Effect of Rate and Timing of Biorational Materials for Control of Second Generation White Apple Leafhopper Nymphs, 1995

1996 ◽  
Vol 21 (1) ◽  
pp. 6-7
Author(s):  
E. H. Beers

Abstract The test was conducted in a mature apple orchard (several strains of ‘Delicious’) at the Tree Fruit Research & Extension Center, Wenatchee, WA. Treatments were replicated 4 times, with each replicate consisting of a single tree. The experimental design was a RCB, using pre-treatment WALH populations as the blocking factor. The experimental treatments (three types of horticultural mineral oil and Neemix, a neem product) were applied at various rates and timings. The timings were selected based on previous experience of WALH phenology. The late Jul timing (27 Jul) coincides with the appearance of the 4th instars, while the mid-Aug timing (14 Aug) coincides with the first appearance of adults of the second generation. Pesticides were applied with a handgun sprayer to the point of drip. WALH populations were sampled ca. weekly by counting in situ all live nymphs on 20 leaves per tree, distributed throughout the tree canopy.

1997 ◽  
Vol 22 (1) ◽  
pp. 2-2
Author(s):  
E. H. Beers

Abstract The test was conducted in a mature apple orchard (several strains of ‘Delicious’) on the grounds of the Tree Fruit Research and Extension Center. Treatments were replicated 4 times, with each replicate consisting of a single tree. The experimental design was a randomized complete block, using pre-treatment leafhopper populations as the blocking factor. The experimental treatments were applied on 21 Aug, which coincided with the 1st appearance of adults of the 2nd generation. Pesticides were applied with a handgun sprayer to the point of drip. WALH populations were sampled c-a. weekly by counting in situ all live nymphs on 20 leaves per tree, distributed throughout the tree canopy.


1995 ◽  
Vol 20 (1) ◽  
pp. 351-351 ◽  
Author(s):  
J. F. Brunner ◽  
M. D. Doerr ◽  
L. O. Smith

Abstract Using a leaf-disk bioassay, B. thuringiensis products were evaluated for residue effects on PLR and OBLR neonate larvae. The test was conducted in an apple orchard at the Tree Fruit Research and Extension Center. The trees were 15-yr-old spur type ‘Red Delicious’ on dwarfing roots. The treatments were applied on 22 Sep at the recommended rate with a handgun sprayer at 300 psi to the point of drip, simulating a dilute spray of approximately 400 gal/acre. Each treatment was replicated three times with one tree in each. Ten leaves were collected from the interior canopy of each tree at 1, 4, 6 and 8 DAT. Two punches (2.3 cm diameter) were taken from each leaf. Four punches were placed in a petri dish (Falcon 1006, 50 × 9 mm), keeping the leaves from each replication separate. Petri dishes were chosen randomly, and five 1- to 2-d-old leafroller larvae were placed on the leaves. Five petri dishes were prepared for each tree and each leafroller species (75 larvae per treatment). The petri dishes were placed inside a food storage container and kept at 20°C constant temperature and a photoperiod of 16:8 (L:D) h. Petri dishes were examined after 7 d and larval survival recorded.


1996 ◽  
Vol 21 (1) ◽  
pp. 12-13
Author(s):  
J. F. Brunner ◽  
M. D. Doerr ◽  
L. O. Smith

Abstract Four highly refined insecticidal oils, Orchex 796 98%, Orchex 692 98%, WS-2928 98%, and Guthion were evaluated for their ability to control CM over the entire season. The test was conducted in an apple orchard at the Tree Fruit Research and Extension Center. The trees were 15-yr-old spur type Delicious on dwarfing roots. Treatments were applied to 1-tree plots replicated 5 times in a randomized complete block. All treatments were applied with a handgun sprayer at 300 psi to the point of drip. The CM injury evaluations were made on 6 Jun following the first generation, and at harvest on 31 Aug. Twenty-five apples per replicate were sampled on 6 Jun and the total number of CM injured fruit and those marked by spray residue recorded. At harvest, all fruit from each replicate were examined and the number of CM and PLR injured fruit recorded. Because of the high percentage of CM injured fruit at harvest, a 10-fruit subsample was chosen at random from each replicate and the number of CM stings and entries per fruit recorded. PLR and WALH were sampled on 8 Aug. Twenty shoots were examined and the total number of active PLR larval feeding sites recorded. Ten leaves were examined for the presence of WALH and the total number of nymphs recorded.


1998 ◽  
Vol 23 (1) ◽  
pp. 64-65
Author(s):  
E. E. Grafton-Cardwell ◽  
C. A. Reagan

Abstract Two insecticide efficacy trials for the control of citrus cutworm were conducted in 1997. In the first experiment, three formulations of Bacillus thuringiensis were tested and compared with a water (check) spray in a commercial block of 32-year-old ‘Washington’ navel orange trees of Exeter Farms, Exeter, California. Applications of MYX 300, MYX 324, and CRYMAX WDG were made on 8 Apr using a Bean hand-sprayer at approximately 300 gpa, 300 psi. In the second experiment, two rates of RH-5992 70 WP and one rate of RH-2485 80WP, each combined with the surfactant Latron CS-7, and a treatment of Spinosad 2SC were compared to a water control spray in a block of 14-yr-old ‘Washington’ navel oranges at the Lindcove Research and Extension Center, Exeter, California. The applications were made on 11 Apr using the same equipment, rate, and pressure as the Exeter Farms test. In both experiments, eight replicated single-tree treatments were used and treatments were assigned on the basis on pre-treatment sampling of larvae. Larvae were collected by placing a canvas beating sheet (112 cm X 75 cm) beneath the outside foliage of the tree and vigorously shaking the foliage 10 times. Citrus cutworm larvae falling on the canvas were counted and recorded, then returned to the foliage. Pre-treatment larval counts involved sampling the Northeast and Southwest corners of the trees at Exeter Farms on 7 Apr and at Lind-cove on 4 Apr. All four tree quadrants were sampled for post-treatment larval counts on 15 Apr and 22 Apr at Exeter Farms; and on 18 Apr and 25 Apr at Lindcove.


2013 ◽  
Vol 10 (1) ◽  
pp. 67-80 ◽  
Author(s):  
W. R. Hunter ◽  
A. Jamieson ◽  
V. A. I. Huvenne ◽  
U. Witte

Abstract. The Whittard Canyon is a branching submarine canyon on the Celtic continental margin, which may act as a conduit for sediment and organic matter (OM) transport from the European continental slope to the abyssal sea floor. In situ stable-isotope labelling experiments were conducted in the eastern and western branches of the Whittard Canyon, testing short-term (3–7 days) responses of sediment communities to deposition of nitrogen-rich marine (Thalassiosira weissflogii) and nitrogen-poor terrigenous (Triticum aestivum) phytodetritus. 13C and 15N labels were traced into faunal biomass and bulk sediments, and the 13C label traced into bacterial polar lipid fatty acids (PLFAs). Isotopic labels penetrated to 5 cm sediment depth, with no differences between stations or experimental treatments (substrate or time). Macrofaunal assemblage structure differed between the eastern and western canyon branches. Following deposition of marine phytodetritus, no changes in macrofaunal feeding activity were observed between the eastern and western branches, with little change between 3 and 7 days. Macrofaunal C and N uptake was substantially lower following deposition of terrigenous phytodetritus with feeding activity governed by a strong N demand. Bacterial C uptake was greatest in the western branch of the Whittard Canyon, but feeding activity decreased between 3 and 7 days. Bacterial processing of marine and terrigenous OM were similar to the macrofauna in surficial (0–1 cm) sediments. However, in deeper sediments bacteria utilised greater proportions of terrigenous OM. Bacterial biomass decreased following phytodetritus deposition and was negatively correlated to macrofaunal feeding activity. Consequently, this study suggests that macrofaunal–bacterial interactions influence benthic C cycling in the Whittard Canyon, resulting in differential fates for marine and terrigenous OM.


2021 ◽  
Vol 2 (Supplement_1) ◽  
pp. A46-A46
Author(s):  
D Levendowski ◽  
E Sall ◽  
W Odom ◽  
B Beine ◽  
D Cruz Arista ◽  
...  

Abstract Purpose Assess the impact of custom oral appliance (CA) fabrication settings on treatment outcomes. Methods CPAP-intolerant patients completed a two-night home-sleep-apnea study (HSAT); Night1=baseline, Night2=Apnea Guard® trial appliance (AG). The AG vertical-dimension-of-occlusion (VDO) selection was based on tongue-scallop (women=5.5/6.5 mm, men= 6.5/8.0 mm), with a target protrusion of 70% from neutral-maximum while in situ. Study1 CA VDO was dependent on sex (women=2.5 mm, men=5 mm), with protrusion set using a George-Gauge measured 70% from maximum retrusion-protrusion with dentist-directed titration. Study2 CA was fabricated to the AG VDO and target protrusion bite-registration. Efficacy HSATs were conducted after completion of Study1 CA titration with vertical-elastics optional, and at the AG target protrusion with vertical-elastics mandatory in Study2. Statistics included Mann-Whitney, Chi-squared, and Bland-Altman analyses. Results The Study1 (n=84) and Study2 (n=46) distributions were equivalent for tongue-scallop (64/63%) and sex (women=45/41%), however, noted differences in age (53.8±11.9 vs. 58.4±12.2; P=0.052), body-mass-index (29.4±5.7 vs. 27.8±4.0; P=0.128) and pre-treatment AHI severities (24.6±14.4 vs. 29.2±17.4 events/h; P=0.155) were observed. The Bland-Altman biases were significant different (Study1=4.2±7.8 vs. Study2=1.3±7.0 events/h, P=0.035). The significant Study1 differences between the CA vs. AG AHIs (12.3±9.2 vs. 8.2±5.9 events/h, P<0.0002) were not apparent in Study2 (11.7±8.0 vs. 10.4±6.7 events/h, P=0.362), however, the Study2 AG AHI values were higher (P=0.055). Discussion Despite the trend toward greater Study2 pre-treatment and AG AHI severities, CA treatment efficacy was equivalent to the AG once VMO was controlled and fabricated using the AG VDO and protrusion bite-registration. These findings confirmed CA fabrication settings impact treatment outcomes.


1981 ◽  
Vol 61 (2) ◽  
pp. 407-411 ◽  
Author(s):  
H. B. HEENEY ◽  
V. WARREN ◽  
S. U. KHAN

Annual yields of mature Kinkead Red Spy apple trees were higher when growth under trees was controlled by a rotation of three herbicides, namely, simazine (2-chloro-4, 6 bis(ethylamino)-s-triazine), terbacil (3-tert-butyl-5-chloro-6-methyluracil) and dichlobenil (2,6-dichlorobenzonitrile) compared to yields of trees in which sod was regularly mowed to control growth of weeds. While weed control with herbicide rotations was not as effective as with continuous usage of a single herbicide, it was commercially acceptable, and the problem of common vetch (Vicia cracca L.) as on escape weed, particularly with continuous simazine was largely avoided. Over the 6-yr period there was little effect on nutrient levels of the foliage. Use of a rotation of herbicides prevented the accumulation of residues in the soil and levels of all herbicides noted in year 1 of the rotation were reduced to negligible amounts 2 yr after a particular herbicide had been applied.


Author(s):  
Ding-Yuan Chen ◽  
Axel R Persson ◽  
Kai Hsin Wen ◽  
Daniel Sommer ◽  
Jan Gruenenpuett ◽  
...  

Abstract The impact on the performance of GaN HEMTs of in situ ammonia (NH3) pre-treatment prior to the deposition of silicon nitride (SiN) passivation with low-pressure chemical vapor deposition is investigated. Three different NH3 pre-treatment durations (0, 3, and 10 minutes) were compared in terms of interface properties and device performance. A reduction of oxygen at the interface between SiN and epi-structure is detected by Scanning Transmission Electron Microscopy-Electron Energy Loss Spectroscopy measurements in the sample subjected to 10 minutes of pre-treatment. The samples subjected to NH3 pre-treatment show a reduced surface-related current dispersion of 9 % (compared to 16% for the untreated sample), which is attributed to the reduction of oxygen at the SiN/epi interface. Furthermore, NH3 pre-treatment for 10 minutes significantly improves the current dispersion uniformity from 14.5 % to 1.9 %. The reduced trapping effects result in a high output power of 3.4 W/mm at 3 GHz (compared to 2.6 W/mm for the untreated sample). These results demonstrate that the in situ NH3 pre-treatment before low-pressure chemical vapor deposition of SiN passivation is critical and can effectively improves the large-signal microwave performance of GaN HEMTs.


1996 ◽  
Vol 4 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Walter Peters ◽  
Dennis Smith ◽  
Stanley Lugowski

There have been three generations of silicone-gel breast implants. First generation implants (thick wall – thick gel with Dacron patches) were made from 1963 to 1972. Second generation implants (thin wall-thin gel) were made from 1972 until the mid 1980s. The introduction of third generation implants (stronger wall, low-bleed) was geographically dependent. In Canada, Dow Corning Silastic II implants were introduced in 1986, and Surgitek SCL implants were introduced in 1988. In the present study, a total of 352 silicone-gel breast implants were removed from 239 patients between 1981 and 1995. Their failure properties were dependent upon their generation (year of manufacture) and, for second generation implants, their duration in situ. Of the 352 implants, 20 were first generation, and all were fully intact. Twenty-eight were third generation implants, and 27 were fully intact. Failure properties of the 302 second generation implants were dependent upon their duration of implantation. A survival curve indicated that these implants began to fail (by leaking or rupturing) after four years in situ. By six years, 40% had failed. After 12 years, 95% had failed. Of the 171 second generation implants removed between 1991 and 1995, 77% had failed. The failure properties were similar for the three main manufacturers: Dow Corning, Heyer-Schulte and Surgitek. The failure rate for second generation implants is much higher than was previously believed. This is particularly significant in view of the current difficulty in diagnosing implant failure.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 472 ◽  
Author(s):  
Sonalika Bhattaccharjee ◽  
Moritz Beck-Broichsitter ◽  
Ajay K. Banga

Although used widely in cosmetic formulations, topical delivery of niacinamide (LogP = −0.35) is unfavorable by conventional means. Poly(lactide-co-glycolide) (PLGA) formulations, can undergo a sol-gel transition triggered by solvent exchange, entrapping molecules and sustaining their release. The current study aims to exploit the ability of PLGA to gel in situ and enhance the topical delivery of niacinamide in microporated skin. In vitro drug permeation studies were performed using vertical Franz diffusion cells. Microporation was performed using Dr. PenTM Ultima A6, where pre-treatment with a 1 mm needle-length for 10 s and a 0.5 mm needle-length for 5 s, both at 13,000 insertions/min were compared. The effect of different grades of PLGA, EXPANSORB® DLG 50-2A (“low” molecular weight), and EXPANSORB® DLG 50-8A (“high” molecular weight) on topical delivery was also determined. Formulations containing PLGA resulted in successful gelation in situ on application over microporated skin. A significantly higher amount of drug was found in the skin with the 0.5 mm treatment for 5 s (892 ± 36 µg/cm2) than with 1 mm for 10 s (167 ± 16 µg/cm2). Hence, the different grades of PLGA were evaluated with 0.5 mm, 5 s treatment, and a significantly larger amount was seen in skin with the higher rather than the lower molecular weight polymer (172 ± 53 µg/cm2).


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