scholarly journals Evaluation of Planting-Time Soil Insecticide Applications for Controlling Corn Rootworm Larvae in South Dakota, 1994

1995 ◽  
Vol 20 (1) ◽  
pp. 167-167
Author(s):  
B. W. Fuller ◽  
M. A. Boetel ◽  
M. A. Catangui ◽  
J. M. Jenson ◽  
D. J. Thompson ◽  
...  

Abstract Efficacy trials were conducted at 5 locations (Aurora, Bruce, Cavour, Delmont, and Garretson) in SD. Individual treatment plots consisted of single rows, 12.2 m to 15.2 m in length, and spaced 96.5 cm apart. Experimental design for all studies was a RCB with 4 replications. Granular insecticide formulations were applied with modified Noble metering units mounted on a specially-adapted Kinze 4-row corn planter. Metering units were ground-driven, and all units were calibrated on the planter. Liquid insecticides were applied using CO2-powered delivery systems individually mounted on each row of the planter. Each system was calibrated to deliver 20 gpa. Banded insecticide treatments (granular or liquid) were applied in an 18-cm swath over the open seed furrow (T-band) in front of the furrow-closing wheels, and were incorporated by the wheels and drag chains. Infurrow treatments were placed directly between double-disk furrow openers and into the open seed furrow. Pioneer IR-3751 (100-day) corn seed was planted at a rate of 23,000 kernels per acre at all study locations. Five roots per replication were dug, washed, and rated using the Iowa 1 to 6 scale to measure rootworm larval damage. Root injury ratings were recorded and analyzed using SAS’s General Linear Models procedure, and DMRT was used to compare treatment means.

1996 ◽  
Vol 21 (1) ◽  
pp. 214-215
Author(s):  
M. A. Boetel ◽  
B. W. Fuller

Abstract Sites near Aurora and Lake Andes, SD were chosen to evaluate Furadan 4F applied post-emergence to corn in comparison of at-plant applications and standard granular insecticide compounds. Insecticide treatments included at-planting applications (Counter 15G, Furadan 15G, and Lorsban 15G) using a 7 to 9 inch band, and Furadan 4F broadcast applied post-emergence at cultivation. All treatments were made at 1.0 lb(AI)/acre. Experimental design was a RCB replicated 4 times. Individual treatment plots consisted of single 50 ft long rows spaced 38 inches apart. Insecticide granules were applied with modified, ground-driven Noble metering units mounted on a specially adapted Kinze 4-row corn planter. At-plant granular treatments were banded in front of the furrow-closing wheels, and incorporated by the wheels and drag chains. Collection of these beetles were made weekly throughout the July and August peak emergence period. Data were analyzed using SAS’s General Linear Models (GLM) procedure with total emergence (per cage) means compared with DMRT.


1995 ◽  
Vol 20 (1) ◽  
pp. 161-161
Author(s):  
M. A. Boetel ◽  
B. W. Fuller ◽  
J. M. Jensen ◽  
D. J. Thompson

Abstract Cornfields were chosen at Aurora and Cavour South Dakota based on corn rootworm egg and adult surveys. Therefore, offering the potential for significant larval pressures during this study. The experiment was conducted to compare efficacy of preplant-incorporation (PPI) with traditional planting-time insecticide application methods (banded or in-furrow) for controlling rootworm larvae. The PPI treatments were applied using a hand-held spray boom equipped with 4 Teejet 8002 nozzles spaced 46 cm apart. Delivery rate was 20 gpa at 25 psi while travelling at 3 mph. Immediately following liquid applications, the soil was tilled with a tandem disk harrow at a 5 to 8 cm depth for insecticide incorporation. Granular materials were applied using Noble metering units on an adapted Kinze 4-row corn planter using band or in-furrow insecticide placement methods. Metering units were calibrated on the planter prior to insecticide applications. Treatment plots (15.25 m long rows spaced 96.5 cm apart) were arranged in a RCBD with 4 replications. Band treatments were applied in an 18-cm swath in front of the furrow-closing wheels, and incorporated by the wheels and drag chains. In-furrow applications consisted of directing granules immediately between double-disk furrow openers. Pioneer TR-3751’ (100-day) corn seed was planted at approximately 23,000 kernels per acre at each location. Five roots per replicate were dug, washed, examined for feeding damage and rated using the Iowa 1 to 6 scale. Data were analyzed with SAS’s General Linear Models procedure, and means were compared using DMRT.


1996 ◽  
Vol 21 (1) ◽  
pp. 212-213
Author(s):  
M. A. Boetel ◽  
B. W. Fuller

Abstract A secondary benefit of corn rootworm insecticide treatments could be the residual control of European corn borer (ECB) larvae. Our study was repeated at sites near Aurora, Cavour, Delmont, and Garretson, South Dakota to assess the efficacy and secondary ECB control provided by 3 insecticides (Furadan, 60720A, & Regent). Treatment plots consisted of single 15.2 m long rows which were spaced 96.5 cm apart. The study was arranged in a RCBD with 4 replicates at each site. Granular insecticide formulations were applied with modified Noble metering units mounted on a specially adapted Kinze 4-row com planter. Metering units were ground-driven, and all units were calibrated on the planter before applications. Banded (B) insecticide treatments were applied in an 18-cm swath over the open seed furrow in front of furrow-closing wheels (T-band), and were incorporated by the wheels and drag chains. In-furrow (F) treatments were placed directly between double-disk furrow openers and into the open seed furrow. Cultivation-time liquids were applied using a CO2-powered backpack canister sprayer system equipped with a single nozzle (Teejet 8003 flat fan) hand-held boom. The system was calibrated to deliver 20 gpa. To evaluate rootworm damage 5 roots per replicate were dug for each treatment. Roots were washed, examined for corn rootworm larval feeding damage, and rated in accordance with the Iowa 1 to 6 scale. For assessment of ECB control, 10 com stalks were randomly chosen from each plot. Plants were split vertically and examined for corn borer tunneling damage. The number and length of ECB cavities were analyzed along with root injury data using SAS’s General Linear Models (GLM) procedure and means were compared by DMRT.


1997 ◽  
Vol 22 (1) ◽  
pp. 324-324
Author(s):  
M. A. Boetel ◽  
B. W. Fuller ◽  
R. J. Braun

Abstract A commercial sunflower field near Mina, in north-central South Dakota, was selected foi our trial of several insecticide treatments at standard and reduced rates for management of SB larvae. The experiment was arranged in a RCBD with 4 replications, and individual treatment plots were 25 ft long by 10 rows (38 inch spacing) wide. In addition, each plot was bordered by two buffer rows to prevent drift. Pre-application evaluations were carried out using whole-plant visual counts of the number of live SB larvae per plant. Twenty plants were examined from each treatment plot and these counts indicated an average of 11 SB larvae per plant within the test area. Treatments were applied on 11 Ju’ using a CO2-propelled backpack sprayer system with a hand-held 6.7-ft long boom. The boom was equipped with 4 TeeJet 8001 nozzles spaced 20 inches apart, and was calibrated to deliver a spray volume of 15 gpa while traveling at 3 mph. Insecticide efficacy was evaluated at 6 DAT using the same count ing technique and number of samples described for pre-application sampling. Data were analyzed with SAS’ s General Linear Models procedure and means were compared using DMRT.


1994 ◽  
Vol 19 (1) ◽  
pp. 188-188
Author(s):  
M. A. Boetel ◽  
B. W. Fuller ◽  
J. M. Jenson

Abstract Three studies were conducted at 3 SD sites (Delmont, Garretson, and Sinai) to evaluate insecticide application rates and techniques (hand and in-furrow) for control of NCR and WCR larvae. A randomized complete block design with 4 replications was used in these studies. Individual treatment plots were single 15.25 m long rows spaced 96.5 cm apart. Insecticide granules were applied with modified, ground-driven Noble metering units mounted on a specially-adapted Kinze 4-row corn planter. Metering units were calibrated on the planter prior to insecticide applications. Banded treatments were applied in an 18 cm swath in front of the furrow-closing wheels, and incorporated by the wheels and drag chains. In-furrow applications consisted of directing granules immediately between double disk furrow openers. Corn was seeded at 23,000 kernels per acre at all locations. Five roots per replicate were dug for each treatment. Roots were then washed, examined for feeding damage, and rated using the Iowa 1 to 6 scale.


2019 ◽  
Author(s):  
Ilana Lambert ◽  
Christine Paysant-Le Roux ◽  
Stefano Colella ◽  
Marie-Laure Martin-Magniette

Abstract Background RNAseq is nowadays the method of choice for transcriptome analysis. In the last decades, a high number of statistical methods, and associated bioinformatics tools, for RNAseq analysis were developed. More recently, statistical studies realized neutral comparison studies using benchmark datasets, shedding light on the most appropriate approaches for RNAseq data analysis. Nevertheless, performing an RNAseq analysis remains a challenge for the biologists. Results DiCoExpress is a workspace implemented in R that includes methods chosen based on their performance in neutral comparisons studies. DiCoExpress uses the pre-existing R packages as well as FactoMineR, edgeR and coseq, to perform quality control, differential, and co-expression analysis of RNAseq data. Users can perform the full analysis, providing a mapped read expression data file and a file containing the information on the experimental design. Following the quality control step, the user can move on to the differential expression analysis performed using generalized linear models with no effort thanks to the automated contrast writing function. DiCoExpress proposes a list of comparisons based on the experimental design, and the user needs only to choose the one(s) of interest for his research question. A co-expression analysis is implemented using the coseq package. Identified co-expression clusters are automatically analyzed for enrichment of annotations provided by the user, and several result outputs proposed. We used DiCoExpress to analyze a publicly available Bra ssica napus L. RNAseq dataset on the transcriptional response to silicon treatment in plant roots and mature leaves. This dataset, including two biological factors and three replicates for each condition, allowed us to demonstrate in a tutorial all the features of DiCoExpress. Conclusions DiCoExpress is an R workspace to allow users without advanced statistical knowledge and programming skills to perform a full RNAseq analysis from quality controls to co-expression analysis through differential analysis based on contrasts inside generalized linear models . Hence, with DiCoExpress, the user can focus on the statistical modeling of gene expression according to the experimental design and on the interpretation of the results of such analysis in biological terms.


1997 ◽  
Vol 22 (1) ◽  
pp. 323-323
Author(s):  
M. A. Boetel ◽  
B. W. Fuller ◽  
R. J. Braun

Abstract A grower-established sunflower field (planted on 25 May with a seeding rate of 23,300 per acre) was found to have sufficient SB larvae (5 per plant) to conduct our insecticide evaluations. This site in north-central South Dakota (Ipswich) was used to evaluate 3 pyrethroid insecticides at standard and reduced rates for management of SB larvae. Plots were 25 ft long by 8 rows (36 inch spacing) wide and the study was arranged in a RCBD with 4 replications. Treatment plots were buffered by 2 untreated rows to prevent cross-contamination between plots due to insecticide drift. Pre-application evaluations used whole-plant counts which were carried out on 20 plants per plot. Treatments were applied to plots on 2 Jul at V-8 stage of sunflower physiological development. Applications were made using a CO2-propelled backpack sprayer system equipped with a 6.7 ft long, 4-nozzle (TeeJet 8001 flat fan; spaced 20 inches apart) boom. The system was calibrated to deliver a spray volume of 15 gpa while traveling at 3 mph. Efficacy was evaluated at 7 and 24 DAT using the same counting technique and number of plants sampled as pre-application sampling. Data were analyzed with SAS’s General Linear Models procedure and means were compared using DMRT.


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