scholarly journals Control of Western Corn Rootworm Larvae, 1997

1998 ◽  
Vol 23 (1) ◽  
pp. 205-205
Author(s):  
R. C. Seymour ◽  
J. B. Campbell ◽  
R. J. Wright
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Western Corn Rootworm ◽  
Corn Rootworm ◽  
Silt Loam ◽  
Hybrid Corn ◽  
Significant Difference ◽  
Bicycle Wheel ◽  
State Scale

Abstract Insecticides were evaluated for rootworm larval suppression in a field composed of Cozad silt loam soils. ‘DeKalb 580’ hybrid corn was ridge planted near North Platte, NE, on 1 May. At the time of planting, soil moisture was adequate for germination. Soil temperature at a depth of 5 cm was about 7°C. Treatments were applied at planting to 5 X 40 ft plots in a RCB design with four replicates. Insecticides were applied with either a planter-mounted “Smart Box” applicator or a bicycle wheel applicator-mounted noble box. On 15 Jul four plants from each plot were collected and the roots were washed. The roots were then rated for rootworm damage using the 1-6 Iowa State scale. Treatment means were analyzed with ANOVA and were separated with Fisher’s protected test of least significant difference.

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 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.

Effect of Trap Size on Efficiency of Yellow Sticky Traps for Sampling Western Corn Rootworm (Coleoptera: Chrysomelidae) Adults in Corn

1996 ◽  
Vol 31 (3) ◽  
pp. 277-285 ◽  
Author(s):  
R. R. Youngman ◽  
T. P. Kuhar ◽  
D. G. Midgarden
Keyword(s):  
Unit Area ◽  
Field Studies ◽  
Diabrotica Virgifera Virgifera ◽  
Western Corn Rootworm ◽  
Trapping Efficiency ◽  
Corn Rootworm ◽  
Sticky Traps ◽  
Significant Difference ◽  
Trap Size ◽  
Yellow Sticky Traps

Field studies were conducted in Virginia cornfields in 1990 and 1991 to evaluate the effect of trap size on numbers of Diabrotica virgifera virgifera LeConte adults caught on unbaited Pherocon AM and Olson yellow sticky traps. No significant differences in trapping efficiency (i.e., catch per unit area) were detected on Pherocon AM traps whose sizes had been reduced by either 50% or 75% when compared with standard Pherocon AM no-bait traps. Likewise, no significant difference in trapping efficiency was detected between Olson traps whose sizes had been reduced 50% and full-size Olson traps (212.9 cm2). However, significantly more western corn rootworm adults per unit area were caught on Olson yellow sticky traps compared to Pherocon AM traps whose sizes had been reduced 50%. Comparative costs and precision values for reduced-size Pherocon AM and Olson yellow sticky traps are discussed.

scholarly journals Timing Study to Evaluate Product Performance of RH-0345 and Imidacloprid to Suppress Green June Beetle Grubs on a Golf Course Fairway in Lancaster County, Pennsylvania, 1996

1998 ◽  
Vol 23 (1) ◽  
pp. 353-354
Author(s):  
P. R. Heller ◽  
R. Walker
Keyword(s):  
Particle Size ◽  
Soil Moisture ◽  
Soil Temperature ◽  
Soil Type ◽  
Clay Soil ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Silt Loam ◽  
Water Ph ◽  
Loam Soil

Abstract The fairway located in Lancaster County, PA, consisted primarily of perennial ryegrass (80%) and creeping bentgrass (50%). Treatment plots were 7 X 6 ft, arranged in a RCB design and replicated 3 times. Liquid formulations were applied by using a CO2 sprayer with 4 8004VS TeeJet nozzles mounted on a 6-ft boom, operating at 28 psi, and delivering 4 gal/1000 ft2. At the 1st treatment time (4 Jun), the following soil and environmental conditions existed: air temperature, 68° F; soil temperature at 1-inch depth, 64° F; soil temperature at 2-inch depth, 62° F; RH, 67%; amount of thatch, 0.125 inch; soil type, silt loam; soil particle size analysis: 30.7% sand, 61.9% silt, 7.4% clay; soil moisture (oven baked), 28.3%; organic matter, 5.6%; water pH, 7.0; soil pH, 6.1; time of treatment, mid-morning; and overcast skies. The experimental area was irrigated with 0.25 inch of water 3 fir after treatment. At the 2nd treatment time (15 Jul), the following soil and environmental conditions existed: air temperature, 78° F; soil temperature at 1-inch depth, 74° F; soil temperature at 2-inch depth, 75° F; RH, 75%; amount of thatch, 0.0625-0.125 inch; soil type; silt loam; soil particle size analysis: 30.7% sand, 61.9% silt, 7.4% clay; soil moisture (oven baked), 37.7%; organic matter, 7.2%; water pH, 7.0; soil pH, 5.9; time of treatment, mid-morning; and cloudy skies. The experimental area was irrigated with 0.25 inch of water immediately after product dried. A the 3rd treatment time (12 Aug), the following soil and environmental conditions existed: air temperature, 65° F; soil temperature at 1-inch depth, 69° F; soil temperature at 2-inch depth, 69° F; RH, 90%; amount of thatch, 0.0625-0.125 inch; soil type, silt loam; soil particle size analysis: 30.7% sand, 61.9% silt, 7.4% clay; soil moisture (oven baked), 40.0%; organic matter, 5.7%; water pH, 7.0; soil pH, 6.5; time of treatment, early morning; and cloudy skies. The experimental area was irrigated with 0.25 inch of water immediately after product dried. Post-treatment counts were made on 29 Aug. The total number of green of June beetle larvae flushed to the surface following an application of Sevin SL over a 24-hr observation interval was recorded from each replicate.

Population dynamics of Paratylenchus nanus in soil under pasture: 1. Aggregation and abiotic factors

Nematology ◽  
2001 ◽  
Vol 3 (2) ◽  
pp. 187-197 ◽  
Author(s):  
Richard Watson ◽  
Nigel Bell
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Soil Depth ◽  
Abiotic Factors ◽  
Soil Phosphorus ◽  
Silt Loam ◽  
Plant Abundance ◽  
Grazed Pasture ◽  
Loam Soil ◽  
Accumulated Temperature

AbstractParatylenchus nanus populations were assessed by seasonal and monthly sampling of grazed pasture on silt loam soil in Waikato, New Zealand. The data were used to investigate P.nanus aggregation and relationships with abiotic factors, including soil temperature, rainfall, soil moisture and soil nutrients. P.nanus was more abundant at 10-20 than 0-10 cm soil depth and populations were greatest in summer. Aggregation declined from spring through to winter. P.nanus populations were positively correlated with soil temperature and negatively with soil moisture (seasonally) and rainfall (monthly). Monthly P. nanus abundance was also positively correlated with a combination of accumulated temperature and rainfall. On single occasions, soil phosphorus and nitrogen were significantly negatively correlated with P.nanus populations, and it is suggested that these associations were mediated through host plant abundance.

scholarly journals Development of an improved and accessible diet for western corn rootworm larvae using response surface modeling

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Man P. Huynh ◽  
Bruce E. Hibbard ◽  
Michael Vella ◽  
Stephen L. Lapointe ◽  
Randall P. Niedz ◽  
...  
Keyword(s):  
Response Surface ◽  
Diabrotica Virgifera Virgifera ◽  
Larval Survival ◽  
Surface Modeling ◽  
Western Corn Rootworm ◽  
Larval Performance ◽  
Response Surface Modeling ◽  
Corn Rootworm ◽  
Corn Root ◽  
Significant Difference

Abstract The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is an important pest of maize (Zea mays L.). Published WCR diets contain corn root powder, which is not available for purchase, thereby limiting the practical use of diets containing this ingredient. We applied response surface modeling combined with mixture designs to formulate a WCR diet that does not require corn root powder. We developed the new formulation by systematically exploring eight protein ingredients from animal, plant, and yeast sources based on simultaneous evaluation of three life history parameters (weight, molting, and survival). This formulation (WCRMO-2) without corn root powder supported approximately 97% of larval survival and successful molting. Larval weight gain after 10 days of feeding on WCRMO-2 was 4-fold greater than that of larvae feeding on the current best published WCR diet. Additionally, there was no significant difference in these larval performance traits when larvae were reared on WCRMO-2 and the best proprietary WCR diet. A commercial version of WCRMO-2 was tested and found to perform comparably for these traits. These improvements met our goal of a diet comprised of available ingredients that supports performance of WCR larvae equal to or better than publicly available formulations and proprietary formulations.

scholarly journals Corn Rootworm Insecticide Screening, 1995

1996 ◽  
Vol 21 (1) ◽  
pp. 221-221
Author(s):  
Keith Jarvi ◽  
Gerald W. Echtenkamp ◽  
John Witkowski
Keyword(s):  
Field Capacity ◽  
Corn Rootworm ◽  
Corn Stalk ◽  
Silt Loam ◽  
Seeding Rate ◽  
Trap Crop ◽  
Planting Time ◽  
Previous Crop ◽  
State 1 ◽  
Bicycle Wheel

Abstract The test plots were planted on 17 May. Seven inch banded (P/TB) and infurrow (P/TF) planting time treatments were applied with a cone-belt distributer mounted on a John Deere Maxemerge equipped with incorporation tines. Cultivation treatments (C/TB) were applied over the row on 22 Jun with the cone-belt distributer mounted on a hand-powered bicycle wheel applicator. The entire plot was cultivated immediately after application of the 22 Jun treatments by a tractor mounted cultivator. The seeding rate was 19,000 seeds/ acre on 30 inch rows. Soil type was silt loam (OM >3%, pH 6.5). Previous crop was late planted corn planted as a trap crop. The field was disked twice prior to planting. Preplant anhydrous ammonia was applied at the rate of 80 lb per acre prior to planting. Approximately 20% corn stalk residue was remaining after field preparation. The experimental design was a RCB with 4 replications, each treatment a single row 47 ft long. Five randomly selected roots from each replication were rated on the Iowa State 1-6 scale (1, no damage; 6, 3 or more nodes pruned to within 1/2 inch of the stalk). The roots were dug and rated on 24, 25, and 26 Jul. Topsoil and subsoil moisture was at field capacity at planting time.

scholarly journals Response of Soil CO2 Efflux to Shelterwood Harvesting in a Mature Temperate Pine Forest

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 304
Author(s):  
Robin Thorne ◽  
Myroslava Khomik ◽  
Emily Hayman ◽  
Altaf Arain
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Soil Co2 Efflux ◽  
Co2 Efflux ◽  
Carbon Exchange ◽  
Soil Co2 ◽  
Ecosystem Carbon ◽  
Significant Difference ◽  
Post Harvesting ◽  
Ecosystem Carbon Exchange

In forest ecosystems, soil CO2 efflux is an important component of ecosystem respiration (RE), which is generally driven by variability in soil temperature and soil moisture. Tree harvesting in forests can alter the soil variables and, consequently, impact soil CO2 efflux. This study investigated the response of total soil CO2 efflux, and its components, to a shelterwood harvesting event of a mature temperate white pine (Pinus strobus L.) forest located in Southern Ontario, Canada. The objective was to explore the response of soil CO2 effluxes to changes in the forest microclimate, such as soil temperature and soil moisture, after shelterwood harvesting removed approximately one-third of the overstory canopy. No significant differences were found in both soil temperature and soil moisture between the pre-harvesting (2008–2011) and post-harvesting (2012–2014) periods. Despite similar soil microclimates, total soil CO2 effluxes were significantly reduced by up to 37%. Soil CO2 effluxes from heterotrophic sources were significantly reduced post-harvesting by approximately 27%, while no significant difference in the mineral-soil horizon sources were measured. An analysis of RE, measured with an eddy covariance tower over the study area, showed an increase post-harvesting. However, the overall net ecosystem carbon exchange showed no significant difference between pre- and post-harvesting. This was due to an increase in the gross ecosystem productivity post-harvesting, compensating for the increased losses (i.e., increased RE). This study highlights the complexities of soil CO2 efflux after a disturbance, such as a harvest. The knowledge gained from this study adds to our understanding of how shelterwood harvesting may influence ecosystem carbon exchange and will be useful for forest managers focused on carbon sequestration and forest conservation.

Factors in Alachlor and Metolachlor Injury to Corn (Zea mays) Seedlings

1989 ◽  
Vol 3 (2) ◽  
pp. 303-306 ◽  
Author(s):  
L. D. Boldt ◽  
M. Barrett
Keyword(s):  
Zea Mays ◽  
Soil Moisture ◽  
Soil Temperature ◽  
Seedling Emergence ◽  
Field Capacity ◽  
Growth Chamber ◽  
Hybrid Corn ◽  
Chemical Factors ◽  
Clear Plastic

Growth chamber experiments were conducted to determine if certain genetic, environmental, and chemical factors or their interactions promote chloroacetamide herbicide injury to corn seedlings. Greater chloroacetamide injury occurred with ‘Pioneer 3320’ than with ‘Pioneer 3780’ hybrid corn, with 15 C than with 30 C soil temperature, with soil moisture at 105% field capacity (FC) than at 75% FC, with alachlor than with metolachlor, and with a herbicide rate of 2.2 kg/ha than with 1.1 kg/ha. Covering the plant containers with clear plastic until seedling emergence caused alachlor to be more phytotoxic to corn than metolachlor. Most factors evaluated increased the injury to corn in an additive manner.

scholarly journals Seasonal dispersal of the Western corn rootworm (Diabrotica virgifera virgifera) adults in Bt and non-Bt maize fields

2012 ◽  
Vol 48 (Special Issue) ◽  
pp. S36-S42 ◽  
Author(s):  
Ľ. Cagáň ◽  
I. Rosca
Keyword(s):  
Diabrotica Virgifera Virgifera ◽  
Western Corn Rootworm ◽  
Corn Rootworm ◽  
Diabrotica Virgifera ◽  
Bt Maize ◽  
Vegetation Season ◽  
Maize Hybrids ◽  
Significant Difference ◽  
Maize Plants ◽  
Experimental Plots

32 experimental plots were sown at Borovce (district Trnava) in Slovakia during 2008 with 8 maize hybrids, including coleopteran-protected MON 88017, the lepidopteran-protected MON 89034, the stacked product, MON 89034 × MON 88017, that same hybrids isoline that did not have the Bt trait or traits, and 4 commercial hybrids. Part of the fourth repetition was unexpectedly infested and damaged with the Western corn rootworm (WCR). High numbers of the WCR adults were found in the damaged plots on July 8. Adult WCR abundance remained concentrated in this area until August 12–19. The beetles apparently began to disperse during August 19–September 2, and after September 2. The trap captures increased in the uninfested areas up to September 16, no significant difference having been found in the adult WCR captures between the infested and uninfested plots, including the plots with MON 88017. Bt-maize hybrids containing MON 88017 strongly influenced the level of the WCR damage as assessed by lodging of the maize plants, and they also influenced the numbers of the WCR adults before maize flowering.  We found that intensive movement of the WCR adults from the place of their origin started later in the vegetation season.

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