Residual toxicity of selected insecticides on Aphis gossypii and their safety limits on honeybees

2021 ◽  
Author(s):  
Wael M. Khamis ◽  
Khaled M. A. Abdel-Hameed ◽  
Ahmed M. El-Sabrout
Keyword(s):  
Evaluation Studies ◽  
Aphis Gossypii ◽  
Foliar Spray ◽  
Laboratory Strain ◽  
Field Trials ◽  
International Organization ◽  
Flowering Period ◽  
Residual Toxicity ◽  
Lethal Time ◽  
Foraging Time

Abstract Evaluation studies were carried out to simulate realistic field exposures of sulfoxaflor and flonicamid against Aphis gossypii at foraging time of Apis mellifera. Semi-field trials of field rates of sulfoxaflor and flonicamid against A. gossypii laboratory strain at 48 h of exposure had equipollent overall mean of mortality of 62.50 and 63.50%, respectively in season of 2020, likewise 60.50 and 62.50%, respectively in season of 2021. Lethal time values (LT1) had ranges of 51.33–32.46 days for sulfoxaflor and 49.00–39.55 days for flonicamid. Laboratory trials on foraging honeybees (∼21 days old) at 5 h of exposure showed an excellence for sulfoxaflor (5.00%) in overall mean of mortality compared to flonicamid (2.75%) in season of 2020. Likewise, sulfoxaflor (4.75%) surpassed flonicamid (2.75%) in season of 2021. The highest LT1s on honeybees for sulfoxaflor and flonicamid reached 27.45 and 10.94 days, respectively. International Organization for Biological Control classified both insecticides to be harmless on honeybees. Survival foraging bees exposed to LD50s of the tested insecticides had malformed digestive tracts gradually vanished along week of exposure. Suggestions for foliar spray stoppages prior to flowering period were mentioned for both insecticides.

Residual Toxicity of Insecticides to Neoseiulus fallacis (Acari: Phytoseiidae) in Apples

2019 ◽  
Vol 112 (5) ◽  
pp. 2262-2267 ◽  
Author(s):  
Raja Zalinda Raja Jamil ◽  
Christine Vandervoort ◽  
John C Wise
Keyword(s):  
North America ◽  
Pest Management ◽  
Production Systems ◽  
Predatory Mite ◽  
Decision Makers ◽  
Neoseiulus Fallacis ◽  
Residual Toxicity ◽  
Lethal Time ◽  
Important Field ◽  
Apple Production

Abstract Neoseiulus fallacis (Garman) is a predatory mite that is common in apple orchards and distributed throughout North America. However, N. fallacis may be susceptible to pesticides used for the management of crop pests. This study aimed to evaluate the temporal effects of commonly used insecticides on N. fallacis survival. Neoseiulus fallacis adults were exposed to field-aged residues, and mortality and lethal time were measured over 96 h of exposure. Carbaryl caused high mortality to N. fallacis and the shortest lethal time values (LT50), followed by spinetoram, with moderate lethal time values. Esfenvalerate, acetamiprid, chlorantraniliprole, and novaluron showed little to no lethality to N. fallacis following exposure to dry field-aged residues. The results of this study provide important field-relevant knowledge that is often void from laboratory-based studies, which can aid integrated pest management (IPM) decision-makers in apple production systems.

Effect of boron on clubroot of canola in organic and mineral soils and on residual toxicity to rotational crops

2014 ◽  
Vol 94 (1) ◽  
pp. 109-118 ◽  
Author(s):  
A. Deora ◽  
B. D. Gossen ◽  
S. F. Hwang ◽  
D. Pageau ◽  
R. J. Howard ◽  
...  
Keyword(s):  
Plasmodiophora Brassicae ◽  
Mineral Soil ◽  
Organic Soil ◽  
Field Trials ◽  
Growth And Yield ◽  
Broadcast Application ◽  
Residual Toxicity ◽  
Negative Effect ◽  
Soil Site ◽  
Mineral Soils

Deora, A., Gossen, B. D., Hwang, S. F., Pageau, D., Howard, R. J., Walley, F. and McDonald, M. R. 2014. Effect of boron on clubroot of canola in organic and mineral soils and on residual toxicity to rotational crops. Can. J. Pant Sci. 94: 109–118. Application of boron (B) has been reported to reduce clubroot severity in various Brassica spp., but residual B can have phytotoxic effects on other crops in the rotation. The objective of this study was to test the efficacy of broadcast application of B for clubroot suppression in canola (B. napus) and the effect of residual B on wheat, barley, field pea and canola. Field trials to assess clubroot suppression by B at various rates (1 to 64 kg B ha−1) were conducted in organic (Ontario) and mineral soils (Alberta, Quebec) heavily infested with Plasmodiophora brassicae in 2011 and 2012. Phytotoxicity was not observed in canola until applications rates exceeded 48 kg B ha−1. Boron did not reduce clubroot incidence at any site, irrespective of rate, and only reduced severity at the organic soil site at 6 wk after seeding. There was a small increase in shoot weight and yield of canola with increasing B application rates at the organic soil site. The potential phytotoxicity of residual B (4 to 16 kg B ha−1) was assessed in mineral soils in Ontario and Saskatchewan in 2012. Toxicity symptoms were noted initially in most of the crops, but seedlings recovered quickly and there was no significant reduction in fresh weight at harvest or seed yield of most of the cultivars. The present study indicates that pre-plant broadcast application of B delays clubroot development and increases vegetative growth and yield compared with non-treated plants in organic soil. Also, even high residual rates (16 kg ha−1) of application are unlikely to have a negative effect on crops in rotation in mineral soil. However, the effect of B application on canola yield found in this study was not sufficient to justify application for commercial canola production, even where clubroot is prevalent.

scholarly journals k-Oligocarrageenan Promoting Growth of Hybrid Maize: Influence of Molecular Weight

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3825
Author(s):  
Pham Trung San ◽  
Chau Minh Khanh ◽  
Huynh Hoang Nhu Khanh ◽  
Truong Anh Khoa ◽  
Nguyen Hoang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Plant Growth ◽  
Grain Yield ◽  
Growth Promotion ◽  
Foliar Spray ◽  
Field Trials ◽  
Grain Weight ◽  
Yield Parameters ◽  
Degradation Reaction ◽  
Hybrid Maize

k-Oligocarrageenan (OC) is an effective biostimulator and a protector against disease infections for plants. However, the effect of OC molecular weight (MW) on plant growth is not fully understood. In this work, OCs with three different MWs (42, 17 and 4 kDa) was prepared by varying the degradation reaction time using ascorbic acid as a reagent. The product structure was confirmed by Fourier-transform infrared spectroscopy (FTIR) data. The growth promotion for maize (Zea mays L.) plants was investigated by foliar spray application of the prepared OCs. Field trials were carried out in two years, 2018 and 2019. The results showed that among treatments, OC with 4 kDa exhibited the best performance in both crop growth and grain yield parameters which indicated increases compared to the control in plant height (6.9–19.9%), length of ears (12.2%), diameter of ears (9.1%), fresh grain weight (17.8%), dry grain weight (20.0%) and grain yield (21.3%). Moreover, low MW OC augmented NP uptake in the plant growth while no effect on K uptake was observed. Therefore, OC with low MWs is potentially promising to apply as a promoter to enhance yield of crops.

scholarly journals The fluctuation of molybdenum content in oilseed rape plants after the application of nitrogen and sulphur fertilizers

2011 ◽  
Vol 52 (No, 7) ◽  
pp. 301-307 ◽  
Author(s):  
J ◽  
D. Pavlíková ◽  
P. Tlustoš ◽  
K. Sýkora ◽  
J. Černý
Keyword(s):  
Oilseed Rape ◽  
Field Trials ◽  
Fertilizer Application ◽  
Molybdenum Content ◽  
Control Treatment ◽  
Flowering Period ◽  
Winter Oilseed Rape ◽  
Cultivation Technology ◽  
Fertilizer Rates ◽  
S Fertilizers

The effect of N-S fertilizers on the molybdenum content in oilseed rape plants was investigated in precision field trials. Evaluation was carried out on unfertilized control and two treatments of single fertilizer rates in the first spring fertilizer application, using 100 kg N/ha in AN treatment (nitrochalk) and 100 kg N/ha + 50 kg S/ha in ANS treatment (ammonium nitrate and ammonium sulphate). The results confirmed the significance of sulphur fertilization for the winter oilseed rape plant’s cultivation technology, even on fertile soils in the CzechRepublic. The control treatment produced a yield of 3.7 t/ha, while in the AN treatment the yield was 49% higher, and the ANS treatment was 60% higher. An antagonistic relationship between the sulphate and molybdenum anions in their absorption by the plants was demonstrated. The molybdenum content in the flowering period of the plants was determined in mg/kg as follows – in the ANS treatment: 0.17 in root, 0.12 in stem, 1.56 in upper leaves, 0.90 in lower leaves, and 1.17 in the flower petals. Higher and statistically more significant molybdenum levels were determined in the AN treatment: 0.21 in the root, 0.19 in the stem, 2.40 in the upper leaves, 1.72 in the lower leaves, and 1.50 mg/kg in the flower petals. The total above-ground biomass of the plants in the flowering period had accumulated molybdenum at 6.06 g/ha in the ANS treatment, and 8.44 g/ha in the AN treatment.

Flowering and pod and seed development in pigeon pea (Cajanus cajan)

1990 ◽  
Vol 115 (3) ◽  
pp. 327-335 ◽  
Author(s):  
A. O. Togun ◽  
T. O. Tayo
Keyword(s):  
Seed Development ◽  
Seed Yield ◽  
Cajanus Cajan ◽  
Pigeon Pea ◽  
Field Trials ◽  
Flowering Period ◽  
Physiological Maturity ◽  
Terminal Inflorescence ◽  
Total Seed ◽  
Ibadan Nigeria

SUMMARYFlower, pod and seed development were studied in the cultivars Cita-1 and Cita-2 in two field trials in 1985–86, in Ibadan, Nigeria. Flowering within any inflorescence was acropetal. On each plant the terminal inflorescence was the first to flower and, generally, inflorescences developed basipetally. A total of 569 flowers (mean of five plants) opened on Cita-1; of these, 20 were on the terminal inflorescence, 130 on axillary inflorescences and 419 on inflorescences on primary branches. For the 605 flowers (mean of five plants) which opened on Cita-2, the distribution was 19, 161 and 425, respectively.On Cita-1, 158 pods formed on average, of which 7 were on the terminal inflorescence, 33 on axillary inflorescences and 118 on inflorescences on primary branches lower down the plant. On Cita-2, for the 185 pods counted at maturity, the distribution was 8, 43 and 134, respectively. Some 72 and 69% of the total number of flowers which opened on Cita-1 and Cita-2, respectively, were aborted. In both cultivars, 99% of the mature pods were formed from flowers which opened within 24 days of the start of anthesis; the number of pods retained largely determined seed yield. The inflorescences which developed on the primary branches contributed 70% (Cita-1) and 66% (Cita-2) of the total seed yield. Early-formed pods were heavier than those formed later. Individual pods attained physiological maturity 35–42 days after successful pollination of the flower. At physiological maturity of the pod, the seed contained 3·72 % N, 0·45% P and 2·76% K, and the husk contained 1·98% N, 0·16% P and 1·96% K. The majority of open flowers which aborted were produced on primary branches, indicating that the primary branches have the greatest potential for increasing seed yield. A shorter flowering period might ensure greater retention of open flowers.

Studies on the Chemical Control of Cacao Mirids, Distantiella theobroma (Dist.) and Sahlbergella singularis Hagl

1959 ◽  
Vol 50 (1) ◽  
pp. 13-23 ◽  
Author(s):  
F. Raw
Keyword(s):  
Prolonged Exposure ◽  
Field Tests ◽  
Field Trials ◽  
Natural Conditions ◽  
Surface Deposit ◽  
Promising Alternative ◽  
Residual Toxicity ◽  
First Instar ◽  
Sahlbergella Singularis ◽  
Incomplete Coverage

Laboratory and field tests were made to investigate the toxicity, mode of action and persistence of technical DDT and γ BHC when applied to cacao in Ghana to control the Mirids, Distantiella theobroma (Dist.) and Sahlbergella singularis Hagl. The insecticides were tested at concentrations previously used in field trials. D. theobroma, S. singularis and Tribolium castaneum (Hbst.) were used as test insects. Preliminary tests with aldrin, chlordane and dieldrin were also made.Cacao pods were sprayed to drip point with the test insecticides and the deposit was allowed to dry. Mirid nymphs were placed on the pods and the rate of knockdown and the mortality after exposure for a test period was recorded. These tests showed that BHC had a higher toxicity and acted much more quickly than DDT. BHC greatly reduced feeding.Fumigant action was tested by spraying cacao leaves to drip point with the test insecticides, allowing the deposit to dry, and then exposing Mirid nymphs and adults over discs cut from the leaves. BHC had a powerful but transient fumigant action; adults, fifth- and second-instar nymphs were killed after, respectively, ½, 4 and 3 hours’ exposure at 28–30°C. over leaves treated with 0·25 per cent, γ BHC. No fumigant effect was observed after prolonged exposure over leaves treated with 2·5 per cent, technical DDT.Persistence was studied by treating cacao leaves and pods growing under natural conditions and then testing the residual deposit at intervals. Tests with T. castaneum showed that when leaves were sprayed to drip point the residual toxicity of 1·25 and 2·5 per cent, technical DDT fell steadily and was negligible after an interval of three and six weeks, respectively; that of 0·25–2 per cent, γ BHC was negligible after 2–3 days. Corresponding tests with Mirids on pods were less consistent but suggested that 2·5 per cent, technical DDT was still effective against first-instar nymphs after three weeks; 0·25 per cent, γ BHC had a residual toxic effect for at least several days and depressed feeding greatly for at least a fortnight. It is suggested that BHC may have a local systemic action which persists after the surface deposit becomes ineffective.Of the other insecticides tested, aldrin had a high toxicity and powerful fumigant action and appeared to be the most promising alternative to BHC.It was concluded that BHC would be more effective than DDT when treating mature cacao because, in addition to its higher toxicity and quicker action, its fumigant action would compensate for incomplete coverage by low-volume spraying.

scholarly journals BACTERIA FOR COTTON PLANT PROTECTION: DISEASE CONTROL, CROP YIELD AND FIBER QUALITY1

2020 ◽  
Vol 33 (1) ◽  
pp. 43-53
Author(s):  
HENRIQUE MONTEIRO FERRO ◽  
RICARDO MAGELA DE SOUZA ◽  
FLAVIA MARA VIEIRA LELIS ◽  
JULIO CARLOS PEREIRA DA SILVA ◽  
FLÁVIO HENRIQUE VASCONCELOS DE MEDEIROS
Keyword(s):  
Plant Protection ◽  
Disease Incidence ◽  
Fiber Quality ◽  
Foliar Spray ◽  
Field Trials ◽  
First Year ◽  
Bacterial Strains ◽  
Water Control ◽  
Chemical Treatments ◽  
Paenibacillus Lentimorbus

ABSTRACT Ramulosis (Colletotrichum gossypii var. cephalosporioides) is an important fungal disease of cotton in Brazil, exclusively controlled by fungicide application. Therefore, sustainable management of ramulosis is essential. This work aimed to evaluate the potential of three bacterial strains, Bacillus amyloliquefaciens (UFLA285), Bacillus velezensis (UFLA401), and Paenibacillus lentimorbus (MEN2), for the biocontrol of ramulosis in cotton and their effects on yield and fiber quality. Seed treatment (ST), foliar spray, and soil drenching application methods were used (separately or combined) under greenhouse and field conditions. Chemical treatments recommended against ramulosis and water were used as controls. Under greenhouse conditions all strains reduced the disease incidence. While B. velezensis UFLA401 and P. lentimorbus MEN2 reduced the incidence by 56.6% and 45.7%, respectively, independent of the application method, B. amyloliquefaciens UFLA285 reduced the disease by about 60% when applied as a foliar spray or ST + foliar spray. Two field trials were performed and all bacterial strains reduced ramulosis incidence. In the first year, B. velezensis UFLA401 sprayed on the plants reduced incidence by 22.3% and ST + two foliar sprays resulted in the best performance, decreasing ramulosis by 57%. In both seasons the yield increased by using either bacterial or chemical treatments compared to the water control. The combination B. velezensis UFLA401 and P. lentimorbus MEN2 sprays provided better fiber quality than chemical treatment. Therefore, Bacillus sp. (UFLA285 and UFLA401) and P. lentimorbus MEN2 are potential tools to reduce ramulosis, increase cotton yield and fiber quality.

Development of Baits for Population Management of Subterranean Termites

2019 ◽  
Vol 64 (1) ◽  
pp. 115-130 ◽  
Author(s):  
Nan-Yao Su
Keyword(s):  
Field Studies ◽  
Field Trials ◽  
Metabolic Inhibitors ◽  
Chitin Synthesis ◽  
Lethal Time ◽  
Frequent Site ◽  
Adequate Evaluation ◽  
The 1960S ◽  
Royal Pair ◽  
Ground Monitoring

The objective of bait application envisioned by early researchers was to eliminate the source of infestation, the colony, but because of the lack of adequate evaluation tools, results of field trials with mirex baits in the 1960s were mostly inconclusive. On-the-ground monitoring stations and mark-recapture protocol developed in the 1970s marked the turning point in the field studies of termite baits. Results of field studies with metabolic inhibitors and chitin synthesis inhibitors (CSIs) in the 1990s indicated that a bait toxicant has to be slow-acting and nonrepellent, and its lethal time has to be dose independent. A recent discovery that termites return to the central nest to molt and CSI-poisoned termites die near the royal pair further explains the success of CSI baits in eliminating colonies. Owing to the availability of durable baits that require less-frequent site inspection, more termite control professionals have adopted baiting systems in recent years.

scholarly journals DCPTA Ineffective as a Production Aid on Field-grown Tomato and Pepper

HortScience ◽  
1995 ◽  
Vol 30 (1) ◽  
pp. 78-79 ◽  
Author(s):  
T.K. Hartz ◽  
L.J. Kies ◽  
A. Baameur ◽  
D.M. May
Keyword(s):  
Seed Treatment ◽  
Foliar Spray ◽  
Field Trials ◽  
Soluble Solids ◽  
Fresh Market ◽  
Tomato Fruits ◽  
Processing Tomato ◽  
Solids Concentration ◽  
Soluble Solids Concentration

Application of DCPTA, as a seed treatment and a foliar spray, was evaluated for effects on productivity and fruit quality of processing tomato (Lycopersicon esculentum Mill.) and fresh-market pepper (Capsicum annuum L.). Two field trials for each crop were conducted in California during 1992. No DCPTA treatment was effective in increasing vegetative growth or fresh fruit yield of either crop at any site. Total soluble solids concentration and color of tomato fruits were unaffected by DCPTA, regardless of application method. We conclude that DCPTA is not a useful production aid for field-grown tomato or pepper. Chemical name used: 2-(3,4-dichlorophenoxy) triethylamine (DCPTA).

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