EVALUATION OF SELECTED INSECTICIDES FOR CONTROL OF CORN EARWORM AND FALL ARMYWORM IN SWEET CORN, 2004

2005 ◽  
Vol 30 (1) ◽  
Author(s):  
J. Kurk Lance ◽  
John N. All ◽  
Michelle Samuel-Foo
2009 ◽  
Vol 44 (4) ◽  
pp. 383-390
Author(s):  
John D. Sedlacek ◽  
Karen L. Friley ◽  
Steve L. Hillman

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.


1996 ◽  
Vol 21 (1) ◽  
pp. 113-114
Author(s):  
P.A. Stansly ◽  
J.M. Conner

Abstract The efficacy of azadirachtin formulations alone and in combination with Bacillus thuringiensis var. aizawai, two formulations of cyhalothrin, and Lannate were compared. Six polyethylene-mulched beds 32 inches wide configured in 2 sets of 3 on 6 ft centers separated by a 15 ft drive middle were planted on 29 Aug in double rows 12 inches between rows and plants. The center bed was used as an untreated source of inoculum and the remaining beds divided into 33 ft plots and assigned treatments in a RCBD with 7 treatments and 4 replications. Whorls of all plants were inoculated with 1-2 neonate fall armyworm larvae on 5 Oct using a bazooka gun and Grito-O-Cobs at 24-4O mesh. Treatments were applied weekly for 6 weeks beginning 7 Oct using a high clearance sprayer configured with 1 overhead nozzle per row equipped with a diaphragm pump operating at 200 psi and calibrated to delivery 21 gpa at 2.5 mph. APSA 80 was tank mixed with Karate and Lannate treatments at 5 oz/100 gallon. The dispersants Petro and Morwet were added to 25% of the spray water at a rate of 0.38 gram of 3% microencapsulated azadirachtin (WRC7305) and mixed for 3 minutes before adding remaining water containing the adjuvant B-1956 at 2 oz/gal. Feeding on inner 3 whorl leaves or tassel was rated weekly for 16 plants on a scale of 1 to 6 corresponding to 0, >1%, 2-5%, 6-10%, 11-30%, and >30% damage respectively. The same 16 plants per plot were harvested twice and number and ears evaluated for weight and marketability. Culls were evaluated as to cause of damage and larvae identified and counted. In addition, 10 stalks from each plot were opened to search for borers but none were found.


2010 ◽  
Vol 35 (1) ◽  
Author(s):  
John F. Smith ◽  
Lucas N. Owen ◽  
Angus L. Catchot

1999 ◽  
Vol 92 (5) ◽  
pp. 1217-1222 ◽  
Author(s):  
R. E. Lynch ◽  
B. R. Wiseman ◽  
H. R. Sumner ◽  
D. Plaisted ◽  
D. Warnick

EDIS ◽  
2019 ◽  
Vol 2005 (14) ◽  
Author(s):  
Gregg S. Nuessly ◽  
Susan E. Webb

Foliar, ear and root feeding insects can routinely cause economic losses to sweet corn if left untreated. The most important pests of sweet corn in Florida are the fall armyworm, corn earworm, lesser cornstalk borer, cutworms, corn silk fly, cucumber beetles, aphids, and wireworms. Less common pests of sweet corn include grasshoppers, corn blotch leafminer, twospotted spider mites, sap beetles, stink bugs, maize weevils and billbugs, white grubs, and white fringed beetles.  This document is ENY-472 (which replaces ENY-449), one of a series of the Department of Entomology and Nematology, UF/IFAS Extension. Original publication date November 2001. Revised September 2005.  ENY-472/IG158: Insect Management for Sweet Corn (ufl.edu)


1999 ◽  
Vol 34 (4) ◽  
pp. 415-425 ◽  
Author(s):  
B. R. Wiseman ◽  
R. E. Lynch ◽  
D. Plaisted ◽  
D. Warnick

A laboratory bioassay was used to evaluate Bt transgenic sweet corn hybrids for resistance against the corn earworm, Helicoverpa zea (Boddie), and the fall armyworm, Spodoptera frugiperda (J. E. Smith). Whorl leaves, silks, and kernels, either fresh or oven-dried and ground with a mill, were incorporated into a dilute pinto bean diet and bioassayed against neonate, 3-, or 6-day-old larvae. Regardless of age of the larvae, results with the diet bioassay using fresh silks, oven-dried silks or fresh kernels were highly correlated with those for the fresh silk bioassay. Differences in susceptibility between insect species to the CrylA(b) toxin produced in the transgenic plants were also readily discernable using the diet bioassay. Based on results of the bioassays, Novartis sweet corn hybrids containing a crylA(b) gene gene for δ-endotoxin production were very highly resistant to leaf, silk and kernel feeding by the corn earworm and highly resistant to leaf and silk feeding by the fall armyworm.


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