Inc., Greensboro, NC). All plots were treated once at silk emergence. Organic and conventional plots were treated again 1 wk later. Twenty-five ears were harvested from row centers in each treatment subplot to quantify ear pests and assess ear damage. The highest number of corn earworm, Helicoverpa zea (Boddie), larvae were found on organically-grown sweet corn. European corn borer, Ostrinia nubilalis (Hübner); southwestern corn borer, Diatraea grandiosella Dyar; and fall armyworm, Spodoptera frugiperda (J.E. Smith), larvae were not found as frequently. Neither corn earworm nor European corn borer larvae were found on Bt sweet corn ears. Sap beetles, Carpophilus lugubris Murray, were found on all 3 types of sweet corn. Organically and conventionally-grown sweet corn had a greater number of tip-damaged ears and numbers of damaged kernels per ear than Bt sweet corn. Ear length and weight were the same for all 3 types of sweet corn. Based on the information generated in this study, growing late-planted sweet corn organically or conventionally on a large commercial scale with a limited spray program and without using other types of ear pest management does not appear to be a practical or profitable option in central Kentucky.

INFESTAÇÃO DE MILHO CRIOULO, CONVENCIONAL E TRANSGÊNICO PELA LAGARTA-DO-CARTUCHO E PELA LAGARTA-DA-ESPIGA E PARASITISMO DE OVOS

2017 ◽  
Vol 16 (3) ◽  
pp. 351
Author(s):  
CAMILA CORRÊA VARGAS ◽  
ROSANA MATOS DE MORAIS ◽  
LUIZA RODRIGUES REDAELLI
Keyword(s):  
Zea Mays ◽  
Spodoptera Frugiperda ◽  
Helicoverpa Zea ◽  
Genetically Modified ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Trichogramma Pretiosum ◽  
Hybrid Corn ◽  
Egg Parasitism ◽  
Santa Maria

RESUMO - O objetivo foi avaliar a infestação, o parasitismo de ovos e danos da lagarta-do-cartucho, Spodoptera frugiperda (J. E. Smith), e da lagarta-da-espiga, Helicoverpa zea (Boddie), em cultivares de milho: variedade crioulo (Lombo Baio), híbrido convencional (Semilha S395) e híbrido geneticamente modificado (Bt) (TC1507 Herculex I ®, Cry1F). O experimento foi conduzido em Santa Maria-RS, no período de segunda safra de 2014. O delineamento foi de blocos ao acaso, com três tratamentos e quatro repetições. Foram registrados os danos, o número de lagartas, de posturas e o parasitismo em ovos da lagarta-do-cartucho, dos 9 aos 72 dias após a emergência das plantas (DAE). A infestação da lagarta-da-espiga e o parasitismo de ovos foram registrados dos 67 aos 101 DAE. Os danos causados pela lagarta-do-cartucho foram semelhantes entre milho crioulo e convencional, os quais foram mais elevados do que no milho geneticamente modificado Bt. O número médio de lagartas-do-cartucho foi maior em milho crioulo. A média do número total de lagartas-da-espiga foi semelhante entre milho crioulo e convencional e superior à do Bt. Foi registrado o parasitismo de ovos para a lagarta-da-espiga por Trichogramma pretiosum Riley, nas três cultivares avaliadas, com porcentagens semelhantes entre milho crioulo e convencional e superior em milho Bt. Palavras-chave: Spodoptera frugiperda, Helicoverpa zea, Trichogramma pretiosum, Zea mays, manejo de pragas. INFESTATION IN INLANDRACE, CONVENTIONAL AND TRANSGENIC CORN BY FALL ARMYWORM AND CORN EARWORM, AND EGG PARASITISM  ABSTRACT - The objective of the work was to estimate the infestation and eggs parasitism of fall armyworm (J. E. Smith) and corn earworm (Boddie), in three corn varieties: landrace (LomboBaio), conventional hybrid (Semilha S395) and genetically modified hybrid (Bt) (TC1507 Herculex I ®, Cry1F). The experiment was carried out in Santa Maria-RS, during the second-season corn crop, in 2014. The experimental design was a completely randomized block with three treatments, and four replicates. We evaluated the damages, number of larvae, number of eggs and fall armyworm egg parasitism from 9 to 72 days after emergence (DAE). The infestation of corn earworm and the eggs parasitism were measured from 67 to 101 DAE. Fall armyworm damage was similar between landrace and conventional hybrid, and both higher than those of genetically modified hybrid Bt. Average number of fall armyworm larvae was higher in landrace cultivar. The average of total number of corn earworm larvae was similar on landrace and conventional hybrid, both higher than Bt hybrid. Corn earworm eggs parasitism by Trichogramma pretiosum Riley was recorded in the three evaluated cultivars and similar parasitism percentage was observed between landrace and conventional hybrid, which was higher in Bt maize. Keywords: Spodoptera frugiperda, Helicoverpa zea, Trichogramma pretiosum, Zea mays, pest management.

scholarly journals Phytotoxicity and Pollination Disorders in Sweet Corn Due to Direct-silk Applications of Materials Used for Alternative Corn Earworm Control

2007 ◽  
Vol 17 (2) ◽  
pp. 163-168 ◽  
Author(s):  
Tori Lee Jackson ◽  
Mark G. Hutton ◽  
David T. Handley
Keyword(s):  
New England ◽  
Helicoverpa Zea ◽  
Sweet Corn ◽  
Corn Oil ◽  
Corn Earworm ◽  
Soy Oil ◽  
Conventional Management ◽  
Repeated Applications ◽  
Materials Used ◽  
Significant Injury

Corn earworm [CEW (Helicoverpa zea)] is one of the most important pests of sweet corn (Zea mays) in New England. Conventional management of this pest is achieved through repeated applications of chemical insecticides through the silking period. Organic growers, however, have few alternatives to prevent CEW infestation. Technology first developed in the 1930s and 1940s, using applications of mineral oil directly into the silk channel with an eyedropper, has been further researched in recent years using vegetable oils with and without pesticides, but pollination problems associated with these treatments have been observed. Several materials were evaluated for efficacy in controlling CEW populations and for phytotoxicity to the developing ear. Materials evaluated were corn oil, soy oil, carrageenan, corn oil mixed with Bacillus thuringiensis ssp. kurstaki (Bt), soy oil mixed with Bt, and carrageenan mixed with Bt. All treatments were compared with an untreated control. Treatments provided a range of 33% to 50% control of CEW infestation. The oil and Bt combinations provided some reduction in infestation compared with the untreated controls (33% vs. 100% infestation), but this level of control was inadequate for all wholesale markets and most direct markets. Additionally, oil-based treatments also caused significant injury to developing ears by reducing pollination quality, impacting the development of the kernels at the ear tip. This condition referred to as “cone-tip” is of concern since it may decrease marketability. The percent unmarketable ears due to cone-tips ranged from 0% to 13% for the untreated and carrageenan-based treatments. From 12% to 42% of ears were unmarketable due to the soy oil treatments. Corn oil treatments caused 10% to 50% cone-tips.

Field Bioassay of Pheromone Lures and Trap Designs for Monitoring Adult Corn Earworm (Lepidoptera: Noctuidae) in Sweet Corn in Southern New England

1920 ◽  
Vol 17 (3) ◽  
pp. 1833-1836
Author(s):  
Norman L. Gauthier ◽  
Patrick A. Logan ◽  
Lisa A. Tewksbury ◽  
Craig F. Hollingsworth ◽  
Donald C. Weber ◽  
...  
Keyword(s):  
New England ◽  
Rhode Island ◽  
Helicoverpa Zea ◽  
Sweet Corn ◽  
Corn Earworm ◽  
Reference Standards ◽  
Fresh Market ◽  
Field Bioassay ◽  
Southern New England ◽  
Lepidoptera Noctuidae

Four commercial pheromones attractive to Helicoverpa zea (Boddie) were used as baits in four insect traps to attract moths in fresh market sweet corn. Moth catches were monitored for 10 wk in nine sites in Connecticut, Massachusetts, and Rhode Island. Zealure attracted twice as many moths as Scentry's corn earworm lure and nine times as many as Pherocon's corn earworm lure. Consep Membrane's Biolure attracted few moths. Hartstack traps caught three times more moths than Heliothis net traps and 15 times more than Multi-pher or International Pheromone Systems traps. Results suggest the need for reference standards in management programs that use pheromones to monitor corn earworm populations.

Combining ability and gene action in experimental hybrids of Sweet Corn (Zea mays var. saccharata)

2018 ◽  
Vol 75 (1) ◽  
pp. 64
Author(s):  
K. Elayaraja ◽  
R.N. Gadag ◽  
Jyoti Kumari ◽  
Upama Mishra
Keyword(s):  
Zea Mays ◽  
Combining Ability ◽  
Sweet Corn ◽  
Gene Action

ChemInform Abstract: New Flavone C-Glycosides from Corn (Zea mays L.) for the Control of the Corn Earworm (Helicoverpa zea)

ChemInform ◽  
2010 ◽  
Vol 25 (42) ◽  
pp. no-no
Author(s):  
M. E. SMOOK ◽  
N. W. WIDSTROM ◽  
B. R. WISEMAN ◽  
R. C. GUELDNER ◽  
R. L. WILSON ◽  
...  
Keyword(s):  
Zea Mays ◽  
Helicoverpa Zea ◽  
Zea Mays L ◽  
Corn Earworm

scholarly journals Molecular Genetics of Rust Resistance in Poplars (Melampsora larici-populina Kleb/Populus sp.) by Bulked Segregant Analysis in a 2 × 2 Factorial Mating Design

Genetics ◽  
1996 ◽  
Vol 143 (1) ◽  
pp. 531-536 ◽  
Author(s):  
M Villar ◽  
F Lefèvre ◽  
H D Bradshaw ◽  
E Teissier du Cros
Keyword(s):  
Rapd Markers ◽  
Sampling Error ◽  
Bulked Segregant Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Genomic Region ◽  
Mating Design ◽  
Analysis Technique ◽  
Factorial Mating ◽  
Recombination Value ◽  
Factorial Mating Design

Abstract With random amplified polymorphic DNA (RAPD) markers, we have tagged a genomic region in Populus sp. involved in qualitative resistance to Melumpsora larici-populina. Our approach was based on three steps: use of RAPD markers that can be quickly and efficiently researched; application of “bulked segregant analysis” technique on individuals of one interspecific family P. trichocarpa × P. deltoides to search for RAPD markers linked to resistance; and validation of these markers in two other families linked with the first one in a 2 × 2 factorial mating design. Of five detected markers, only one marker M03/04_480 was polymorphic in the three segregating families, involving 89 individuals and four different parents. We have estimated the recombination value of 1 cM with 1 cM sampling error.

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