Biology, Ecology, and Evolving Management ofHelicoverpa zea(Lepidoptera: Noctuidae) in Sweet Corn in the United States

2016 ◽  
Vol 109 (4) ◽  
pp. 1667-1676 ◽  
Author(s):  
Daniel L. Olmstead ◽  
Brian A. Nault ◽  
Anthony M. Shelton
Keyword(s):  
United States ◽  
Sweet Corn ◽  
The United States ◽  
Lepidoptera Noctuidae

scholarly journals Stewart's Wilt Reactions of an International Collection of Zea mays Germ Plasm Inoculated with Erwinia stewartii

Plant Disease ◽  
2000 ◽  
Vol 84 (8) ◽  
pp. 901-906 ◽  
Author(s):  
Jerald K. Pataky ◽  
Lindsey J. du Toit ◽  
Noah D. Freeman
Keyword(s):  
United States ◽  
Germ Plasm ◽  
Sweet Corn ◽  
The United States ◽  
River Valley ◽  
Ohio River ◽  
Ohio River Valley ◽  
The World ◽  
The Mean ◽  
Stewart's Wilt

Maize accessions were evaluated in 1997, 1998, and 1999 to identify additional sources of Stewart's wilt resistance and to determine if reactions differed among accessions collected from various regions of the United States and throughout the world. The distributions of Stewart's wilt reactions rated from 1 (no appreciable spread of symptoms) to 9 (dead plants) were relatively similar among groups of accessions from all regions of the world except for those from the Mid-Atlantic/Ohio River Valley region of the United States, the southern United States, and the northeastern United States. The mean and median Stewart's wilt rating for 1,991 accessions evaluated in 1997 was 4. The mean Stewart's wilt rating for 245 accessions collected from the Mid-Atlantic/Ohio River Valley region was 3.1, which was significantly lower than that for accessions from all other regions. The mean rating for accessions from the southern United States was 3.7, which also was lower than mean ratings for accessions from all other regions. Ratings from trials in 1997 and 1998 were highly correlated (r = 0.87) for 292 accessions and 15 sweet corn hybrid checks evaluated in both years. Of 20 accessions rated below 2 in 1997 and 1998, seven were from Virginia, seven were from the Ohio River Valley or central Corn Belt of the United States, four were from the northern or western Corn Belt of the United States, and two were from Spain. Ratings for these accessions ranged from 1.7 to 3.1 in 1999. Ratings ranged from 2.6 to 3.7 for F1 hybrids of these accessions crossed with one of two susceptible sweet corn inbreds, CrseW30 or Crse16, which were rated 5.7 and 5.4, respectively. Based on the reactions of this collection of germ plasm, it appears that high levels of Stewart's wilt resistance are prevalent only among accessions collected from areas where the disease has been endemic for several years, whereas moderate levels of resistance can be found in accessions collected from nearly everywhere in the world.

scholarly journals Foliar Application of Liquid Urea-triazone-based Nitrogen Fertilizers and Crop Safety

1993 ◽  
Vol 3 (4) ◽  
pp. 442-444 ◽  
Author(s):  
J.G. Clapp
Keyword(s):  
United States ◽  
Ammonium Nitrate ◽  
Sweet Corn ◽  
Foliar Application ◽  
The United States ◽  
Nitrogen Fertilizers ◽  
Leaf Injury ◽  
Foliar Fertilizer ◽  
Horticultural Crops ◽  
Commercial Grower

Urea-triazone-based nitrogen (N) solutions were evaluated for potential leaf injury on agronomic and horticultural crops at 61 commercial grower sites throughout the United States. Poliar spray solutions containing triazone N were used at concentrations ranging from 1.5% to 15.7%. Safe N concentrations for urea-triazone-based N products ranged from 1.5% for crops such as sweet corn, apple, cherry, and pear, and up to 15.7% for nursery root stocks. Urea-triazone-based N solutions were found to be much safer on crop foliage than ammonium-, nitrate-, and/or all urea-based foliar fertilizer products than reported in the literature.

scholarly journals Widespread Occurrence of Common Rust, Caused by Puccinia sorghi, on Rp-Resistant Sweet Corn in the Midwestern United States

Plant Disease ◽  
1999 ◽  
Vol 83 (12) ◽  
pp. 1177-1177 ◽  
Author(s):  
J. K. Pataky ◽  
W. F. Tracy
Keyword(s):  
United States ◽  
North America ◽  
Sweet Corn ◽  
The United States ◽  
Rock Falls ◽  
Corn Hybrids ◽  
Widespread Occurrence ◽  
Puccinia Sorghi ◽  
No Formation ◽  
Leaf Surfaces

Single, dominant resistance genes have been used successfully for the past 15 years to control common rust, caused by Puccinia sorghi, on sweet corn in the United States. Most sweet corn hybrids grown in the Midwest for mid- to late-season processing have Rp resistance, which is expressed as hypersensitive reactions resulting in chlorotic or necrotic flecks with little or no formation of urediniospores. Many, but not all, Rp-resistant sweet corn hybrids carry the gene Rp1D. Biotypes of P. sorghi in North America have been avirulent on plants with the Rp1D gene, except for an isolate collected in Kansas in 1990 (1). In a sweet corn nursery in Urbana, IL, in 1997, small uredinia of P. sorghi occurred on 27 of 79 Rp-resistant sweet corn hybrids that also were infected severely with southern rust caused by P. polysora (2). During August and September 1999, small uredinia or fully susceptible reactions to common rust were observed on several Rp-resistant sweet corn hybrids grown in an area bounded by Mendota, IL, Ripon, WI, and Le Sueur, MN. Southern rust also was prevalent and frequently severe in the area. Isolates of P. sorghi from Rp-resistant corn were collected during September 1999 from Mendota, Rock Falls, and Dekalb, IL; Sun Prairie, Madison, and Ripon, WI; and Rochester, Stanton, and Le Sueur, MN. Ten two-leaved seedlings of one susceptible sweet corn hybrid and five Rp-resistant hybrids, including hybrids known to carry the gene Rp1D, were inoculated in greenhouse trials. Each location (collection) was a separate trial. Inocula were prepared from several uredinia of P. sorghi per location. One set of seedlings also was inoculated with P. polysora. Susceptible reactions (uredinia with urediniospores) were observed on all inoculated seedlings. Uredinia and urediniospores of P. sorghi and P. polysora from seedlings inoculated in the greenhouse were compared directly. All isolates of P. sorghi were confirmed based on 6- to 7-day latent periods, formation of uredinia on both leaf surfaces, and urediniospores that were mostly spherical, cinnamon colored, and moderately echinulate. This is the first widespread occurrence in North America of a biotype of P. sorghi that is virulent on Rp-resistant sweet corn. References: (1) S. H. Hulbert et al. Plant Dis. 75:1130, 1991. (2) J. K. Pataky et al. Purdue Univ. AES Bull. No. 758:99, 1997.

scholarly journals Pest Management Needs and Limitations for Corn Earworm (Lepidoptera: Noctuidae), an Emergent Key Pest of Hemp in the United States

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kadie E Britt ◽  
Thomas P Kuhar ◽  
Whitney Cranshaw ◽  
Christopher T McCullough ◽  
Sally V Taylor ◽  
...  
Keyword(s):  
United States ◽  
World War Ii ◽  
Pest Management ◽  
Helicoverpa Zea ◽  
Cannabis Sativa ◽  
Insect Pest ◽  
The United States ◽  
Corn Earworm ◽  
Minimal Risk ◽  
Lepidoptera Noctuidae

Abstract Corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), has emerged as an injurious insect pest to hemp, Cannabis sativa L., a crop newly reintroduced to the United States. Growing hemp presents a potential alternative economic opportunity for farmers but can be challenging with a market that is unstable and just developing. One of the most notable production challenges is managing corn earworm, an insect pest that is particularly damaging when it feeds on flower buds produced in cannabinoid varieties, creating extensive bud tunneling and wounds that allow entry of pathogens that can aid development and presence of bud rot. Damage to seeds is of lesser concern in hemp cultivars grown for grain and minimal risk is associated with hemp grown for fiber. Our ability to research hemp has only recently been allowed as production was largely suspended following World War II and, as such, there has been limited opportunity to develop information for empirically-based pest management recommendations. Further complicating development of integrated pest management (IPM) strategies are regulatory challenges associated with providing registration support to add hemp to pesticide labels, as it was not formally recognized as a crop by U.S. regulatory agencies until late 2019. Research needs and challenges to develop effective IPM programs for corn earworm on hemp are discussed here.

INFLUENCE OF COMPANION PLANTS ON OVIPOSITION OF IMPORTED CABBAGEWORM, PIERIS RAPAE (LEPIDOPTERA: PIERIDAE), AND CABBAGE LOOPER, TRICHOPLUSIA NI (LEPIDOPTERA: NOCTUIDAE), ON COLLARD PLANTS

1983 ◽  
Vol 115 (11) ◽  
pp. 1529-1531 ◽  
Author(s):  
M. A. Latheef ◽  
J. H. Ortiz
Keyword(s):  
United States ◽  
Trichoplusia Ni ◽  
Pieris Rapae ◽  
The United States ◽  
Cabbage Looper ◽  
Small Farm ◽  
Area Basis ◽  
Public Exposure ◽  
Companion Plants ◽  
Lepidoptera Noctuidae

Public participation in home vegetable gardening and small farm operations is increasing in North America. This is expected to intensify the use of insecticides and disproportionately increase public exposure to them. For instance, von Rurnker et al. (1972) estimated that on an area basis homeowners in the midwestern United States applied ca. 5.0 lb of pesticides per acre. This amount when compared with 1½ to 3 lb per acre applied by the farmer suggests that backyard gardens receive a heavier pesticide application than most other land areas in the United States. It is, therefore, important to develop ecologically less aggressive control methods for small farm operations.

Effects of Temperature, Humidity, and Larval Weight on the Duration of Prepupal and Pupal Stages of the Pale Western Cutworm, Agrotis orthogonia Morr. (Lepidoptera: Noctuidae)

1960 ◽  
Vol 92 (3) ◽  
pp. 161-163 ◽  
Author(s):  
P. E. Blakeley ◽  
L. A. Jacobson
Keyword(s):  
United States ◽  
Life Cycle ◽  
New Mexico ◽  
The United States ◽  
Prepupal Stage ◽  
Larval Weight ◽  
Wide Range ◽  
Effects Of Temperature ◽  
Lepidoptera Noctuidae

The pale western cutworm, Agrotis orthogonia Morr., a pest of crops in the plains areas, occurs in central Alberta and Saskatchewan in Canada southward to various areas of Oklahoma, Texas, and New Mexico in the United States. It has been suggested that in the prepupal stage this cutworm is able to adapt itself to a wide range of climatic and geographic conditions and to retain a univoltine life cycle. The investigations reported here were made to determine the effects of temperature, moisture, and larval weights on the duration of the prepupal and pupal stages.

scholarly journals Morphological Characterization and Classification of Open-pollinated Sweet Corn Cultivars

1995 ◽  
Vol 120 (1) ◽  
pp. 112-118 ◽  
Author(s):  
Pedro Revilla ◽  
W.F. Tracy
Keyword(s):  
United States ◽  
Sweet Corn ◽  
Morphological Variability ◽  
Principal Component ◽  
The United States ◽  
Morphological Characterization ◽  
Vegetable Crops ◽  
The North ◽  
And Cluster Analysis ◽  
Sugar Levels

Sweet corn is one of the most important vegetable crops in the United States, however the morphology and phylogeny of open-pollinated sweet corn cultivars has not been studied. Fifty eight open-pollinated sweet corn cultivars were characterized with thirty-four descriptors to provide information for breeders interested in broadening the genetic base of sweet corn. Principal component analysis and cluster analysis were performed to classify sweet corn cultivars based on morphology. Also, relationships among morphological variables in this set of cultivars were determined. The general ordination of cultivars followed an axis representing earliness, and plant, leaf, and tassel size, while ear and kernel attributes were less variable. The morphological variability among all of the widely used sweet corn cultivars, except `Country Gentleman', was not greater than the variability found among the `Golden Bantam' strains. Based on morphology, 52 of the cultivars could be considered as one race, which we propose be called `Northeastern Sweets'. These may be a subset of the race `Northern Flint'. Five of the remaining cultivars are from the north-central or southwestern United States and may represent races from those areas. The sixth cultivar is `Country Gentleman', a commercially important sweet corn cultivar. Due to the importance of `Country Gentleman' and the introgression of nonsweet germplasm into modern sweet corn, we believe that sweet corn should be defined based on its use as a vegetable and on the presence of one or more genes that increase sugar levels in the endosperm.

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