Genetic-relatedness of Tuba plants from Peninsular Malaysia and quantitative analysis of their rotenone

Background and Objective: Tuba plants is a small flowering shrub originating in the humid rainforest of Malaysia. Tuba plants is known to contain the chemical rotenone, which is have an insecticidal properties. The objectives of this study were conducted to identify the Tuba plants and quantify their rotenone contents. Materials and Methods: Nine tuba plants of different local names were collected from various locations in Peninsular Malaysia. Random Amplification of Polymorphic DNA (RAPD) and internal transcribed spacer (ITS) marker of 9 Tuba plant accessions were used to identify the species. Results: Both methods were equally adequate for Tuba plants species identification. Four different species were obtained from nine accessions and they were Derris elliptica, Paraderris elliptica, Fordia splendidissima and Paraderris piscatoria. These species are the new record in Peninsular Malaysia. All accessions contained rotenone with the concentration varying from 0.25-1.02 μg mL–1. The highest rotenone content, 1.02 μg mL–1 was from D. elliptica (Tuba merah). This indicated that the two techniques (RAPD and ITS) are equally appropriate for the analysis of genetic diversity in Tuba plants. Conclusion: The study will provide information for the conservation of Tuba plants and further improvement of rotenone contents

Effect of six insecticides on oil palm pollinating weevil, Elaeidobius kamerunicus (Coleoptera: Curculionidae)

The oil palm pollinator, Elaeidobius kamerunicus is a weevil that belongs to Curculionidae It has been found to have the highest capacity for efficient insect pollinator of oil palm. In order to control the damage from reaching or nearing the economic threshold level (ETL), planters are left with the option to use insecticides due to its fast action. Therefore, in this study the efficacy of chlorantraniliprole, cypermethrin, flubendiamide, Bacillus thuringiensis, cnidiadin and Isaria fumosorosea were tested on oil palm pollinator, E. kamerunicus. The pollens and pollinators were collected from FELDA Besout, Perak, Malaysia. Adult of E. kamerunicus were exposed to the insecticides residue and mortality was observed at 24, 48, 72 and 96 hours after exposure. The percentage of mortality E. kamerunicus was recorded to determine the insecticides efficacy. Mortality of E. kamerunicus was highest when exposed to cypermethrin and chlorantraniliprole with 100% mortality of the population, followed by flubendiamide (42%), B. thuringiensis (39%), cnidiadin (11%), I. fumosorosea (3%) and control (2%) at 96 hours post-exposure. Cypermethrin gave the shortest LT50 to killed E. kamerunicus at 17 hours, followed by chlorantraniliprole, flubendiamide and B. thuringiensis which were 31, 136 and 137 hours, respectively. Whilst, lethality index of cypermethrin showed the highest value, which was 91.50%, followed by chlorantraniliprole (76.50%), flubendiamide (27.25%), B. thuringiensis (25.25%), cnidiadin (5.25%) and I. fumosorosea (1.75%)

Molluscicidal and feeding deterrent activity of crude plant extracts on Pomacea maculate Perry

This study was focused on molluscicidal effect and feeding deterrent activity of saponin from five different plant materials; Andrographis paniculata, Entada spiralis, Ficus deltoidea, Furcraea selloa and Ipomoea batatas. Crude plant extracts were prepared from plant powders using methanol. The crude extracts were then tested on Pomacea maculata using five different concentrations (5, 10, 15, 20 and 25 ppm, respectively) against niclosamide (control). After 72 h of exposure, the highest percentage of mortality of 80% was achieved from 15 ppm of F. selloa. Two analyses were conducted to observe the feeding deterrent activity and after 24 h, both analyses demonstrated the feeding deterrent activity in both crude extracts (F. selloa and E. spiralis) similar in niclosamide

Preparation and characterization of neem oil nanoemulsion formulations against Sitophilus oryzae and Tribolium castaneum adults

This study aimed to improve the efficacy of azadirachtin (Azadirachta indica. A. Juss) against two serious pest species of stored products, Sitophilus oryzae (L.) and Tribolium castaneum (Herbst), through nano-emulsion formulations. Pseudoternary phase diagrams were constructed consisting of an emulsion system of an active ingredient (neem oil), surfactant (polysorbate or alkylpolyglucoside), and water. Isotropic regions were formed in the pseudoternary phase diagrams, and four formulations were selected from the isotropic regions and characterized according to particle size, particle aging, zeta potential, stability and thermostability, surface tension, viscosity, and pH. The selected formulations showed particle sizes of 208–507 nm in diameter. The result of contact toxicity demonstrated excellent mortality of S. oryzae and T. castaneum adults, with a mortality range of 85–100% and 74–100%, respectively, at a 1% azadirachtin concentration after only 2 days of exposure. Compared to non-formulated neem oil, the nano-emulsion formulations significantly increased the mortality of the tested species

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, 30DAT. 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

A rapid liquid chromatography method for determination of gylphosate in crude palm oil with fluorescence detection

A rapid and simple method for the determination of glyphosate in crude palm oil (CPO) was developed and validated using high performance liquid chromatography with fluorescence detector. Glyphosate was derivatized with 9-fluorenylmethylchloroformate (FMOC-Cl) and then separated using a C18 reverse phase column with potassium dihydrogen phosphate and acetonitrile as the mobile phase. A linear correlation was obtained for the concentration of glyphosate from 0.05-1.5 μg mL-1 with a correlation coefficient of 0.9998. The average recovery obtained for glyphosate ranged between 80% and 100% at five fortification levels with the relative standard deviation (RSD) of less than 3% of all cases. The limit of detection and limit of quantification for glyphosate were 0.05 and 0.1 μg/g, respectively. The method will facilitate palm oil trade through quality assurance in terms of glyphosate residues in palm oil products and also to counter any issues related to food safety for palm based products

Toxicity Azadirachta indica and Piper Sarmentosum extract mixture formulations against Nilaparvata lugens (Hemiptera: Delphacidae) in paddy field

Infestation of Nilaparvata lugens on rice in Malaysia is not as heavy compared to other Asian countries, but still lower the rice yield production. Nilaparvata lugens is developing resistance against chemical pesticide, therefore an alternative approach such as the application of botanical pesticide is potential to control the N. lugens. The aims of this research were to determine the synergistic activity in combination of Azadirachta indica and Piper sarmentosum emulsion formulations extract against Nilaparvata lugens. Three formulations were developed were coded as F1, F2, and F3. The F1 was selected as the best formulation because it in range of good zeta potential value (-48.3 mV) and viscosity value (100.1 mPa/s), the lowest particle size (202.5 nm), remained homogenous for centrifugation and stability test, polydispersity index (PDI) value indicated it is in ideal monodisperse phase (0.359), low surface tension (31.3 mN/m) and low pH (3.65). The lethal concentration, LC50 and sub lethal, LC10 and LC25 were determined from nymph mortality bioassay test on third instar N. lugens nymphs. Mortality rate of F1 and F2 were 0.011 mg/l and F3 was 0.031 mg/l. The value of lethal and sublethal concentration were used in a test against female N. lugens to determine the effect of formulations on fecundity of N. lugens. There were significant differences between formulations on the number of eggs produced after treatments. The lowest egg produced from F1 with 128.11 number of eggs. It can be concluded that all formulations showed promising result in controlling N. lugens

Preparation and physicochemical evaluation of emulsified virgin coconut oil (VCO)-Carica papaya extract concoction using Tween80

Carica papaya is a member of the Caricaceae. Its leaves have been used in folk medicine for centuries. Recent studies have shown its beneficial effects as an anti-inflammatory agent (Owoyele et al 2008) and anti-tumour15 as well as antioxidant and wound healing properties7. The study has shown that the effect of carica papaya leaves juice intake also can accelerate the rate of increase in platelet count among the patients infected with dengue fever and dengue haemorrhagic fever18. With all the goodness of carica papaya leaves, a formulation with addition of virgin coconut oil (VCO) is produced to give an enhanced supplement beverage to market nowadays. Virgin coconut oil is well known as anti-oxidant4. The combination of these two substances gives a balance combination in healthy supplement. In recent years the application of emulsion is rapidly increasing in many fields such as cosmetics and paints. Emulsions are dispersions of droplets of one liquid in another, immiscible, liquid in which the droplets are of colloidal or near-colloidal sizes. The combination of water and oil (VCO) with addition of non-ionic surfactant Tween80 was constructed using ternary phase diagram. By considering the Hydrophilic-Lipophilic Balance (HLB) value of each substance will help in producing a stable emulsion

Optimization and characterization of palm oil-based nanoemulsion loaded with parthenium hysterophorus crude extract for natural herbicide formulation

The present study revealed the optimization of nanoemulsion containing palm oil derivatives and Parthenium hysterophorus L. crude extract (PHCE) as pre-emergence herbicide formulation against Diodia ocimifolia. The nanoemulsion formulation was prepared by high energy emulsification method, and it was optimized by mixture experimental design (MED). From the optimization process, analysis of variance (ANOVA) showed a fit quadratic polynomial model with an optimal formulation composition containing 30.91% of palm kernel oil ester (PKOE), 28.48% of mixed surfactants (Tensiofix and Tween 80, 8:2), 28.32% of water and 12.29% of PHCE. The reading of both experimental and predicted particle size in the verification experiment were acceptable with a residual standard error (RSE) was less than 2%. Under the optimal condition, the smallest particle size obtained was 140.10 nm, and the particle was shown by morphology analysis to be spherical and demonstrated good stability (no phase separation) under centrifugation and different storage conditions (25 ± 5°C and 45°C). Nanoemulsion stored for 60 days exhibits monodisperse emulsion with a slight increase of particle size. The increase in particle size over time might have contributed by Ostwald ripening phenomenon which is shown by a linear graph from Ostwald ripening rate analysis. In the in vitro germination test, P. hysterophorus nanoemulsion (PHNE) was shown to cause total inhibition of D. ocimifolia seed at lower concentration (5 g L-1) as compared to PHCE (10 g L-1). The finding of the research could potentially serve as a platform for the development of palm oil based formulation containing plant crude extract for green weed management

Drone payload and flying speed effects on rotor blades' RPM and traveling pattern for agricultural chemical spraying

The sprayed chemicals by drones have been widely reported to be off-targeted and not uniformly distributed. This study aims to evaluate the drone blade’s revolutions per minute (RPM) and its travelling pattern at different payloads and flight speeds. The obtained results were used to relate to the potential effects on the quantity and quality of spraying. In a test flight on an area of 1000 m2, a hexacopter, Advansia A1 was tested in 6 different flying paths of 56 m length. The drone was set to fly at 5 payloads (10, 8, 6, 4, and 2 kg) and 4 flying speeds (i.e. 1, 3, 5, and 7 m.s-1) combinations. The drone travelling pattern and individual rotor blade rpm at each payload-flying speed combinations were analysed. From the result, the RPM of each rotor blade were found to decrease by 14 to 20% as the payload was decreased from 10kg to 0kg. Thus, in actual spraying activities, the changes in RPM could produce a downwash airflow pattern that continually varies from starting point up to the finishing point that would effect on pesticide's distribution along the flying path. On drone travelling pattern, at higher flying speed, a much lesser time and distance was required for the drone to be stabilized to the targeted speed. This relates to the longer time needed by the drone to accelerate and decelerate. The average real speed of the drone was notably reduced to 0.96, 2.72, 3.83 and 4.05 m.s-1, in which, it was, far less than the initial specified speed set at 1, 3, 5, and 7 m.s-1, respectively. The drone flying pattern during spraying needs to be considered for application rate determination to avoid for the crops to be under or over pesticide applications. The obtained finding is remarkably critical and useful in ensuring the efficiency of agricultural chemical spraying activities using drone