scholarly journals Evaluating Insecticide Application Techniques to Control Aphids in Vegetable Leaf Crops

1995 ◽  
Vol 5 (4) ◽  
pp. 317-326 ◽  
Author(s):  
Celeste Welty ◽  
Sandra Alcaraz ◽  
H. Erdal Ozkan

Insecticide application techniques were evaluated to find the most effective way to spray contact insecticides to control aphids on leaf crops under field conditions. A hydraulic boom sprayer was tested with several nozzle types, nozzle positions, and pressures, and compared with an electrostatic sprayer and a controlled droplet applicator (CDA). Spray deposition in the canopy and drift were evaluated with moisture-sensitive cards. Trials were conducted on collards and red leaf lettuce in 1989, mustard greens in 1990, and turnip greens in 1991. Green peach aphid [Myzus persicae (Sulzer)] was the major species in all trials. Among hydraulic boom treatments in all trials, aphid control was not significantly different when insecticide applied at 60 psi (414 kPa) was delivered by hollow cone, twin flat-fan, or standard flat-fan nozzles mounted directly on the boom. In most trials, hollow cones were more effective when mounted on drop pipes and directed sideways into rows than when mounted on the boom and directed over rows. Hollow cone nozzles used at 150 psi (1035 kpa) vs. 60 psi did not control aphids significantly better, but higher pressure caused significantly more drift. Contact insecticide applied by an electrostatic sprayer controlled aphids somewhat less satisfactorily than by a conventional hydraulic sprayer. Insecticide applied by a CDA controlled aphids the same as by a hydraulic boom sprayer but with slightly less drift. The desired objective of maximum aphid control, good coverage of downward-facing surfaces in the canopy, and minimum drift was most consistently provided by the hydraulic boom sprayer with hollow cone nozzles on drop pipes directed sideways into the canopy using a pressure of 60 psi.

1996 ◽  
Vol 21 (1) ◽  
pp. 171-171
Author(s):  
Robert L. Stoltz ◽  
Nancy A. Matteson

Abstract Experimental plots were established on the UI Research and Extension Center, Kimberly, Idaho. Potatoes were planted on 25 Apr and irrigated by solid set sprinkler. The soil type was Portneuf silt loam. Four treatments and one untreated check plot were replicated four times in a RCB design. Individual treatment plots were 4 rows (36 inch row spacing) wide by 25 ft long with 5 ft alleyways separating the plots. Green peach aphids were mass reared on greenhouse sweet pepper plants (California Wonder) for release into individual plots. Aphid releases were made into test plots the last wk in Jun and again in the first wk of Jul. A total of four heavily infested pepper plants was released per plot. Treatment sprays were broadcast applied using a CO2 pressurized backpack sprayer (30 psi) and delivering 20 gal finished spray per acre (four, 10X hollow cone nozzles). Aphid counts were made from non-destructively examining 10 randomly selected leaves in the center two rows of each plot. Leaves were sampled from the top, middle, and bottom sections of the plants. The data collected and presented are the total number of aphids per 20 leaves. On 19 Jul a pre-count was taken and on 21 Jul all treatment applications were made. Data were analyzed using ANOVA and Student-Newman-Keuls multiple means comparison.


1995 ◽  
Vol 20 (1) ◽  
pp. 230-230
Author(s):  
R. M. Anderson ◽  
G. L. Teetes

Abstract Foliar treatments of 2 organophosphates and imidachloprid (Confidor) were evaluated for yellow sugarcane aphid (YSA) and greenbug (GB) control in a research greenhouse at Texas A&M University. Hybrid grain sorghum seedlings (ATx399 × RTx430) were grown in 110-mm germination pots containing a prepared soil mixture composed of peat, vermiculite, and periite in a 2:1:1 ratio, respectively. Four days after plant emergence and 3 d prior to insecticide applications, each seedling plant was infested with 10-20 YSA or GB. There were 5 singleseedling replications for each treatment. Insecticides were applied by using a CO2-pressurized backpack sprayer, through TX-3 hollow-cone nozzles at 35 psi, producing a finished spray volume of 5.6 gpa. Pre-treatment counts of YSA and GB were made the day of insecticide application; post-treatment counts of aphids were made 1, 2, and 3 DAT. Percent control was calculated by using Abbott’s (1925) formula. Data were statistically analyzed by using ANOVA and LSD.


2018 ◽  
Vol 49 (3) ◽  
pp. 164-173 ◽  
Author(s):  
Gianfranco Pergher ◽  
Nicola Zucchiatti

Spray deposition from a tunnel, air-assisted sprayer was analysed during the whole season, following canopy development in a vertical-shoot-positioned vineyard. Four field tests were performed using hollow-cone, turbulence nozzles between the BBCH 15 (5 leaves unfolded) and BBCH 77 (berries beginning to touch) growth stages, plus an additional test with flat-fan, air-injection nozzles at BBCH 77. The main canopy parameters were assessed, including the canopy height range (0.6 m to 1.4 m), the leaf area index (LAI; 0.15 to 1.60) and the leaf layer index (LLI; 0.69 to 2.74). Total deposition on target (leaves and bunches) increased from 14.8% to 53.9% of volume applied, and was significantly related to the LLI (R² = 0.943); the relevance of such relationship in connection with the leaf wall area model for volume rate adjustment is discussed in the paper. Losses to the ground (1.9% to 8.1% of volume applied), spray recovery rate (31.0% to 67.2%) and losses owing to evaporation of the recycled liquid (0.1% to 3.5%) were also analysed. At BBCH 77, air-injection nozzles did not improve overall deposition in comparison to hollow-cone nozzles, but increased spray recovery (from 31.0% to 36.1%) and reduced (to 0.1%) evaporation of the recycled liquid, so that they may represent an option to avoid an excessive concentration in the tank towards the end of application.


2000 ◽  
Vol 25 (1) ◽  
Author(s):  
Robert L. Stoltz ◽  
Nancy A. Matteson

2012 ◽  
Vol 28 (3) ◽  
pp. 325-331 ◽  
Author(s):  
R. C. Derksen ◽  
P. A. Paul ◽  
H.E. Ozkan ◽  
H. Zhu

2005 ◽  
Vol 30 (1) ◽  
Author(s):  
Paul J. Semtner ◽  
Lakshmipathi Srigiriraju

Sign in / Sign up

Export Citation Format

Share Document