Studies on loss of bio-efficacy of two indirect neem application over time (seed and soil) against Bemisia tabaci (Homoptera: Aleyrodidae) under semi-field conditions

2008 ◽  
Vol 11 (4) ◽  
pp. 185-190 ◽  
Author(s):  
Prabhat Kumar
Keyword(s):  
Bemisia Tabaci ◽  
Field Conditions ◽  
Over Time

Response of seashore paspalum and bermudagrass to topramezone and triclopyr mixtures

2020 ◽  
pp. 1-8
Author(s):  
Clebson G. Gonçalves ◽  
Austin M. Brown ◽  
Suma Basak ◽  
J. Scott McElroy
Keyword(s):  
Field Conditions ◽  
Single Application ◽  
Seashore Paspalum ◽  
Application Timing ◽  
Application Programs ◽  
Over Time

Abstract Few options are available for controlling bermudagrass invasion of seashore paspalum. Bermudagrass and seashore paspalum tolerance to topramezone, triclopyr, or the combination of these two herbicides were evaluated in both greenhouse and field conditions. Field treatments included two sequential applications of topramezone (15.6 g ai ha−1) alone and five rates of topramezone + triclopyr (15.6 + 43.2, 15.6 + 86.3, 15.6 + 172.6, 15.6 + 345.2, or 15.6 g ai ha−1 + 690.4 g ae ha−1). Secondary greenhouse treatments included a single application of topramezone (20.8 g ha−1) or triclopyr (258.9 g ha−1) alone, or in combination at 20.8 + 258.9 or 20.8 + 517.8 g ha−1, respectively. Greenhouse and field results showed that topramezone applications in combination with triclopyr present opposite responses between bermudagrass and seashore paspalum. Topramezone increased bermudagrass injury and decreased seashore paspalum bleaching injury compared to topramezone alone. In field evaluations, topramezone + triclopyr at 15.6 + 690.4 g ha−1 used in sequential applications resulted in >90% injury to bermudagrass, however, injury decreased over time. Furthermore, sequential applications of topramezone + triclopyr at 15.6 + 690.4 g ha−1 resulted in >50% injury to seashore paspalum. Application programs including topramezone plus triclopyr should increase bermudagrass suppression and reduce seashore paspalum injury compared to topramezone alone. However, additional studies are needed because such practices will likely require manipulation of topramezone rate, application timing, application interval, and number of applications in order to maximize bermudagrass control and minimize seashore paspalum injury.

Evaluation of bioefficacy potential of entomopathogenic fungi against the whitefly (Bemisia tabaci Genn.) on cotton under polyhouse and field conditions

2021 ◽  
pp. 107618
Author(s):  
Satish Kumar Sain ◽  
Dilip Monga ◽  
Neelkanth S. Hiremani ◽  
Dipak T. Nagrale ◽  
Sandhya Kranthi ◽  
...  
Keyword(s):  
Bemisia Tabaci ◽  
Entomopathogenic Fungi ◽  
Field Conditions

Microcosm assessment of potential molluscicides for control of the rice snail Isidorella newcombi sens. lat. (Gastropoda: Basommatophora: Planorbidae)

1996 ◽  
Vol 47 (5) ◽  
pp. 673 ◽  
Author(s):  
MM Stevens ◽  
RJ Faulder ◽  
NE Coombes
Keyword(s):  
Field Conditions ◽  
Initial Screening ◽  
Screening Rate ◽  
Irrigated Rice ◽  
Fish Toxicity ◽  
Further Development ◽  
Over Time ◽  
Delayed Exposure

Twenty-seven pesticides were evaluated for their toxicity to mature Isidorella newcombi (Adams & Angas), a serious pest of irrigated rice in NSW, Australia. Evaluations were conducted using microcosms in which typical field conditions were simulated. Only 3 compounds, niclosamide, n-tritylmorpholine, and nicotinanilide, provided >95% mortality at an initial screening rate of 3 mg/L. These compounds were assessed at a range of rates using both immediate and delayed-exposure bioassays to determine LC values and comparative persistence. Niclosamide (as Bayer Bayluscide� 250 g/L EC) and n-tritylmorpholine (as Shell FresconB 165 g/L EC) were the most toxic (LC90, immediate exposure, 0.19 mg/L for both compounds), whilst the corresponding LC90 value for nicotinanilide (laboratory grade in DMSO) was 0.53 mg/L. Persistence (reflected by a slower increase in LC90 values over time in delayed exposure bioassays) was strongest in nicotinanilide and weakest in n-tritylmorpholine. Although niclosamide is the most promising compound for the control of I. newcombi, further development of nicotinanilide is also recommended, as it represents a potentially valuable tool for use in situations where low fish toxicity is required.

scholarly journals EVALUATION OF SELECTED INSECTICIDES AGAINST WHITEFLY (Bemisia tabaci) ON BRINJAL CROPS AND THEIR EFFECT ON NATURAL ENEMIES

2017 ◽  
Vol 7 (4) ◽  
pp. 1151-1161 ◽  
Author(s):  
Mohd Rasdi Zaini
Keyword(s):  
Field Study ◽  
Bemisia Tabaci ◽  
Natural Enemies ◽  
Chemical Control ◽  
Post Treatment ◽  
Field Conditions ◽  
Pre Treatment ◽  
Treatment Observation ◽  
Control Water

A field study was carried out for two cropping periods in the first season in year 2014 and the second season in 2015. This study was carried out at share farm, Agrotechnology Plantation UiTM Melaka, Campus Jasin to examine the efficacy of selected insecticides against whitefly (Bemisia tabaci) on brinjal crops and the effect on natural enemies (Spider) under field conditions. Five treatments with four replications were applied. The treatments were T0= Control (water), T1= Imidacloprid (Confidor), T2= Acetamiprid (Mospilan), T3= Dinotefuran (Oshin) and T4= Cyantraniliprole (Benevia). Pre-treatment and post-treatment observation were recorded which is one day before application and 1, 3, 7 and 14 days after application of insecticides. A total of two applications of treatments were done. The results revealed that Imidacloprid was recorded as the most effective and the highest reduction of whiteflies during the first season with 96.73%, followed by Acetamiprid (92.44%), Cyantraniliprole (82.65%) and Dinotefuran (80.74%) while during the second season, Imidacloprid also was recorded as the highest reduction with 79.99%, followed by Acetamiprid (76.34%), Cyantraniliprole (54.09%) and Dinotefuran (36.87%). Overall, chemical control of Imidacloprid was the most effective against whiteflies populations in brinjal particularly in the first season as compared to second season. The effect of these selected insecticides on natural enemies (Spider) revealed that chemical control of Imidacloprid gave the highest reduction of spider with 65.69%), followed by Cyantraniliprole (64.47%), Acetamiprid (41.44%) and Dinotefuran (15.45%). Imidacloprid and Cyantraniliprole were classified as moderately harmful to spider while Acetamiprid and Dinotefuran were classified as harmless or slightly harmful.

scholarly journals Controlled-release Potassium Fertilizers for Turfgrass

1992 ◽  
Vol 117 (3) ◽  
pp. 411-414 ◽  
Author(s):  
George H. Snyder ◽  
John L. Cisar
Keyword(s):  
Controlled Release ◽  
Direct Measurement ◽  
Cynodon Dactylon ◽  
Laboratory Method ◽  
Hot Water ◽  
The Other ◽  
Field Conditions ◽  
Laboratory Studies ◽  
K Release ◽  
Over Time

Field and laboratory studies were conducted to evaluate the K retention properties of several resin-coated (RC), sulfur-coated (SC), and plastic-coated (PC) K fertilizers. Substantial differences in K release were found among the controlled-release K materials, based both on the K content of `Tifgreen' bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burt-Davvy] clippings and on direct measurement of K remaining in fertilizer granules in the field over time. One SC material appeared to release K too rapidly, and one RC material appeared to release K too slowly to be useful for providing extended plant-available K to turfgrass. The other sources appeared to have release characteristics that would be favorable for turfgrass maintenance. Because differences in K release were observed among the sources, a laboratory method for assessing K release would be useful. Toward this-end, models were developed relating K retention of sources in hot water (70C) to K retention under field conditions.

scholarly journals Differential Efficacies of Nomuraea Rileyi and Isaria Fumosorosea on Some Serious Pests and the Pests’ Efficient Predator Prevailing in Tomato Fields in Egypt

2013 ◽  
Vol 53 (2) ◽  
pp. 103-109 ◽  
Author(s):  
Mamdouh Maher Matter ◽  
Magda Mahmoud Sabbour
Keyword(s):  
Bemisia Tabaci ◽  
Myzus Persicae ◽  
Microbial Control ◽  
Field Conditions ◽  
Lethal Concentration ◽  
Nomuraea Rileyi ◽  
Isaria Fumosorosea ◽  
Tomato Yield ◽  
Coccinella Undecimpunctata ◽  
Efficient Predator

Abstract The efficiency of the two microbial control agents Nomuraea rileyi and Isaria fumosorosea, were evaluated against Bemisia tabaci and Myzus persicae pests in tomato cultivations The safety levels of the agents, to the predator Coccinella undecimpunctata, were also studied under laboratory and field conditions. Results showed that under laboratory conditions, LC50 values for N. rileyi and I. fumosorosea were 103.7x104 and 139.4x104 spores/ml against B. tabaci, respectively, while the corresponding values for M. persicae were 89.1x104 and 149.8x104 spores/ml, respectively. Under the field conditions, the percentages of infested plants with B. tabaci and M. persicae were significantly decreased after treatments with both fungi as compared with the corresponding controls. At the El-Esraa farm (Nobaria region), the weights of the tomato yield were 2,417 and 2,911 kg/feddan when I. fumosorosea and N. rileyi were applied respectively, as compared with 2,010 kg/feddan in the corresponding controls. The corresponding yields in El-Kassaseen were 2,699 and 2,999 kg/feddan, respectively, as compared to 1,990 kg/feddan in the control. The present study showed that C. undecimpunctata exhibit relatively high and reasonable resistance to N. rileyi and I. fumosorosea at the highest lethal concentration (1x108 spores/ml) for both tested preys.

Interference Between Soybeans (Glycine max) and Common Cocklebur (Xanthium strumarium) Under Indiana Field Conditions

Weed Science ◽  
1989 ◽  
Vol 37 (6) ◽  
pp. 753-760 ◽  
Author(s):  
William T. Henry ◽  
Thomas T. Bauman
Keyword(s):  
Spatial Distribution ◽  
Regression Analysis ◽  
Glycine Max ◽  
Seed Yield ◽  
Soybean Seed ◽  
Growing Season ◽  
Field Conditions ◽  
Xanthium Strumarium ◽  
Soybean Yield ◽  
Over Time

The effects of interference between soybeans and common cocklebur were investigated. Common cocklebur interference reduced soybean growth at each of four sample dates during the growing season. The area of interference surrounding individual common cocklebur plants within the soybean row fluctuated over time with respect to intensity and spatial distribution. Soybean growth was significantly reduced up to 10 cm away from individual cocklebur plants at 6 weeks after planting (WAP), 30 cm at 8 WAP, 20 to 30 cm at 10 WAP, and 40 cm at 12 WAP. The maximum possible distance of cocklebur influence, determined by regression analysis, also varied during the growing season. When areas of interference from adjacent cocklebur plants overlapped, the cumulative influence was found to be additive, especially late in the growing season. Soybean interference caused a 50 to 90% reduction in the size of common cocklebur plants grown within the soybean row compared to plants grown without interference. At harvest, soybean yield was reduced up to 40 to 50 cm within the row from individual cocklebur plants. The maximum distance of interference on one side of individual cocklebur plants was 75 cm. One cocklebur plant reduced soybean yield 16.0% within 1.5 m of soybean row as the result of full-season interference. Interference of common cocklebur plants spaced 60 cm apart within the row overlapped and caused an additive reduction in soybean seed yield. Across all cocklebur treatments, there was a consistent ratio of approximately 1 kg/ha loss in soybean seed yield for each 4 kg/ha of cocklebur herbage produced.

scholarly journals Laboratory apparatus and techniques for the rearing and insecticidal treatment of whitefly Bemisia tabaci (Homoptera: Aleyrodidae) under simulated field conditions

1990 ◽  
Vol 80 (2) ◽  
pp. 209-216 ◽  
Author(s):  
Mark Rowland ◽  
Barry Pye ◽  
Mary Stribley ◽  
Barbara Hackett ◽  
Ian Denholm ◽  
...  
Keyword(s):  
Bemisia Tabaci ◽  
Large Population ◽  
Field Conditions ◽  
Laboratory Apparatus ◽  
Testing Strategies ◽  
Application Rates ◽  
Insecticidal Treatment ◽  
Simulated Field ◽  
Selection Of ◽  
Selection Of Resistance

AbstractLaboratory apparatus and techniques are described for the rearing and insecticidal treatment of whitefly, Bemisia tabaci Gennadius, under simulated field conditions. Insects were reared on cotton plants inside large population cages and treated from an overhead sprayer. The effects of these treatments were assessed accurately, without interfering with insects or plants, by monitoring adult numbers with an endoscope over one or more generations. Examples of single-generation and multiple-generation tests with cypermethrin are described. The apparatus is suitable for testing strategies for delaying the selection of resistance (e.g. using insecticides applied singly, alternately, or in mixture, at various application rates and frequencies), for controlling populations already resistant to insecticides, and for integrated pest management using chemical and biological control agents together.

Sign in / Sign up

Export Citation Format

Share Document