scholarly journals Evaluation of Dimilin and Boron on Soybean in Virginia, 1997

1998 ◽  
Vol 23 (1) ◽  
pp. 282-282
Author(s):  
D. A. Herbert ◽  
D. L. Holshouser

Abstract Dimilin 2 L and Boron 10 (1.0 lb B/gal), alone and tank mixed, were evaluated for effects on BLB adults, GCW larvae, leaf defoliation, pod number and yield of soybean. Asana XL was included as an insecticide standard, as was an untreated control. ‘Accomac’ soybean was planted 29 May at the Tidewater Agric. Res. and Ext. Ctr., Suffolk, VA, using a 36-inch row spacing. All treatments were applied as foliar sprays with water on 8 August at the R3 soybean growth stage (beginning pod development, with a 3/16-inch long pod at one of the 4 uppermost nodes on the main stem with a fully developed leaf) using a tractor sprayer calibrated to deliver 15.0 gpa at 50 psi through 3, D3-23 hollow cone nozzles per row. A RCB experimental design was used with 4 replicates; plots were 8 rows by 50 ft. Insect samples were taken using a standard beat cloth on 6 row ft per plot on 18, 26, 31 and 38 days after treatment (DAT). Defoliation was assessed by visual inspection of all leaves on 10 plants per plot. Pod number was determined just prior to harvest by counting all pods on 20 plants per plot (5 adjacent plants in the row, in 4 locations in each plot). Yield was determined by harvesting 2, 2-row samples per plot (a total of 200 row ft per plot) using a commercial soybean combine.

2016 ◽  
Vol 22 (1) ◽  
Author(s):  
Maicon Nardino ◽  
Velci Queiróz de Souza ◽  
Carlos André Bahry ◽  
Ivan Ricardo Carvalho ◽  
Braulio Otomar Caron ◽  
...  

Objective was to evaluate the influence of defoliation of a soybean cultivar indeterminate growth in different vegetative stages on morphological characters and yield components. The study was conducted in the years 2010/11 and 2011/12. The experimental design was a randomized block design with seven treatments and four replications for each year. The treatments were: T1: No defoliation; T2: Defoliation in V4, T3: Defoliation in V4 and V5, T4: Defoliation in V4, V5 and V6, T5: Defoliation in V4, V5, V6 and V7, T6: Defoliation in V4, V5, V6, V7 and V8 and T7: Defoliation in V4, V5, V6, V7, V8 and V9. The variables analyzed were: main stem height, number and length of branches, first pod, number of pods per node on the main stem, and the branches per plant, number of reproductive nodes on the main stem, the branches, number of us total on the main stem, the branches, distance between us and grain yield. Grazing did not influence most of the morphological characters and increments the number of pods on the stem in years with good water availability and high levels of defoliation, and yield of soybean.


1996 ◽  
Vol 21 (1) ◽  
pp. 252-253
Author(s):  
D. A. Herbert

Abstract Different application schedules with insecticides at different rates were evaluated for control of bollworm in VA. ‘Sure-Grow 501’ cotton was planted 1 May at the Virginia Tech Tidewater Agric. Res. & Ext. Ctr., Suffolk, VA, using a 36-inch row spacing. All treatments were applied with a CO2 pressurized backpack sprayer calibrated to deliver 14.5 gpa at 50 psi through three, D2-13 disc-core hollow cone nozzles per row, one over the top of the row and one on each side. Four application schedule/insecticide rate combinations were tested: 1)3 applications at the standard rate, the 1 st at the egg threshold, the 2nd in 5d, and the 3rd in l0d; 2) 2 applications at the standard rate, the 1st at the egg threshold, the 2nd in 5d; 3) 2 applications, the 1st at the egg threshold using 1.6x the standard rate, and the 2nd in 5d using the standard rate; 4) 1 application at the egg threshold using 1.6x the standard rate. Egg threshold application was based on the presence of 10 or more bollworm eggs per 100 plant terminals, or 2 or more per 100 fruil (squares or bolls). A RCB experimental design was used with 4 replicates; plots were 6 rows by 30 ft. Boll damage and bollworm numbers were determined by sampling 25 randomly selected bolls per plot. Samples were taken at roughly weekly intervals after the occurrence of the egg threshold. Yield was determined by harvesting the 2 center rows of each plot (60 row ft per plot) using a commercial 2-row John Deere cotton combine. Lint values were calculated as 37% of total plot weights, assuming 63% was seed and trash. Data were analyzed using ANOVA and LSD statistical procedures.


1998 ◽  
Vol 23 (1) ◽  
pp. 308-308
Author(s):  
G. F. Chappel ◽  
D. A. Herbert

Abstract Efficacy of selected insecticides and application timing was evaluated against CLB and aphids in wheat. Pioneer 2580 was planted 8 Nov in a producer’s field in Dinwiddie County, VA, using a 7-inch row spacing. All treatments were broadcast as foliar sprays with water using a CO2 pressurized backpack sprayer calibrated to deliver 20.0 gpa at 30 psi through 8004VS flat fan nozzles spaced 19 inches apart on the spray boom. A RCB experimental design was used with 4 replicates: plots were 17 rows by 50 ft. CLB sampling involved recording the number of eggs and larvae/ft2 (20.57 inches of a 7-inch row). Aphids were sampled by removing 5 randomly selected grain heads per plot. Samples were placed in a mild soapiwater solution (2 drops liquid dish detergent per gal water) for 10 minutes. Samples were then rinsed over a U.S.A. Standard Testing Sieve No. 60 mesh, and the total number of aphids per sample recorded. Defoliation was evaluated by removing 10 randomly selected flag leaves from each plot and visually recording the percent defoliation per leaf. Average percent defoliation was recorded per plot. Treatments 1-5 were applied at Zadok’s growth stage (GS) 31 (3 Apr), treatments 6-10 at Zadok’s growth stage 37 (23 Apr) and treatments 11-15 at Zadok’s growth stage 56 (6 May). Post-treatment CLB egg and larvals samples were taken 3 days after final treatment (9 May). Post-treatment aphid and defoliation samples were taken 24 days after final treatment (24 May).


1998 ◽  
Vol 23 (1) ◽  
pp. 91-91
Author(s):  
J. V. Edelson ◽  
M. Peters ◽  
J. Duthie ◽  
W. Roberts

Abstract Collard seed was planted in Mar at the AREC, Lane, OK. The experimental design was a RCB with 4 replicates and 9 treatments. Plots were 2 rows wide (72 inches) and 20 ft long with 20 ft alleys cut between plots. Plots were treated with insecticides using a CO2-powered backpack sprayer with a broadcast application of 72 inches from 4 hollow-cone nozzles applying 33 gal/A at 40 psi. Plots were treated on 4, 8, and 14 Jul. Plots were surveyed to determine larval abundance on 7, 11, and 17 Jul by examining 3 plants per plot and recording all larvae present.


1998 ◽  
Vol 23 (1) ◽  
pp. 105-106
Author(s):  
Philip A. Stansly ◽  
C. Mayra ◽  
G Avilez

Abstract A commercial field of staked eggplant was used ap-proximately 45 days after transplanting for this trial in the Culican Valley of Sinaloa, Mexico. The field was 100 m wide and approximately 2 km in length, located between 2 fields of corn. The crop had recently been sprayed with endosulfan (Thiodan®). Consequently, relatively few adult whiteflies could be observed although the presence of eggs and young nymphs indicated the likelihood of increasing infestation, and no further applications were made by the grower for the duration of the trial. Experimental design was completely randomized block with 5 treatments and 4 replicates. Beds were 100 m in length running north and south with 1.5 m between centers and 2 rows per bed. Plots were 4 beds wide and 15 m long with 1.5 m between plots (90m2). Three weekly applications were made beginning on 12 Feb with 2 Maruyama™ motorized backpack sprayers equipped with a hand-held boom carrying 2 bronze T-Jet™ D2 hollow cone nozzles containing #45 spinner plates. Each bed was sprayed from both sides with 5 liters per replicate of each treatment, delivering a volume of 60.5 gpa. Each plot was sampled for whitefly adults and immature stages prior to application. A beat pan made of an aluminum cake pan 22.5cm X 32.5 cm painted black and covered with a film of vegetable oil and liquid detergent (9:1) was used to sample adults. Three samples were taken in each plot by beating the pan 10 times against the foliage in the middle 2 rows and counting the whiteflies trapped in the oil mixture. Immatures were sampled by counting all whitefly eggs, small nymphs, large nymphs, and pupae in 4 lensfields of 1.77 cm2 per leaf (3 leaves per plot). Additional samples were taken 3 days after each successive treatment. Small nymphs, large nymphs, and pupae were combined as “immatures” for analysis.


2003 ◽  
Vol 83 (2) ◽  
pp. 319-326 ◽  
Author(s):  
B. L. Johnson

Growth compensation of dwarf sunflower (Helianthus annuus L.) hybrids to low initial stands, later stand losses, or plant defoliation has not been reported regarding replanting decisions and crop insurance yield loss assessment. Three experiments were conducted to study the affect of stand reduction, defoliation, and row spacing on dwarf sunflower yield and quality when grown in eastern North Dakota. Experiment 1 evaluated stand reduction (0, 25, 50 and 75%) applied at growth stages (V4, R1 and R6) in 15, 45 and 76 cm spaced rows. Row spacing interactions with stand reduction and growth stage were not significant for yield indicating growth stage and stand reduction effects on yield response were independent of row spacing. In exp. 2, significant growth stage (V4, V8, R1, R2, R3, R5 and R6) by stand reduction (0, 12, 25, 37, 50, 62 and 75%) interaction showed stand reduction at vegetative growth stages not influencing yield, but as maturity progressed yield reductions became greater with increased stand reduction. Achene weight increased with increasing stand reduction at vegetative and early reproductive stages. A reciprocal relationship was noted between achene weight and achene oil content where oil content decreased as achene weight increased. Interaction of growth stage (R1 and R6) and defoliation (0, 25, 50, 75 and 100%) in exp. 3 indicated greater reduction in yield, test weight, 1000-achene weight, and achene oil conte nt as defoliatin increased at growth stage R6. Yield compensating ability of dwarf sunflower is dependent on type and level of damage and growth stage of occurrence, with total yield reduction considering all effects. Key words: Sunflower, Helianthus annuus L., row spacing, stand reduction, defoliation


2019 ◽  
Vol 3 (1) ◽  
pp. 23
Author(s):  
Rahmantika Kurnia Romadhani ◽  
M. Noor Rochman Hadjam

The purpose of this research is to reduce parents’ stress by increasing their mindfulness ability using Mindfulness intervention. Participants in this study consisted of 15 mothers with stress from mild to severe. The design use in this study is quasi experimental design with untreated control group with pretest and postest. The program consists of 8 session intervention. The instruments used in this research are DASS Scale and KIMS scale. Quantitaive analysis was conducted through  statistical test using Mann-Whitney and also qualitative analysist. The result of this study showed that intervention with mindfulness was effective to reduce stress in parents (U=0,000; p<0,001).


1994 ◽  
Vol 19 (1) ◽  
pp. 271-272
Author(s):  
J. D. Thomas ◽  
A. T. Wier ◽  
M. L. Boyd ◽  
S. Lingren ◽  
D. J. Boethel

Abstract The efficacy of selected insecticides for control of VBC was evaluated in 3 small plot insecticide trials at the St. Gabriel Research Station near St. Gabriel, LA. Treatments in all 3 tests were applied to ‘Buckshot 723’ soybean in the R5 growth stage using a tractor and compressed air sprayer calibrated to deliver 93.5 1/ha at 2.66 kg/cm2 through 8002 flat fan nozzles. Plots in all tests were 5 rows wide (0.91 m row spacing) by 15.2 m, arranged in a RCBD with 4 replications. At 2 and 7 DAT in each test, one 25 sweep sample was taken from each plot with a standard 38.2 cm diam sweep net. Test 1 was applied 6 Sep, Test 2 was applied 8 Sep, and Tesi 3 was applied 14 Sep.


1997 ◽  
Vol 22 (1) ◽  
pp. 137-137
Author(s):  
J. V. Edelson ◽  
M. Peters

Abstract A commercial production field of mustard was used for this trial. Plants were grown in 6 row beds on 6 ft centers. The field was direct seeded in Apr approximately 1 mile west of Webbers Falls, OK. Small plots were delimited on one edge of the field. The experimental design was a RCB with 4 replicates and 7 treatments. Insecticide applications were made on 23 and 29 May using a bicycle tire mounted sprayer with 4 hollow cone nozzles (TXVS26) per bed applying 40 gpa solution at 42 psi. Plots were 1 bed wide and 20 ft long with 5 ft alleys between plots. Insect populations were surveyed by examining 5 plants per plot on 29 May (prior to the second application of insecticides) and 3 Jun to determine treatment effects.


Sign in / Sign up

Export Citation Format

Share Document