Wettable Powder Formulation Research Articles

Mortality Effects of Beauveria bassiana and Purpureocillium lilacinum Isolates and Efficacy of a Wettable Formulation on Palemona prasina (Hemiptera: Pentatomidae) Nymphs

In this study, the mortality effect of two Beauveria bassiana and two Purpureocillium lilacinum isolates on the 4th stage nymphs of Palemona prassiana was determined. The most lethal isolate was formulated as wettable powder and tested on the pest. Furthermore, Y-tube olfactometry tests were conducted to detect behavioral response of the nymphs in presence of the fungus. All the experiments were carried out under controlled conditions. The mortality varied depending on the isolates between 28.51% and 82.14% on the 12th day. Beauveria bassiana FAI-38 caused the highest mortality (82.14% at 1x108 conidia ml-1) with LC50 and LT50 estimations of 3.3x106 conidia ml-1 and 8.4 days, respectively. According to data taken 6 and 12 days after application, the wettable powder formulation was found to be significantly more effective (89.65% at 1x107 conidia ml-1, LT50 6.08 days). According to the Y-tube olfactometry tests, the nymphs exhibited avoidance from unformulated B. bassiana spores; however, once the spores were formulated as wettable powder, the behavior of the insects changed to neutral. It is concluded that Beauveria bassiana FAI-38 presents a potential as a control agent, and the wettable powder formulation of the fungus improves its effectiveness by increasing mortality and removing repellency effect of the fungal spores.

Biocontrol of Botrytis cinerea by Streptomyces noursei C27 and preliminary identification of antimicrobial metabolites

A wide variety of soluble bioactive secondary metabolites and volatile organic compounds are produced by species of Streptomyces, making them potential candidates for controlling phytopathogenic microorganisms. In the present study, Streptomyces noursei C27, isolated from soil, was found to exhibit broad spectrum inhibitory activity against several phytopathogenic fungi. Furthermore, volatile organic compounds (VOCs) produced by S. noursei C27 exhibited total inhibition of Botrytis cinerea. An analysis of the complete genome sequence confirmed the identification of C27 as Streptomyces noursei. Liquid chromatography-tandem mass spectrometry analysis was used to characterize antimicrobial metabolites present in the fermentation broth of Streptomyces C27, that were identified as gougerotin, natamycin, nystatin, and anisomycin. Streptomyces C27 was shown to control gray mold on grape leaves and fruit in vitro, inhibiting infections by 72.5% and 71.9%, respectively. Gas chromatography-mass spectrometry analysis revealed that thirty alkenes, alcohols, esters, and alkanes were among the VOCs secreted by Streptomyces C27 and contributed to the inhibition of B. cinerea growth and development in inoculated grape leaves and fruit. The biocontrol efficacy of a wettable powder formulation of Streptomyces C27 against gray mold was tested on tomato seedlings in pot experiments and greenhouse experiment. Results indicated 61.86% and 67.25% control in the pot and field tests, respectively. In summary, Streptomyces noursei C27 has excellent potential to be a commercial biocontrol agent of plant diseases caused by pathogenic fungi, especially gray mold infections of vegetables and fruits caused by B. cinerea.

Using Fungal and Bacterial Bioagent Formula Antagonists to Combat Fusarium Oxysporum f. sp. Lycopersici Under Greenhouse Conditions

Objective: This study aimed to test fungal and bacterial bioagents as formula antagonists of Fusarium oxysporum f. sp. lycopersici under greenhouse conditions. Methods: The fungal and bacterial formulations' shelf life under different temperatures as well as under growth chamber and greenhouse conditions, as well as their effects on biochemical alterations involved in the induction of plant defense against the causative pathogen were investigated. Results: In-vitro antagonist screening of bacterial and fungal isolates on radial growth, reduction and inhibition percentages revealed that T. harzianum exhibited 45.6% of inhibition followed by B. pumilus with 36.7%. Among the fungal and bacterial bio-agents, the highest effect on disease incidence and efficiency against pathogenic fungus under greenhouse conditions was B. pumilus 27 and 69%, respectively followed by T. harzianum 33 and 62% when applied before pathogen inoculation. Under greenhouse conditions, the effects of bio-fungicides also affected defense enzymes like peroxidase and polyphenol oxidase. The shelf life of the wettable powder formulation of bio-agents under different temperature was very important factor and established that the most suitable temperature for long term storage is 25 ºC for both B. pumilus and T. harzianum. Conclusion: Target application of disease control techniques in tomato plants demonstrated the efficacy of B. pumilus and T. harzianum in reducing Fusarium wilt. These results pave the way for the development of bio-agents that can replace fungicides in agriculture, offering a practical substitute.

Evaluation of a Formulation of Bacillus subtilis for Control of Phytophthora Blight of Bell Pepper.

Phytophthora blight, caused by Phytophthora capsici, is one of the most economically significant diseases of bell pepper in the United States. Over the past several decades, isolates of P. capsici exhibiting resistance to mefenoxam and other fungicides have been reported. Fungicide resistance coupled with an increased market for organically grown crops has led to interest in biological control as a disease management option. In this work, an isolate of Bacillus subtilis (AFS032321) was evaluated for control of Phytophthora blight of bell pepper in the greenhouse and field. A 28% active ingredient wettable powder formulation of the strain was applied as a soil drench at transplanting prior to inoculation. Treatment with this formulation of B. subtilis significantly reduced the area under the disease progress curve (AUDPC) by up to 52% compared to untreated control plants in greenhouse tests. Comparisons between applying the biocontrol weekly after seeding for 5 weeks versus a single application at transplanting (5 weeks) indicated no significant benefits of additional applications. The formulation of B. subtilis reduced disease caused by a mefenoxam-resistant isolate of P. capsici, while mefenoxam failed. The biocontrol efficacy of formulated strains was not affected in different soil types or potting media. However, disease was more severe in sandy soils. In field experiments that were conducted with a mefenoxam-sensitive isolate, disease incidence and severity of Phytophthora blight were significantly reduced at all rates of B. subtilis in 2019 except the 16.8 kg ha-1 rate. In both years, mefenoxam was more effective than B. subtilis in controlling disease in the field. B. subtilis did not affect the spatial dynamics of pathogen spread within rows. While the precise mechanism(s) of action is unclear, in vitro dual-culture tests suggest direct antagonism, as B. subtilis significantly inhibited colony growth of P. capsici. AgBiome has recently released a new formulation of the AFS032321 strain named Theia, with higher active ingredients for commercial applications and biocontrol of P. capsici.

Biocontrol of Diplodia bulgarica, the causal agent of apple canker, using Trichoderma zelobreve.

Apple (Malus domestica Borkh) is one of the most consumed and nutritious fruits. Iran is one of the main producers of the apple in the world. Diplodia bulgarica is the major causal agent of apple tree decline in Iran. Biological control is a nature-friendly approach to plant disease management. Trichoderma zelobreve was isolated from apple trees infected with Diplodia bulgarica in West Azarbaijan province of Iran. The results showed that T. zelobreve strongly inhibited the colony growth of D. bulgarica. In vivo assay on detached branches of apple tree cv. Golden Delicious using T. zelobreve mycelial plug showed that canker length/stem length (CL/SL) and canker perimeter/stem perimeter (CP/SP) indices decreased by 76 and 69%, respectively, 21days after inoculation. Additionally, wettable powder formulation (WPF) containing the antagonistic fungus "T. zelobreve" decreased CL and CP/SP by 75 and 67%, respectively, 6months after inoculation. Moreover, canker progress curves and the area under the disease progress curve (AUDPC) supported these findings. The growth temperatures of the antagonist and pathogen were similar, indicating the adaptation of T. zelobreve for biocontrol of apple canker caused by D. bulgarica. The results also showed that T. zelobreve-based WPF stored at 25°C assure excellent shelf life at least 4months, allowing the bioproduct to be stored at room temperature, which is a great advantage and cost-effective option.

A simple and rapid reverse-phase high-performance liquid chromatographic method for the determination of propineb and tricyclazole pesticides from the wettable powder formulation

A simple and rapid reverse-phase high-performance liquid chromatographic method for the determination of propineb and tricyclazole pesticides from the wettable powder formulation

Effectiveness of Cordyceps fumosorosea Wettable Powder Formulation against Metisa plana (Walker) and Its Side Effects on Elaeidobius kamerunicus in Oil palm Plantation.

Development of mycoinsecticides with Cordyceps fumosorosea as an active ingredient is established as an alternate way to control the Metisa plana population while reducing chemical insecticide dependence. Three mycoinsecticide formulations (SS6, SS7, and SS8) with dispersing and wetting agents were developed as wettable powder formulations in this trial. SS8 demonstrated the best wettability, suspensibility, and dispersibility with viability at 107 (CFU)/mL even after three months of storage. However, SS7 developed with C. fumosorosea as an active ingredient was found to effectively reduce the bagworm population by more than 95%. The application of all mycoinsecticide formulations in the infested oil palm area was able to reduce the M. plana population by more than 95%, 30 DAT. The formulations also show no significant increase in mortality of the oil palm pollinator, Elaeidobius kamerunicus. This finding indicates that the C. fumosorosea tested has potential for managing bagworms without harming pollinators on oil palm plantations.

Laboratory evaluation of broflanilide (TENEBENAL™) against Anopheles gambiae in Moshi, Tanzania – delayed mortality, cross-resistance, and residual efficacy

IntroductionBroflanilide is a novel meta-diamide insecticide, which has a distinct mode of action compared to other active ingredients used for Indoor Residual Spraying (IRS). This study details a laboratory evaluation of broflanilide, of putative discriminating concentrations, potential cross-resistance, and residual efficacy on two substrates.MethodsMosquitoes were exposed to broflanilide in bottle bioassays to determine lethal concentrations (LC50 and LC95). These were used to calculate resistance ratios between the susceptible Kisumu and the pyrethroid-resistant Muleba-Kis strains of Anopheles gambiae s.s. Prototype wettable powder formulations of broflanilide were applied to mud and concrete to determine the optimal observation period for determining delayed mortality, and a Cox proportional hazards model was fitted to determine a potential dose response effect. Subsequently, residual efficacy of application rates ranging between 25 mg/m2 and 300 mg/m2 were monitored monthly.ResultsLC values of tested strains were not significantly different; therefore, the polyfactorial resistance mechanisms possessed by the resistant strain did not confer resistance to broflanilide. A significant effect of concentration and time since spraying was found on mosquito survival, indicating that higher broflanilide concentrations are more effective and that this effect was strongest immediately after spraying. Knockdown at 60min post exposure was negligible, with on average only 1% of all mosquitoes knocked down. On the mud surface, but not on concrete, there was a delayed killing effect, with mortality increasing until 72 hours after exposure. The residual efficacy test indicated that on concrete the 100 mg/m2 and 200 mg/m2 concentrations of both broflanilide 50WP formulations remained efficacious for 9 months post spraying. On mud, there were large variations in mosquito mortality from month to month. Generally, higher concentrations resulted in higher mortality, despite variation over time.DiscussionCross-resistance to broflanilide was not detected in mosquitoes with multiple resistance mechanisms. This opens up the possibility for wide-scale use of broflanilide, especially in areas with established pyrethroid resistance. Like some other insecticide classes, delayed mortality up to 72 hours post exposure was found for broflanilide. Promising residual efficacy was found with broflanilide 50WP formulations on concrete. On mud, efficacy varied and further testing with a refined formulation is recommended.

Endophytic fungi-based wettable powder formulation for Rhizoctonia solani AG-4 biocontrol

Endophytic fungi-based wettable powder formulation for Rhizoctonia solani AG-4 biocontrol

A non-inferiority and GLP-compliant study of broflanilide IRS (VECTRON™ T500), a novel meta-diamide insecticide against Anopheles arabiensis

Management of insecticide resistance in vector control requires development and evaluation of active ingredients (AIs) with new modes of action. VECTRON™ T500 is a wettable powder formulation used for Indoor Residual Spraying (IRS) containing 50% of broflanilide as an AI. This study evaluated the efficacy of VECTRON™ T500 sprayed on blocks of different substrates (concrete, mud and plywood) against pyrethroid susceptible and resistant Anopheles gambiae sensu stricto (s.s.) strains, and wild An. arabiensis. It also assessed the efficacy of VECTRON™ T500 in experimental huts plastered with mud and concrete against wild free-flying An. arabiensis; and non-inferiority to a World Health Organization listed indoor residual spraying product Actellic® 300CS in terms of mortality in Moshi, Tanzania.Monthly cone bioassays on blocks and in experimental huts (against pyrethroid susceptible and resistant An. gambiae s.s.) were conducted over a 12-month period after spraying of VECTRON™ T500 and Actellic® CS300. Collections of wild free-flying An. arabiensis were also done in the sprayed huts. The main outcome for cone bioassays was mortality while for the wild hut trial collections, it was mortality and blood feeding inhibition. Grouped logistic regressions with random effects were used to analyse all dichotomous outcome variables from wild collections.The results showed residual efficacy of VECTRON™ T500 of at least 80% mortality was longest on concrete, followed by plywood and then mud substrates for all mosquito strains. Furthermore, VECTRON™ T500 significantly increased the likelihood of mortality (OR:> 1.37, P<0.001) in wild collections of An. arabiensis compared to Actellic® 300CS. Blood feeding was not significantly different in the wild collection of An. arabiensis between VECTRON™ T500 and Actellic® 300CS arms.These results show that VECTRON™ T500 is efficacious against pyrethroid-resistant An. gambiae s.s. and non-inferior to Actellic® 300CS. Therefore, it should be an important addition to the current arsenal of insecticides used for insecticide resistance management and vector control.

Preliminary assessment of nursery workers’ exposure to applied pesticides

Nursery workers can be exposed to pesticides via skin contact and respiratory inhalation when they mixing/loading pesticide product(s) and applying pesticide solution on a single spraying day. This study investigates how pesticide usage and agricultural practices among nursery workers affect their exposure to and potential health risk of pesticides applied over a 2-month period. Ten workers from different nurseries were involved in both personal interview and questionnaire survey to collect data for exposure modelling purposes. On a single spraying day, individuals’ total daily exposure to single active substances ranged from 0.002 to 0.024 mg kg-bw-1 day-1, mainly constituted of pesticide exposure during application activities (57.3 – 99.9% of total daily exposure). The total daily exposures were assessed against the respective acceptable operator exposure levels (AOELs) for single active substances. Overall, four nursery workers had at least one active substance application that exceeded the AOEL, indicating health risk is possible. While respondents generally worn long sleeves and long pants as the basic protective measures, the exceedances were likely caused by the usage of hazardous active substance (i.e., cypermethrin) and wettable powder formulation, and improper use of gloves. Future studies can consider the influence of different nursery plants on workers’ exposure to pesticides handled.

VECTRON™ T500, a new broflanilide insecticide for indoor residual spraying, provides prolonged control of pyrethroid-resistant malaria vectors

BackgroundBroflanilide is a newly discovered insecticide with a novel mode of action targeting insect γ-aminobutyric acid receptors. The efficacy of VECTRON™ T500, a wettable powder formulation of broflanilide, was assessed for IRS against wild pyrethroid-resistant malaria vectors in experimental huts in Benin.MethodsVECTRON™ T500 was evaluated at 100 mg/m2 in mud and cement-walled experimental huts against wild pyrethroid-resistant Anopheles gambiae sensu lato (s.l.) in Covè, southern Benin, over 18 months. A direct comparison was made with Actellic® 300CS, a WHO-recommended micro-encapsulated formulation of pirimiphos-methyl, applied at 1000 mg/m2. The vector population at Covè was investigated for susceptibility to broflanilide and other classes of insecticides used for vector control. Monthly wall cone bioassays were performed to assess the residual efficacy of VECTRON™ T500 using insecticide susceptible An. gambiae Kisumu and pyrethroid-resistant An. gambiae s.l. Covè strains. The study complied with OECD principles of good laboratory practice.ResultsThe vector population at Covè was resistant to pyrethroids and organochlorines but susceptible to broflanilide and pirimiphos-methyl. A total of 23,171 free-flying wild pyrethroid-resistant female An. gambiae s.l. were collected in the experimental huts over 12 months. VECTRON™ T500 induced 56%-60% mortality in wild vector mosquitoes in both cement and mud-walled huts. Mortality with VECTRON™ T500 was 62%-73% in the first three months and remained > 50% for 9 months on both substrate-types. By comparison, mortality with Actellic® 300CS was very high in the first three months (72%-95%) but declined sharply to < 40% after 4 months. Using a non-inferiority margin defined by the World Health Organization, overall mortality achieved with VECTRON™ T500 was non-inferior to that observed in huts treated with Actellic® 300CS with both cement and mud wall substrates. Monthly in situ wall cone bioassay mortality with VECTRON™ T500 also remained over 80% for 18 months but dropped below 80% with Actellic® 300CS at 6–7 months post spraying.ConclusionVECTRON™ T500 shows potential to provide substantial and prolonged control of malaria transmitted by pyrethroid-resistant mosquito vectors when applied for IRS. Its addition to the current list of WHO-approved IRS insecticides will provide a suitable option to facilitate rotation of IRS products with different modes of action.

Development Of Saponin Based Wettable Powder Formulation from Phaleria macrocarpa To Control Pomacea maculate

Apple snail is one of the 100 invasive alien species of the world and saponin proved to be the most effective and promising bioactive compound to manage this pest. This study was conducted to develop a saponin based wettable powder formulation from Phaleria macrocarpa (Scheff.) Borel and to evaluate its efficacy against Pomacea maculata Perry undrer laboratory and glasshouse conditions. Results revealed that all prepared saponin based wettable formulations shown molluscicide effects towards P. maculata. However, F4 formulation consisted of Terwet® 157, Terspers® 2700 and Kaolin at proportion of 15:15:70 revealed significantly higher feeding deterrent activities among prepared formulations and it was not significantly different from positive controls niclosamide and tea seed cake. In terms of lethel effects, the shortest LT50 (154 minutes) was recorded in niclosamide followed by 702 minutes in F4 formulation and 728 minutes in tea seed cake. F4 formulation along with positive control tea seed cake was further assessed in glasshouse condition. F4 formulation illustrated shortest LT50 value (750 minutes) with lowest feeding consumption percentage (0.6%) compared to LT50 (784 minutes) and feeding consumption percentage (1.3%) in positive control tea seed cake. Feeding consumption percentage (40.6%) was recorded for negative control water. Results sugest that F4 saponin based wettable powder overall performed better and can be efficiently used to control the apple snails as an eco friendly botanical molluscicide.

Efficacy of Dust and Wettable Powder Formulation of Diatomaceous Earth (Detech®) in the Control of Tyrophagus putrescentiae (Schrank) (Acari: Acaridae).

Simple SummaryAcaricidal efficacy of two Turkish diatomaceous earth (DE) formulations (Detech® WP95 and Detech® Dust) were applied on a concrete surface at five different concentrations at 25 ± 1 °C and 75 ± 5% RH. Mite mortalities were observed after 6- and 18-hour exposure periods dust and WP formulations, respectively. In conclusion, our laboratory tests indicated that both WP and dust formulations of local diatomaceous earth can cause 100% mortality in 24 h on average and can be a promising alternative to conventional chemical acaricides.Tyrophagus putrescentiae (Schrank) (Acari: Acaridae) is a cosmopolite mite species commonly in found food and stored products. In this study, the acaricidal activity of two Turkish diatomaceous earth (DE) formulations (Detech® WP95 and Detech® Dust) were applied on a concrete surface at five different concentrations (1, 2.5, 5, 7.5, and 10 g/m2) and dead individuals were counted at 11 different time intervals (1, 3, 6, 9, 12, 15, 18, 21, 24, 27, and 30 h) at a temperature of 25 ± 1 °C and 75 ± 5% relative humidity (RH). Mite mortalities were observed after 6- and 18-hour exposure periods at all concentrations of dust and wettable powder (WP) formulations, respectively. Specifically, 100% mortality for the WP formulation was achieved at the highest concentration of 10 g/m2 after 15 h of exposure and after 27 h and 30 h for the lowest concentration. In the case of dust formulation, mortalities were observed after 3 h of exposure at all concentrations except at 1 g/m2, while a 100% mortality rate was achieved after 21 h of exposure to all concentrations and after 18 h of exposure for 7.5 g/m2 and 10 g/m2. This study indicates that both WP and dust formulations of local diatomaceous earth can cause 100% mortality in 24 h on average and can be a promising alternative to conventional chemical acaricides.

Bioefficacy of different formulations of Metarhizium anisopliae (Metchnikoff) Sorokin IOF strain (KF408075) against Oryctus rhinoceros (Linnaeus) in vitro condition

The laboratory experiments were carriedout at the Institute of Organic Farming (IOF), UAS, Dharwad, during 2014-2015 to study the bioefficacy of different formulations of Metarhizium anisopliae against coconut rhinoceros grubs, Oryctus rhinoceros (Linnaeus). Among different oil based formulation, rice bran oil (60%) + corn oil (40%) formulation found least LC50 value (1.99 x 106 cfu/ml) at 432 h. In granular and wettable powder formulation, the granular formulation recorded least LC50 value 0.44 x 108 cfu/g at 240 h. The medean lethal time (LT50) of different oil based formulations, the rice bran oil (60%) + corn oil (40%) formulation @ 3 x 106 cfu / ml recorded lower LT50 value of 319.89 h (13.32 days). Among granular and wettable powder formulation, the granular formulation @ 5 x 108 cfu / g, proved most effective exhibiting 50 per cent of mortality with least LT50 value of 162.88 h (6.78 days).

Biosafety evaluation of two Beauveria bassiana products on female albino rats using acute oral test

Application of bio-pesticides in agriculture has been developed as alternative agents to conventional pesticides due to residues accumulating which causing detrimental effects to human and environment. The aim of this investigation is to evaluate biosafety of a bio-insecticide Beauveria bassiana using two products in female rats by single oral dose through hepato- and renal toxicity, hematotoxicity and lipid profile. The two products from B. bassiana (AUMC 9896) were metabolic crude (MC), and wettable powder formulation (WP) of the local isolate. Results showed a significant increase in values of erythrocytes (RBCs), leucocytes (WBCs), platelet count (Plt) and the absolute differential WBC counts. Liver enzymes (AST, ALT, and ALP) and globulin (Glb) content were reduced in the exposed female rats with both types of B. bassiana in comparison to controls. While ratio of AST/ALT and A/G, total protein level (TP) and albumin (Alb) were raised in Beauveria bassiana -treated rats (Bb - treated rats). Urea and creatinine concentrations decreased or increased significantly in treated rats. Moreover, there was a decline in the serum of lipid profiles in WP - treated rats, but LDL levels increased in all treated animal. Additionally, no mortality or toxicity in all treated. All animals treated showed non-significant modifications in body weight gain and a slight change in relative liver weights when compared to controls. These results suggest that both treatments effect markedly on function and somatic index of the liver and slight effects on CBC and lipid profile aspects of treated female rats.

Inhibition of Oomycetes by the Mixture of Maleic Acid and Copper Sulfate.

Since the protective activity of the Bordeaux mixture against plant disease caused by oomycetes was discovered, copper compounds have been used for more than a century as an effective plant protection strategy. However, the application of excessive copper can cause adverse effects through long-term heavy metal accumulation in soils. Therefore, it is necessary to develop new strategies to reduce or replace copper in pesticides based on organic and low-input farming systems. Organic acids are eco-friendly. In this study, we tested the antifungal and anti-oomycete activity of maleic acid (MA) and copper sulfate (CS) against 13 plant pathogens. Treatment with a mixture of MA and CS showed strong anti-oomycetes activity against Phytophthora xcambivora, P. capsici, and P. cinnamomi. Moreover, the concentration of CS in the activated mixture of MA and CS was lower than that in the activated CS only, and the mixture showed synergy or partial synergy effects on the anti-oomycete activity. Application of a wettable powder formulation of MA and CS mixture (MCS 30WP; 26.67% MA and 3.33% CS) had excellent protective activity in pot experiments with control values of 73% Phytophthora blight on red pepper, 91% damping-off on cucumber, and 84% Pythium blight on creeping bentgrass, which are similar to those of the CS wettable powder formulation (6.67% CS) containing two times the CS content of MCS 30WP. These observations suggest that the synergistic effect of the MA and CS combination is a sustainable alternative for effective management of destructive oomycete diseases.

Development of novel spray-dried and air-dried formulations of Metarhizium robertsii blastospores and their virulence against Dalbulus maidis.

The present research addressed spray-drying and air-drying techniques applied to Metarhizium robertsii blastospores to develop wettable powder (WP) formulations. We investigated the effect of co-formulants on blastospore viability during drying and assessed the wettability and stability of formulations in water. The effect of oxygen-moisture absorbers was studied on the shelf life of these formulations stored at 26°C and 4°C for up to 90days. Additionally, we determined the virulence of the best spray-dried and air-dried formulations against the corn leafhopper Dalbulus maidis. While sucrose and skim milk played an essential role as osmoprotectants in preserving air-dried blastospores, maltodextrin, skim milk, and bentonite were crucial to attain high cell survival during spray drying. The lowest wettability time was achieved with spray-dried formulations containing less Ca-lignin, while charcoal powder amount was positively associated with formulation stability. The addition of oxygen-moisture absorbers inside sealed packages increased from threefold to fourfold the half-life times of air-dried and spray-dried formulations at both storage temperatures. However, the half-life times of all blastospore-based formulations were shorter than 3months regardless of temperature and packaging system. Spray-dried and air-dried WP formulations were as virulent as fresh blastopores against D. maydis adults sprayed with 5 × 107 blastospores mL-1 that induced 87.8% and 70.6% mortality, respectively. These findings bring innovative advancement for M. robertsii blastospore formulation through spray-drying and underpin the importance of adding protective matrices coupled to oxygen-moisture absorbers to extend cell viability during either cold or non-refrigerated storage. KEY POINTS: • Cost-effective wettable powder formulations of M. robertsii blastospores were developed. • Bioefficacy of formulations against the corn leafhopper was comparable to fresh blastospores. • Cold storage and dual oxygen-moisture absorber are critical for extended shelf life.

Hygienic evaluation of diflubenzuron-based pesticides in various application technologies

Introduction. In connection with the widespread introduction of new preparative forms of pesticides and methods of their introduction into the environment, the urgent task of the modern period is to minimize the risk of exposure to pesticides on the health of workers and the population-the use of diflubenzuron of low and medium toxicity increases. Therefore, a mandatory criterion for assessing risk is registration tests, carried out during several stages - as hazard identification, hazard characterization, exposure assessment, risk characterization. Purpose of work. To assess the regularities of the formation of the risk of diflubenzuron by exposure and by the absorbed dose, depending on the type of preparative form of pesticides with different technologies of their introduction and regulating safe use measures. Materials and methods. The obtained exposure levels of insecticides based on diflubenzuron in the air and on the skin were compared with the hygienic standards calculated and experimentally established as follows: MPC (mg/m3) in the air of the working area and approximate admissible level (AAL) (mg/cm2) of skin contamination. The exposure level risk was determined by the safety level (SL) SLsumm value. The risk of exposure to insecticides based on diflubenzuron for the operator / user / refueller / pilot / signaller based on the absorbed dose, determined by the safety factor - SLp, and the exposure -SBsumm, is considered acceptable when SLsumm and SLp &lt;1. Results. The paper presents the risk analysis results of the impact of diflubenzuron-based insecticides studied in natural conditions using 27 drugs with different preparative forms and methods (technologies) of their introduction into the environment. The risk of exposure to insecticides (SLsumm) for all technologies is acceptable SL. The risk of absorbed dose (SLp) was more significant regardless of the type of formulation. Wettable powder formulations are more unfavourable to use than other formulations. Conclusion. The conditions for the use of preparations based on diflubenzuron in the technologies of ground boom spraying and fan spraying of field and horticultural crops, in the treatment of field and forest crops by the aerial method, in the treatment of field and horticultural crops in private household plots, in the treatment of champignons in protected ground, compliance with regulations and measures safety meet hygienic requirements.

Bio-efficacy of Plants based Formulations for the Management of Cowpea Aphid (Aphis craccivora Koch.)

Background: The cowpea (Vigna unguiculata) is damaged by various insect pests of which cowpea aphid (Aphis craccivora) causes heavy damage to the tender leaves of the plant and reduces its yield. Two plant based formulation (prepared in the Chemistry Laboratory) viz. Polygonum hydropiper floral parts and Tobacco (Nicotiana tabacum) leaf, were used for safe management. Methods: The studies were done during 2019-2020 in BCKV, Kalyani, West Bengal, India for controlling of cowpea aphid by using plant based formulation. For preparing wettable powder formulation from Polygonum hydropiper floral parts and tobacco leaf the different ingredients are required viz. china clay, silica gel, wetting agent, dispersing agent etc. Physico-chemical analysis was done for preparation of accurate Wettable Powder formulation. Result: Cowpea aphid causes damage the tender leaves of the plant. It was revealed that imidacloprid (Confidor 17.8 SL) @ 1.0 ml/3L was found the most effective treatment against aphids giving more than 80% control followed by tobacco leaf (50 WP) @ 8 g/L of water (more than 70% control), fipronil (Regent 5% SC) @ 2.5 ml/L of water and Polygonum floral parts (50 WP) @ 8 g/L of water (more than 65% control both). The quality parameters of WP (50%) formulation was satisfactory as per the FAO specifications in terms of wet sieved test, wettability, foaming and suspensibility performed on the 0-day and also after 15th day at room temperature, at 65°C and at freezing temperature conditions.