scholarly journals Control of Western Corn Rootworm Larvae in West Central Nebraska, 1992

1994 ◽  
Vol 19 (1) ◽  
pp. 209-209
Author(s):  
R. C. Seymour ◽  
J. B. Campbell ◽  
R. J. Wright
Keyword(s):  
Growth Stage ◽  
Rating Scale ◽  
Western Corn Rootworm ◽  
Corn Rootworm ◽  
Root Damage ◽  
Time Of Application ◽  
Field Corn ◽  
West Central ◽  
The Press ◽  
Corn Plants

Abstract Granular insecticides were applied to suppress larval rootworm populations in 2 fields in west central NE. ‘Pioneer 3394’ hybrid field corn was ridge-planted in Field 1 with a John Deere Max-emerge planter, to a non-tilled seed bed on 11 May. Insecticides were applied at planting with insecticide boxes attached to the planter. Three replications of each treatment were arranged in a RCB design. T-band applications were made by applying a 7 inch band of insecticide in front of the press wheel. In-furrow applications were made by applying insecticide directly into the seed furrow. All insecticides were applied at a rate of 1114.5 g (AI)/ha. Field 2 was ridge-planted to ‘Fontanelle 4435’ and ‘Fontanelle 6240’ hybrid field corn with a John Deere Max-emerge planter, to a non-tilled seed bed on 6 May. With the exception of 4 strips, 12 rows in width, Counter 15G was applied at planting with insecticide boxes on the planter at a rate of 1114.5 g (AI)/ha. A granular and a liquid insecticide were applied to untreated strips in Field 2 immediately prior to cultivation on 15 Jun. The field corn plants were in the early whorl stage (growth stage 2) of development at the time of application. The granular application was applied over the whorl of the plants with insecticide boxes attached to a tool bar. The liquid insecticide was applied in a 7 inch band to the base of the plants in total volume of 120 liter/ha at 206,786 Pa (30 psi). Cultivation treatments were applied at a rate of 1114.5 g (AI)/ha. Each treatment in Field 2 was applied to 10 × 4 m plots which were replicated 4 times and arranged in a RCB design. Two blocks of treatments were applied to ‘Fontanelle 4435’ hybrid field corn plants and 2 blocks of treatments were planted to ‘Fontanelle 6240’ hybrid field corn plants. Treatments in both fields were evaluated 13 Jul by rating washed roots, using the 1-6 Iowa Root Damage Rating Scale, of 4 plants from each replicate.

scholarly journals Control of Western Corn Rootworm Larvae in West Central Nebraska, 1995

1996 ◽  
Vol 21 (1) ◽  
pp. 227-227
Author(s):  
R. C. Seymour ◽  
J. B. Campbell ◽  
R. J. Wright
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Rating Scale ◽  
Silt Loam ◽  
Time Of Application ◽  
Field Corn ◽  
Stage Of Development ◽  
Corn Plants ◽  
Over The Top ◽  
Bicycle Wheel

Abstract Insecticides were applied to suppress larval rootworm populations in 2 fields near North Platte, NE. Both fields were composed of Cozad silt loam soils. In Field 1 ‘DeKalb 566’ hybrid field corn was ridge-planted with a John Deere 7100 Max-emerge planter, to a non-tilled seed bed on 19 May. At the time of planting, soil moisture was adequate for germination and the soil temperature at a depth of 5 cm was about 8° C. Several insecticides were applied at planting to plots 2 rows wide, 10 m in length, with a bicycle wheel type applicator. Four replications of each treatment were arranged in a RCB design. T-band applications were made by applying a 7 inch band of insecticide to an open seed furrow. In-furrow applications were made by applying insecticide directly into the seed furrow. After the insecticides were applied, furrows were closed with a rotary hoe and insecticides were incorporated with a rake. Field 2 was ridge-planted to ‘BoJac 577’ field corn with a John Deere 7100 Max-emerge planter, in a non-tilled seed bed on 18 May. At the time of planting, soil moisture was adequate for germination and the soil temperature at a depth of 5 cm was about 13° C. With the exception of 4 field length strips, 12 rows in width, Lorsban 15G was applied at planting with insecticide boxes on the planter at a rate of 1100 g Al/ha. Granular and liquid insecticides were applied to untreated strips in Field 2 immediately prior to cultivation on 22 Jun. The corn plants were in the early whorl stage (V3 stage) of development at the time of application. The plots for the granular treatments in Field 2 were 10 m in length and 4 rows wide. The granular treatments were applied in a 7 inch band, over the whorl of the plants, with a bicycle wheel type applicator. Furadan 4F was applied to 10 X 4 m plots in Field 2, either broadcast over the top of the plants or in 7 inch bands to the base of the plants. All liquid treatments were applied in a total volume of 120 liters/ha at 30 psi. All treatments were replicated 4 times and arranged in a RCB design. Treatments in both fields were evaluated 26 Jul by rating washed roots, using the 1-6 Iowa root damage rating scale, of 4 plants from each replicate.

scholarly journals Control of Western Corn Rootworm Beetles and Effect on Spider Mites in West Central Nebraska, 1992

1994 ◽  
Vol 19 (1) ◽  
pp. 209-210
Author(s):  
R. C. Seymour ◽  
J. B. Campbell ◽  
R. J. Wright
Keyword(s):  
Spider Mite ◽  
Plant Size ◽  
Western Corn Rootworm ◽  
Large Individual ◽  
Corn Rootworm ◽  
Pesticide Application ◽  
Field Corn ◽  
West Central ◽  
Arthropod Predators ◽  
Predatory Insects

Abstract Various pesticides were applied to blister stage (R6 stage) hybrid field corn on 10 Aug, near North Platte, in west central NE. The treatments were applied with a CO2 charged backpack sprayer through 8001 flat fan nozzles at 206,786 Pa (30 psi), in a total volume of 196.4 liter/ha (21 gal/ acre). Each treatment was applied to 3 × 10 m plots, replicated 4 times in a RCBD. Five days before the pesticide application Banks grass mites were applied to 2 plants in the center of each plot by attaching 2 well-infested leaves with strapping tape. Four days following application the number of rootworm beetles and predatory insects were evaluated by counting all beetles on four randomly selected plants in the middle of each plot. For each artificially infested plant size of mite colonies was rated on the underside of 3 leaves below the ear, the ear leaf and 2 leaves above the ear at 9, 17, 27 and 46 DAT. Ratings were made on a 0-6 scale where 0 = no mites, 1 = individual mites, 2 = small colonies, 3 = large, individual colonies, 4 = large connected colonies but not completely covering the underside of the leaf, 6 = leaf dead due to spider mite damage. In addition to evaluation of spider mite colonies, arthropod predators were also counted.

scholarly journals Response of Mexican Corn Rootworm to Insecticides, 1991

1995 ◽  
Vol 20 (1) ◽  
pp. 329-329
Author(s):  
E. Guerrero-Rodriguez ◽  
S. Davalos-Luna ◽  
J. Corrales-Reynaga
Keyword(s):  
Petri Dish ◽  
Mortality Data ◽  
Corn Rootworm ◽  
Field Corn ◽  
Paper Towel ◽  
Percent Mortality ◽  
Petri Dishes ◽  
Mexican Corn Rootworm ◽  
Corn Plants ◽  
Commercial Field

Abstract Populations of MCR of commercial field corn from Arenal, Jalisco were exposed to nine insecticides of organophosphorous (OP), cabamate, organo chlorinated and pyrethroid groups. Larvae were collected from the roots of corn plants daily, and confined in polyethylene black bags of two kg capacity with humidity and germinated corn as food for larvae. Insects were taken to the laboratory of Sanidad Vegetal in Guadalajara, Jalisco. Dilutions of the insecticides tested were prepared using acetone from 500 to 5000 ppm (6 to 9 dosage/product). For this study 20 larvae of last instar were selected and 1 u, liter of the solution was placed topically on the thorax, after this, each larva was placed in a petri dish with a moistened paper towel and the petri dishes confined in a cardboard box to eliminate light. Mortality counts were carried out at 24 hours. Percent mortality was corrected by Abbott’s formula. The mortality data were analyzed by probit to obtain LC50 and LC,5 values for each insecticide.

scholarly journals Control of Western Corn Rootworm Larvae in West Central Nebraska, 1993

1994 ◽  
Vol 19 (1) ◽  
pp. 211-211
Author(s):  
R. C. Seymour ◽  
J. B. Campbell ◽  
R. J. Wright
Keyword(s):  
Western Corn Rootworm ◽  
Corn Rootworm ◽  
West Central

scholarly journals Control of Western Corn Rootworm Larvae in West Central Nebraska, 1994

1995 ◽  
Vol 20 (1) ◽  
pp. 178-178
Author(s):  
R. C. Seymour ◽  
J. B. Campbell ◽  
R. J. Wright
Keyword(s):  
Western Corn Rootworm ◽  
Corn Rootworm ◽  
Central Research ◽  
Silt Loam ◽  
West Central ◽  
The University ◽  
Extension Center

Abstract Insecticides were applied to suppress larval rootworm populations in 2 fields in west central NE. Both fields located at the University of Nebraska West Central Research and Extension Center were composed of Cozad silt loam soils.

EFFICACY OF VARIOUS SOIL INSECTICIDES AGAINST WESTERN CORN ROOTWORM IN FIELD CORN, 2002

2003 ◽  
Vol 28 (1) ◽  
Author(s):  
R. R. Youngman ◽  
C. A. Laub ◽  
T. A. Dellinger
Keyword(s):  
Western Corn Rootworm ◽  
Corn Rootworm ◽  
Field Corn ◽  
Soil Insecticides

Competition of Transgenic Volunteer Corn with Soybean and the Effect on Western Corn Rootworm Emergence

Weed Science ◽  
2012 ◽  
Vol 60 (2) ◽  
pp. 193-198 ◽  
Author(s):  
P. Marquardt ◽  
C. Krupke ◽  
W. G. Johnson
Keyword(s):  
Yield Loss ◽  
Larval Survival ◽  
Western Corn Rootworm ◽  
Growth And Yield ◽  
Corn Rootworm ◽  
Soybean Yield ◽  
Emergence Traps ◽  
Volunteer Corn ◽  
Corn Plants ◽  
The Impact

Glyphosate-resistant (GR) volunteer corn has emerged as a problematic weed in corn:soybean rotational systems, partly because of the rapid increase in adoption of corn hybrids that contain traits for both glyphosate and insect resistance. Volunteer GR corn can decrease soybean yields. The objectives of this study were to quantify the impact of volunteer corn on soybean growth and yield and determine how volunteer corn densities affect western corn rootworm (WCR) emergence. Volunteer corn seed was hand-planted at targeted densities of 0.5, 2, 4, 8, 12, and 16 seeds m−2at soybean planting and 21 d after planting to evaluate both early- and late-emerging cohorts. WCR emergence was assessed with the use of field emergence traps placed over individual corn plants in the 0.5- and 16-plants-m−2plots in 2008 and 2009. In 2010, WCR emergence traps were also placed over individual and clumped volunteer corn plants at densities of two and eight plants m−2. Soybean yield reductions ranged from 10 to 41% where early-emerging volunteer corn densities ranged from 0.5 to 16 plants m−2. No soybean yield loss occurred with the late-emerging cohort of volunteer corn. Twice as many adult WCRs emerged from a single volunteer corn plant growing at densities of 8 and 16 plants m−2, compared with plots containing 0.5 and 2 plants m−2. These results demonstrate that controlling volunteer corn will not only prevent soybean yield loss, but also may reduce the risk of WCR larval survival after exposure to Bt (Bacillus thuringiensisBerliner derived) corn.

Effects of Adult Western Corn Rootworm (Coleoptera: Chrysomelidae) Ear Feeding on Irrigated Field Corn in Colorado

1986 ◽  
Vol 79 (6) ◽  
pp. 1609-1612 ◽  
Author(s):  
J. L. Capinera ◽  
N. D. Epsky ◽  
D. C. Thompson
Keyword(s):  
Western Corn Rootworm ◽  
Corn Rootworm ◽  
Field Corn

EVALUATION OF AN OVIPOSITION TRAP FOR MONITORING EGG POPULATIONS OF DIABROTICA SPP. (COLEOPTERA: CHRYSOMELIDAE) IN FIELD CORN

1995 ◽  
Vol 127 (6) ◽  
pp. 839-849 ◽  
Author(s):  
Barbara S. Mulock ◽  
Cliff R. Ellis ◽  
Gary H. Whitfield
Keyword(s):  
Water Saturation ◽  
Aggregate Size ◽  
Economic Damage ◽  
Metal Ring ◽  
Corn Rootworm ◽  
Field Corn ◽  
Corn Plants ◽  
Clay Aggregates ◽  
Oviposition Sites ◽  
Oviposition Trap

AbstractTraps consisting of open, cylindrical tins containing moistened clay aggregates were evaluated as field oviposition sites for corn rootworm, Diabrotica spp. Six trap features were investigated: clay aggregate size, water saturation level, trap opening, trap cover, trap volume, and trap position relative to corn plants. More eggs were recovered in traps containing clay aggregates ranging from 0.5 to 3.5 mm diameter compared with aggregates from 2.5 to 8.0 mm diameter. Saturation of the trap to 2.5 cm from the opening resulted in greater egg recovery compared with traps saturated to 6.0 cm from the opening. Covering the exposed surface of the trap with a metal ring and/or a corn leaf increased egg recovery in the field.Oviposition traps were placed in four commercial corn fields in 1990 and three in 1991 to monitor egg populations. Egg recovery from traps and estimates of the absolute egg population in the soil were compared with densities of adult corn rootworm to predict larval damage on roots of corn planted the next year. In five fields, adult populations were above the current economic threshold of one beetle per plant. However, economic damage to roots occurred only in the field in which the most eggs were recovered from traps (226.6 eggs per trap) and soil samples (30.2 eggs per litre). Mean egg recovery per trap per field was correlated with mean damage ratings from untreated corn.

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